Section 3 Flashcards

Question

A 35-year-old woman presents to the neurology clinic following persistent headaches and progressive diminution of her vision. Her fundoscopic exam revealed bilateral early optic atrophy. The image of her MRI brain is shown. The symptoms in the patient were refractory to medical management. Which of the following modality is most effective in the management of the patient? 1. Optic nerve fenestration 2. Bariatric surgery 3. Ventriculoperitoneal shunt 4. Veno-sinus stenting

Answer 1

**4. Veno-sinus stenting** ## Footnote * The patient has clinical and radiological features (empty sella syndrome) consistent with idiopathic intracranial hypertension (IIH). * Venous sinus narrowing and stenosis are now considered to play an important and curable role in the pathogenesis of IIH. * Veno-sinus stenting has shown to have the best clinical and visual benefits among various forms of operative interventions considered for IIH. * The optic nerve fenestration has benefits in managing visual diminution. Bariatric surgery is considered among patients with a normal venogram study.

Answer 2

**2. Give a dose of PCC or Fresh Frozen Plasma with Vitamin K to reduce INR 1.3** ## Footnote * Monitoring the hematoma expansion is the next step after achieving the target INR with a reversal agent. * The goal of reversal agents is to achieve a target INR 1.3 to avoid hematoma expansion. If the repeat INR after 6 hours of a previous reversal agent is still >1.3, the repeat dose of either PCC or FFP is required. * INR should be checked every four to six hours for the first 24 hours and then checked daily for a few days. * Vitamin K is always given with FFP, PCC, or Factor VII for warfarin-associated intracranial hemorrhage. Vitamin K has a delayed onset of action compared to PCC and FFP but achieves a steady decrease in INR over the next 12 to 24 hours compared to PCC or FFP alone.

Answer 3

**4. Incudomalleolar joint** ## Footnote * Temporal bone fractures typically result from high-impact blunt head trauma. The temporal bone has complex anatomy including four geographic parts (squamous, mastoid, petrous, tympanic) and numerous named foramen/canals (foramen lacerum, carotid canal, internal acoustic meatus, jugular foramen). * Common associated injuries include hearing loss, facial palsy, extra-axial hemorrhage, and cerebral contusion. * In this case, CT demonstrates a longitudinal fracture of the right temporal bone with ossicular chain disruption. Temporal bone fractures that violate the otic capsule have a much higher association with CSF leak, sensorineural hearing loss (SNHL), and certain intracranial pathology. * Treatment and management of associated life-threatening, intracranial pathology should be the primary focus. Formal audiological evaluation is deferred several weeks post-injury to ensure edema and hemotympanum have completely resolved.

Answer 4

**3. Persistent, intractable pain following exhaustion of all possible nonoperative treatment options (physical therapy, rest, NSAIDs).** ## Footnote * The most common indication for surgical intervention is persistent, intractable pain following exhaustion of all possible nonoperative treatment options (physical therapy, rest, NSAIDs) for a minimum of a dedicated 6 week period. * Even in the setting of acute injuries with MRI evidence of a lumbar disc herniation and correlating clinical symptoms in the motor/sensory distribution of the specific nerve root(s) involved, nonoperative management remains the mainstay of initial treatment. * Greater than 95% of lumbar disc herniations involves the L4/L5 and/or L5/S1 disc spaces, with patients typically presenting with low back pain with sharp, stabbing pain often traceable form the lower lumbar region to the lower leg and foot. * Lower extremity radiculopathy, often ambiguously ill-defined even by healthcare providers and physicians as "Sciatica," is often attributable to nerve root(s) compression and impingement at one or multiple nerve roots in the lumbosacral plexus. These roots ultimately contribute innervation (motor/sensory) peripherally as the sciatic nerve, manifests as shooting, stabbing, and/or burning pain radiating from the back to the ipsilateral or contralateral lower extremity.

Answer 5

**1. Arterial ischemia** ## Footnote * Thalamic infarcts are often the result of vertebrobasilar disease. Rarely, occlusion of the artery of Percheron (common vascular trunk that arises from one P1 segment) can be causative. * Presentation depends on the region affected and may include cognitive/behavioral disturbances, aphasia, hemineglect, ophthalmoplegia, and sensorimotor deficits. * In this case, DWI demonstrates small areas of restricted diffusion in bilateral central thalami, which do not appear engorged. * Thalamic infarcts are often managed medically. Outcome is usually positive with return to baseline neurological function.

Answer 6

**2. Prone** ## Footnote * A provocative discography (PD) is an invasive diagnostic spine procedure. Contrast is administered into the nucleus pulposus of an intervertebral disc. The test is based on the premise that discs can be a source of spine pain, and symptomatic, internally disrupted disc causes pain when it is mechanically loaded; therefore, it should be similarly painful when pressurized with injected contrast. * PD should only be employed when there is a moderate to high pretest probability that the spine pain is suspected to be of discogenic origin. This is based on history and advanced imaging findings. The information obtained from the test will be used to rule out or plan subsequent treatment decisions such as therapeutic intradiscal procedures (e.g., intradiscal electrothermal therapy, annuloplasty, regenerative medicine) or surgery (e.g., disc arthroplasty, interbody fusion). * PD is performed in a procedural suite with x-ray fluoroscopy. The patient is positioned prone, except in the case of cervical discography where they are supine. * Several decades have passed since the advent of PD. Arguably it is the best method to determine with reasonable certainty the presence or absence of discogenic spine pain.

Answer 7

**1. Hydrocephalus** ## Footnote * Dandy-Walker is comprised of hypoplasia of the cerebellar vermis, dilation of the 4th ventricle, and elevation of the cerebellar tentorium. * 70-90% of patients with Dandy-Walker malformation present hydrocephalus. * Dandy-Walker is also associated with malformations of the face, limbs, heart * DWM may be isolated or associated with chromosomal abnormalities, Mendelian disorders, syndromic malformations, congenital infections, and various other comorbidities.

Answer 8

**1. Abdominal visceral injuries** ## Footnote * A Chance fracture of the spine is a flexion-distraction injury of the spine with the center of rotation at the abdominal viscera where the anterior spinal column fails in compression, and the middle and posterior spinal columns fail under tension. * Chance fractures have a very high (50%) association with gastrointestinal injuries due to the center of rotation being at the abdominal viscera. * A thorough gastrointestinal examination is warranted in all cases of bony chance fractures, and patients with any signs of abdominal trauma due to seatbelt injuries. * Bony chance fractures, as seen in this image, can be managed non-operatively, whereas ligamentous chance fractures necessitate surgical stabilization.

Answer 9

**3. Intubation with sedation, hyperventilation, mannitol, and decompressive craniectomy** ## Footnote * Since the patient has large ICH with edema, mass effect, and midline shift, he requires maximum antiedema measures. * Decompressive craniectomy, evacuation of hematoma, and expansive duraplasty improve outcomes in patients with large hematoma and coma with GCS below 8. * Intubation should be with sedation; otherwise, intracranial pressure will rise further. * Hyperventilation should be to maintain a pCO2 of 28 to 32 mmHg.

