Section 5

Question 1

A 24-year-old male patient presents with progressive difficulty with fine motor skills in his right hand. He has a tumor resected from the left frontoparietal region two years prior. Histological analysis from that surgery demonstrated dysmorphic ganglion cells with a separate glial component containing numerous mitoses, nuclear atypica, and invasion of white matter tracts. An MRI demonstrates a recurrent tumor. What is the most appropriate next step for the evaluation and treatment of this patient?
1. Radiation therapy alone
2. Repeat resection with adjuvant radiation therapy
3. Chemotherapy alone
4. Present the patient at a multidisciplinary tumor board conference to discuss further evaluation and treatment recommendations

Answer 1

4. Present the patient at a multidisciplinary tumor board conference to discuss further evaluation and treatment recommendations

• Anaplastic ganglioglioma is an aggressive neuronal brain tumor associated with a poor prognosis despite maximal therapy, including surgery and adjuvant chemoradiation therapy.
• Patients with anaplastic ganglioglioma should be discussed at multidisciplinary tumor board conferences due to the rare nature of the lesion and the lack of standardized treatment paradigms.
• Anaplastic ganglioglioma often shows more aggressive features within the glial component of the tumor.
• Increasing extent of resection is associated with improved survival in anaplastic ganglioglioma patients.

Question 2

A 32-year-old male was on top of a ladder approximately 15-feet in height. He was painting his house exterior when he lost his balance, fell landing on his right shoulder and right side of his neck on the grass. There was no loss of consciousness and he experienced right shoulder pain and numbness on the lateral aspect of his right upper arm and shoulder. He also immediately recognized that he was unable to flex his right elbow. The initial examination in the emergency department showed that he also could not abduct his right shoulder in addition to impaired pinprick sensation in the same distribution of numbness. The x-ray studies revealed a non-displaced clavicular fracture that required conservative treatment only. The patient was evaluated by neurosurgery and neurology teams in the ER and scheduled for neuroimaging and electrodiagnostic study after three weeks. Magnetic resonance imaging demonstrated no spinal nerve roots avulsion, yet there was a high-intensity signal on one of the brachial plexus trunks with increase contrast enhancement. Somatosensory evoked potentials (SSEPs), electromyography (EMG) and nerve conduction velocity (NCV) showed complete denervation with no voluntary motor units in the right supraspinatus, infraspinatus, biceps and deltoid muscles as well as a loss of SSEP and median nerve sensory conduction. No other significant changes. Given his closed injury, the patient was scheduled for another follow-up appointment. After 4 months, his clinical and electrodiagnostic re-evaluation showed no improvement and no features of re-innervation. Given the lack of recovery, the patient was scheduled for surgical exploration. What type of pre-operative study is mandatory in this case?
1. Repeat magnetic resonance neurography to follow the signal changes in the brachial plexus overtime
2. Repeat clavicular x-ray
3. Spine x-ray for intraoperative patient’s neck positioning for the surgical approach
4. Chest x-ray

Answer 2

4. Chest x-ray

• This is a clinical scenario for a closed brachial plexus injury- traction injury. Ideally, electrodiagnostic studies should be performed three weeks after the injury to allow for denervation changes of the muscle to evolve. Loss of sensation and sensory conduction response are indicative of post-ganglionic nerve injury, which is backed by the absence of pseudo-meningocele and rootlets severing on MRI images. The clinical scenario and the diagnostic studies refer to upper trunk traction injury.
• The upper trunk of brachial plexus is formed from anterior( ventral) rami of mainly C5 and C6 nerve roots. C4 spinal nerve may contribute to the upper trunk innervation. The clinicians should always be vigilant to differentiate between preganglionic and postganglionic injuries. A specific consideration, in this case, is the right phrenic nerve, which originates from C3,4 and 5. Injury of the phrenic nerve is not uncommon in this scenario. Phrenic nerve injury results in diaphragmatic paralysis that can be seen as an elevated diaphragmatic level in Chest x-ray.
• To rule out phrenic nerve injury and diaphragmatic paralysis, a chest x-ray should be done one with full inspiration and followed by another one with full expiration to detect diaphragmatic movement.
• It is of paramount significance to assess phrenic nerve function preoperatively in upper trunk surgical exploration. During the surgical exposure, identification and isolation of the phrenic nerve is an essential step before conducting the neurolysis of scarred nerves. This will help to differentiate between iatrogenic injury of the phrenic nerve or due to the primary injury.

Question 3

A 17-year-old female with a history of intravenous drug use presents with fever, back pain, and inability to ambulate. She has been experiencing back pain for the past three days. She reports that the weakness has been progressively worsening for the last 6 hours, and she is now unable to walk. On exam, the patient has reduced sensations of her umbilicus and 2/5 strength in her lower extremities bilaterally. Her temperature is 101 F (38.3 C), her heart rate is 89 beats per minute, and her respiratory rate is 17 breaths per minute. Magnetic resonance imaging (MRI) is obtained, and an enhancing lesion is noted from T10-L1. What is the most appropriate next step in the management of this patient?
1. Intravenous antibiotics after culture reports are available
2. Broad-spectrum intravenous antibiotics
3. Surgical incision and drainage and spinal decompression
4. Request an additional MRI with intravenous contrast to confirm the diagnosis

Answer 3

3. Surgical incision and drainage and spinal decompression

• Given that the patient is experiencing symptoms of spinal cord compression, treatment with intravenous antibiotics alone is not appropriate.
• Surgical decompression and drainage with concurrent use of systemic antibiotic therapy is the treatment of choice for many patients with spinal epidural abscess and is essential for those with neurologic deficits, spinal instability, ring-enhancing lesions on MRI, or disease progression on antibiotic therapy.
• Waiting for cultures or the start of surgical drainage is not recommended before starting with empiric intravenous antibiotics when clinical suspicion is high.
• Empiric antibiotics include a combination of vancomycin (to cover methicillin-resistant Staphylococcus aureus), and ceftriaxone, cefotaxime, ceftazidime, cefepime, or meropenem. The choice of the later three antibiotics is especially considered in the suspicion of Pseudomonas.

Question 4

A 65-year-old female presents to the clinic complaining of low back and buttock pain. She reports the insidious onset of pain without any inciting event. Provocative testing is most consistent with sacroiliac joint pain. Which of the following tests are most reliable in diagnosing sacroiliac joint pain?
1. FABER test
2. Sacral distraction test
3. Ultrasound-guided corticosteroid injection
4. Fortin finger sign

Answer 4

3. Ultrasound-guided corticosteroid injection

• The likelihood of sacroiliac (SI) joint mediated pain increases as the number of positive-provocative tests increase.
• The most informative test for the diagnosis of sacroiliitis is SI joint injection with local anesthetics and corticosteroids. If this procedure relieves the pain, it is likely the SI joint is the cause of the pain.
• Typically range of motion, neurologic, and strength testing are unremarkable in patients with sacroiliitis although the patient may experience pain during some of these tests.
• Sacroiliitis commonly presents as lower back pain but the pain presentation varies greatly, and patients could describe pain in one or both buttocks, hip pain, thigh pain, or even pain more distal.

Question 5

A 65-year-old male with Parkinson disease has had symptoms for 10 years and is no longer responding to medications. He is unable to do activities of daily living. Electrical stimulation of which areas would most likely improve his symptoms?
1. Hippocampus, globus pallidus interna, and medulla
2. Thalamus, globus pallidus interna, and hippocampus
3. Thalamus, globus pallidus interna, and subthalamic nucleus
4. Medulla, hippocampus, and subthalamic nucleus

Answer 5

3. Thalamus, globus pallidus interna, and subthalamic nucleus

• It is theorized that loss of dopaminergic neurons in Parkinson disease leads to the thalamocortical pathway over inhibition.
• Thalamic deep brain stimulation was used for tremor but other symptoms continued to progress.
• Current treatment includes stimulation of the subthalamic nucleus and globus pallidus interna.
• Criteria for surgery include medically refractory motor complications and the absence of significant mental or physical problems.

Question 6

A 65-year-old patient with a long-standing history of lower back pain presents with pain in his right leg for the past two days. It radiates from his back to his right thigh, leg, and toes. His pain worsens on lying down, bending, and walking uphill. A magnetic resonance imaging (MRI) of the lumbosacral spine shows disk degeneration with mild bulging at the L3/L4 level. According to the McKenzie classification, the patient’s condition will be classified as which of the following?
1. Postural syndrome
2. Derangement syndrome
3. Dysfunction syndrome
4. Radiculopathy

Answer 6

2. Derangement syndrome

• Derangement syndrome is the most commonly encountered pain syndrome, with a prevalence as high as 78% of patients classified by the McKenzie method.
• In derangement syndrome, pain is caused by a dislocation of articular tissue, causing a disturbance in the normal position of affected joint surfaces. This disturbance will deform the capsule and periarticular supportive ligaments, generating pain and obstructing movement in the direction of the displacement.
• Seven different subsyndromes are classified by the location of pain and the presence or absence of deformities.
• The centralization phenomenon is unique to derangement syndrome, and treatment is targeted in the patient’s directional preference.

Question 7

A patient developed an ischemic stroke after long periods of sitting. Which of the following is the most likely cause?
1. Atrial septal defect
2. Atrial embolism
3. Coronary atherosclerosis
4. Underlying malignancy

Answer 7

1. Atrial septal defect

• An atrial septal defect results in a shunt between the venous and arterial systems without the pulmonary vasculature to screen out emboli. Initially, the flow is left to right as the left system is higher pressure. Over time, Eisenmenger physiology may develop, leading to a right to left shunt.
• Emboli can bypass the lungs and end up in the arterial system, causing strokes.
• The paradoxical embolus originates in the lower extremities and becomes lodged in the cerebral vasculature.
• An ASD can result in right sided heart failure, pulmonary hypertension, atrial fibrillation, atrial flutter, and Eisenmenger syndrome.

Question 8

A 50 year old male patient who is referred to your clinic reports a history of a brain vascular malformation in his right frontal lobe which was diagnosed on brain MRI. He states that he was told that it is assocated with a mutation in the CCM1 gene. What is the best estimated annual rate of hemorrhage of this lesion if it has not previously hemorrhaged?
1. 1%
2. 5%
3. 10%
4. 50%

Answer 8

1. 1%

• The annual rate of hemorrhage for a cavernous malformation that has not previously had a hemorrhagic event is approximately 0.7% to 1.1%.
• For a cavernous malformation that has previously hemorrhaged, the annual rate of hemorrhage is 4.5%.
• Infratentorial location is associated with a higher risk of hemorrhage.
• An associated developmental venous anomaly is indicative of a higher risk of hemorrhage.

Question 9

A 32-year-old male presents to the office with complaints of headache and nausea for the past week. The headache is aggravated by standing or sitting upright, and it is relieved by lying down. Nausea occurs with the episodes of headache. The healthcare professional decides to perform brain and spinal MRI based on his clinical suspicion. Which of the following tests would be best to identify the precipitation cause associated with this disease?
1. MRI of the brain with contrast
2. MR myelography
3. CT scan of the lumbosacral spine
4. CT scan of the brain

Answer 9

2. MR myelography

• Spontaneous intracranial hypotension is secondary to a spinal CSF leak.
• Symptoms include positional headache, nausea, vomiting, neck stiffness, anorexia, diaphoresis, diplopia, photophobia, hiccups, unsteady gait, hyperacusis, tinnitus, blurred vision, and dysgeusia, etc. MRI of the brain shows diffuse pachymeningeal enhancement.
• MR myelography, CT myelography, or radioisotope cisternography can identify the leak.
• MR myelography is noninvasive and does not involve ionizing radiation but the images may be affected by motion, paravertebral veins, fat, or CSF pulsatile flow.

Question 10

A 3-year-old male child is brought with delayed milestones of development. He has not yet started running, and his speech output is also not normal compared to his peers. On examination, the child is brachycephalic, has an increased distance between his eyes, has a tongue that he struggles to keep in his mouth, and his nose appears small and set-back from the plane of his face. Extremity examination reveals flat, wide thumbs and mild webbing of the toes. There is a history of tracheostomy done in the neonatal period. Which of the following conditions might have necessitated the tracheostomy?
1. Congenital tracheal cartilaginous sleeve
2. Respiratory distress syndrome
3. Cystic fibrosis
4. Vocal cord paralysis

Answer 10

1. Congenital tracheal cartilaginous sleeve

• The child has characteristics of Pfeiffer syndrome (PS) type 1.
• The clinical features of Pfeiffer syndrome include craniosynostosis, midface hypoplasia, and limb anomalies. Broad thumbs and great toes are often associated with partial syndactyly of the second and third fingers, as well as second and third toes in Pfeiffer syndrome.
• Tracheal cartilaginous sleeve (TCS) is an airway malformation, seen in PS, in which distinct tracheal rings cannot be identified.
• Patients having TCS usually requires tracheostomy, mainly to treat obstructive sleep apnea that results from maxillary hypoplasia, choanal stenosis, and macroglossia.

Question 11

A 49-year-old woman presents to the clinic for follow up. She has had extensive workup for neck pain that radiates to their arm had an MRI of their cervical spine that demonstrated degeneration at the C5/C6 and C6/C7 level. The patient has failed conservative treatment and had a cervical provocation discography, which is positive at the C7 level. Which of the following features is most consistent with the patient’s syndrome?
1. Worsening of pain with forward flexion
2. Worsening of pain from sitting to lying
3. Worsening of pain with palpation
4. Improvement of pain with rest

Answer 11

1. Worsening of pain with forward flexion

• Positive findings in the cervical provocation discography support the diagnosis of cervical discogenic pain syndrome (CDPS). Patients have pain that is especially noticeable with prolonged flexion or with a protruded head posture.
• A common presentation of CDPS is of individuals that use computers for extended periods of time with there head protruded with prolonged flexion.
• A test used to diagnose CDPS is the Lhermitte test. This test utilizes neck flexion with the patient in a sitting position to reproduce pain down the neck and arm, which is present in patients CDPS.
• Cervical discogenic pain syndrome usually presents with pain at rest. Bending can exacerbate this pain. Patients may find relief in frequently changing their position. It may be worse in the morning, secondary to inappropriate postural position while sleeping.

Question 12

A 16-year-old football player presents to the clinic with complaints of severe headaches, nausea, and vertigo. The patient is oriented to time, place, and person at that time. The patient gives a history that three days ago, during a game, he took off his helmet and appeared confused, and then suddenly fell on his knees and began to vomit. This happened only once. He recalls being hit during the game 2 or 3 times on his head a week back. On neurologic examination, the Glasgow Coma Scale score is 15. Pupils are equally reactive to light. X-rays of the cervical, thoracic, and lumbosacral are normal. A computed tomographic (CT) scan is performed, which shows a hyperdense area, a crescent-shaped mass between the inner table of the skull and the surface of the cerebral hemisphere, which is measured to be 1.3 cm, with an equivalent left-to-right shift. The patient is treated conservatively. Which of the following limits the use of phenytoin in this patient?
1. Phenytoin is not recommended in this age group
2. Phenytoin can worsen the symptoms of this patient
3. Phenytoin has no proven benefit in the prevention of late post- traumatic epilepsy
4. Phenytoin does not reduce the incidence of early post-traumatic seizures

Answer 12

3. Phenytoin has no proven benefit in the prevention of late post- traumatic epilepsy

• Subdural hematomas are very common in athletes.
• Phenytoin is often added as a prophylactic treatment for early post-traumatic seizures, but it is not recommended for the prevention of late post-traumatic seizures.
• NSAIDs are started when the patient is having headaches.
• Surgery is not required until there are severe symptoms or the patient’s GSC is deteriorating.

Question 13

An indigent patient presents in an emergency room with confusion, bilateral sixth nerve palsies, horizontal nystagmus, and gait ataxia. Which of the following is the most likely diagnosis?
1. A subdural hematoma
2. A brain tumor
3. Hydrocephalus
4. The Wernicke-Korsakoff syndrome

Answer 13

4. The Wernicke-Korsakoff syndrome

• A malnourished patient with confusion, bilateral sixth nerve palsies, horizontal nystagmus, and gait ataxia has the Wernicke- Korsakoff syndrome and should be treated as a medical emergency with intravenous thiamine.
• The individual with Wernicke-Korsakoff Syndrome will usually present with (1) ocular disturbances which may include diplopia, painless vision loss, or strabismus, (2) gait abnormalities that include a wide-based, short-stepped gait and an inability to stand or ambulate without assistance, and (3) mental status changes that include apathy, paucity of speech, and indifference to the environment. As the disorder progresses, other symptoms may develop, including agitation, anger, hallucinations, and confabulations.
• The diagnosis of Wernicke-Korsakoff Syndrome is made by the history and clinical findings that are supplemented with lab studies showing thiamine deficiency. The aim of treatment is to prevent the disorder from getting worse. One should maintain a high level of suspicion for thiamine deficiency to avoid precipitation of severe symptoms of Wernicke-Korsakoff syndrome. Prophylactic thiamine administration is relatively safe and should be started even if the diagnosis has not been confirmed.
• To better understand this disorder, one should think of Wernicke encephalopathy and Wernicke-Korsakoff syndrome as two separate syndromes. Wernicke encephalopathy is characterized by an acute confusional state and often reversible clinical features while Wernicke-Korsakoff syndrome has persistent but often irreversible clinical features, including dementia and gait abnormalities.

