Section 1 Flashcards

Question

The husband of a 73-year-old female calls emergency medical services (EMS) after noticing slurred speech and right-sided weakness in his wife. EMS personnel evaluates the patient and suspects a possible large vessel occlusion stroke using the Los Angeles Motor Scale. The patient’s last known normal was 30 minutes ago. According to the American Heart Association and American Stroke Association ‘Severity-Based Stroke Triage Algorithm for EMS’, to which of the following facilities should the patient be transported? 1. The closest acute stroke-ready hospital 45 minutes away 2. The closest primary stroke center 55 minutes away 3. The closest comprehensive stroke center 60 minutes away 4. The closest hospital regardless of stroke center certification

Answer 1

**3. The closest comprehensive stroke center 60 minutes away** ## Footnote * Eligible patients with a large vessel occlusion may benefit from mechanical thrombectomy. * Several stroke scales can be used by emergency medical services (EMS) to help identify possible large vessel occlusions including the Los Angeles Motor Scale (LAMS), Cincinnati Prehospital Stroke Severity Scale (CSTAT), Rapid Arterial Occlusion Evaluation (RACE), and Field Assessment Stroke Triage for Emergency Destination (FAST-ED). * The 2018 American Heart Association and American Stroke Association guidelines state, “It remains unknown whether it would be beneficial for emergency medical services to bypass a closer IV tPA-capable hospital for a thrombectomy-capable hospital.” * The American Heart Association and American Stroke Association ‘Severity-Based Stroke Triage Algorithm for EMS’ recommends patients with suspected large vessel occlusion and last known normal within 6 hours be transported directly to nearest thrombectomy-capable stroke center or comprehensive stroke center, as long as bypass does not add more than 15 minutes to transport and does not preclude use of IV tPA.

Answer 2

**4. Inability to abduct the right eye** ## Footnote * This patient has a cavernous sinus thrombosis (CST) or the formation of a blood clot within the cavernous sinus. * Cavernous sinus thrombosis (CST) may be either septic or aseptic in etiology. Septic causes include spreading infections from the ears, nose, sinuses, or teeth. This patient had a sinus infection, predisposing him to a CST. Aseptic causes are typically traumatic in nature. * Cavernous sinus thrombosis may occur due to a superficial infection of the face due to the anastomosis of the pterygoid venous plexus via the inferior ophthalmic vein. * Cavernous sinus thrombosis commonly affects the cranial nerves of the cavernous sinus, nerves III, IV, V(1), and VI. Of these, the abducent nerve is the most commonly affected, which would result in the inability of the eye to abduct.

Answer 3

**2. Posterior cerebral artery** ## Footnote * Subdural hemorrhage is most often due to tearing of bridging veins. This can occur secondary to acute high-speed impact to the skull. The geriatric population is at higher risk due to brain atrophy. * Herniation can occur in patients who have large hematomas. With a transtentorial herniation, a cerebral infarct occurs when the posterior cerebral artery is compressed. * A transtentorial herniation will also cause compression of the oculomotor nerve and dilatation of the ipsilateral pupil and decreased reactivity. * With a subfalcine herniation, the cerebral infarct occurs because of compression of the anterior cerebral artery.

Answer 4

**1. Pallister-Hall syndrome** ## Footnote * Hypothalamic hamartomas are associated with rare genetic disorders such as Pallister-Hall syndrome. * Pallister-Hall syndrome is an autosomal dominant disorder caused by a mutation to the GLI3 gene which classically presents with hypothalamic hamartoma and polydactyly. * Pallister-Hall syndrome is also associated with other abnormalities such as hypopituitarism, growth hormone deficiency, bifid epiglottis, and genital hypoplasia. * Pallister-Hall syndrome is typically diagnosed in early childhood presenting with seizures, central precocious puberty due to hypothalamic hamartomas, and polydactyly.