Answer 10

**2. CN III** ## Footnote * The CT scan shows a subdural hematoma with subarachnoid hemorrhage on the right. The complication would include an increase in the size of the hemorrhage as well as edema of the right temporal lobe. This may predispose to herniation of the medial temporal lobe leading to uncal herniation. * Uncal herniation compresses CN III. The clinical presentation consists of a dilated ipsilateral pupil, which does not respond to light. On further compression, the affected eye will be looking down and out. * Further herniation may compress the brainstem and cause a decrease in sensation. * The uncus and the adjacent temporal lobe slide down the tentorial incisura and compress the posterior cerebral arteries and the brain stem. It carries a poor prognosis.

Answer 11

**1. Cerebrum** ## Footnote * This patient has an arteriovenous malformation of the brain. Arteriovenous malformations (AVMs) are a developmental anomaly of the vascular system, consisting of tangles of poorly formed blood vessels in which the feeding arteries are directly connected to a venous drainage network without any interposed capillary system. * The majority of AVMs of the brain are found in the cerebral hemispheres. Seizures are due to cortical irritation, which would be less likely to occur from a lesion in the pons, cerebellum, or internal capsule. * AVMs are the second most common cause of intracranial bleed after cerebral aneurysms, responsible for 10 percent of all cases of subarachnoid hemorrhage. * Hemorrhages are usually intraparenchymal but can primarily occur in the subarachnoid space. Symptoms due to hemorrhage include loss of consciousness, sudden and severe headache, nausea, and vomiting as the coagulated blood makes its way down to be dissolved in the individual's spinal fluid.

Answer 12

**2. Posterior spinal fusion T2-pelvis** ## Footnote * This patient has clinical and radiological features of scoliosis secondary to Duchenne Muscular Dystrophy. These patients have typical difficulty in standing (Gowers sign). This is an X- linked recessive disease that may present with progressive weakness, scoliosis, equinovarus foot, and cardiomyopathy. * The radiograph reveals coronal thoracolumbar scoliosis with pelvic obliquity. There is no hemivertebra which excludes the possibility of congenital scoliosis. Cobb angle is measured from the end vertebra of both curves to plan for surgery. * Posterior spinal fusion from T2-sacrum is indicated in this patient. If the pelvic obliquity is more than 15 degrees then fusion should be done to include the sacrum which improves sitting balance and coronal alignment. Proximal fusion should be extended to T2 to prevent junctional kyphosis. * If the forced vital capacity (FVC) is greater than 40, the scoliosis is greater than 25 degrees, and a 2-year life expectancy is projected, surgery is recommended. In contrast to a posterior- only technique, an anterior approach to the spine is not recommended in Duchenne patients because it requires lung deflation, which can lead to respiratory difficulties and increased blood loss.

Answer 13

**4. 15/30 occipitomental view** ## Footnote * 15/30 occipitomental views are used when a zygomatic- maxillary complex fracture is suspected. * Zygomatic arch fractures have four components: lateral orbital wall, orbital floor, zygomatic arch, and the maxilla and zygoma separation. * Zygomatic arch fractures are also known as quadripod fractures or quadramalar fractures. * The occipitomental view is also known as the Waters’ view, and the x-ray passes from behind the patient's head toward the radiographic plate.

Answer 14

**3. Glucocorticoid therapy** ## Footnote * Lymphocytic hypophysitis is a rare autoimmune disease of the pituitary gland classically seen in peripartum women with headache or middle-aged men with diapedes insipidus. * Lymphocytic hypophysitis may present with pituitary dysfunction, such as central diabetes insipidus, anterior pituitary hormone deficiency, and hypo/hyperprolactinemia. The degree of lymphocytic infiltration corresponds to the degree of pituitary enlargement, which may secondarily cause mass effect and contribute to visual loss, ophthalmoplegia, and headache. * Lymphocytic hypophysitis is a diagnosis of exclusion, and histopathology with tissue biopsy is needed for a definitive diagnosis. Clinical information, laboratory data, and imaging, however, can help with the diagnosis. Gadolinium-enhanced MRI of the pituitary is the modality of choice, and may demonstrate an avidly-enhancing, thickened pituitary stalk, enlarged pituitary gland, and loss of the normal posterior pituitary "bright spot". Gutenberg scoring was developed to correctly distinguish lymphocytic hypophysitis from pituitary adenoma. * The main goal of treatment of lymphocytic hypophysitis is to manage pituitary hormone deficiencies and mass effect. Treatment consists of conservative management and anti- inflammatory medication. Surgery is employed for patients suffering from visual problems, compression of nearby structures, or equivocal imagining findings that require histology for diagnosis.

Answer 15

**2. Posterior** ## Footnote * The radial nerve comes from the posterior cord of the brachial plexus. * Compression of the superficial branch of the radial nerve at the level of the wrist is known as cheiralgia paresthetica. It is also commonly called Wartenberg syndrome or superficial radial nerve palsy. * Chordoroff et al. reported a case in which a steroid injection to the 1st dorsal compartment of the wrist for de Quervain tenosynovitis causes subdermal atrophy in the surrounding area which later led to the development of cheiralgia paresthetica from the patient's wristwatch. * Cheiralgia paresthetica causes symptoms such as pain, burning, paresthesia, numbness, etc. to the dorsoradial aspect of the wrist, hand, and fingers.

Answer 16

**4. Highly-conformal radiotherapy** ## Footnote * Chordomas are relatively radioresistant which necessitates high-dose radiation including proton beam radiation or radiosurgery (highly conformal radiotherapy). * When a needle biopsy is performed, the surgical resection should include the needle tract as chordomas can seed the needle biopsy tract. * En bloc resection followed by high-dose radiation provides the best current long-term outcomes for chordoma treatment. * Chordomas are slow-growing and chemotherapy is not a generally used treatment strategy. If chemotherapy is given, it is usually given as part of a clinically trial.

Answer 17

**1. Brodmann area 17** ## Footnote * The patient likely has an acute ischemic stroke in the occipital cortex secondary to dilated cardiomyopathy. * The defect in his perception of color, form, and movement of an object indicates the involvement of his primary visual cortex. * Brodmann area 17 represents the primary visual cortex in the brain. * Brodmann area 22 controls the lexical-semantic processing of sound. Brodmann area 40 is the supramarginal gyrus, and damage to this region can lead to alexia and agraphia.

Answer 18

**3. Surgical decompression and fusion** ## Footnote * While bony chance fractures are considered stable and may be managed non-operatively in the absence of a neurological deficit, ligamentous chance fractures, as seen here that disrupt the posterior ligamentous complex, are unstable and should be treated with surgical decompression and fusion. * A Chance fracture of the spine is a flexion-distraction injury of the spine where the anterior spinal column fails in compression, and the middle and posterior spinal columns fail under tension. * The center of rotation of chance fractures is through the abdominal viscera, and there is a high incidence in restrained passengers. Therefore, abdominal injuries must be also ruled out. * Disruption to the posterior ligamentous complex renders the spine unstable, and stabilization must be provided surgically.