Question 14

An 85-year-old female diagnosed with Alzheimer disease 2 years ago was brought by her daughter to the emergency department due to dysphagia. She started to have difficulty in swallowing solid food and eventually had difficulty even with drinking liquids. She also started bladder and bowel incontinence and had difficulty recognizing her daughter, who takes care of her recently. An MRI of the brain showed bilateral hippocampal atrophy. Which of the following arteries supply the anterior hippocampus?
1. Anterior cerebral artery
2. Posterior cerebral artery
3. Middle cerebral artery
4. Anterior choroidal artery

Answer 14

4. Anterior choroidal artery

• Anterior choroidal arteries supply anterior hippocampus, lower posterior limb/sub retrolentiform portions of the internal capsule, globus pallidus, and tail of caudate nucleus.
• The posterior hippocampus is supplied by PCA branches.
• The corpus striatum (caudate and putamen) and upper parts of anterior limb, genu, and posterior limb of internal capsule are supplied by lenticulostriate branches of MCA.
• It has been seen that patients with early Alzheimer disease have 15-30% of volume loss of hippocampus while those with moderate Alzheimer disease may reach to the extent of 50%.

Question 15

A 40-year-old woman with glioblastoma undergoes chemoradiation. Three months following treatment, she complains of a worsening headache. An MRI is inconclusive and cannot clearly define if there is any progression of the disease. Pseudoprogression is suspected. Which of the following investigations is most likely confirm the suspected diagnosis in this patient?
1. Amyloid PET scan
2. HMPAO PET scan
3. Tau PET scan
4. FDOPA PET scan

Answer 15

4. FDOPA PET scan

• FDOPA PET is a very sensitive tool to evaluate brain tumor patients at diagnosis or during follow-up. It can be successfully used as a problem-solving tool when the MRI is inconclusive.
• FDOPA PET scans can differentiate glioma recurrence/progression from treatment-induced changes, e.g., pseudoprogression, radionecrosis.
• If a biopsy is contemplated to evaluate for a recurrence site or during initial diagnosis, FDOPA PET scans can define the optimal biopsy site.
• Amyloid and Tau PET scans are used in the evaluation of dementia patients. HMPAO is a SPECT, not a PET radiotracer

Question 16

A 65-year-old female patient with progressive memory loss for the past six months presents with an inability to recognize faces that should be familiar to her. She is also complaining of headaches for the past month that is worse upon waking up. She has a history of stage 2 breast cancer, post- mastectomy, and underwent chemotherapy and radiation therapy 2 years ago. On examination, she is awake, alert, and able to follow commands. She is not oriented to time but oriented to place and person. Her mini-mental status exam is 18/30. She is unable to name objects presented visually, like a watch and a pen but is able to name them when placed in her hand. She cannot copy simple objects but is able to draw them after their purpose is described. There is no motor or sensory disturbance. What is the location of the lesion in this case?
1. Fronto-parietal cortex
2. Parieto-occipital cortex
3. Temporo-occipital cortex
4. Parieto-temporal cortex

Answer 16

2. Parieto-occipital cortex

• Apperceptive visual agnosia is typically associated with parietal and occipital cortex lesions. This refers to an abnormality in visual perception and discriminative process, despite the absence of elementary visual deficits.
• These people are unable to recognize objects, draw, or copy a figure. They cannot perceive the correct forms of the object, although knowledge of the object is intact.
• Associative visual agnosia refers to difficulty in understanding the meaning of what they see. They can draw or copy but do not know what they have drawn.
• They correctly perceive the form and know the object when tested with verbal or tactile information but cannot identify it.

Question 17

A 17-year male has been referred to the clinic with severe, sharp pain in his throat for the last two months. He was on a road trip with his friends when he got into an altercation with a gang member. When he woke up the following day, he was found to have a hematoma around his eyes and behind his ears. He was immediately taken to the hospital nearby, where he was found to have a minor fracture in the base of the skull. He was conservatively managed for three days and discharged home. Two months after the incident, he started having pain in his throat. He describes the pain as intermittent with the episode lasting from a few seconds to a minute. His pain is exacerbated by swallowing, chewing, and talking. He was treated by his primary provider with acetaminophen, ibuprofen, gabapentin, and a short course of tramadol, but all these medicines failed to control his pain. On exam, he does not have any tenderness in his mouth or jaw except for his left tonsillar area and the left side of the base of the tongue. Which of the following ganglions should be targetted for a diagnostic block?
1. Cervicothoracic ganglion
2. Meckel’s ganglion
3. Inferior petrous ganglion of Andersch
4. Ganglion cervicale superius

Answer 17

3. Inferior petrous ganglion of Andersch

• The clinical vignette described in the case is a case of glossopharyngeal neuralgia (GN). Per the International Classification of Headache Disorders (ICHD)-3 definition, the pain of GN happens in paroxysmal attacks that last from a few seconds to a minute. The description of the pain is severe, sharp, stabbing, shooting, or electrical in nature. Painful areas are typically below the ear, in the epiglottis, palatine tonsils, the base of the tongue, and/or the posterior pharynx. Paroxysmal pain is precipitated or exacerbated by coughing, yawning, swallowing, or talking.
• The patient developed GN due to the skull base fracture. There are two forms of GN. 1. Idiopathic or essential: caused by vascular compression. 2. Secondary form: caused by traumatic skull base fractures, infections like tonsillitis, pharyngitis, and parapharyngeal abscesses, as well as an elongated styloid process.
• The first line of management of GN pain should be medical management. The most common medications that are used to treat this condition include gabapentin, carbamazepine, duloxetine, valproic acid, and clonazepam.
• The inferior petrous ganglion of Andersch is the target for pain caused by glossopharyngeal neuralgia. The block should be reserved for patients that fail conservation management options and medications. A diagnostic block with a local anesthetic should be tried first in order to confirm the origin of the pain. If diagnostic blocks are successful, chemical neurolysis or thermal radiofrequency ablation can be performed on the nerve. Chemical neurolytic agents such as alcohol, glycerol, or phenol are typically used. Radiofrequency ablation is typically performed at the jugular foramen to target the inferior petrous ganglion of Andersch. Accurate needle placement is extremely important as life-threatening bradycardia and hypotension can occur if the vagus nerve is stimulated during the procedure.

Question 18

A 78-year-old female presents with neck pain after falling off of the toilet. A CT of the cervical spine shows a fracture through the base of the dens with 3 mm of superior displacement. She is neurologically intact and has numerous medical comorbidities, including uncontrolled diabetes mellitus, anemia, osteoporosis, smoking, chronic obstructive pulmonary disease, congestive heart failure, and two previous heart attacks. Which of the following is the most rational management strategy for this patient?
1. Rigid cervical orthosis
2. Halo vest immobilization
3. Odontoid screw
4. C1-C2 posterior fixation

Answer 18

1. Rigid cervical orthosis

• A type II odontoid fracture can be treated with various modalities depending on the characteristics of the fracture and patient factors.
• The application of a rigid cervical collar is a valid treatment option for this patient.
• Aged patients have increased morbidity with halo vest immobilization.
• Surgery is best avoided owing to multiple medical morbidities in the patient. The patient also has minimal displacement and no angulation of the odontoid fracture.

Question 19

A 56-year-old patient has been diagnosed with terminal pancreatic cancer. Recently, the tumor has encased upon his left t9-t11 rootlets, thereby causing severe and refractory nocturnal pain in the patient. The patient has been referred to the pain clinic for the management of the same. The treating clinician opts for intrathecal alcohol injection in the appropriate dorsal rootlets of the patient. What is the most appropriate positioning of the patient to ensure maximum efficacy following the procedure in the patient?
1. Prone
2. Supine
3. Left lateral positioning
4. Right lateral positioning

Answer 19

4. Right lateral positioning

• The alcohol (specific gravity of 0.8) is comparatively hypobaric in relation to the cerebral spinal fluid (specific gravity of 1).
• The alcohol, therefore, floats amidst the CSF environment. This necessitates the appropriate positioning of the patient to ensure that the dorsal rootlets are above the presumed site of injection.
• The appropriate lateral positioning, therefore, ensures that the selected dorsal root entry zones (DREZs) are above the level of the corresponding ventral rootlets, thereby facilitating the action of the injected alcohol therapy.
• The prone positioning minimizes the efficacy of the action of the alcohol selectively upon the dorsal rootlets. Moreover, alcohol is also rapidly absorbed. Thereby the large volume of alcohol is required, which increases the risk of adverse neurological events.

Question 20

A 58-year-old female with a previous history of transsphenoidal surgery for the management of Cushing disease seven years ago and bilateral adrenalectomy due to endocrinological failure despite a complete removal by the postoperative brain magnetic resonance imaging is evaluated by the endocrinologist and the neurosurgeon for the appearance of a new tumor in the pituitary fossa. Her adrenocorticotropic hormone had increased to 780 pmol/L (Normal: 1.3-16.7 pmol/L) and had developed significant skin hyperpigmentation. The magnetic resonance imaging performed last year only suggested a 3 mm abnormality within the pituitary gland. Still, the current study clearly shows an 18 mm lesion with contrast enhancement touching the chiasm. Which is the next best management in this patient?
1. Surgical removal of the tumor
2. Medical treatment with somatostatin-analogs
3. Medical treatment with dopamine agonists
4. Observation until next year magnetic resonance imaging to evaluate the growth pattern

Answer 20

1. Surgical removal of the tumor

• The initial recommended treatment for Nelson syndrome is the surgical removal of the tumor. Risk factors for developing Nelson syndrome have been studied in an attempt to achieve early detection and treatment. High levels of plasma ACTH one year after bilateral adrenalectomy have the strongest predictive capabilities. Fasting ACTH plasma levels above 154-220 pmol/L (700-1000 pg/ml) are predictive of Nelson’s syndrome one year after bilateral adrenalectomy. Screening is done with the help of brain magnetic resonance imaging (MRI) to visualize the sellar area for pituitary tumors. If tumors are not detected, a brain MRI should be performed at regular intervals. MRI may reveal a small tumor forming.
• Surgery can be performed microsurgical or endoscopically by the transsphenoidal route. Extensive tumors with lateral extensions may require a craniotomy. Endocrinological cure is achieved in approximately 50% of the cases. This is due in part to the infiltration of the cavernous sinus and extrasellar extension.
• Surgery can be complicated by postoperative hypopituitarism in 30% of the cases and permanent diabetes insipidus in 20% of the cases.
• Medical treatment is limited, and the results are not curative. Radiotherapy in the form of fractionated radiotherapy or stereotactic radiosurgery can be given to the tumor but is usually used in patients who can not undergo surgical resection. Sometimes, close clinical follow-up is recommended as many of the tumors do not develop clinically meaningful symptoms or have a slow growth pattern of less than 5 mm per year.

Question 21

A 17-year-old male with a history of C5 incomplete spinal cord injury presents to the clinic with a complaint of increased pain in his left upper extremity and difficulty with activities of daily living. On physical examination, his left arm is in flexion with increased muscle tone. Passive extension of his arm is possible but difficult. When completing his chart, what should be recorded for his modified Ashworth scale score?
1. 1
2. 1+
3. 2
4. 3

Answer 21

4. 3

• The modified Ashworth scale is a quick clinical scale that measures spasticity and increased tone.
• A score of 3 represents a considerable increase in muscle tone with passive movement of the limb being difficult.
• Passive movement is difficult but possible in a modified Ashworth score of 3.
• The modified Ashworth scale score differs from the Ashworth score because it includes the “1+” option. 1+ is a slight increase in muscle tone manifested by a catch, followed by minimal resistance throughout the rest of the range of motion. This must be less than half of the range of motion.

Question 22

A sonogram of a 20-week gestational age fetus of a 23-year-old female reveals an outpouching of the head with encephalic mass and cerebrospinal fluid protruding from a skull defect at the nasofrontal suture area. The outpouching was noted in an earlier sonogram performed at her 10th weeks of gestation. The mother had a previous normal pregnancy when she was 17. There is no family history of developmental anomalies. Which is the pathophysiologic mechanism for the sonographic imaging finding?
1. Gastrulation abnormality
2. Incomplete primary neurulation
3. Separation of surface ectoderm from neuroectoderm after the closure of the neural folds
4. Failure of regression of dural diverticulum at the fonticulus frontalis

Answer 22

4. Failure of regression of dural diverticulum at the fonticulus frontalis

• A frontal encephalocele is believed to be caused by the failure of the regression of a dural diverticulum that forms at the recess in the anterior fossa called the fonticulus frontalis that is closely associated with the foramen caecum.
• Typically there is a separation of surface ectoderm from neuroectoderm after the closure of the neural folds. Failure of this process has been related to the formation of encephaloceles.
• Sincipital encephaloceles are classified as nasofrontal, nasoethmoidal, or naso-orbital. Nasofrontal encephalocele is the most common type, seen in 46.4% of the patients. It is followed by nasoethmoidal type in 39.2% of the patients. The naso-orbital and the combined type are the least common with 14.2%.
• It was believed that encephaloceles were a problem with primary neurulation, but this idea has been abandoned.

Question 23

A male neonate born at 31 weeks is undergoing neonatal evaluation. Transcranial ultrasound examination reveals the presence of a cystic space in the pineal region. The color doppler shows the internal cerebral veins adjacent to the cystic space. What is the most likely diagnosis?
1. Cavum veli interposity
2. Cavum septum pellucidum
3. Mega-cistern ambient
4. Cerebral arteriovenous malformation

Answer 23

1. Cavum veli interposity

• The cavum velum interpositum (CVI) is a potential cisternal space between the two layers of the tela choroidea of the third ventricle located between the internal cerebral veins and posterior medial choroidal artery.
• CVI has a triangular shape with a wide base dorsally.
• Its boundaries include superiorly: the fornix and the hippocampal commissure, inferiorly: the tela choroidea of the third ventricle and the internal cerebral veins, laterally: the thalami, anteriorly the roof of the third ventricle and the interventricular foramina, posteriorly: the splenium of the corpus callosum and the habenular commissure.
• The cavum septum pellucidum is a potential liquid space between the two layers of septum pellucidum. It is present in the normal fetus, but over 85% of them fuse by 3-6 months of age meaning that a CSP persists in ~15% of the adult population. Its boundaries include anteriorly: genu of the corpus callosum, superiorly: corpus callosum, posteriorly: fornix, inferiorly: anterior commissure and the rostrum of the corpus callosum, and laterally: leaflets of the septum pellucidum. The ambient cistern is a cerebrospinal fluid-filled space lateral to the cerebral crus. It contains the posterior cerebral artery, superior cerebellar artery, basal vein (Rosenthal’s), and the trochlear nerve. Cerebral arteriovenous malformations (CAVMs) are vascular malformations composed of a nidus of vessels through which arteriovenous shunting occurs. In our clinical scenario the color doppler revealed only normal internal cerebral vein.

Question 24

A 35-year-old woman is brought to a hospital in Kentucky in an altered state of consciousness. She is accompanied by her husband, who states she fell of stairs. Physical examination shows multiple bruises on the patient’s forehead and arms in different stages of healing. She has a GCS of 7/15 and is intubated. CT head reveals an epidural hematoma. Medical records indicate that the patient has had multiple admission due to domestic violence in the past but had wished it not to be reported to the authorities. While waiting for neurosurgical intervention, the patient suffers brain herniation and passes away. Which of the following needs to be informed of the patient’s history of domestic violence by law at this point?
1. Family
2. Police
3. Hospital ethics committee
4. Adult protection services

Answer 24

2. Police

• In the United States, as many as one in four women and one in nine men are victims of domestic violence. Domestic violence is thought to be underreported.
• Intimate partner violence is not mandated by law to be reported to authorities if the victim wishes it not to be reported.
• However, statutes of certain states require reporting to law enforcement any relevant information on the death of a victim of domestic violence.
• Kentucky is one of three states (with Oklahoma and Arkansas) with a mandatory reporting law specific to domestic violence.

Question 25

A 32-year-old female patient started 3 weeks ago with mild perianal numbness but did not seek medical attention. This has significantly progressed during the last week, and since last night, she complains of numbness in the saddle area distribution, has urinary retention, and absent bilateral motor function below the knee. There is lax sphincteric tone on the rectal exam. Emergency magnetic resonance imaging shows a very large intraspinal lesion occupying all the spinal canal at the level of L3. Which is the best time-frame to operate this patient? 1. Within the first 48 hours after the presentation of symptoms 2. Within the first 96 hours after the presentation of symptoms 3. Within the first week after the presentation of symptoms 4. Any time as the patient has already bladder dysfunction and absent rectal tone and surgery time will not improve these deficits

Answer 25

**1. Within the first 48 hours after the presentation of symptoms** ## Footnote * The timing of surgical decompression is a significant factor in the prognosis and outcome, the best results are obtained when surgery is done within the first 48 hours after the presentation of symptoms. * Some reports give the benefits until the 72-hour mark. * Bladder dysfunction has a negative prognostic factor for poor outcome. The return of bladder function is estimated to occur in approximately 50% of patients with cauda equina syndrome. * Steroids can be useful in patients with tumors, but surgery should be performed before the 72-hour mark.

Question 26

A 17-year-old male military recruit presents to the emergency room complaining of nausea, fever, and a severe headache. He is currently living in barracks and shares a living space with his fellow recruits. On physical exam, he has a rash on his abdomen and states that it hurts to look into the light and bending his neck downward produces pain as well. It assumed the patient has an infection of the central nervous system. The patient undergoes a lumbar puncture and 10 ml of fluid are removed. How long will the brain take to replenish the lost fluid? 1. 1 hour 2. 12 hours 3. 24 hours 4. 72 hours

Answer 26

**1. 1 hour** ## Footnote * Normal cerebrospinal fluid production is about 0.3 ml/min and most of the fluid is produced by the choroid plexus. The total amount of fluid in the brain is 120 ml. * Most of the fluid removed during a lumbar puncture is easily replaced within one hour. * The normal route of clearance of cerebrospinal fluid is to the lateral ventricles, then to the interventricular foramen of Monro, the cerebral aqueduct of Sylvius, the subarachnoid space, the dural sinus, and into the venous drainage. * CSF returns to the vascular system via the dural venous sinuses by first entering the arachnoid granulations.

Question 27

A 22-year-old male experiences the acute onset of severe painful unilateral headache lasting 15 to 20 minutes. The pain is described as boring and drilling and located primarily around the eye. During the attack, he develops red eyes, rhinorrhea, and a red flushed face. What is the most likely diagnosis? 1. Tension headache 2. Migraine headache 3. Cluster headache 4. Headache due to brain tumor

Answer 27

**3. Cluster headache** ## Footnote * The presentation is classic for a cluster headache. * Migraines sometimes have an aura and last 6-72 hours. It starts as a dull pain getting worse over minutes to an hour. Many times it has been associated with neurological symptoms. * Cluster headaches are severe, recurrent, periorbital, and unilateral. They fall under the category of trigeminal autonomic cephalgias (TACs). There is often associated autonomic disruption seen as watering eye, periorbital swelling, and nasal congestion, all ipsilateral to the headache. * Cluster headaches are more common in men (3:1) and affect about 1 in 500 people. Acute attacks are treated with oxygen and triptans. Prophylaxis is with verapamil.

Question 28

A 3-month-old girl is brought to the clinic for being increasingly irritable. She reports that in the last 3 days, her baby has not been able to keep down her milk. On examination, the anterior fontanelle is open and bulging significantly. There is also evidence of ridging of the cranial suture between the parietal bones and the occipital bone. The baby is also visibly lethargic. Fundoscopy reveals bilateral papilledema. Which of the following conditions is most likely responsible for this patient's symptoms? 1. Positional plagiocephaly 2. Apert syndrome 3. Bicoronal synostosis 4. Bilambdoid synostosis

Answer 28

**4. Bilambdoid synostosis** ## Footnote * 15% of cases of lambdoid synostosis are bilateral. 86% of the cases are associated with raised intracranial pressure. * Bilateral lambdoid synostosis is usually associated with an elongated vertex. * In general, lambdoid synostosis is rare. They have a prevalence of only 0.1 per 10 000 live births. * The presence of suture ridges excludes a positional skull deformity. Apert syndrome is characterized by bicoronal synostosis.

Question 29

A 16-year-old boy undergoes a repair of his ulnar nerve, following a physical assault with a knife, in his elbow region. Three months later, the patient complains of pain along the course of the nerve during the movement at his elbow joint. Now the patient has severe pain even with the slightest touch in the region. The ultrasound reveals a neuroma formation at the previously operated site along the course of the nerve. The patient did not show any improvement with oral pain medications as well as repeated steroid injections. The pain has hampered his quality of life as well. Which of the following is the next best step in the management of this patient? 1. Direct transcutaneous electrical stimulation 2. Dynamic magnetic flux induced neuro-modulation 3. Repeat steroid injection 4. Excision of the neuroma

Answer 29

**2. Dynamic magnetic flux induced neuro-modulation** ## Footnote * The patient has typical features of allodynia following traumatic neuroma formation. The neuroma results following the fascicular escape, leading to sprouting axons recruitment within the epineural space, along with fibromatosis. * The dynamic magnetic flux induced neuromodulation has shown to improve allodynia in patients with a traumatic neuroma significantly. This also has shown to aid in neuronal regeneration and repair. * Low-frequency magnetic stimulation results in neuronal inhibition thereby obviating pain. Moreover, since there is no direct device-patient contact, this is more ideal in managing patients with neuronal hypersensitivity. * The patient has already failed repeated steroid injections. The need for device-patient contact in electrical stimulation is a limiting factor in this patient with allodynia. The excision of neuroma along the ulnar nerve is not justified due to the risk of impending neurological deficits.

Question 30

A 7-month-old boy is brought to the clinic for evaluation for an abnormal head shape. Premature closure of the metopic suture is suspected. Which of the following sets of findings is most likely to be seen on the patient's head computed tomographic scan and physical examination? 1. Midline bone ridge at the vertex and hypotelorism only 2. Midline forehead ridge at the forehead, hypotelorism, and widened parietal bones 3. Bilateral harlequin eye and hypertelorism with forehead bone ridge 4. Flattening of the occipital bone with widened temporal bones

Answer 30

**2. Midline forehead ridge at the forehead, hypotelorism, and widened parietal bones** ## Footnote * In premature closure of the metopic suture, the most obvious sign for the diagnosis is palpation of a midline bony ridge over the forehead. Craniofacial anomalies like hypotelorism and temporal narrowing with parietal widening are, in most cases, sufficient to accurately diagnose craniosynostosis. * The premature fusion of the metopic suture produces a narrow forehead, causing the eyes' position to be closer than usual (hypotelorism) with associated bitemporal narrowing. Early closure before the third month will cause trigonocephaly. * Metopic craniosynostosis produces a visible midline forehead bone ridge. Hypotelorism is frequently associated. Patients have a narrow bitemporal skull dimension with a compensatory expanded biparietal dimension. Eyebrows are usually raised. * Early operative treatment is recommended to provide the best possibility for the brain to expand and produce a normal configuration of the skull. Surgery goals are to remove the bony ridge of the metopic suture, advance both orbits and the frontal bones, achieve a rounder forehead contour, and prevent the psychosocial impact and neurodevelopmental delay.

Question 31

A healthy male is involved in a motor vehicle collision. He loses consciousness but regains it within a few hours and appears normal to friends. He later presents to the emergency department very lethargic, weak, and with a dilated left pupil. Which of the following is most likely to be seen on a head CT scan? 1. Cresent shaped hyperdensity close to the skull 2. Hyperdensity on the basal cisterns and subarachnoid space 3. Biconvex hyperdensity close to the skull 4. Hyperdensity on the brain parenchyma

Answer 31

**3. Biconvex hyperdensity close to the skull** ## Footnote * An epidural hematoma is due to an accumulation of blood between the dura and the bone and may occur intracranially or in the spinal cord. * An epidural hematoma should be suspected in any individual who sustains head trauma. It is associated with a lucid interval followed by an altered level of consciousness. * Other symptoms of an epidural hematoma may include weakness, numbness, urinary incontinence, and fecal incontinence. Focal neurological deficits may include loss of vision, aphasia, and seizures. * Findings may include hemotympanum, anisocoria, weakness, ataxia, visual field defects, and weakness of extremities. Bradycardia and hypertension may be indicative of raised intracranial pressure.

Question 32

A 62-year-old woman is undergoing a right retrosigmoid craniotomy for resection of a cerebellopontine angle tumor. During the surgery, the tumor appears to compress the facial nerve, and resection of the lesion causes some traction on the nerve. Her right facial function was a House Brackman of 4/6 before the procedure but is a 6/6 after the surgery. One year after the procedure, she has not recovered any facial function. What is the most appropriate management strategy for this patient? 1. Conservative management 2. Direct distal facial nerve stump coaptation to the brainstem with the aid of a nerve stimulation probe 3. Sural nerve interneural graft to reconnect the pontine facial nerve with the extratemporal facial nerve 4. Hypoglossal nerve transfer to the extratemporal segment of the facial nerve

Answer 32

**4. Hypoglossal nerve transfer to the extratemporal segment of the facial nerve** ## Footnote * Delayed repair of the facial nerve after damage to the cisternal portion of the nerve is best done with a hypoglossal nerve transfer to the intraparotid segment of the facial nerve. * During surgery, if a nerve is cut, the best repair is direct end-to- end anastomosis if it can be approximated without tension. * Lack of clinical and electrophysiological signs of spontaneous recovery after 3–6 months indicates surgical intervention. Endoneurial tubes must be in contact with regenerating axons within 18–24 months after injury; otherwise, degeneration will occur. * Sural nerve interneural graft is used to connect two healthy nerve stumps which cannot be approximated without tension.

Question 33

Lumbar spinal stenosis may present with which of the following? 1. Back pain that increases upon standing 2. Back pain upon lying in the prone position 3. Numbness in the arms 4. Shooting pain in the legs

Answer 33

**1. Back pain that increases upon standing** ## Footnote * Back pain and paresthesias that worsen upon standing but are absent when sitting is indicative of spinal stenosis. * Severe stenosis is associated with weakness. * Cervical spinal stenosis can present with decreased hand dexterity and mild proximal lower extremity weakness and progress to neck and arm pain. * As with standing, one expects lying prone to worsen or exacerbate the symptoms of spinal stenosis (whereas prone positioning may improve the symptoms of HNP).

Question 34

A 59-year-old woman presents with left-sided weakness. The symptoms started 30 mins ago when she was having lunch in a restaurant. The patient has a past medical history of hypertension and type 2 diabetes mellitus. On examination, the patient is awake, alert, able to follow commands, and is oriented to time, person and place. Cranial nerve examination reveals preferential gaze to the right and dysarthria. The patient is unable to recognize left-sided stimulus on double simultaneous stimulation. The motor examination shows 3/5 strength on the left upper and left lower limb. There is a 20% sensory deficit on the left to pain and light touch. Babinski sign is positive on the left. A head CT is performed. Which of the following do you expect to see on this scan? 1. Encephalomalacic changes in the right periventricular region 2. A small area of hyperdensity in the pons 3. Insular ribbon sign with obscuration of the lentiform nucleus 4. Hyperdensity at the Sylvian fissure and base of the skull

Answer 34

**3. Insular ribbon sign with obscuration of the lentiform nucleus** ## Footnote * Ischemic brain tissue stops working in seconds and suffers necrosis in as soon as 5 minutes after complete lack of oxygen and glucose supply, prompting a myriad of potential symptoms and disability. * Cerebral ischemia can be focal or generalized and cause varying clinical pictures. * While generalized cerebral ischemia is generally related to syncope and pre-syncope, focal cerebral ischemia usually causes a stroke or transient ischemic attacks. * As a rule of thumb, acute cerebral ischemia is never painful.

Question 35

A 68-year-old woman with a history of metastatic breast cancer presents to the office for follow up. She is currently taking hydromorphone/acetaminophen 10/325 mg 4 times a day for severe pelvic pain due to boney metastasis. Despite this medication use, the patient still complains of 9 out of 10 pain. After a careful review of the source of pain, it is suspected to be coming from a neurologic dermatome from the spinal cord. A spinal opioid injection for pain control is then performed. Soon after the injection, the patient describes pain in the frontal and occipital areas that is worse in the upright position and improved in the supine position. She states the pain is also made worse with coughing. Which of the following is the next best step in the management of this patient? a. Reassurance b. Head CT scan c. MRI head d. Oral hydration

Answer 35

**d. Oral hydration** ## Footnote * While serious complications from spinal opioid use in anesthesia are rare, when complications do occur, they are specific to both the medication and the approach utilized in the procedure. In the prototypical example of spinal morphine use, complications include respiratory depression, constipation, altered mentation, and somnolence. * Complications of spinal opioid injection also include the risk of paresthesias, temporary pain at the injection site, and post-dural puncture headache. * Rarer procedural complications of spinal opioids also include infection, urinary retention, and epidural hematoma. * The first step in managing post-dural puncture headache from spinal opioids is using conservative measures with oral rehydration and simple oral analgesia.

Question 36

A 39-year-old man presents with lower back pain. The patient used to be a semi-professional golf player and says the pain started during a game. This pain did not let him continue with the game. Upon waking up the next morning, he felt the pain now radiates down the right leg. He has no past medical history and takes no medication. Which of the following examinations is the most appropriate to make the diagnosis of this patient's condition? 1. Ankle jerk reflex 2. Lumbar puncture 3. Straight leg raise 4. Head flexion in a sitting position

Answer 36

**3. Straight leg raise** ## Footnote * Straight leg raise is performed with the patient supine and will reproduce the pain if a herniated disc is compressing the nerve root. * Deep tendon reflexes can be normal, decreased, or absent with nerve root compression. Many pathologies can affect them. * The crossed straight leg raise is less sensitive but more specific. It is more specific for disc herniation. This maneuver reproduces the pain in the leg when you raise the contralateral leg. * Head flexion used for Lhermitte's sign causes a sudden sensation resembling an electric shock that passes down the back of your neck and into your spine and may then radiate out into your arms and legs. This is usually caused by cervical cord compression.

Question 36

Which of the following is characterized by progressive basal ganglia calcification and encephalopathy? 1. Neuroacanthocytosis 2. Harp syndrome 3. McLeod syndrome 4. Fahr syndrome

Answer 36

**4. Fahr syndrome** ## Footnote * Fahr syndrome is also known as idiopathic basal ganglia calcification. * It is thought to have autosomal dominant inheritance but no specific gene location has been found. * Age of onset is variable but in children there may be senile appearance, dwarfism, retinitis pigmentosa, ataxia, intellectual disability, seizures, dysarthria, and choreoathetotic movements. * The calcification usually starts in the pons and dentate followed by the basal ganglia and finally at the corpus callosum.

Question 36

A 6-year-old boy is brought to the clinic to establish care after recently moving to the city. His mother reports that they needed a new physician to take care of their child due to the condition he has. The parents were told that their child had “premature closure of a skull suture.” The parents deny any symptoms except for the abnormal head shape and mention that he has achieved all milestones adequately for his age but is not doing well in school. He has good attention, but his performance is below most other students. He has good communication with the teacher and interacts well with many students. On examination, there is an elongated, narrow skull with ridging of the sagittal suture with frontal and occipital bossing. Which of the following is the most likely cause for his poor school performance? 1. Hyperactivity-attention deficit 2. Venous occlusion 3. Increased intracranial pressure 4. Adaptive and psycho-social issues

Answer 36

**3. Increased intracranial pressure** ## Footnote * In a premature single suture fusion, elevated intracranial pressure occurs in approximately 11% of cases. In sagittal synostosis, this can be as high as 44%. * Having signs/symptoms of increased intracranial pressure has significant implications and can lead to detrimental outcomes for which management is required. * Monitorization of intracranial pressure during regular follow-up (i.e., fundoscopic examination) is very important. * The diagnosis and treatment of craniosynostosis can produce a significant impact on families. Careful explanation of the diagnosis, treatment modalities, postoperative care, and prognosis can help families deal with the initial struggle after the diagnosis is made.