Answer 19

**4. Hard cervical collar** ## Footnote * Odontoid fractures are managed conservatively or surgically based on various factors, including the degree of displacement, type of fracture (Anderson and D’Alonzo type 2 mainly), age of the patient, associated injuries, comorbidities, and presence of osteoporosis. * Un-displaced fractures, defined as less than 2 mm fracture gap, less than 5 mm anteroposterior displacement, and less than 11- degree angulation, are best managed conservatively. * The overall union rates following hard collars and halo-vest immobilization in stable odontoid fractures are reported to be reasonably similar. However, studies have revealed a much better reduction in the cervical range of motion after the halo- vest application. In younger individuals, the use of halo-vest immobilization is typically recommended, although, in the older population, hard cervical collar application is associated with the lowest complication rates. * The major complications with halo-vest immobilization in the elderly include infection, aspiration pneumonia, and respiratory failure.

Answer 20

**4. Compression of a nerve during prolonged prone positioning intraoperatively** ## Footnote * Meralgia paresthetica is a well-known complication of prone positioning used for the posterior approach to the spine. Insufficient care with positioning of the bolsters may result in pressure over the lateral femoral cutaneous nerve (LFCN) of the thigh, causing numbness in its distribution. Symptoms usually resolve with time but can sometimes become painful while the nerve is recovering. * Meralgia paresthetica is typically benign and self-limited with frequent spontaneous remission. * Treatment focuses on patient reassurance and ways to reduce pressure and irritation over the nerve and groin region. * Medications that may be helpful include nonsteroidal- antiinflammatory drugs (NSAIDs), topical capsaicin, lidocaine, or tacrolimus for epidermal dysesthesia or cutaneous hypersensitivity.

Answer 21

**3. Pituitary adenoma** ## Footnote * Pituitary adenomas are benign tumors of the adenohypophysis. A macroadenoma is a sellar mass greater than 10 mm without a separate identifiable pituitary gland. * Pituitary adenomas are often found incidentally on imaging. Up to 75% are endocrinologically active, and may be prolactin-, growth hormone-, or ACTH-secreting. Visual field defects (bitemporal hemianopsia) may present secondary to mass effect in cases of large tumors. Headache is commonly reported though is nonspecific. * In this case, contrast-enhanced T1W MR demonstrates a hypoenhancing mass inseparable from an enhancing and enlarged pituitary gland, with minimal superior extension. The mass contacts and surrounds the right supraclinoid internal carotid artery without compression. * Dopamine agonists are the first-line treatment for prolactin- secreting tumors. Transsphenoidal resection is recommended in patients with macroadenomas and visual field deficit, ophthalmoplegia, optic nerve compression, pituitary apoplexy, or loss of endocrine function.

Answer 22

**2. Below the red nuclei** ## Footnote * Decerebrate posturing is characterized by adduction and internal rotation of the shoulder, extension at the elbows with pronation of the forearm, and flexion of the fingers. The lower limbs show extension and internal rotation at the hip with knee extension and plantar flexion of the feet. Toes are typically abducted and hyperextended. * Decerebrate posturing suggests damage to the corticospinal and rubrospinal tracts with the preservation of the vestibulospinal tract. This places the lesion below the red nucleus but above the vestibular nuclei in the rostral medulla. Therefore a pontine lesion is most likely. * Overall, children requiring admission to hospital due to head injury have a mortality of 10 to 13%; however, in severe cases with decerebrate posturing, the mortality is 71%. Factors that favor survival in traumatic brain injury with decerebrate posturing include younger patient age, admission within 6 hours of injury, and extradural hematoma. Poorer outcomes are seen in acute subdural hematoma and older age. * Clear bloodstained fluid running from the nose of a patient with a head injury likely indicates a base of skull fracture.

Answer 23

**2. Magnetic resonance imaging of the brain and orbits** ## Footnote * Optic neuritis is often the presenting symptom of multiple sclerosis. Another common visual complaint is abnormal eye movement, known as internuclear ophthalmoplegia (INO). Patients often complain of diplopia. INO results from a demyelinating lesion of the medial longitudinal fasciculus. * A contrast-enhanced magnetic resonance imaging (MRI) scan is the most appropriate next step in the management of this patient. * The presence of typical lesions on an MRI negates the need for lumbar puncture in most cases. * A lumbar puncture can be obtained if the MRI is equivocal.

Answer 24

**1. CT spine** ## Footnote * The clinical and radiological features in the patient are highly suggestive of cervical myelopathy resulting from an ossified posterior longitudinal ligament (OPLL). * The CT spine is the most rational next step in the management of the patient presenting with such clinical characteristics. * CT spine helps in diagnosing as well as categorizing the patterns of involvement of the vertebral bodies and the disc spaces, thereby helping to formulate the appropriate surgical intervention in the patient. * Anterior or posterior surgical approaches in the management of OPLL depend upon its subtypes as classified by the CT findings. It also depends upon the age, neurological status, medical comorbidities, and the cervical lordosis of the patient.

Answer 25

**1. Start empirical 4-drug anti-tubercular therapy with steroids** ## Footnote * Diagnosis of tuberculoma is based on characteristic imaging of ring-enhancing lesions on contrast-enhanced CT scan or MRI of the brain. * When the diagnosis of tuberculoma is not possible with imaging or response to ATT is unsatisfactory, there is a progression of brain lesion, the definitive diagnosis can be made by stereotactic biopsy depending upon the availability of such a modality. * Brain tuberculomas are managed pharmacologically with first- line ATT and dexamethasone. * Surgery is indicated when tuberculoma >20 mm or if it is causing a mass effect in the form of midline shift or obstruction to CSF flow or when medical therapy fails.

Answer 26

**1. Otic capsule involvement by the fracture** ## Footnote * The old classification of temporal bone fractures was based on whether the fracture was transverse or longitudinal to the petrous pyramid of the temporal bone. * Because many temporal bone fractures are complex and not easily categorized using the old classification, the new classification of whether the otic capsule (including the labyrinth and the cochlea) is involved is more useful. * Otic capsule involvement by trauma can lead to hearing loss, vertigo, and facial paralysis. * Damage to the ossicles can also lead to hearing loss, but this hearing loss would be considered conductive rather than sensorineural, which would more likely result from otic capsule involvement.

Answer 27

**3. Orbital floor fracture with trigeminal nerve dysfunction** ## Footnote * The second branch of the trigeminal nerve runs through the maxillary bone forming the inferior portion of the orbit. Dysfunction may be the result of an orbital floor fracture. * Ocular motility disturbance results from incarcerated ocular muscles or surrounding fat tissue in bone fragments. * Vertical ocular motility disturbance, hypesthesia of the ipsilateral upper central incisor, and subcutaneous crepitus are all signs of this condition. * Facial nerve dysfunction is not common in midfacial trauma.