Question 36

A 12-year-old male presented with acute onset of headache, nausea, vomiting, and diplopia. Ophthalmological examination showed a limited upward gaze. Light reflex was lost, but pupils responded to near stimuli. Nystagmus was noted when he attempted upward gaze. The remaining physical examination was unremarkable. An axial non-contrast computed tomography (CT) scan showed a lobulated, hyperdense mass, pineal calcification, and obstructive hydrocephalus. An external ventricle drain was placed. What is the next best step in the patient's management? 1. Immediate surgical resection of the tumor 2. Magnetic resonance imaging (MRI) 3. Lumbar puncture 4. Biopsy of the mass

Answer 36

**2. Magnetic resonance imaging (MRI)** ## Footnote * Pineal region germinoma usually presents acutely with signs and symptoms of raised intracranial pressure like headache, nausea, vomiting, and diplopia due to obstructive hydrocephalus. Parinaud syndrome is also a common presentation, caused by the compression of the midbrain tectum by the tumor and is characterized by the classical triad of upward gaze palsy, pupillary near-light dissociation, and convergence nystagmus. * CT and MRI are crucial for the assessment of tumor site and size. However, MRI is the most sensitive imaging modality and is considered a gold standard in detecting central nervous system (CNS) tumors. * On MRI, germinoma shows a well-circumscribed, lobulated homogenous mass of variable intensity and maybe isointense or hypointense on T1 and isointense or hyperintense on T2 weighted images. In more advanced disease, germinomas may become heterogeneous with a partially cystic appearance and may invade adjacent brain structures with edema of surrounding brain parenchyma. * Imaging is followed by laboratory evaluation of tumor oncoproteins, biopsy for histological diagnosis, and cerebrospinal fluid (CSF) cytology to rule out disseminated disease. Surgery is not recommended for germinomas. Whole- ventricular radiotherapy or chemotherapy combined with reduced dose ventricular radiotherapy is the standard of care.

Question 36

A 16-year-old male diagnosed with a unilateral vestibular schwannoma presents with upper limb weakness and tremors. He reports his symptoms started three months ago and have gradually increased in intensity. Computed tomography (CT) of the brain with contrast shows a hyperdense 3x2 cm circumscribed dural based lesion located at the left sphenoid wing. Which is the most common neurocutaneous syndrome associated with this type of lesion? 1. Neurofibromatosis type II 2. Neurofibromatosis type I 3. Ataxia telangiectasia 4. Sturge weber syndrome

Answer 36

**1. Neurofibromatosis type II** ## Footnote * Neurofibromatosis type II is one of the most common neurocutaneous syndromes that is usually associated with multiple meningiomas and vestibular schwannoma. * Unlike neurofibromatosis type II, meningiomas are uncommon in patients with neurofibromatosis type I. Neurofibromatosis type I is frequently associated with optic gliomas, neurofibromas, café- au-lait spots, lisch nodules, and bony lesions. * Meningiomas are also associated with affected first-degree relatives with meningioma, genetic syndromes such as neurofibromatosis type 2, von Hippel Lindau disease, multiple endocrine neoplasia type 1, Li-Fraumeni, Cowden disease, and Gorlin syndrome. * Sturge Weber syndrome is a neurocutaneous syndrome that causes leptomeningeal malformations known as angiomas. Patients usually present with a port-wine stain of the face or eyelid and can be associated with intellectual disabilities and seizures.

Question 36

A 40 years old male complains of severe neck pain and bilateral upper extremity numbness after a car accident 5 hours ago, a flexion-extension mechanism is suspected. His medical history is positive for a rare cervical anomaly called Os Odontoideum. Knowing the physiopathology of this rare condition, which of the following is the primary diagnosis? 1. Subaxial cervical fracture-dislocation 2. C1-C2 instability 3. Atlas fracture (Jefferson fracture) 4. Isolated spinous process fracture

Answer 36

**2. C1-C2 instability** ## Footnote * Although cervical fracture-dislocation is a possibility after a car accident, a previous history of Os Odontoideum suggests that the primary diagnosis is cervical instability. * The patient has a history of Os Odontoideum, and after a cervical trauma experiences symptoms of spinal cord compression, C1-C2 instability must be ruled out. This atlantoaxial instability can lead to cervical spinal stenosis with resultant cervical myelopathy due to vascular compromise, bony compression, and/or stretching of the spinal cord. This instability is almost always anterior; posterior atlantoaxial subluxation has been described; however, it is extremely rare. * Atlas fracture usually results from axial compression forces; it is not the mechanism described in this case. * Isolated spinous process fracture has to be considered within the differential diagnosis. However, they are not usually associated with neurological symptoms.

Question 37

An 18-year-old man is brought to the hospital after a high-speed car accident. He is mildly confused and has a GCS of 14/15, his heart rate is 100/min, and his blood pressure is 110/70 mmHg. Admission labs have been sent and are pending. He has large bruises around each eye and is complaining of significant left flank pain. During the primary survey, he begins to have multiple episodes of emesis. Two large-bore IV lines are placed. Which of the following is the next best step in the management of this patient? 1. Place a nasogastric tube 2. Turn the patient on his side to minimize aspiration risk and continue the primary survey 3. Turn the patient on his side and administer supportive care such as ondansetron 4. Proceed emergently to the operating room

Answer 37

**2. Turn the patient on his side to minimize aspiration risk and continue the primary survey** ## Footnote * Turning the patient on his side to avoid aspiration and continuing the survey is correct for this patient. As he is a trauma patient, it is imperative to complete the primary and secondary surveys to ensure no major injury is missed. * If the emesis continues and becomes intractable, it should raise suspicion for possible increased intracranial pressure, especially in this patient who was injured in a high-speed accident and has bilateral periorbital ecchymoses. * However, symptoms associated with increased intracranial pressure, such as blown pupils, are evaluated in the primary survey, which should be performed in a systematic manner. * The bilateral ecchymoses around each eye, also known as raccoon eye sign, should raise suspicion for a basilar skull fracture. Placement of a nasogastric tube under these conditions is contraindicated as it may worsen the fracture, or the tube may even slip inside the skull cavity. Turning the patient on his side to minimize aspiration risk is the correct maneuver, but providing supportive care should wait until the primary and secondary surveys are completed in order to ensure significant injuries are not missed. Given the information provided in the question stem, it is unclear whether this patient needs to go to the operating room. Completing the primary and secondary surveys are imperative to determine the best option for this patient.

Question 38

A 25-year-old man with no prior medical history is brought to the hospital after a motor vehicle accident. Upon presentation, the patient is unresponsive. The left pupil is larger and sluggishly reactive compared to the right. The patient is noted to have flexion response to pain. Initial CT head shows left epidural hematoma, causing midline shift and possible left uncal herniation with hyperdensities with the brainstem. Which of the following locations is most likely to have Duret hemorrhages in this patient? 1. Tectum of midbrain 2. Occipital lobe 3. Pontomedullary junction 4. Ventral and paramedian aspects of midbrain and pons

Answer 38

**4. Ventral and paramedian aspects of midbrain and pons** ## Footnote * Duret hemorrhages are typically seen in ventral and paramedian aspects of the midbrain and pons. * The vignette describes a case with uncal herniation which can cause secondary brainstem hemorrhages, which are called Duret hemorrhages. * These are believed to result from distortion of the pontine perforators against a relatively immobile basilar artery, which explains why these hemorrhages are typically seen in ventral and paramedian midbrain and pons. * Tectum of the midbrain, brachium pontis, and pontomedullary junction are not the usual location of Duret hemorrhages. Petechial hemorrhages in case of diffuse axonal injuries can be present in these areas.

Question 39

A 10-year-old paralympian swimmer presents with worsening of mild chronic neck pain, limiting her neck movement. Her past medical history includes Down syndrome. Over the past month, she has also developed gait disturbance and bladder dysfunction. What is the most appropriate test to perform to diagnose the condition underlying this patient's symptoms? 1. Pelvic x-ray 2. Cervical x-ray with flexion and extension 3. Lumbar spine MRI 4. Cystogram

Answer 39

**2. Cervical x-ray with flexion and extension** ## Footnote * Children with Down syndrome should be screened with dynamic lateral flexion and extension radiographs of the cervical spine. * The atlantodental interval in Down syndrome may be up to 5 mm. At distances greater than 5 mm, there is an increased risk of spinal cord injury with contact sports, including swimming. * The normal radiographic atlantodental interval in adults is 3 mm or less. * The atlantodental interval is the distance, in the median plane, between the posterior cortex of the anterior aspect of the atlas and the anterior part of the dens.

Question 40

What are the imaging characteristics of an annuluar fissure? 1. Hyperintesnse on T2 MRI 2. Hypointesnse on T2 MRI 3. Hypointense on T1 MRI 4. Hyperdense on CT

Answer 40

**1. Hyperintesnse on T2 MRI** ## Footnote * An annular fissure is hyperintense on T2 MRI compared to the normally hypointense normal annulus fibrosus. * The normal annulus fibrosus is hypointense on T2 MRI. * Annular fissure is not well visualized on T1 MRI which normally shows fat as hyperintense and fluid as relatively hypointense. * CT does not visualize soft tissue structures, such as the annulus fibrosus well. CT is better for imaging bony abnormalities of the spine.

Question 41

A 75-year-old male presents with a complaint of gradually increasing back pain for the past 6 months. He reports the pain initially responded to ibuprofen, but for the past 2 months, the pain is continuous and it is no longer helping. He also reports an 8- kilogram (18-pound) weight loss over the last 2 months. He denies any falls or back injuries and there has been no change in his bowel habits. His abdominal exam is negative and a digital rectal examination reveals an enlarged prostate gland without any suspicious nodules. His PSA is pending. The patient most likely has developed which of the following? 1. Osteoarthritis of the spine 2. Degenerative disc disease 3. Prostate cancer 4. Vertebral compression fracture

Answer 41

**3. Prostate cancer** ## Footnote * This patient most likely has developed prostate cancer with vertebral metastases. Prostate cancer is the most commonly diagnosed organ cancer in men and the second leading cause of male cancer death in the United States. The other choices provided may all cause back pain, but his pain level, age, and unexplained weight loss suggest cancer. * Prostatic carcinoma is most commonly found in the peripheral zone of the prostate, which is primarily that portion of the gland that can be palpated via a digital rectal examination. * As the cancer cells grow and begin to multiply, they initially occupy the immediately surrounding prostate tissue forming a tumor nodule. But a normal rectal exam, without suspicious nodules, does not rule it out. * Metastatic prostate cancer can cause severe bone pain, often in the vertebrae, pelvis, hips, or ribs. Spread into the femur is usually limited to the proximal part of the bone.

Question 42

A 65-year-old male patient presents to the hospital with unilateral hearing loss. He works at the airport. He noted symptoms to be progressive for the past three months. He initially thought that the right side of his earphones was not working properly, but noticed that when answering the phone, he can only hear garbled words in his right ear. He has no known medical illnesses. He smokes half a pack of cigarettes a day and drinks occasionally. On examination, vital signs are normal. The cranial nerve exam is unremarkable except that Weber exam lateralizes to the left and bone conduction (BC) is better than air conduction (AC) on the right. The motor and sensory examinations are normal. A head MRI with contrast reveals a 1.1 cm enhancing lesion on the right vestibular nerve and a 0.5 cm enhancing lesion on the left vestibular nerve. Which of the following chromosomes is likely to be involved in this patient? 1. Chromosome 9 and 12 translocation 2. Chromosome 17 duplication 3. Chromosome 22q12.2 4. Chromosome 15q11-q13

Answer 42

**3. Chromosome 22q12.2** ## Footnote * One disorder commonly associated with bilateral acoustic tumors in neurofibromatosis type II. It is inherited through an autosomal dominant pattern. * It is caused by mutation at chromosome 22q12.2 inactivating the NF2 gene. * Most patients with neurofibromatosis type II present late with acoustic neuromas. These slow-growing tumors typically appear in the fifth to seventh decade of life. * The diagnosis of an acoustic neuroma is made with a contrast magnetic resonance imaging (MRI) or a computed tomogram scan. Contrast is essential; otherwise, the non-enhanced scan can miss small tumors.

Question 43

A 14-year-old obese male patient with significant short stature who had been on cortisol replacement since very young just started with increase urine output and thirst in the last four months. He was ordered a brain magnetic resonance imaging, and a tiny anterior pituitary gland is noted. There is evidence of absent pituitary stalk, with a possible ectopic posterior pituitary tissue near the lamina terminalis. Damage to which structure is causing his new symptoms? 1. Lamina terminalis 2. Rathke pouch 3. Anterior pituitary 4. Infundibular stalk

Answer 43

**1. Lamina terminalis** ## Footnote * Pituitary stalk interruption syndrome presents with a triad that consists of the ectopic posterior pituitary, thin or absent pituitary stalk, and anterior pituitary hypoplasia. * The neurohypophysis has axonal projections from the hypothalamus. Vasopressin is transported down the infundibular stalk to be released by the neurohypophysis. * Central diabetes insipidus occurs in up to 10% of cases of pituitary stalk interruption syndrome. * Vasopressin and oxytocin are packed in secretory vesicles and granules at the magnocellular neurosecretory cells in the hypothalamus. They are released from the paraventricular nuclei and supraoptic nuclei of the hypothalamus, where they travel down to the neurohypophysis by the axons of the magnocellular cells which project from the hypothalamus to the neurohypophysis. The hormones are then stored at the herring bodies of the neurohypophysis, which are the terminal end of the axons.

Question 44

A 65-year-old male patient presents to a clinic stating that he has difficulty going upstairs because he cannot see where he is going. His past medical history of diabetes, hypertension, and smoking are positive. Upon further evaluation, He states that he is easily able to go downstairs. What area of the brain is being affected? 1. Red nucleus 2. Inferior colliculus 3. Superior colliculus 4. Crus Cerebri

Answer 44

**3. Superior colliculus** ## Footnote * The patient has Parinaud syndrome, as noted by the limited upward gaze when trying to go up a staircase. Parinaud's syndrome is characterized by a lesion affecting the dorsal aspect of the midbrain. * The corpora quadrigemina are found on the dorsal aspect of the midbrain and thus can be affected by lesions in this area. * The corpora quadrigemina include the superior colliculi and the inferior colliculi. The superior colliculi are responsible for visual information processing while the inferior colliculi process auditory information. * In Parinaud syndrome, the lesion lies near the superior colliculus as this is the area that processes visual information, and this area also lies near the vertical gaze center, which causes the deficits noted in this syndrome

Question 45

A 35-year-old patient presents with acute onset drooping of his bilateral eyelids. His cranial nerve examination revealed the presence of bilateral ptosis along with restriction of elevation of both eyeballs. Based on the above clinical findings, what is the most probable site of injury to the cranial nerve? 1. Midbrain 2. Interpeduncular cisterns 3. Cavernous sinus 4. Superior orbital fissure

Answer 45

**1. Midbrain** ## Footnote * The presence of bilateral ptosis suggests an involvement of the levator palpebrae superioris, whereas restricted elevation of bilateral eyeballs suggests an involvement of the superior rectus. * Both the levator palpebrae superioris and the superior rectus are supplied by the oculomotor nerve. * The involvement of the bilateral levator palpebrae superioris and the superior rectus are characteristic features of the involvement of the oculomotor nucleus in the midbrain. * The involvement of the oculomotor fascicles within the interpeduncular cisterns will lead to hemiparesis as well following the involvement of the corticospinal tract. The involvement at the cavernous sinus will lead to the involvement of the fourth, fifth, and sixth cranial nerves as well.

Question 46

A 25-year-old man with no past medical history is brought to a small standalone emergency department (ED) after a high-speed motor vehicle collision. He has an obvious large frontotemporal laceration. Initially, the patient is alert and oriented without focal neurological deficits, complaining of only headache and nausea. Alcohol and drug use are suspected based on the clinical exam. While preparing to close the laceration, the patient loses consciousness. An optic nerve sheath ultrasound (ONSUS) is performed. Which of the following findings is the strongest indication for neurosurgical evaluation? 1. Optic nerve sheath diameter (ONSD) of 6 mm on the right and 3 mm on the left 2. Bilateral optic nerve sheath diameter (ONSD) of 5.7 cm 3. Obvious signs of an open globe on the right and optic nerve sheath diameter (ONSD) of 4.6 mm on the left 4. Optic nerve sheath diameter (ONSD) of 4.4 mm bilaterally

Answer 46

**2. Bilateral optic nerve sheath diameter (ONSD) of 5.7 cm** ## Footnote * In the absence of advanced imaging, ocular nerve sheath ultrasound can be used to assist in the need to transfer a patient with suspected intracranial hypertension. In this setting, CT is unavailable, and the patient may suffer alcohol or illicit drug intoxication vs. a traumatic neurological insult. * ONSUS does not rule out intracranial hemorrhage but will suggest the patient's intracranial pressure. If ONSUS demonstrated intracranial hypertension, the patient should be transferred immediately with consideration of neuroprotective strategies en route to a center with neurosurgical capabilities. * In the absence of neuroanatomical abnormalities, ONSD should be relatively uniform bilaterally. If there is a large discrepancy between right and left, it should alert the sonographer to a possibility of technical error, and they should rescan. Possible sources of error are excess pressure on the globe with the ultrasound probe or measuring the optic nerve sheath in an off- axis. * If there are any signs of open globe injuries, the procedure should be aborted, and an ophthalmologist should be consulted. If the patient has an open globe injury, he will likely need transport to a facility with ophthalmology surgical services (not neurosurgical).

Question 47

A 76-year-old woman is being evaluated for a 2- year history of urinary incontinence and progressive problems with ambulation. Her provider felt she had stress urinary incontinence after urine studies were normal. For the past four months, she has become withdrawn, confused, and forgetful. On examination, she is unable to recall three items, and her gait shows short steps and is wide-based. When she turns, she almost falls over. Which of the following findings is most likely to be present on a CT scan of the brain? 1. Slit-like ventricles 2. Generalized atrophy 3. Disproportionately enlarged subarachnoid space 4. Atrophy of the frontal and temporal lobes

Answer 47

**3. Disproportionately enlarged subarachnoid space** ## Footnote * The patient has signs and symptoms of normal pressure hydrocephalus. * Disproportionately enlarged subarachnoid space hydrocephalus (DESH) sign demonstrates a strong positive predictive value of 77%. However, it has a weak negative predictive value (25%). * Other radiological signs suggestive of idiopathic normal pressure hydrocephalus (iNPH) are Evans index greater than or equal to 0.3 and a callosal angle between 40 to 90 degrees. * Cerebral atrophy alone is not a sign of idiopathic normal pressure hydrocephalus (iNPH).

Question 48

A 35-year-old woman with recurrent seizures secondary to mesial temporal sclerosis undergoes a peri-insular hemispherectomy. She continues to have seizures postoperatively. The frequency and duration of her seizures have improved. A repeat MRI reveals good resection of the temporal region of interest. Which of the following is the most appropriate next step for the long-term control of seizures in this patient? 1. Functional MRI 2. Escalate the dose of antiepileptics 3. Redo surgery 4. MRI tractography

Answer 48

**4. MRI tractography** ## Footnote * One of the main factors responsible for the recurrence of seizures following epilepsy surgery is an inadequate disconnection of all the epileptogenic pathways. * Advances in diffusion tensor imaging help isolate all the connectivity of the epileptogenic zones, thereby isolating any missed disconnections during the surgery. * A tractography study is paramount in ensuring complete disconnection and isolating the remaining network of the neural connectome involved in the seizure occurrence despite normal anatomical postoperative MRI images. * Redo surgery is only justified in cases of incomplete disconnection procedures in the previous surgery. Escalation of the antiepileptic is only considered after ensuring the complete disconnection of the epileptogenic neural networks.

Question 49

A 21-year-old male was presented to the clinician after experiencing a seizure 2 hours ago. His friends revealed they were at a party when the patient suddenly fell to the ground and started shaking vigorously. There was foam coming out of his mouth. The patient did not have another episode of seizure. The clinician diagnosed it as a tonic-clinic seizure and ordered a magnetic resonance imaging (MRI) scan of the brain. T2-weighted images of the brain showed a lesion with a "salt-and-pepper" reticulated core with a hypointense rim. What is the most common presenting feature of this lesion? 1. Neurological deficit 2. Hemorrhage 3. Seizure 4. Monocular vision loss

Answer 49

**2. Hemorrhage** ## Footnote * The clinical presentation of symptomatic cerebral cavernous malformations varies by location, but the most common manifestations are intracranial hemorrhage, seizures, and focal neurological deficits without radiographic evidence of recent hemorrhage. Incidental diagnosis of this condition on magnetic resonance imaging is also not uncommon. * Cerebral cavernous malformations (CCMs) are abnormally large collections of "low flow" vascular channels without brain parenchyma intervening between the sinusoidal vessels. * The pathogenesis of cerebral cavernous malformations-related epilepsy has been attributed to the peri-lesional reactive gliosis due to clinically silent micro-hemorrhages, which alter the conduction within the adjacent white matter pathways. * Surgical excision is the only definitive treatment for cavernous cerebral malformations, but the decision to operate remains challenging as postoperative morbidity may approach or exceed the complications of the untreated disease. Conservative management and observation are therefore favored for all patients with solitary cerebral cavernous malformations who are asymptomatic.

Question 50

A 6-year-old girl had been diagnosed with cryptococcal meningitis and has been on intravenous antifungal for 3 weeks but still has positive cerebrospinal fluid cultures. She was recommended daily intrathecal chemotherapy for 21 days. Pediatric neurosurgery is consulted and takes the patient to the operating room for placement of an Ommaya reservoir. A computed tomography scan shows very small ventricles. The pediatric neurosurgery fellow wants to improve the accuracy of the procedure. Which among the following would help him improve the placement of the catheter? 1. Preoperative cisternography 2. Intraoperative magnetic resonance imaging 3. Image guidance system 4. Freehand placement

Answer 50

**3. Image guidance system** ## Footnote * The image guidance system provides real-time feedback regarding a position in all three planes. * The entry and target points are set up on the surgical planning software. * Image guidance systems have been found to improve the accuracy of ventricular puncture. * Cisternography and magnetic resonance imaging provide static images, which is less desirable compared to dynamic feedback from neuronavigation systems. Freehand placement is found to require approximately 2 to 3 passes for accurate placement in very small ventricles.

Question 51

Anterior skull base surgery is being performed in the reconstruction of a CSF leak. A nasoseptal flap is planned considering the incision and boundaries of the pedicle. Topical decongestant and local anesthetic are be done with 4% cocaine topically and infiltrate the mucosa with an additional medication. Which of the following combinations would be effective and safe for infiltration within the nasal cavity? 1. 1% lidocaine and 1% phenylephrine 2. 4% lidocaine and 1:100,000 epinephrine 3. 1% lidocaine and 0.05% oxymetazoline 4. 2% lidocaine and 1:100,000 epinephrine

Answer 51

**4. 2% lidocaine and 1:100,000 epinephrine** ## Footnote * Oxymetazoline, phenylephrine, and cocaine are commonly used topical decongestants; if injected, they can cause fatal arrhythmias. * Lidocaine at 1 or 2% is safely injected; 4% is a topical concentration for lidocaine. Each has weight-based dosing and maximums. * Epinephrine is a helpful adjunct to local infiltration and is often used; 1:100,000 or 1:200,000 are often used safe concentrations. * Epinephrine at 1:1,000 infiltrated is a lethal dose. This concentration should only be used topically in select patients.

Question 52

A 20-year-old male student presents to the emergency department following a fight with one of his classmates. He was stabbed in the neck and is now complaining of left upper extremity weakness. A primary survey reveals an average-built, conscious young man with a stab wound on the left side of his neck, a few inches above his clavicle. The wound is not actively bleeding, and his vital signs show a heart rate of 94 beats/minute, a blood pressure of 115/70 mmHg, and a respiratory rate of 16/minute. An initial evaluation demonstrates a drooping eyelid on the left side and an ipsilateral constricted pupil. Which of the following is most likely associated with the injury pattern seen in this patient? 1. Abnormal histamine test 2. Decrease or loss of paraspinal muscle activity on electromyography 3. Electromyographic abnormality on isolated testing of the distal portion of the upper extremity 4. Lateral winging of the scapula on physical exam

Answer 52

**2. Decrease or loss of paraspinal muscle activity on electromyography** ## Footnote * Ptosis and miosis are part of Horner syndrome along with anhidrosis and are indicative of preganglionic or root avulsion injuries of the brachial plexus. * Preganglionic brachial plexus injuries will demonstrate normal histamine test with redness, wheal, and flare. The dorsal root ganglion is intact to the distal nerve along its cutaneous course; therefore, when a drop of histamine is placed on the skin and scratched, normal axonal response will be present. This leads to vasodilation and redness, wheal appearance, and flare response. * Similarly, because the dorsal root ganglion is intact to the nerves distally, peripheral stimulation will lead to an intact SNAP response in preganglionic BPI. * Other manifestations of preganglionic BPI include loss of paraspinal muscle activity on EMG, lateral scapular winging due to loss of serratus anterior innervation, and elevated hemidiaphragm due to phrenic nerve involvement.

Question 53

A 65-year-old male patient presents with tinnitus for the past two months. He has no known medical illnesses. He is a non-smoker but drinks six bottles of beer daily. His vital signs are within normal limits. On examination, he has a moderate sensorineural hearing loss on the right. The rest of the cranial nerve examination is normal. The motor and sensory exam did not show any deficits. The imaging study done reveals a lesion of the cerebellopontine angle. Which cranial nerve would most likely become symptomatic as this lesion increases in size? 1. Cranial nerve VI 2. Cranial nerve VII 3. Cranial nerve VIII 4. Cranial nerve X

Answer 53

**2. Cranial nerve VII** ## Footnote * Most cranial nerve schwannomas originate from cranial nerve VIII. In the pons, the facial nerve (cranial nerve VII) lies medial to the vestibular nerve. As the lesion enlarges, these patients may present with peripheral facial palsy. * The vestibular schwannomas by mass effect can also affect the cerebellar peduncle, causing instability and cerebellar signs. * It is often seen in patients with neurofibromatosis type 2. * The majority of acoustic neuromas presents with unilateral hearing loss.

Question 54

On the evening after transsphenoidal hypophysectomy, the nursing staff notices a blood-tinged thin discharge from the patient's nose. The patient also complained about this discharge, which was more noticeable when he sat up to drink water. The senior provider in charge advises starting oral acetazolamide. What other vital advice should be included in this patient's charts? 1. Bed rest with head elevation 2. Application of topical thrombin to the leakage site 3. Insertion of a lumbar cerebrospinal fluid (CSF) drain 4. Magnetic resonance cisternography

Answer 54

**1. Bed rest with head elevation** ## Footnote * The initial management of a CSF leak should include bed rest with head elevation to lower the intracranial pressure. * Many leaks will heal spontaneously. * Topical thrombin is not helpful because the primary problem is a hole in the dura, not a blood coagulation defect. * Insertion of lumbar drains is a debatable topic and is adopted based on institutional protocols. Exploration is done when CSF leak does not decrease after 24-48 hours of conservative management.

Question 55

A 16-year-old female patient presents to the hospital for the evaluation of chronic back pain and difficulty standing up straight. She has no significant past medical history other than being diagnosed with scoliosis in the 3rd grade. Since that time, she feels she is leaning further and further forward. She reports that she was offered surgery at that time, but her mother had always been fearful of surgery; thus, she was given a brace but was never taken back to see a spine surgeon. Her radiographs reveal a 28-degree coronal curve with 75 degrees of maximal kyphosis. What is the next best step in the management of this patient? 1. Observe with serial X-rays for possible progression 2. Pedicle screw fixation with rigid construct 3. Rigid bracing 4. Pedicle screw fixation with growing rod

Answer 55

**2. Pedicle screw fixation with rigid construct** ## Footnote * This patient has idiopathic juvenile scoliosis, which went untreated and thus requires surgical fixation without further delay, given the patient's report of progression. * If allowed to progress, it may be life-threatening. Those patients with untreated early-onset scoliosis over the age of 40 have a 50% increase in mortality. Furthermore, those with a curve of greater than 70 degrees equally showed increased mortality. * Given the patient's current age, she would not need a growing rod, given she is not expected to continue to grow. Growing rods are utilized in infantile and juvenile scoliosis treatment. * Rigid bracing is rarely helpful in this pathology, and thus, surgical correction of her spinal deformity is needed.

Question 56

A 78-year-old man presents to the emergency department after he finds he is unable to move his right arm and right leg. Clinical examination reveals spastic paralysis of his upper and lower limbs of the right side, hyperreflexia, and positive Babinski sign on the right side. Cranial nerve examination reveals paralysis of muscles of the lower half of the right side of the face. Pain, touch, pressure sensations of face and body are normal. Which is the most likely explanation of the above signs and symptoms? 1. Occlusion of the paramedian branch of the basilar artery 2. Parkinson’s disease 3. Occlusion of anterior spinal artery 4. Lateral medullary syndrome

Answer 56

**1. Occlusion of the paramedian branch of the basilar artery** ## Footnote * The paramedian branch of basilar artery supplies the basilar part of pons near the midline. * The corticonuclear and corticospinal tracts pass through the basilar part of the pons. * Damage to the left corticospinal tract is responsible for the weakness of muscles of limbs of the right side. Damage to the left corticonuclear tract of the facial nerve leads to paralysis of muscles of the contralateral lower half of the face. * The tegmental part of pons is not affected so pain, temp and pressure sensations usually remain intact.

Question 57

A 52-year-old man presents with double vision. The patient noticed the symptoms about a month ago along with blurring of vision and headaches. He has a past medical history of hypertension, 20 pack-year smoking history, and alcohol use disorder. There is a family history of stroke on his father's side. On examination, his right pupil is 5 mm and sluggishly reactive to light. The left pupil is 3 mm and briskly reactive to light. His right eye has a mild limitation when looking medially, with double vision more prominent when looking to the left. There is no weakness or sensory deficit. Babinski sign is negative bilaterally. Where is this patient's lesion most likely located? 1. Cervical sympathetic chain 2. Myoneural junction 3. Posterior communicating artery 4. Edinger-Westphal nucleus

Answer 57

**3. Posterior communicating artery** ## Footnote * A posterior communicating artery aneurysm can impinge on the third cranial nerve and cause this patient's symptoms. A history of hypertension and a family history of stroke at a young age makes it more likely. * Anisocoria may be completely benign, but there can be serious causes. * In a patient presenting with uneven pupils and a headache or pain, one should also think of compressive third nerve palsy, carotid artery dissection, or intracranial aneurysms. * A ruptured aneurysm at this location can cause severe headaches and signs of meningeal irritation.

Question 58

A 65-year-old female with uncontrolled hypertension and a smoking history presents to the emergency department with sudden onset of vertigo, unsteady gait, and numbness affecting her left face and right arm. Which finding has a minimal association with the suspected diagnosis? 1. Left facial sensory loss 2. Left-sided ataxia 3. Right-sided temperature loss 4. Right-sided proprioceptive loss

Answer 58

**4. Right-sided proprioceptive loss** ## Footnote * This clinical picture is typical for left-sided Wallenberg syndrome, which is caused by an acute vascular lesion. * It is characterized by contralateral pain and temperature loss with an ipsilateral facial sensory loss. * Wallenberg syndrome is also known as lateral medullary syndrome or posterior inferior cerebellar artery syndrome. This neurological disorder is associated with a variety of symptoms that occur as a result of a loss of function in the lateral segment of the medulla. * Wallenberg syndrome presents with sensory deficits that affect the extremities and trunk on the opposite side of the infarction. The sensory deficits in the face and cranial nerves affect the ipsilateral side of the injury. On clinical exam, there is a loss of temperature sensation and pain on the opposite side of the body and the same side of the face. This crossed-clinical neurological feature is the key to the diagnosis of Wallenberg syndrome.