Answer 28

**3. DNA methylation** ## Footnote * DNA methylation profile is used to define the molecular/genetic diagnosis for the new 2016 classification of central nervous system tumors. * In 2016, the World Health Organization published a revised classification of central nervous system tumors using molecular parameters. Altered DNA methylation has been implicated in many tumors. Epigenetic alterations can explain the transformation of a normal cell to a cancerous cell. DNA methylation microarrays are used in studying the epigenetics of cancer. * Embryonal tumors are classified depending if they have on chromosome 19 an amplification of the C19MC region (19q13.42). If they have the amplification, they will be called embryonal tumor with multilayered rosettes, C19MC-altered (WHO 9478/3*). If they do not have the amplification, they are called embryonal tumor with multilayered rosettes, NOS (WHO 9478/3). * Histochemistry and Ki67 index are used in the histological analysis but will not provide genetic analysis. Electron microscopy shows the organelle structure of the cell but does not provide genetic characteristics.

Answer 29

**3. Decompressive craniectomy** ## Footnote * In patients with evidence of cerebral herniation, neurosurgery should be consulted, and decompressive craniectomy should be considered. * Complete obliteration of suprasellar cistern and midbrain that is both effaced and displaced inferiorly are signs of uncal herniation that require emergent decompressive craniectomy. Mechanical thrombectomy is not indicated because there is no evidence of large vessel occlusion due to a clot on imaging. For isolated cortical vein thrombosis, typically, the clot will present as an area of hypointensity within the cortical vein only on MRI. * Emergent decompressive craniectomy is the treatment of choice in the setting of cerebral herniation as confirmed by imaging. There is no evidence of large vessel occlusion to suggest that a mechanical thrombectomy will be beneficial. * Subcutaneous low molecular weight heparin is the treatment course for isolated cortical vein thrombosis, but it cannot treat uncal herniation. Anticoagulation treatment with dabigatran has no role in the management of uncal herniation.

Answer 30

**2. L5** ## Footnote * The patient has characteristic signs and symptoms of lumbar canal stenosis. * The weakness of extensor hallusus longus and bilateral wasting of extensor digitorum brevis suggest the prime involvement of the L5 nerve root. * The EMG of the L5 nerve root is very helpful in determining the degree and duration of the canal stenosis in the patient. * The involvement of L4 presents with weakened plantar flexion and diminished ankle reflex. The involvement of S1 presents with weakened flexor hallusus longus and diminished ankle reflex.

Answer 31

**2. Immediate surgical spinal decompression** ## Footnote * Any patient with large metastatic vertebral deposits and significant spinal canal compromise presenting with progressive neurological deficit (conus medullaris syndrome, in this case), requires immediate spinal decompression surgery. This is a surgical emergency. * Duration and severity of neurological deficit are the most important prognostic indicators in such scenarios, and surgical decompression provides the quickest relief of compression of the spinal cord. * Such surgical decompression can be achieved by the posterior approach alone, a posterolateral approach involving 360° decompression of the spinal canal with or without anterior column reconstruction [with polymethyl methacrylate (PMMA) or cage reconstruction], anterior approach alone or combined anterior-and-posterior approach. With the recent advances in technology, all the surgical goals can be achieved with posterior or posterolateral approaches only. * Although steroids may have some role in ameliorating the neurological prognosis in cancer patients, there is no evidence supporting its role as the sole definitive treatment in these patients. Similarly, even in highly radiosensitive tumors with progressive neurological deficits, radiotherapy (cEBRT or SSRS) may not be the best approach to ensure immediate spinal canal decompression.

Answer 32

**3. Mild obesity** ## Footnote * The patient in the clinical scenario most likely presents with amyotrophic lateral sclerosis (ALS), which is a neurodegenerative disease of the motor neurons. * The diagnosis of ALS is made when there is upper and lower motor neuron degeneration, together with the clinical progression of signs and symptoms. * The median survival rate is 3 to 5 years; however, around 30% of patients survive five years from the diagnosis and only 10 to 20% survive for ten years. * Factors associated with a better survival rate include increased weight at diagnosis (mild obesity), younger age at onset, higher ALS functional rating scale score, forced vital capacity (FVC) at presentation, and limb rather than bulbar symptoms.

Answer 33

**3. Measurements of prolactin and insulin-like growth factor 1 (IGF-1)** ## Footnote * The establishment of a microadenoma versus a macroadenoma occurs with the size seen on an MRI, and the workup is dictated by this classification. All microadenomas require the complete pituitary hormonal panel to rule out hypersecretory tumors and must include insulin-like growth factor 1 (IGF-1) (for growth hormone) and prolactin levels. * On imaging or gross pathology, they can be classified according to their size as macroadenomas when greater than 1 centimeter or microadenoma when less than 1 centimeter. * Early morning cortisol levels are reserved for patients with symptomatic manifestations of Cushing's syndrome. * Referral to a surgeon for transsphenoidal resection is required when adenomas are refractory to medical therapy, are specific secretory tumors, or cause visual field defects. Visual field testing is indicated in all tumors that are large in size, macroadenomas, or are abutting the optic chiasm or nerves on imaging. This microadenoma that the patient has no signs of abutting the optic chiasm. The patient also does not have any changes in her vision. Repeating an MRI and labs at 6 months is a reasonable option once a functioning pituitary tumor has been ruled out.

Answer 34

**2. It can take up to 12 months on average for her back pain to resolve.** ## Footnote * Pregnancy-related sacroiliac (SI) joint pain often resolves in the months following delivery. Sixty-two percent of women state their back pain has resolved three months postpartum. * SI joint injury is prevalent in pregnancy. Twenty percent of cases of SI joint injury are pregnancy-related. Eighty-six percent of women state their back pain is resolved 12 months postpartum. * Patients who experience pelvic girdle pain during pregnancy have high rates of disability than patients suffering mechanical back pain, but most cases resolve following delivery. * During pregnancy, laxity occurs within many of the joints in the pelvis. The hormone relaxin causes joint mobility during pregnancy. As the pelvis widens during pregnancy, the SI joint becomes more mobile. The expecting mother can experience SI joint pain as the hips rotate, putting stress on the SI joint. Over a period, the pelvis returns to its prior state.

Answer 35

**4. Superior aspect of the medial rectus** ## Footnote * The infratrochlear nerve runs anteriorly on the superior border of the medial rectus. It can be injured concominantly with injuries of the medial rectus. * The medial rectus is responsible for medial movement of the eyeball. * The medial rectus is innervated by oculomotor nerve (CN III). * The infratrochlear nerve receives a branch from the supratrochlear nerve (a branch of the frontal nerve) and moves through the medial aspect of the extraconal space of the orbit inferior to the trochlea. It exits the orbit under the superior orbital margin and above the medial canthal tendon.

Answer 36

**2. Pilocytic astrocytoma** ## Footnote * This 5-year-old patient with symptoms of cerebellar pathology evident by dysmetria, ataxia, and an MRI revealed a cystic mass lesion in the cerebellum is most likely a case of pilocytic astrocytoma. * Brain tumors in children are most likely to be located in the infratentorial region and hence present with signs of cerebellar pathology. * Pilocytic astrocytoma is the most common tumor of childhood followed by medulloblastoma. The tumor typically consists of a cystic component that presents are hypodensity within the hyperdense tumor mass. * Glioblastoma is a tumor found in elderly patients and is poorly circumscribed and butterfly-shaped. Ependymoma is a periventricular solid mass lesion without any cystic component. Medulloblastoma is found in the infratentorial region but is a midline tumor and arises from the vermis and is unlikely to present with dysmetria. Instead, it would present with truncal ataxia.