Question 59

A 54-year-old female patient presents with complaints of right orbital/retroorbital pain and pain with eye movements. Her symptoms started about four days ago and have persisted ever since. She could not tolerate the pain anymore and came to the emergency department (ED) for evaluation. There is no vision loss. She also tells that she had similar complaints in her left eye two years ago, she did not seek treatment at that time given lack of insurance. Her symptoms spontaneously resolved in a week during her prior episode. During her current evaluation in ED, vital signs are stable, and examination is unremarkable except for restricted painful movements of the right eye. CT scan of the head in the ED does not show any acute intracranial abnormality. Which of the following would be found pathologically with her diagnosis? 1. Demyelination 2. Necrosis 3. Inflammation with or without noncaseating granulomas 4. Lewy bodies

Answer 59

**3. Inflammation with or without noncaseating granulomas** ## Footnote * Tolosa-Hunt syndrome causes severe unilateral headaches (can be rarely bilateral) secondary to inflammation with or without noncaseating granulomas at the superior orbital fissure and the cavernous sinus. * The hallmark of this syndrome is a pain, which can be described as a sharp, shooting, stabbing, boring, severe, and intense. Pain is usually located in the periorbital region but can often be retro- orbital, with extension into the frontal and temporal areas. Pain tends to be the presenting symptom and can precede ophthalmoplegia by up to 30 days. * Tolosa Hunt syndrome is diagnosed through the clinical presentation, neuroimaging studies, and response to steroids. Laboratory tests and cerebrospinal fluid (CSF) studies are supportive tests but help in ruling out other causes of ophthalmoplegia. Tissue biopsy is diagnostic but is considered the procedure of the last choice and rarely performed, given high risk and technical difficulties. MRI identifies the condition in the majority of patients. * Glucocorticoids have been the mainstay of the treatment ever since the syndrome was first described. But there is no specific data to give recommendations about dose, duration, or route of administration. Spontaneous remission of symptoms is known to occur. Although orbital pain drastically improves with steroid treatment, there is no evidence to suggest cranial nerve palsies improve faster with it. As with any glucocorticoid regimen, treatment for Tolosa Hunt syndrome involves initial high-dose therapy for a few days followed by a gradual taper over weeks to months. Symptom resolution guides the degree and rapidity of the taper. Imaging studies like MRI can be repeated for follow-up, but usually, lag behind a few weeks as compared to symptomatic improvement.

Question 60

A 5-year-old boy, born of the non- consanguineous marriage, is brought to the outpatient department with recurrent episodes of tonic-clonic seizures for the past two years. Seizures occurred six times over the past six months, and each one lasted for almost 2 minutes. She denies having any antenatal illness, and the child was born by a full-term normal delivery. On examination, the child is active and has no neurological deficits. He has multiple hypopigmented macules on his body and areas of thick leathery and pigmented orange-peel like skin scattered across the trunk. A magnetic resonance imaging (MRI) of the brain is ordered, which shows multiple, less than 1 cm irregular nodules, with their long axis perpendicular to the lateral ventricular surfaces. Some of them show blooming on susceptibility-weighted images. What could these MRI findings suggest? 1. Gliomas 2. Subependymal glial nodules 3. Meningeal psammoma bodies 4. Granulomas

Answer 60

**2. Subependymal glial nodules** ## Footnote * More than 50% of patients with tuberous sclerosis develop calcified subependymal glial nodules by 5 years. Most of them are calcified. * These do rarely become malignant but can enlarge to the point where they cause obstructive hydrocephalus. * If this occurs ventriculoperitoneal shunting is needed. * The subependymal nodules can occur anywhere in the brain but are most common in the area around the foramen of Munro. Neurological deficits and blindness are common when hydrocephalus develops.

Question 61

A 16-year-old male trauma patient has multiple brain contusions and is being managed with paralyzing agents under ventilatory support. He has also sustained multiple rib fractures with left hemothorax for which a chest tube has been placed. The treating clinician is worried about the possible risk of blooming of the contusions and the resultant intracranial hypertension. What is the best step for the initial evaluation of intracranial pressure in the patient? 1. Computed tomography (CT) head 2. Magnetic resonance imaging (MRI) brain 3. External ventricular drain placement 4. Ocular ultrasound

Answer 61

**4. Ocular ultrasound** ## Footnote * There is a risk of intracranial hypertension resulting from the blooming of the traumatic contusions. * Optic nerve sheath diameter assessment (ONSD) via ocular ultrasound is a reliable bedside technique for assessing the risk of intracranial hypertension in high-risk trauma patients. * The optic nerve sheath expands in response to raised cerebrospinal fluid pressure, thereby leading to an increase in the optic nerve sheath diameter. It allows for bedside monitoring and aids in timely corrective plans in assessing intracranial pressure. * External ventricular drain (EVD) is an invasive procedure that may be needed. It has a high risk of infections. Repeat CT scan in a critical and hemodynamically unstable patient is problematic and imposes hazards on the patient.

Question 62

A 65-year-old patient presenting with persistent headache is found to have a butterfly-shaped lesion in the frontal lobe involving the corpus callosum. The lesion was well enhancing in contrast MRI with areas of hypointensities within the lesion. MR spectroscopy showed a choline peak within the margins of the lesion. What is a novel molecular marker to differentiate between the primary and the secondary forms of the lesion seen in the patient? 1. 1p19q co-deletion 2. IDH1 mutation 3. EGFR overexpression 4. T53 mutation

Answer 62

**2. IDH1 mutation** ## Footnote * The enhancing type of butterfly-shaped lesion involving the corpus callosum with areas of necrosis and a high choline peak in MR spectroscopy is characteristic of a GBM. * Primary GBM occurs de novo without any precursor, whereas secondary GBM develops from initially low-grade astrocytoma. * Interestingly, IDH1 mutations are also found in 80% secondary GBM, and in less than 5% of primary GBM. Thus, the IDH1 mutation is a reliable molecular marker for secondary GBM. * T53 mutation is also seen in secondary GBM but less common than IDH1 mutation. EGFR overexpression is common in primary GBM. 1p19q co-deletion is helpful in olgodendroglioma.

Question 63

A 29-year-old man is scheduled for left Spetzler- Martin grade IV sylvian fissure arteriovenous malformation resection after preoperative embolization. After a pterional craniotomy, a subsequent transsylvian approach is initiated with extensive subarachnoid dissection. During the procedure, motor evoked potential signal is lost temporarily for the contralateral arm and leg. Disruption of which of the following structures is most likely to have led to this finding? 1. Deep M2 perforator artery 2. Arcuate fasciculus 3. Deep middle cerebral vein 4. Ventral posteromedial nucleus

Answer 63

**1. Deep M2 perforator artery** ## Footnote * This patient is undergoing resection of a large AVM (> 6 cm) in the left Sylvian fissure. Surgery to this area for either gliomas or AVMs is tedious and difficult given the adjacent eloquent anatomy and intricate vasculature. * Deep perforator branches of M2 extend through the insula and help to supply the corona radiata and corticospinal tract. If a patent branch was sacrificed or injured during surgery, this could manifest as signal loss in neuromonitoring, a common intraoperative procedure to ensure eloquent structure integrity. * The Sugati classification of AVMs in the Sylvian fissure can aid operative management planning and is determined by the AVM's nidus: pure, lateral, medial, and deep. * The arcuate fasciculus connects Broca's and Wernicke's areas. The deep middle cerebral vein (DMCV) is the deep draining conduit for the insula. The ventral posteromedial nucleus (VPM) of the thalamus receives sensation from the contralateral face.

Question 64

An older homeless man in his late 60s presents with altered mental status, seizures, and vomiting. There was no photophobia or neck stiffness. He was currently being treated for otitis media. He has a past medical history of diabetes for which he takes insulin. His vitals include a heart rate of 79/min, blood pressure of 135/70 mmHg, respiratory rate of 18/min, temperature of 101.1 F (38.4 C), and oxygen saturation of 97% on air. On physical exam, he has dental caries and 3/5 power in his right hand. A CT brain demonstrated an intracerebral lesion with an outer hypodense and inner hyperdense rim. What is the most appropriate initial treatment for this patient? 1. IV ceftriaxone + metronidazole 2. IV cefazolin + metronidazole 3. IV piperacillin/tazobactam 4. IV ceftriaxone

Answer 64

**1. IV ceftriaxone + metronidazole** ## Footnote * Brain abscess is one consideration and presents sometimes without fever, elevated WBC, and signs of meningeal irritation. * Brain abscesses develop by either contiguous spread or hematogenous spread. Common sites of infection include sinuses, mouth/teeth, and ears. Contrast-enhanced CT and MRI reveal a ring-enhancing lesion usually at the gray-white interface with surrounding edema. * Treatment involves identification of organism through relief of mass effect with aspiration vs. open excision followed by IV antibiotics. * Treatment of choice is a third-generation cephalosporin as it crosses the blood-brain barrier and metronidazole.

Question 65

A 16-year-old patient with TB meningitis developed acute communicating hydrocephalus. He underwent emergent EVD(external ventricular drain) placement. However,10 minutes after the procedure, the patient became unresponsive and was showing a decorticating posture. Urgent CT revealed the presence of punctate hemorrhages in the brainstem with infarction in the occipital regions. What might be the probable cause of this rapid neurological deterioration in the patient? 1. Intracranial hypertension 2. Seizure 3. Rapid egress of CSF 4. Sepsis

Answer 65

**3. Rapid egress of CSF** ## Footnote * The patient has classical features of an upward transtentorial herniation. * There is superior displacement of superior parts of the cerebellum through the tentorial notch. * Rapid egress of CSF can lead to rapid upward transtentorial herniation thereby leading to sudden neurological deterioration in the patient. * EVD placement cause egress of CSF, thereby minimizing intracranial pressure. Seizures would not cause brainstem punctate hemorrhages.

Question 66

A 44-year-old man, with a history of acute lymphoblastic leukemia diagnosed 3 years ago, presents to the clinic for follow up. He is currently receiving intrathecal chemotherapy for relapse with central nervous involvement through a ventricular access device. His first chemotherapy was one week ago. He developed fever and chills last night associated with a headache. Vital signs show temperature 39 C. Oral examination is unremarkable and he denies any cough. There is mild neck rigidity. His Ommaya reservoir wound is not swollen or red. What is the most likely cause of his symptoms? 1. Tumor necrosis associated fever 2. Malfunction of the system 3. Septicemia 4. Reservoir infection

Answer 66

**4. Reservoir infection** ## Footnote * A low proportion of patients get Ommaya reservoir related infections, varying from 5.5% to 8%. * Approximately 60% of the infections occur within 10 days of accessing the device. The most common manifestations are cellulitis, meningitis, or meningoencephalitis. * The most robust entry point and trajectory with the highest hit rate follow the 3-2-1 rule: entering at a point 3 cm lateral to the midline and 2 cm anterior to the bregma by targetting the contralateral medial canthus and 1 cm anterior to the tragus * Signs of surgical site infection are redness or wound dehiscence in the postoperative period and signs of implanted device infection include meningismus.

Question 67

A 73-year-old female with a history of metastatic melanoma to the lung and liver with BRAF wild type who is currently on pembrolizumab monotherapy. Her disease has been in control for the last six months. Her husband called the oncology office and concerned about her recent behavioral changes. She was evaluated in the emergency room for concern for brain metastases, and an MRI of the brain showed about 20 lesions, which are 5 mm to 10 mm in diameter. Which of the following the ideal local therapy for the local control brain metastases? 1. Surgery 2. Stereotactic radiosurgery (SRS) 3. Surgery followed by stereotactic radiosurgery (SRS) 4. Whole-brain radiation therapy (WBRT)

Answer 67

**4. Whole-brain radiation therapy (WBRT)** ## Footnote * Due to a large number of brain metastases, whole-brain radiation therapy is the ideal local therapy to control her brain metastases and help her symptoms. * The patient has multiple brain metastases, and her symptoms are likely related to it. The goal of WBRT is to improve neurologic deficits and surrounding edema and to prevent any further deterioration of neurologic function. Unfortunately, these patients develop cognitive decline as a long term side effect. * Stereotactic radiosurgery is usually recommended in patients with a limited number of lesions, ideally less than 5. * Surgery is not the ideal local therapy in a patient with a large number of metastases.

Question 68

A 29-year-old female comes into the primary care office. The patient has complaints of headaches and an inability to become pregnant. The patient has been trying to get pregnant for one year now. The patient's husband has one child of his own. Her past medical history is unremarkable. On physical examination, she is found to have bitemporal hemianopia. The clinician order an MRI scan for the patient. What part of the brain would most likely show the lesion on the MRI scan resulting in her visual field defects? 1. Wing of sphenoid 2. Petrosal sinus 3. Foramen ovale 4. Sella turcica

Answer 68

**4. Sella turcica** ## Footnote * The compression of the optic chiasm will lead to bitemporal hemianopia. * The sella turcica is located above the optic chiasm. Enlargement of the pituitary gland can cause compression of the optic chiasm and infertility symptoms. * The most common cause of compression of the optic chiasm is from a prolactinoma. * A prolactinoma compressing the optic chiasm will lead to bitemporal hemianopia. The overproduction of the prolactin hormone results in the inhibition of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The suppression of FSH and LH causes infertility.

Question 69

A 45-year-old patient with a massive head injury shows a complete absence of brainstem reflexes on repeated clinical examination. No responses to noxious stimuli in the cranial nerve distribution can be obtained. An apnea test reveals no respiratory effort. Neurology was consulted, and it is decided that the criteria for brain death are met. Which American society of anesthesiologists' physical status classification applies to this patient? 1. ASA IV 2. ASA V 3. ASA VI 4. ASA VII

Answer 69

**3. ASA VI** ## Footnote * An ASA IV patient is a patient with severe systemic disease that is a constant threat to life. These include unstable angina, poorly controlled chronic obstructive pulmonary disease (COPD), symptomatic congestive heart failure (CHF), myocardial infarction less than 3 months ago, and stroke. The present patient, however, is an ASA VI patient by virtue of being declared to be brain dead. * An ASA V patient is a moribund patient who is not expected to survive without the operation. The patient is not expected to survive beyond the next 24 hours without surgery. Examples include ruptured abdominal aortic aneurysm, massive trauma, and extensive intracranial hemorrhage with mass effect. The present patient, however, is an ASA 6 patient by virtue of being declared to be brain dead. * The patient is an ASA 6 patient by virtue of being declared to be brain dead. * There is no ASA VII classification.

Question 70

A 35-year-old man is rushed to the emergency department following a motor vehicle collision. The patient is alert, conscious, and well-oriented to time, place, and person. His blood pressure is recorded at 60/40 mmHg with a pulse rate of 56/min. He has complete sensory loss below the T10 dermatome. He has no voluntary movement in the lower extremities nor any movement in his lower extremities to noxious stimuli. On rectal examination, he has no perceived sensation, voluntary sphincter contraction, and a loose anal sphincter. The magnetic resonance imaging (MRI) spine revealed compression and retropulsion of the T8 vertebral body into the spinal canal. Which of the following will be the first to reappear, suggesting that spinal shock has resolved? 1. Babinski sign 2. Patellar reflex 3. Bulbocavernosus reflex 4. Cremasteric reflex

Answer 70

**3. Bulbocavernosus reflex** ## Footnote * The patient has typical features of a traumatic spinal shock with the complete absence of both motor and sensory modalities as well as complete loss of deep tendon reflexes below the level of injury. * A spinal shock is a form of neurological concussion injury that may hinder the assessment of the correct neurological status of the patient. * The time interval for the complete resolution of the spinal shock in the patient may be variable. * Of the options listed, the bulbocavernosus reflex would be the first neurologic sign that would be expected to reappear.

Question 71

A 51-year-old man is brought in by emergency medical services (EMS) after being struck by a car while walking at night. An MRI shows that his L1 vertebral superior articular processes lie posterior to the inferior articular processes of the T12 vertebrae. On examination, he displays no motor function and has no sensation in his legs. He has no perianal sensation, and there is a poor rectal tone. He is otherwise alert and oriented and has a full motor function of both arms. What is the most appropriate management for this patient? 1. Non-operative management 2. Decompression and posterior fusion of the spine 3. Electromyography (EMG) to assess for residual motor function of bilateral lower extremities 4. Decompression and anterior fusion of the spine

Answer 71

**2. Decompression and posterior fusion of the spine** ## Footnote * In a complete spinal cord injury, decompression is the standard of care. * The locked facet joint is a type of facet joint dislocation that results from jumping of the inferior articular process anterior to the superior articular process of the vertebra below and becomes locked in the position. * In the case of neurological weakness and lumbar facet dislocation, urgent surgical decompression is warranted. After decompression, the spine must be fused at the affected levels. * Electromyography would be inappropriate and unnecessary in the setting of an acute complete spinal cord injury.

Question 72

A 55-year-old woman presents to the clinic for a follow-up. She was recently diagnosed with advanced colorectal carcinoma, Eastern cooperative oncology group score 1 with solitary brain metastasis. She has no involvement of the hippocampus and surrounding region. She has a past medical history of ulcerative colitis, taking oral and rectal mesalazine, with a history of multiple exacerbations in the past 2 months. What is the most appropriate management strategy for this patient? 1. Stereotactic radiosurgery plus whole-brain radiotherapy 2. Hippocampal avoidance whole-brain radiotherapy 3. Hippocampal avoidance whole brain radiotherapy plus memantine 4. Best supportive care

Answer 72

**4. Best supportive care** ## Footnote * Active ulcerative colitis is considered a contraindication to radiotherapy. In addition to idiopathic inflammatory bowel disease, collagen vascular diseases such as systemic lupus erythematosus and Sjogren disease are also conditions that may preclude the use of radiotherapy. * Stereotactic radiosurgery without WBRT has been shown to be non-inferior in patients with five to ten metastases. A minimal degree of invasiveness and fewer side effects, when compared to neurocognitive function has been positioned as the major advantages of the procedure. * Strategies that have been used to preserve the neurocognitive function include the use of hippocampal avoidance strategies and a combination of HA-WBRT with memantine or donepezil. A randomized control trial has shown preservation of neurocognitive outcomes along with a reduced incidence of adverse effects with the use of hippocampal avoidance whole- brain radiotherapy in combination with memantine without an adverse impact on overall or progression-free survival. * The use of intensity-modulated radiotherapy with conformal avoidance of the hippocampus and the parahippocampal region has been proposed to avoid irradiation to the stem cell niche and prevent the development of negative neurocognitive outcomes. The quantum of radiation exposure to the hippocampal stem cell niche is reduced by seven times.

Question 73

A 23-year-old man is brought to the emergency department (ED) after sustaining a severe traumatic brain injury from a motorcycle collision, during which his speed was estimated to be 45 miles per hour. On arrival to the ED, his helmet is removed, maintaining C-spine stabilization, and he is intubated for a GCS of 5/15. A non-contrast head CT demonstrates diffuse cerebral edema and small subarachnoid hemorrhage. An external ventricular drain connected to a pressure transducer is placed into the lateral ventricle. The patient is admitted to the ICU for close monitoring. He is otherwise hemodynamically stable and has no other injuries requiring major intervention. Over the next 12 hours, the patient's spontaneous respirations increase over the set ventilator rate from 12/min to 20/min, his mean arterial pressure starts to increase from 67 mmHg to 82 mmHg, and his intracranial pressure (ICP) increases from 15 mmHg to 23 mmHg. Which of the following is the next best step to prevent cerebral ischemia in this patient? 1. Increase the sedation to facilitate permissive hypercapnia 2. Open up the external ventricular drain to drain the cerebrospinal fluid (CSF) 3. Initiate a vasopressor infusion to target the mean arterial pressure to greater than 100 mmHg 4. Place a radial arterial catheter for invasive monitoring of blood pressure

Answer 73

**2. Open up the external ventricular drain to drain the cerebrospinal fluid (CSF)** ## Footnote * Traumatic brain injury, cerebral edema, hemorrhage, and mass lesions all increase intracranial pressure. * Increases in intracranial pressure are normally offset by cerebral autoregulation, by shifting fluid components into other compartments - cerebrospinal fluid (CSF) is shifted into the subarachnoid space, and cerebral vessels are vasoconstricted to shift blood volume into the extra-cranial circulation. * In a clinical situation where increased intracranial pressure (ICP) is compromising cerebral perfusion pressure, ICP must be lowered first. If an external ventricular drain is present, removal of cerebrospinal fluid at a rate of 1-2 mL/minute over 2 to 3 minutes can be a rapid method of decreasing ICP until a more permanent solution can be found. * Increasing the respiratory rate will decrease retention of carbon dioxide and cause cerebral vasoconstriction. Permissive hypocapnia - targeting a pCO2 of 26 to 30mmHg for a short period of time can be a temporizing measure to manage cerebral perfusion in the setting of a severe ICP elevation.

Question 74

A healthy 31-year-old woman presents to clinic two weeks post-partum due to an inability to breastfeed. After an uncomplicated pregnancy, she gave birth to a healthy male infant at 39.5 weeks. Delivery of the placenta was complicated by cord rupture, and two units of blood were administered emergently. The infant exhibits adequate latch, but no milk is expulsed from either breast. The mother recounts no issues breast feeding her previous child. The provided explains that her problem stems from a hormonal deficiency. Where is the hormone responsible for her clinical syndrome synthesized? 1. Anterior pituitary gland 2. Posterior pituitary gland 3. Hypothalamus 4. Uterus

Answer 74

**3. Hypothalamus** ## Footnote * This patient has Sheehan's syndrome- a condition where hypovolemia typically associated with blood loss during birth leads to pituitary ischemia and necrosis. * The pituitary becomes rapidly hyperplastic during pregnancy, therefore it is at particular risk of ischemia. * Ischemia results in decreased secretion of oxytocin from the posterior pituitary. Because oxytocin stimulates milk letdown, this deficiency can impair breastfeeding. * While oxytocin is secreted from the posterior pituitary, it is synthesized in neuronal cell bodies within the hypothalamus and transported through axons into the posterior pituitary for release.

Question 75

A 27-year-old female presents to the obstetric clinic from a remote village for an antenatal check-up. Her previous child, who died after 6 months of birth, had a lump on his backside. She is worried about the risk of a similar occurrence in the present child as well. Which of the following is the gold standard diagnostic modality to rule out the same in the child? 1. AFP (alpha-fetoprotein) levels 2. Ultrasound 3. Amniocentesis 4. Chorionic villus sampling

Answer 75

**2. Ultrasound** ## Footnote * Spina Bifida is a congenital anomaly that arises from incomplete development of the neural tube. It is commonly used as a nonspecific term referring to any degree of neural tube closure. It can be further subdivided into spina bifida occulta and spina bifida aperta. * These spinal dysraphisms are due to incomplete closure of the posterior spinal elements and typically occur between 17 and 30 days of fetal development. The process of neuralization occurs in two phases, primary and secondary neuralization. Primary neuralization refers to the closure of the neural tube, forming the brain and spinal cord. Secondary neuralization involves the formation of the caudal structures of the neural tube, forming the sacral and coccygeal portions. These caudal structures develop around day 26 of gestation, and closure failure of these portions results in the varying degrees of spinal dysraphisms. * Women should undergo routine screening to identify NTD early and help with therapeutic intervention and counseling. Initial screening is done with serum AFP, but in cases of high suspicion, amniocentesis can be pursued for confirmation. However, given the risk of amniocentesis and the accuracy of ultrasound, the latter has become the gold standard for diagnosis in-utero. * Several ultrasound signs have been identified as reliably diagnostic. The small biparietal diameter has been associated with NTD. However, the most cited signs include the lemon sign and banana sign.

Question 76

A 65-year-old man was managed conservatively following a right-sided hypertensive thalamic bleed with the involvement of the internal capsule as well. The patient had hemiplegia as well as hemisensory loss following the stroke. Though the patient was managed in the rehabilitation unit, he developed severe spasticity along his hemiparetic limb that severely effected his rehabilitation. The patient was then referred to the outpatient clinic for any newer modalities to aid in the improvement of the current neurological status of the patient. Peripheral magnetic stimulation therapy is being considered. Which of the following possible benefits, if any, is most likely expected following peripheral magnetic stimulation therapy in this patient? 1. Sensory improvement 2. Motor recovery 3. Improvement in spasticity 4. No improvement

Answer 76

**1. Sensory improvement** ## Footnote * Peripheral magnetic stimulation has the potential to achieve neuromodulation. The dynamic magnetic flux can, therefore, be modulated to either excite or inhibit the neuronal activity. * The use of low-frequency magnetic stimulation therapy has shown benefits among patients with neuronal hyperactivation, resulting from traumatic neuromas. This has also shown promises in improving sensory modality following strokes. * The transcutaneous magnetic stimulus with a low frequency of 0.5 Hertz has shown to improve the allodynia as well as cause sensory recovery following neuromodulation. The main benefits of the therapy are seen through neuronal inhibition. * A systematic review of the role of transcutaneous magnetic stimulation therapy has shown no sustained benefits on the recovery of the motor weakness and the improvement of the spasticity among the cohort patients.

Question 77

A 65-year-old patient presents with features suggestive of right-sided sciatica. His straight leg raising test on the right side was positive at 25 degrees. The knee and ankle reflex were normal. He had altered sensation localized at the first dorsal web space of his right foot. The electromyography test revealed features of early denervation of the extensor digitorum brevis muscle. What is the nerve root implicated for the radiculopathy in the patient? 1. L3 2. L4 3. L5 4. S1

Answer 77

**3. L5** ## Footnote * L5 nerve root supplies the first dorsal web space of the foot. * It characteristically does not any contribution to any deep tendon reflexes in the lower limb. * It innervates the extensor digitorum brevis muscle in the foot; thereby, features of its early denervation in the electromyography can be applied as a diagnostic test of its involvement following acute disc herniation. * L2, L3, and L4 govern the knee reflex. S1 and S2 nerve roots govern the ankle reflex.

Question 78

Which of the following spinal injury levels is associated with autonomic dysreflexia? 1. T1 2. T8 3. L3 4. S2

Answer 78

**1. T1** ## Footnote * Autonomic dysreflexia is associated with a spinal injury at or above T6. * Headache, fatigue, blurred vision, and dizziness are common unspecific symptoms of autonomic dysfunction. * It is the result of sympathetic and parasympathetic imbalance. * The higher and more complete the cord lesion, the more likely a noxious stimulation from below will cause a sympathetic/parasympathetic imbalance resulting in an autonomic dysreflexic syndrome. Treatment involves eliminating the triggering stimulus, which is a distended bladder or blocked Foley catheter in the majority (85%) of cases.

Question 79

A 34-year-old female patient presents to the hospital with severe headache, vomiting, photophobia, and neck stiffness of acute onset. On examination, GCS is 15/15, and no focal neurological deficit exists. A CT scan of the brain is unremarkable. A lumbar puncture is performed, which reveals a yellowish tinge to the CSF. What is the most common presenting complaint of the underlying disorder? 1. Nausea and vomiting 2. Headache 3. Photophobia 4. Neck pain

Answer 79

**2. Headache** ## Footnote * Patients presenting with a SAH classically present with a “thunderclap” headache characterized as a severe and rapidly progressing headache that develops within seconds to minutes and has a maximal intensity at its onset. Associated features are neck stiffness, vomiting, decreased level of consciousness, hemiparesis, and occasionally seizures. * Patients typically complain of severe headaches. However, only 10% of patients who present to the emergency department complaining of a thunderclap headache have a SAH. The typical headache pattern is described as a pulsatile pain propagating toward the occiput. * Seizures are more common if the SAH is caused by an aneurysm, and a SAH in a patient with a history of seizures is often diagnostic of cerebral arteriovenous malformation. * Neck stiffness typically does not occur until about six hours after the onset of a SAH.

Question 80

A 72-year-old woman presents to the clinic for follow-up of chronic axial lower back pain. She is taking high-dose hormonal therapy for recently treated breast cancer. Basivertebral nerve ablation is being considered. Which of the following complications is most likely to occur with this treatment in this patient? 1. Persistent post-procedure radiculopathy 2. Retroperitoneal hematoma 3. Transient radiculitis 4. Vertebral fracture

Answer 80

**3. Transient radiculitis** ## Footnote * Vertebral fracture has been reported in one subject among all clinical studies, particularly in a patient undergoing hormonal therapy. This is a complication to keep in mind in these patients, particularly with the transpedicular approach of this intervention. * While transient radiculitis was reported more often the persistent radiculopathy, the latter must be kept in mind when performing this intervention, particularly in the setting of potential transpedicular tract errors during the procedure. * Only one case of retroperitoneal hematoma was reported to date among all subjects, likely due to misdirected pedicle access during the procedure. It is required to utilize fluoroscopy or CT-image guidance when performing basivertebral nerve ablation to minimize adverse events related to technical aspects. * Among all clinical studies, transient radiculitis was the most commonly reported adverse event, which was self-limiting and treated with oral medication.

Question 81

A 67-year-old right-handed woman with a history of neurofibromatosis type 2 presents to the clinic with a 6-month history of headaches and sensory deficits. An MRI is obtained, which reveals a dural mass overlying and compressing the right superior parietal lobule. Which of the following sensory deficits is most consistent with this mass? 1. Left-sided astereognosis 2. Right-sided astereognosis 3. Broca aphasia 4. Homonymous hemianopsia with macular sparing

Answer 81

**1. Left-sided astereognosis** ## Footnote * The superior parietal lobule is the location of the somatosensory association cortex, which is involved in the processing of tactile sensory information. This area receives information from the postcentral gyrus of the parietal lobe and integrates it in object recognition. * Meningiomas are one of the pathologies that are associated with lesions to the somatosensory association area. Additional etiologies of these lesions include cerebrovascular stroke, cerebral palsy, and cortical dementia. * A lesion in the patient's right primary somatosensory association area will produce left astereognosis, which is an inability to identify objects based on tactile stimuli alone. Due to the decussation of sensory inputs from the extremities before reaching the cerebrum, tumors of the somatosensory association area will produce contralateral sensory deficits. * Due to the decussation of sensory inputs from the extremities before reaching the cerebrum, tumors of the somatosensory association area will produce contralateral sensory deficits.

Question 82

A 57-year-old woman presents with progressive numbness of the left hand and foot in addition to pain in the right retro-orbital area that gets worse when she bends forward. She describes the retroorbital pain as throbbing. The numbness started about a week ago and was accompanied by nausea and occasional vomiting. She has a past medical history significant for breast cancer for which she underwent a total mastectomy fifteen months prior. Vital signs show oxygen saturation of 98% on room air, respiratory rate of 16 per minute, heart rate of 72 beats per minute, blood pressure 140/90 mmHg, and temperature of 98 degrees F. On physical examination, her pupils are isocoric, equally reactive to light with full extraocular muscle movement. There are no visual field deficits. There is a left lower facial droop with no dysarthria. The motor examination is unremarkable. There is a partial sensory deficit to pain and light touch on the left hemibody, and she is unable to recognize stimulation on the left side on double simultaneous tactile stimulation. What is the most appropriate next step in the management of this patient? 1. Electroencephalogram 2. Magnetic resonance imaging (MRI) of the brain with and without contrast 3. Computed tomography (CT) head with and without contrast 4. Electromyogram/nerve conduction study

Answer 82

**2. Magnetic resonance imaging (MRI) of the brain with and without contrast** ## Footnote * An MRI is indicated in a patient with a history of malignancy and focal neurologic signs. Contrasted MRI is helpful for evaluating for enhancing lesions, including malignancy, infection, etc. * CT scans are helpful for evaluating osseous anatomy as well as hemorrhage. A CT scan could be an alternative if this patient had a contraindication to undergoing an MRI scan. However, if no contraindication, such as a pacemaker, spinal cord stimulator, etc then an MRI scan would provide significantly higher resolution than a CT scan. * An electroencephalogram (EEG) would be helpful for working up a suspected seizure. While brain lesions can certainly be irritating and predispose patients to seizures, her clinical presentation is more progressive and is likely due to the mass effect from the brain lesion itself rather than a persistent epileptic event. * EMG/NCV can be helpful for working up peripheral neuropathies. Given her clinical presentation and history of cancer, her presentation is more concerning for a lesion within the central nervous system, specifically the brain.

Question 83

Which of the following is the most common neoplasm seen within the submandibular triangle? 1. Adenoid cystic carcinoma 2. Adenolymphoma 3. Pleomorphic adenoma 4. Mucoepidermoid carcinoma

Answer 83

**3. Pleomorphic adenoma** ## Footnote * Neoplasms within the submandibular triangle are diagnosed with ultrasound, computerized tomography, or magnetic resonance imaging, followed by fine-needle aspiration biopsy for confirmation. Treatment of all submandibular triangle neoplasms requires surgical resection. * Neoplasms found within the submandibular triangle can be divided into benign and malignant masses. Pleomorphic adenoma is the overall most commonly seen neoplasm within the submandibular triangle. * The next most common benign neoplasm to pleomorphic adenoma is adenolymphoma, also known as Warthin tumor. * Malignant neoplasms found within the submandibular triangle include adenoid cystic carcinoma and mucoepidermoid carcinoma.

Question 84

A 40-year-old man is brought to the hospital with abnormal movements of his hands intermittently. His family members have also noticed a worsening of mood in the last one year. The patient's sister also had abnormal movements in her late forties and committed suicide due to severe depression. Genetic testing done in the patient due to this positive family history revealed an increased number of CAG repeats. What is most likely to be seen on brain imaging in this patient? 1. Hypertrophy of inferior olives 2. Atrophy of intermediolateral cell column 3. Enlargement of lateral ventricles due to a reduction in caudate nucleus volume 4. Atrophy of cerebellum

Answer 84

**3. Enlargement of lateral ventricles due to a reduction in caudate nucleus volume** ## Footnote * The case presented here strongly suggests Huntington disease, as suggested by the occurrence of abnormal movements (dyskinesias) in this middle-aged male along with depression. There is also a positive family history as the disease is transmitted in an autosomal dominant fashion. Genetic testing showed an increased number of CAG repeats in the Huntington gene on Chromosome 4. * Depression is very common in Huntington disease with a high prevalence of suicide. VMAT inhibitors like tetrabenazine that help with the chorea of Huntington disease sometimes can worsen the depression. * Caudate nucleus atrophies as the disease advances resulting in enlargement of ventricles. The lateral ventricles are described as 'boxcar ventricles'. * Currently, there is no cure for the disease.