Answer 37

**2. Upper outer quadrant** ## Footnote * The lateral mass screw fixation is a common surgical procedure applied during the posterior fixation of the cervical spine. However, there are risks of inadvertent injury to the vertebral artery and the exiting nerve roots during the procedure. * The lateral mass can be divided into four quadrants with a horizontal and verticle imaginary lines. The vertebral artery courses through the upper inner and the lower inner quadrants. The exiting nerve root lies underneath the lower outer quadrant. * The safest point of insertion of the lateral mass screw is just below and medial of the intersection of the two lines. The screw should then be inserted projecting towards the upper outer quadrant so as to safeguard form the injury to the vertebral artery and the exiting nerve root. * The insertion of the screw towards the medial quadrants of the lateral mass herald the risk of vertebral artery injury. The insertion of the screw towards the lower outer quadrant increases the risk of injury to the exiting nerve root.

Answer 38

**4. Surgery** ## Footnote * The patient has low-grade glioma (LGG) in the frontal lobe. In this age, LGGs are among the common brain cancers. * Nausea, vomiting, and headache are common presentations for a brain tumor due to compression effects. Surgery is the mainstay of treatment for LGG. * MRI shows well defined, low intensity, and no enhancement of the mass, and this is the description of low-grade glioma. * Surgery is recommended in LGGs. Radiotherapy should be given to any patient with progressive neurologic symptoms. Chemotherapy and radiotherapy can be given in the recurrence of the tumor or post-operatively if needed rather than adjunctively.

Answer 39

**4. Water deprivation test** ## Footnote * Given the clinical history and exclusion of other common causes of polyuria and polydipsia including normal calcium, potassium, and negative urine dipstick for glucose, the patient is likely to have antidiuretic hormone deficiency and diabetes insipidus. * The initial evaluation is the water deprivation test. ACTH stimulation test and triple bolus test are used for anterior pituitary function. * Irradiation may have affected growth hormone secretion, however, there is no complaint regarding short stature. * Pituitary pathology is a complication of childhood cranial irradiation.

Answer 40

**1. Digital subtraction angiography** ## Footnote * The description in this question is consistent with the dural arteriovenous fistula. Chronic dural arteriovenous fistula (dAVF) typically thromboses and contains a network of vessels that can be seen as flow voids on magnetic resonance imaging (MRI). The transverse-sigmoid junction is a common site where dAVF is seen. * Digital subtraction angiography is necessary to definitively establish a diagnosis of dAVF. * Digital subtraction angiography is necessary for treatment planning to define the fistulous point, where treatment is targeted, as well as associated relevant anatomy. * Computed tomography angiography can often identify dural fistula but lacks the sensitivity, specificity, and ability for treatment planning as with catheter angiography.

Answer 41

**4. Clear fluid from the nose** ## Footnote * Le Fort fractures may be associated with a cerebrospinal fluid (CSF) leak; Le Fort III fractures predispose the patient to CSF leak. * In patients with sinus fractures and suspected CSF leaks, IV antibiotics should be administered. * Controlling hemorrhage from the nose and oral cavity is also important and should be simultaneously performed by anterior packing. However, the control of epistaxis may be difficult. Immediate reduction of fracture should be performed if packing fails to control epistaxis. * Posterior nasal packing should be avoided because of the risk of skull base injuries.

Answer 42

**4. GH level after OGTT 4 months after surgery** ## Footnote * To assess for remission for acromegaly after surgery, IGF-1 level should be done. The timing is important. Immediate post- surgery IGF-1 levels are elevated due to their long half-life and can take at least 3 months to normalize. * In addition to checking IGF-1 levels, one can check a GH level after 75 g of glucose being administered. Some argue that checking GH levels after a normal IGF-1 level may not add additional information; however, up to 30% of patients can have discordant results. * A normal IGF-1 level and GH suppressed to less than 1 ng/mL after OGTT is indicative of remission. These levels should be checked at least annually as relapse can occur many years after remission. * Even though repeat imaging should be done after surgery, it should be done a minimum of 3 months after the surgery as it can take that long for the sterile compressed sponge and fat packing to be resorbed and not affect image interpretation assessing for disease recurrence.

Answer 43

**2. Cerebral angiogram** ## Footnote * The sign and symptoms in this patient are suggestive of a carotid-cavernous fistula. * A carotid-cavernous fistula (CCFs) is an abnormal shunt from the carotid artery to the cavernous sinus. * Trauma, such as basilar skull fractures, projectile or slash injuries, or iatrogenic injuries, accounts for 70% to 75% of all CCFs. * A cerebral angiogram is the gold standard test for diagnosing a CCF, which can show filling of the cavernous sinus through the fistula, drainage pattern of the fistula, and presence of reflux into cortical veins following an injection of CCA (common carotid artery), ECA, or ICA.

Answer 44

**3. PTEN** ## Footnote * Dysplastic cerebellar gangliocytoma (Lhermitte-Duclos disease) is often seen in the background of PTEN hamartoma tumor syndrome (Cowden syndrome). * The tiger-stripe appearance of dysplastic cerebellar gangliocytoma is due to the expansion of the internal granular layer from cellular replacement with abnormal ganglion cells. * Dysplastic cerebellar gangliocytoma is a WHO grade 1 lesion based on the 2021 WHO brain tumor classification schema. * Mutation in BRAF is commonly seen in other neuronal brain tumors.

Answer 45

**4. Hemorrhagic stroke** ## Footnote * Holmes tremor is characterized by resting or intention tremor of low frequency and high amplitude. It is extremely rare, and only a few hundred cases have been diagnosed since its discovery. * Pharmacological treatments include antiepileptics (levetiracetam, topiramate), dopamine agonists, anticholinergics (e.g.trihexyphenidyl), benzodiazepines, and botulinum toxin injections. Surgical options for refractory cases include thalamic stereotactic ablation, gamma-knife thalamotomy, and deep brain stimulation (DBS) in the thalamic ventralis intermedius nucleus and globus pallidus internus. * Surgical complications of thalamotomy include intracerebral hemorrhage, dystonia, and speech disturbance. * Surgical complications of DBS include intracerebral hemorrhage and foreign body implant infections.

Answer 46

**4. Left maxillary artery** ## Footnote * This patient is undergoing open reduction internal fixation (ORIF) of the left anterior maxillary sinus. * The blood supply to the maxillary sinus comes from branches of the maxillary artery: posterior superior alveolar artery, infraorbital artery, and the posterior lateral nasal artery. * The first step to controlling bleeding in the OR is generally packing and electrocautery. If this does not work, the next best step is ligation or embolization of the arteries supplying the surgical field. * The maxillary artery is a branch of the external carotid artery.