Question 85

A 30-year-old, 32-week gravid woman is brought to the emergency department of a tertiary care hospital after being involved in a motor vehicle collision. During the initial assessment and evaluation, she complains of neck pain and is unable to be cleared by the national emergency x-radiography utilization study criteria. The vital measurement indicates a blood pressure of 110/80 mm Hg, a heart rate of 90 beats per minute, and a breathing rate of 21 breaths per minute. How should she be transported? 1. Trendelenburg 2. Left lateral decubitus 3. Supine on a backboard 4. Supine on a backboard with her right hip elevated

Answer 85

**4. Supine on a backboard with her right hip elevated** ## Footnote * The supine position can compress the great vessels after 20 weeks of gestation. Trendelenberg may push the uterus upward into the diaphragm, causing respiratory embarrassment. * The left lateral decubitus position is acceptable for transportation; however, not in the setting of traumatic neck pain. In-line immobilization is required. * Supine position can result in aortocaval compression syndrome and decrease systolic blood pressure as much as 30 mm Hg, stroke volume 30 percent, and uterine blood flow. * Due to potential cervical spine injury, using a backboard and elevating the right hip is the best option.

Question 86

A 23-year-old woman undergoes resection of a parotid gland tumor that was engulfing the facial nerve. The nerve had to be cut during the procedure as a small 1 cm segment was involved with the tumor, but a direct end to end coaptation was not possible during the surgery. Both proximal and distal stumps were sharply transected, and pathological examination of the removed nerve revealed clear margins free of any tumoral invasion. The postoperative period was uneventful, except for the expected ipsilateral facial paralysis. What is the most appropriate management strategy for this patient? 1. Direct end to end coaptation under tension 2. Interneural sural nerve graft 3. Masseteric nerve transfer 4. Hypoglossal nerve transfer

Answer 86

**2. Interneural sural nerve graft** ## Footnote * In the case of nerve gaps that cannot be approximated without tension, the current gold standard of repair is autologous nerve grafting. Donor sites include the medial antebrachial cutaneous nerve, lateral antebrachial cutaneous nerve, superficial sensory branch of the radial nerve, dorsal cutaneous branch of the ulnar nerve, and sural nerve. * When both nerve stumps are healthy, they can be approximated if they are not under tension. Otherwise, a nerve graft is required. Tension at the repair site will cause scarring that blocks the advance of regenerating sprouts. * Tissue-engineered nerve grafts can be used as supplements or even substitutes for autologous nerve grafts to bridge peripheral nerve defects. The biomaterial-based scaffold offers physical structural support for the growth of injured nerves. * Hypoglossal or masseter nerve transfer are used when the proximal stump is damaged.

Question 87

A 45-year-old woman presents to the outpatient clinic after being referred by her palliative medicine specialist. The patient has a history of metastatic breast cancer with debilitating pain severely impacting her quality of life. Her pain severity is at level 3 in the WHO ladder of pain management and she is not getting any relief with the best medical management. She is starting to experience thoughts of suicidal ideation because of her discomfort. The patient requests to be provided with information about the well- known invasive surgical procedure, which is often performed in patients with cancer with refractory somatic pain. What is the most common result of this procedure? 1. Contralateral loss of pain sensation 2. Urine retention 3. Saddle anesthesia 4. Ipsilateral loss of pain sensation

Answer 87

**1. Contralateral loss of pain sensation** ## Footnote * Cordotomy is a procedure used for intractable pain. * It interrupts the spinothalamic tract, causing a contralateral loss of sensation to pain and temperature. * Bilateral cordotomy is needed for visceral pain. * The procedure is usually done under local anesthesia with fluoroscopic guidance.

Question 88

A 65-year-old male present with left-sided progressive hearing loss. The pure tone audiometry reveals a sensorineural pattern of hearing loss. Magnetic resonance imaging (MRI) of the brain reveals a 2 cm vestibular growth within the internal auditory meatus without a dural tail. What is the most common anatomical location of the nerve of origin of the tumor in this patient within the internal auditory canal? 1. Anterosuperior quadrant 2. Anteroinferior quadrant 3. Posterosuperior quadrant 4. Posteroinferior quadrant

Answer 88

**4. Posteroinferior quadrant** ## Footnote * The patient has sensorineural hearing loss due to a vestibular schwannoma within the internal auditory canal. The internal auditory canal is divided into four quadrants by the transverse crest and the Bill's bar. * The most common origin of a vestibular schwannoma is the inferior vestibular nerve. * The inferior vestibular nerve is located in the posteroinferior quadrant of the internal auditory meatus. * The facial nerve is located in the anterosuperior quadrant, the cochlear nerve is located in the anteroinferior quadrant, and the superior vestibular nerve is located in the posterosuperior quadrant.

Question 89

The paramedic brings a patient with facial injuries. On physical examination, there is swelling of the upper lip and bleeding from the nose. There is malocclusion and ecchymosis of the maxillary buccal sulcus. A CT scan of facial bone shows bilateral transverse fractures passing through the maxilla above the level of the teeth. Which of the following is consistent with the injury described? 1. Le Fort I fracture 2. Le Fort II fracture 3. Le Fort III fracture 4. Le Fort IV fracture

Answer 89

**1. Le Fort I fracture** ## Footnote * Le Fort I is a transverse fracture that separates the body of the maxilla from the pterygoid plate and nasal septum. It is essentially a separation of the hard palate from the upper maxilla. The fracture line passes through the maxilla, above roots of the teeth; it causes floating palate. * Symptoms include malocclusion and facial tingling or numbness due to infraorbital nerve involvement. * A Le Fort I fracture occurs when the force of injury is directed low on the maxillary alveolar rim in a downward direction. * A Le Fort I fracture is usually stable; maxilla and hard palate may be mobile.

Question 90

A 45-year-old man with no medical problems presents to the healthcare provider with a complaint of dizziness. He has been experiencing a spinning sensation and profound nausea when rolling over in bed for the past two days. The symptoms last for a few minutes and improve with positional change. The provider has already tried repositioning maneuvers. Which of the following could be considered for further management? 1. Labyrinthectomy 2. Lifestyle modifications 3. Observation 4. Posterior canal occlusion

Answer 90

**4. Posterior canal occlusion** ## Footnote * Most patients with BPPV will get better with repositioning maneuvers or resolve completely. * However, surgical intervention is reserved for resistant cases. There are two surgical options for BPPV, singular neurectomy and posterior canal occlusion. * The recommended surgical option is posterior canal occlusion because it has been proven to be highly effective and safe. * Labyrinthectomy is a treatment option for Meniere disease.

Question 91

A 48-year-old female presents with dizziness. Her MRI shows a cyst that occupies almost half of the posterior fossa. There is an inferior incomplete fusion of the cerebellum but no hydrocephalus. Based on the most likely diagnosis, what is her life expectancy? 1. Reduced by 25% 2. Reduced by 50% 3. Reduced by 75% 4. Normal

Answer 91

**4. Normal** ## Footnote * The clinical and radiological findings are characteristics of Dandy-Walker malformation. * DWM results from developmental abnormalities affecting the roof of the rhombencephalon, leading to variable degrees of vermian hypoplasia and cystic enlargement. * This may lead to obstructive hydrocephalus and is the prime variable prognosticating the outcome in these patients. * Without any clinical and radiological features of obstructive hydrocephalus, these patients will have a normal life expectancy.

Question 91

A 47-year-old woman presents to the emergency department for abnormal fluid leaking from her ear. She states that recently she fell from a flight of stairs and hit her head on the side of her ear. She does not notice any bleeding from her ear. Her hearing is slightly muffled. She does report having some dizziness and a feeling of spinning of the room for the past few days. What is the most likely diagnosis? 1. Basilar migraine 2. Meniere disease 3. Perilymph leakage from a fistula 4. Vertebrobasilar insufficiency

Answer 91

**3. Perilymph leakage from a fistula** ## Footnote * The patient most likely has a labyrinthine fistula. * A labyrinthine fistula is an abnormal opening in the inner ear and can occur after head trauma. * Perilymph leakage from a fistula commonly occurs after a trauma to the head associated with vertigo, headache, with leakage of fluid from a fistula that can form within the inner from the pressure from the trauma. * Basilar migraine is less likely in the setting of trauma and is rare. It has been associated with dizziness and vertigo but no leakage of fluid. Meniere disease is is a disease of the inner ear, but it is not associated with leakage of the perilymph into the middle ear. Meniere disease can cause vertigo, the sensation of spinning or dizziness, hearing problems, and a ringing sound in the ear at times. Vertebrobasilar insufficiency (VBI) is poor blood flow to the posterior brain, by two vertebral arteries that join to become the basilar artery. Common symptoms of VBI include loss of vision, diplopia, dizziness or vertigo, numbness or tingling in the hands or feet, nausea and vomiting, slurred speech, mental status changes, and sometimes confusion and weakness throughout the body, ataxia, and sometimes. difficulty swallowing. This patient does not have any of these symptoms.

Question 91

A 50-year-old man presents to the emergency department with new-onset ataxia and dysarthria. Vital signs show a blood pressure (BP) of 220/115 mmHg. He has a history of poorly controlled hypertension. A non-contrast head CT shows a 4 cm right cerebellar hemisphere hemorrhage. In addition, compression of the 4th ventricle and dilation of the lateral and 3rd ventricles is also present. Which of the following is the next best step in the management of this patient? 1. Intravenous mannitol 2. Intraventricular drain 3. Surgical evacuation 4. Cerebral angiogram

Answer 91

**3. Surgical evacuation**

Question 91

Which of the following is defined as the anterior slippage of one vertebra on another? 1. Spondylomalacia 2. Spondylolisthesis 3. Spondylolysis 4. Spondyloarthropathy

Answer 91

**2. Spondylolisthesis** ## Footnote * Spondylomalacia is a defect of bone metabolism. * Spondylolisthesis is slippage of one vertebra on another. * Spondylolysis is a specific term referring to the presence of defects of the pars interarticularis but not necessarily associated with spondylolisthesis. * Spondyloarthropathy refers to an inflammatory arthritis of the spine such as ankylosing spondylitis.

Question 91

A 17-year-old Asian male recently stopped playing guitar because of "poor playing," as reported by his band. He presents with right-hand thenar eminence atrophy, decreased grip strength, and wrist extension of 3 out of 5. Right elbow and shoulder strength are 5 out of 5. Left upper extremity is 5 out of 5 on manual muscle exam. Bilateral sensory is intact. Reflexes are 2+/4. The patient is unable to identify any injury or trauma. EMG showed prolonged action potentials of high amplitudes without any sharp waves or fibrillation. What further studies may provide the most relevant information for the diagnosis in the patient? 1. Dynamic X-ray spine 2. Muscle biopsy 3. MRI brachial plexus 4. Dynamic MRI cervical spine

Answer 91

**4. Dynamic MRI cervical spine** ## Footnote * The clinical signs and symptoms in the patient are highly suggestive of a Hirayama disease. * Dynamic MRI spine has been advocated in diagnosing the condition in patients presenting with such characteristic clinical signs and symptoms. * Dynamic MRI spine characteristically shows anterior displacement of the dura, especially at the C7-T1 levels, during the flexion posturing. * Muscle biopsy is advocated in muscular dystrophies. Dynamic X-ray is advocated in cases of spinal instability.

Question 91

A 62-year-old woman is undergoing a right retrosigmoid craniotomy for resection of a cerebellopontine angle tumor. During the surgery, the tumor appears to compress the facial nerve, and resection of the lesion causes some traction on the nerve. Her right facial function was a House Brackman of 4/6 before the procedure but is a 6/6 after the surgery. One year after the procedure, she has not recovered any facial function. What is the most appropriate management strategy for this patient? 1. Conservative management 2. Direct distal facial nerve stump coaptation to the brainstem with the aid of a nerve stimulation probe 3. Sural nerve interneural graft to reconnect the pontine facial nerve with the extratemporal facial nerve 4. Hypoglossal nerve transfer to the extratemporal segment of the facial nerve

Answer 91

**4 - Hypoglossal nerve transfer to the extratemporal segment of the facial nerve** ## footnote * Delayed repair of the facial nerve after damage to the cisternal portion of the nerve is best done with a hypoglossal nerve transfer to the intraparotid segment of the facial nerve. * During surgery, if a nerve is cut, the best repair is direct end-toend anastomosis if it can be approximated without tension. * Lack of clinical and electrophysiological signs of spontaneous recovery after 3–6 months indicates surgical intervention. Endoneurial tubes must be in contact with regenerating axons within 18–24 months after injury; otherwise, degeneration will occur. * Sural nerve interneural graft is used to connect two healthy nerve stumps which cannot be approximated without tension.

Question 92

Lumbar spinal stenosis may present with which of the following? 1. Back pain that increases upon standing 2. Back pain upon lying in the prone position 3. Numbness in the arms 4. Shooting pain in the legs

Answer 92

**1. Back pain that increases upon standing** ## footnote * Back pain and paresthesias that worsen upon standing but are absent when sitting is indicative of spinal stenosis. * Severe stenosis is associated with weakness. * Cervical spinal stenosis can present with decreased hand dexterity and mild proximal lower extremity weakness and progress to neck and arm pain. * As with standing, one expects lying prone to worsen or exacerbate the symptoms of spinal stenosis (whereas prone positioning may improve the symptoms of HNP).

Question 93

A 59-year-old woman presents with left-sided weakness. The symptoms started 30 mins ago when she was having lunch in a restaurant. The patient has a past medical history of hypertension and type 2 diabetes mellitus. On examination, the patient is awake, alert, able to follow commands, and is oriented to time, person and place. Cranial nerve examination reveals preferential gaze to the right and dysarthria. The patient is unable to recognize left-sided stimulus on double simultaneous stimulation. The motor examination shows 3/5 strength on the left upper and left lower limb. There is a 20% sensory deficit on the left to pain and light touch. Babinski sign is positive on the left. A head CT is performed. Which of the following do you expect to see on this scan? 1. Encephalomalacic changes in the right periventricular region 2. A small area of hyperdensity in the pons 3. Insular ribbon sign with obscuration of the lentiform nucleus 4. Hyperdensity at the Sylvian fissure and base of the skull

Answer 93

**3. Insular ribbon sign with obscuration of the lentiform nucleus** ## footnote * Ischemic brain tissue stops working in seconds and suffers necrosis in as soon as 5 minutes after complete lack of oxygen and glucose supply, prompting a myriad of potential symptoms and disability. * Cerebral ischemia can be focal or generalized and cause varying clinical pictures. * While generalized cerebral ischemia is generally related to syncope and pre-syncope, focal cerebral ischemia usually causes a stroke or transient ischemic attacks. * As a rule of thumb, acute cerebral ischemia is never painful.

Question 94

A 68-year-old woman with a history of metastatic breast cancer presents to the office for follow up. She is currently taking hydromorphone/acetaminophen 10/325 mg 4 times a day for severe pelvic pain due to boney metastasis. Despite this medication use, the patient still complains of 9 out of 10 pain. After a careful review of the source of pain, it is suspected to be coming from a neurologic dermatome from the spinal cord. A spinal opioid injection for pain control is then performed. Soon after the injection, the patient describes pain in the frontal and occipital areas that is worse in the upright position and improved in the supine position. She states the pain is also made worse with coughing. Which of the following is the next best step in the management of this patient? 1. Reassurance 2. Head CT scan 3. MRI head 4. Oral hydration

Answer 94

**4. Oral hydration** ## footnote * While serious complications from spinal opioid use in anesthesia are rare, when complications do occur, they are specific to both the medication and the approach utilized in the procedure. In the prototypical example of spinal morphine use, complications include respiratory depression, constipation, altered mentation, and somnolence. * Complications of spinal opioid injection also include the risk of paresthesias, temporary pain at the injection site, and post-dural puncture headache. * Rarer procedural complications of spinal opioids also include infection, urinary retention, and epidural hematoma. * The first step in managing post-dural puncture headache from spinal opioids is using conservative measures with oral rehydration and simple oral analgesia.