Answer 47

**4. Facetal instability** ## Footnote * The patient has a typical presentation of lumbar canal stenosis with neurological claudication. Spinal stenosis is a condition in which the nerve roots are compressed by a number of pathologic factors, leading to symptoms such as pain, numbness, and weakness. * The most recent theory suggests the facetal instability to be the pivotal point governing the pathogenesis of the lumbar canal stenosis. The facetal instability leads to compromised motion dynamics; therefore, the body compensates for the same with secondary compensatory mechanisms such as facetal hypertrophy, ligamental hypertrophy, and osteophytes formation. This leads to canal stenosis and, thereby, neurological claudication. * Risk factors are multifactorial. A detailed history of symptoms and physical exam is the initial evaluation of a patient with spinal stenosis. Diagnosis can be made through imaging with extended-release x-ray, CT, and MRI. Canal diameter reduced by less than 10 mm with a positive 'sedimentation sign' of the rootlets is a characteristic MRI finding. * Ligamental hypertrophy, osteophytes formation, and disc protrusion are now considered the compensatory chances following the facetal instability that compromise the supportive dynamics of the spine. Atherosclerosis of tibial arteries is seen in peripheral vascular disease.

Answer 48

**3. Radiation alone** ## Footnote * Radiation alone can be utilized in the setting of bilateral glomus jugulare tumors and can represent an adjunct to limited surgical approaches with associated subtotal resection. * Radiation modalities include standard fractionated radiotherapy and stereotactic radiosurgery. Standard fractionated radiotherapy requires multiple sessions while radiosurgery can be given in a single session providing focused radiation and, at the same time, sparring the vulnerable surrounding tympanic bone. * The middle ear examination will reveal a red mass that blanches with a positive pressure during pneumatic otoscopy. * Observation provides an excellent treatment alternative, as 65% of tumors remained stable or even regressed in size. Approximately 40% of tumors demonstrated growth at an average of 0.9 mm per year.

Answer 49

**2. It will likely resolve over the course of six weeks** ## Footnote * Most cases of lumbosacral radiculopathy are self-limited. Counseling is essential for patients with radicular symptoms since most cases are mild and will resolve within six weeks after the onset of symptoms. * Lumbosacral radiculopathy is very common. On average, 3 to 5% of adults will experience symptoms in their lifetime. Spontaneous improvement following a disc herniation or lumbar spinal stenosis is very high. * There are three categories of radicular symptoms and signs; mild, moderate, and severe. This is a case of mild radiculopathy. It is considered in a patient experiencing a sensory loss and pain without motor deficits. This has the best prognosis and most likely to spontaneously recover. * Bed rest has not been shown to effective in the treatment of lumbar radicular pain, and results of physical therapy have been shown to be inconclusive. Given mild symptoms patient will likely recover and not require surgery.

Answer 50

**1. Arrange emergency evacuation of the epidural hematoma** ## Footnote * Evaluation of airway, breathing, and circulation should precede the neurological evaluation, and their stabilization should be the priority. Another priority is to optimize perfusion and oxygenation to prevent hypoxia and hypotension. * Patients with epidural hematoma (EDH) should receive operative intervention; this includes craniotomy followed by evacuation of hematoma and cessation of intracranial bleeding. In general, patients with EDH greater than 30 mL in volume should receive surgical intervention regardless of the GCS score. * The presence of EDH is a true neurosurgical emergency; the time between neurologic deterioration and surgical intervention greatly influences the outcome. * After initial stabilization, an immediate CT scan of the brain should be obtained in order to decide whether prompt operative treatment is required. The patient must be stabilized prior to transfer to another facility.

Answer 51

**4. Transsphenoidal resection of mass followed by octreotide administration** ## Footnote * There are several treatment options for treating pituitary tumors. Tumors are classified as micro- or macroadenomas and need to have laboratory testing to determine if these are hypo or hypersecretory masses. 0.2% of pituitary masses are malignant carcinomas, and therefore no staging or grading system exists. * Somatotrophic macroadenomas are adenomas with an excess of growth hormone production. Insulin-like growth factor 1 (IGF- 1) elevation is very common and routinely tested early in the workup of a pituitary tumor and is followed by a growth hormone (GH) suppression test. All growth hormone-producing tumors, regardless of symptoms, require transsphenoidal surgical resection as first-line therapy. Somatostatin analogs, such as octreotide, are then used to suppress remaining tumor tissue, and can often require repeat surgery to remove 100% of the adenoma. * Macroadenomas that are found to be nonsecretory and do not cause and vision loss need to be followed with an MRI after 6 months of diagnosis. An increase in size or growth towards the optic nerves and chiasm should prompt consultation for surgical resection. Secretory adenomas almost always require medical, surgical, radiological, or a combination of them all at the time of diagnosis. * Stereotactic radiosurgery (SRS) is a form of radiological treatment with gamma rays. Radiological therapy is never done alone and only augments medical or surgical therapy.

Answer 52

**4. Radiotherapy, transcatheter embolization, pamidronate, and denosumab** ## Footnote * Aggressive spinal giant cell tumors (CTGs) are considered to be unresectable. * Radiotherapy is recommended for the spinal, sacral, or aggressive tumors when complete excision or curettage is impractical for any functional or medical reasons. * A trans-catheter embolization of the blood supply can be used for the unresectable GCTs (e.g., specific pelvic or sacral tumors). * Reports show that topical or systemic bisphosphonates like zoledronate or pamidronate can be used as a novel adjuvant therapy for GCT. Bisphosphonates induce apoptosis and limit the tumor progression by targeting the osteoclast-like giant cells

Answer 53

**4. Ilioinguinal, iliohypogastric, and genitofemoral** ## Footnote * The patient likely has chronic post-herniorrhaphy pain. Ilioinguinal and iliohypogastric cryoablation would be appropriate in this setting with or without the addition of genitofemoral. Pudendal nerve block would not be chosen in this setting. * The ilioinguinal nerve is smaller and courses caudad to the iliohypogastric nerve, both nerves course between the internal oblique and the transverse abdominis muscle. * When blocking or ablating the iliohypogastric and ilioinguinal nerves, a proximal target should be chosen prior to the nerve branching (close to where the nerves transverse the muscles near the iliac crest). * The injection of a small amount of fluid to hydro dissect the correct plane can assist with localization and reduce the chances of intramuscular injection/ablation.

Answer 54

**1. Spinal cord stimulator** ## Footnote * Spinal cord stimulator implantation has been shown in studies to be effective for failed back surgery syndrome (FBSS). This has been reported in large randomized trials. * Opioids and reoperation have been shown to be ineffective in FBSS treatment but are still commonly used. * Epidural steroid injections have been shown in some studies to be of benefit, but these studies are generally of weaker quality. * Repetitive use of opioids remains subpar as efficacy decreases chronically. Only spinal cord stimulator implants have been shown to mitigate low back pain from FBSS.

Answer 55

**2. Posterior decompression and C3 -C7 fusion** ## Footnote * The above vignette reveals a C5 fracture in an ankylosed spine. * Posterior decompression and instrumentation are indicated in this patient. * The posterior approach is easy and has the benefit of using long lever arm instrumentation. * Long lever-arm of instrumentation is preferred, which is not possible in the anterior approach.

Answer 56

**2. Vascular endothelial invasion** ## Footnote * Humid nasal cavity and sinuses make initial implantation favorable for fungal spores. * Necrosed tissue is the nidus for the growth and spread of fungi. * Invasion and erosion of bone lead to bone destruction that creates a direct path of transmission of fungi. * Rapid progression of rhinocerebral mucormycosis is due to vascular endothelial invasion and thrombosis, which leads to ischemia and tissue necrosis.

Answer 57

**4. 75% to 80%** ## Footnote * Epidural blood patches (EBPs) will likely resolve post-dural puncture headache (PDPH). * Most of PDPH's resolve spontaneously within 7 to 10 days. * There is a greater than 90% success rate with a second EBP if the first fails. * Typically 75% to 80% of PDPH's resolve rapidly with an EBP.

Answer 58

**3. No movement of the eyes** ## Footnote * The caloric reflex test is a component of an electronystagmography used to assess the patency of the vestibulo-ocular reflex. * The vestibulo-ocular test in a brain stem death will not show any conjugate movement of the eyeballs. * Normally, ice-cold water will suppress the firing of vestibular firing, thereby simulating head turn to the opposite side, resulting in the ipsilateral conjugate deviation of the eyes. * On the other hand, the warm water increases the vestibular firing and results in the contralateral conjugate deviation of the eyes.

Answer 59

**4. Endoscopic procedures** ## Footnote * Endoscopic third ventriculostomy is the most rational surgical strategy in the patient. * This allows for the histological confirmation of the lesion as well as CSF analysis for the tumor markers for proper stratification. * ETV also obviates the need for permanent shunt procedures in most cases of obstructive hydrocephalus. * Gross microsurgical resection may be obviated in selected few cases of pineal region tumors through radiation. VP shunting has many short and long-term complications such as infections and obstructions.

Answer 60

**3. Lateral medulla** ## Footnote * Lateral medullary syndrome (also known as Wallenberg syndrome) is a constellation of symptoms that occur due to a lesion or infarct in the lateral part of the medulla. * The lateral medulla includes the nucleus ambiguus, which primarily innervates the motor branches of cranial nerves IX and X. * Damage to the nucleus ambiguus causes dysphagia, hoarseness, and absent/reduced gag reflex. * Median medullary syndrome classically involves CN XII. Lateral pontine syndrome involves cranial nerve VII and causes ipsilateral Bell's palsy. Median pontine syndrome affects CN VI, which causes the ipsilateral eye to look down and towards the nose.

Answer 61

**1. Ceftriaxone and vancomycin** ## Footnote * Bacterial meningitis is caused by a bacterial infection of the meninges, resulting in inflammation. * Bacterial meningitis causes the following CSF profile: elevated opening pressure of 200-300 mmH2O, WBC >1000 cells/mm^3 with more than 80% PMNs, glucose 40 mg/dL, and protein >150 mg/dL. * Empiric treatment with ceftriaxone and vancomycin should strongly be considered if the diagnosis is going to be delayed. * Patients who are immunocompromised or older than 50 should also receive ampicillin.

Answer 62

**4. CT head** ## Footnote * Often in polytrauma cases, multiple specialties are involved, and the more obvious serious injuries take precedent. Any head injury is normally picked up in the primary or secondary survey. This appears to be a small scalp defect, and the seriousness of it may not have been appreciated initially. * A wound infection can be wet. But in this case, it is important to establish if the discharge is clear as a traumatic cerebrospinal fluid (CSF) leak is the concern. * The most important action is to order a CT head scan, or review one if previously done on admission, to view the bony windows in detail for a bony fracture or breach in the skull. The fluid can also be collected and sent off for beta-2-transferrin to confirm if it is CSF. * If a fracture with a CSF leak is found, surgical management of the CSF leak would take priority.

Answer 63

**1. Iron pigments** ## Footnote * The patient is having a cavernous angioma of the brain. Also because of their propensity to act as an epileptogenic focus CMs should always be considered in the workup of a patient with a seizure disorder, especially if the patient is aged 20-40 years. * The lesions also may vary in consistency from soft to hard depending on the degree of calcification and thrombosis. * The increased leakage of iron from hemoglobin is one reason that explains the high prevalence of seizures in patients who have cavernous angiomas. * The adjacent brain tissues appear gliotic and are usually yellow due to the leaked hemosiderin.

Answer 64

**4. Cervical dynamic (flexion-extension) imaging.** ## Footnote * The treatment of atlas fractures remains controversial, in part due to frequent occurrence of other cervical injuries in association such injuries. * Non-operative treatment consists of external orthoses or bracing and is often effective if the fracture is stable. This includes a hard cervical collar, halo vest, cervical traction, and Minerva jacket. * Before discontinuing the orthosis in these patients, dynamic cervical imaging is of utmost importance to rule out any chronic C1-C2 instability secondary to transverse atlantal ligament rupture. * The patients with instability at C1-C2 (dynamic cervical imaging) greater than 5 mm (at three months) need surgical C1-2 fusion, to ensure that there is no delayed worsening of displacement or neurological deficits.

Answer 65

**3. Pons** ## Footnote * The patient exhibits a syndrome called internuclear ophthalmoplegia (INO) which is due to a lesion in the medial longitudinal fasciculus (MLF). * MLF is a heavily-myelinated tract in the pons that allows conjugate eye movement by connecting the paramedian pontine reticular formation (PPRF), the abducens nucleus complex of the contralateral side to the oculomotor nucleus of the ipsilateral side. * In young patients, INO is most likely due to multiple sclerosis. In the elderly, it is more commonly caused by a brainstem stroke. * Bilateral INO is almost pathognomonic of a demyelinating disease such as multiple sclerosis.

Answer 66

**2. 0.1% of the population above 80 develop this condition** ## Footnote * The prevalence of probable iNPH is 0.2%-0.5% in those aged 70–79 years and increases beyond 5%-7% after 80 years of age. * The lumbar tap test is performed to obtain cerebrospinal fluid pressure, obtain a sample for analysis (normal in iNPH) and a large (30-40 ml) drainage to see if there is any improvement of symptoms to aid diagnosis and prognosis. A negative response does not necessarily indicate that a patient will not improve with shunting but reduces the chances of clinical success. * Additional testing includes external lumbar drainage for several days and radionuclide cisternogram in which a radioactive agent is injected and serial radiographic studies assess time to clear which is delayed in iNPH. * Surgeries involve ventriculoperitoneal shunt and lumboperitoneal shunt.

Answer 67

**2. Endoscopic cranial vault remodeling** ## Footnote * The patient has sagittal craniosynostosis with severe deformity features that have a surgical indication for which surgical treatment is the best option for this patient. * There are different types of surgical techniques for treating craniosynostosis. In this patient with 3 months of age in an experienced facility, endoscopic surgery is the best option since it decreases associated blood loss in comparison to open surgery. The addition of helmets post-operative has been associated with better outcomes. * More than for any other suture, endoscopic treatment of sagittal synostosis has proved to be very effective and is becoming the treatment of choice at many institutions. * Skull molding helmets are an option when the deformity is not severe, especially in patients where the deformity is not associated with craniosynostosis (ie. positional plagiocephaly). Observation is an option in patients with mild/subtle deformities without any associated signs/symptoms (ie. increased ICP)

Answer 68

**2. Central cord** ## Footnote * Upper motor neuron signs cause hyperreflexia, paresis, and sometimes paralysis. Upper motor neuron lesions can occur anywhere between the cortex and the spinal cord. In contrast, lower motor neuron deficits cause hyporeflexia. * Central cord syndrome is caused by damage to the central regions of the spinal cord. It is commonly elicited by hyperextension of the cord at the cervical level. * Central cord syndrome causes damage to the dorsal column tracts (i.e., fasciculus gracilis and cuneatus). Fasciculus gracilis has axons that represent the lower body, while fasciculus cuneatus has axons that carry touch information for the upper body. Because fasciculus gracilis is located medially, it has more axons within the central portion of the spinal cord. Therefore, patients with central cord syndrome will typically have deficits with touch sensation more in the lower body than the upper body. * Central cord syndrome causes damage to the lateral corticospinal tract. The lateral corticospinal tract homunculus has feet represented peripherally and the upper body represented centrally within the cord. Therefore, central cord syndrome would show upper body motor impairment more than lower body impairments.

Answer 69

**2. Pneumoventriculi** ## Footnote * Pneumoventriculi is a common cause of dry tap during ventriculostomy. * A breach in the air-locked system of the ventricular drainage bag causes a high incidence of air in the ventricular system. This can lead to a dry tap during ventriculostomy. * Other probable causes include head-up positioning of the patient during ventriculostomy. The inadequate cruciate incision at the dura can lead to subdural pneumocephalus, thereby altering the position of the ventricles due to the resultant brain shift. * The possibility of a collapsed ventricle is minimal because the external ventricular drain is also clamped for hours before ventricular-peritoneal shunting. Wrong trajectories, despite multiple attempts from an experienced surgeon, are a rare occurrence.

Answer 70

**2. Referral for physical therapy** ## Footnote * The patient is experiencing the phenomenon of central sensitization following traumatic acute back pain, which has become chronic. The initial management for this patient would be first to correct the underlying back pain. * Given this patient's pain is likely due to birth trauma, if the patient's mechanical back pain can be corrected, her discomfort may resolve completely. * The patient's acute pain became chronic after three months of duration. This lowered her threshold for pain, leading to central sensitization. To correct her central pain syndrome, the sacroiliac joint pathology must be corrected. The initial management for this case would be a trial of physical therapy. * If there is a failure to correct the origin of chronic pain, the best step in management for a patient with central sensitization would be a trial of antidepressants such as duloxetine. Given that she is considering pregnancy, medications should only be considered if she agrees to delay conception.

Answer 71

**4. Spread through Batson's venous plexus** ## Footnote * Along with lung cancer and multiple myeloma, prostate cancer is one of the top three malignancies associated with metastatic spinal cord compression. Metastatic spread of prostate cancer is hematogenous in nature. * Unlike other sources of hematogenous spread, pelvic tumors, including prostatic malignancies, are postulated to metastasize via Batson venous plexus, a network of valveless veins that shunts venous blood to the spinal epidural venous plexus during a Valsalva maneuver such as sneezing, coughing, or bearing down. * Patients with metastatic spinal cord compression most commonly present with isolated back pain. Any patient with active malignancy and new-onset back pain should be evaluated for the possibility of metastatic spinal disease. * Direct extension of paraspinal malignancy into the spinal canal is most commonly seen with lymphoma, which accesses the spinal canal via neural foramina.

Answer 72

**4. Ruptured intracranial aneurysm** ## Footnote * Sudden onset of very severe headache with photophobia is the classic presentation of SAH (subarachnoid hemorrhage) in which 85 percent of the time cerebral angiography (CT or MR) will reveal one or more aneurysms. * Most neurosurgeons recommend immediate surgery to avoid complications of rebleeding and treat vasospasm more aggressively. Surgical options today increasingly include endovascular percutaneous options. * SAH is graded on Hunt and Hess scale I-V with I being minimum symptoms and V being deep coma with poor prognosis. * AVMs are also possible causes of SAH, but much less common than cerebral aneurysms.

Answer 73

**3. A pulsatile red middle ear mass behind the right tympanic membrane** ## Footnote * The most common finding on physical examination of a glomus jugulare is a pulsatile red middle ear mass behind an intact tympanic membrane during the otoscopic examination. * The tympanic membrane can show increased vascularity, and with an inferiorly based red ear mass, the characteristic rising sun appearance is demonstrated. * Sometimes, the tympanic portion of the tumor may erode into the ear canal, resulting in bloody otorrhea. * Because of their vascularity, pulsatile tinnitus is often the presenting symptom. Hearing loss occurs in 50% of these individuals and the tumors also have the potential to secrete catecholamines.

Answer 74

**1. Perform a straight leg raise test to assess a possible L5 nerve root irritation** ## Footnote * Based on the clinical scenario, the best initial step is to perform a straight leg raise test, as this maneuver could help assess the possibility of L5 nerve root irritation. * The patient is probably affected by a lumbar disc herniation. The most important step is to evaluate nerve root irritation through the straight leg raise test. * The presence of leg pain irradiated from the gluteal region to the foot may indicate a nerve root compromise in the lumbosacral region; the clinical examination is the most crucial step, motor and sensitive exam and nerve irritation maneuvers such as straight leg raise test are the most important tools at this moment. * Based on this clinical scenario, the most common cause is a lumbar disc herniation that compromises the L5 nerve root; the next step is to perform a straight leg raise test to assess L5 nerve root irritation. MRI is an important imaging study in this case but is not the next step. Usually, MRI is indicated when there is a motor weakness or after six weeks of conservative management. CT scan is not typically requested in this case. NSAIDs are important in the management of this case. However, the next step is to perform the Straight leg raise test.

Answer 75

**2. Non-dominant temporal lobe onset seizures** ## Footnote * The description is typical of temporal lobe seizure. Lip-smacking is probably the most common type of oroalimentary automatism observed, but other forms of oroalimentary automatism like repetitive swallowing or chewing may also be seen. * Preserved speech and comprehension indicate nondominant temporal lobe seizure; however, speech arrest is not a reliable localization finding. * Temporal intermittent rhythmic delta activity (TIRDA) has a strong correlation with temporal lobe onset seizures. * A normal brain MRI does not rule out the possibility of seizure.

Answer 76

**1. S100** ## Footnote * Chordomas are benign but locally aggressive tumors with high recurrence rates which arise from the notochord. * Chordomas are classically described as lobules or cords of physaliferous cells separated by fibrous septa and the presence of extensive myxoid stroma. * There is a high propensity for chordomas to seed along biopsy tracts or recur locally. * Chordomas are S100 positive and negative for CK7, CK20, and chromogranin.