Answer 5

**4. Meningeal myelomatosis** ## Footnote * Back pain is a common complaint of patients with multiple myeloma due to the development of new lesions or pathological fractures. The possibility of vertebral infections should also be considered. Both disease and treatment-related complications can lead to infections. Chemotherapy with high-dose corticosteroids may be a predisposing factor for vertebral infections. Radiological appearance is similar to vertebral osteomyelitis and discitis. * Spinal cord compression can be seen in 20% of multiple myeloma cases during the disease. Neurological symptoms may also occur due to meningeal involvement. Meningeal myelomatosis is a rare finding. They can present as altered mental status, lower limb weakness, cranial nerve palsies, headache, speech disorder, or features of meningismus. Diagnosis is usually made by finding myeloma cells in cerebrospinal fluid. The median survival is one month in those who had no initial response to therapy while it is five months in those who showed remission on initial treatment. * CT findings of meningeal myelomatosis have been reported as a peripheral markedly hyperdense mass with associated edema and mass effect. MRI shows heterogeneous to homogenous intensity on T2 of extra-axial mass and diffuse enhancement on post-contrast T1 images. Abnormal leptomeningeal enhancement along sulci and cranial nerves. * In conclusion, meningeal myelomatosis is a rare form of multiple myeloma and is more aggressive and resistant to treatment.

Answer 6

**3. MRI** ## Footnote * Although this patient presents with risk factors for failed back surgery syndrome (FBSS), psychiatric comorbidity, history of failed back pain surgery, litigation, “red flag” symptoms must still be evaluated in the patient presenting with lower back pain. * This patient’s saddle anesthesia and urinary incontinence are concerning for cauda equina syndrome and should be urgently diagnosed with an MRI and likely managed with surgery. * Red flags should always be ruled out before addressing chronic symptoms from FBSS. * Clinical presentations such as saddle anesthesia and urinary continence require emergent surgery. Failure to recognize this presentation can result in irreversible nerve damage.

Answer 7

**1. Desmopressin** ## Footnote * Desmopressin is used in patients suffering from diabetes insipidus. * A rare side effect of desmopressin is the occurrence of thrombocytopenic purpura. * Patients with a history of thrombocytopenic purpura in the past are more at risk for developing purpuras when on desmopressin. * Desmopressin acts as an ADH analog in patients suffering from diabetes insipidus to help retain water in these patients.

Answer 8

**2. C1-C2 facetal joint instability** ## Footnote * The above case scenario is classical for basilar invagination. * Currently, the most logical pathological genesis of the condition is the C1-C2 facetal joint instability thereby allowing for the odontoid peg to migrate upwards into the foramen magnum. * Studies have confirmed that C1-C2 Facetal distraction with the use of spacer and C1-C2 fusion alone reverses the pathological changes seen in the basilar invagination. * Though previously many etiological factors were considered for the condition, facetal instability is currently the most favored one.

Answer 9

**3. Non-steroidal anti-inflammatory medication** ## Footnote * First line treatment for an annular disc tear is nonsteroidal anti- inflammatory medications and low-impact physical therapy. * Annular disc tears can be symptomatic or asymptomatic. * Chronically an annular disc tear can lead to granulation tissue accumulation which can cause nerve irritation and radiculopathy. * A transforaminal corticosteroid injection can be considered for annular disc tear if the patient fails an adequate trial of more conservative treatment.

Answer 10

**2. Epidural hematoma** ## Footnote * Cauda equina syndrome is a known complication of lumbar puncture procedures involving direct trauma or an epidural hematoma although the most common cause overall is disk herniation. * Medicolegal litigation is high in these syndromes due to missed diagnoses and the high degree of residual functional impairment. * Surgical decompression within 48 hours is paramount in acute cauda equina and conus medullaris syndromes. * Saddle anesthesia is one of the most common presenting symptoms.

Answer 11

**1. V2 segment of the vertebral artery** ## Footnote * Segments of the vertebral artery include V1 - origin to C6 transverse foramen, V2 - C6-C2 transverse foramen, V3 - C2 transverse foramen to dura, V4 - intradural vertebral artery ending at basilar artery. * The V2 segment of the vertebral artery is the structure most at risk in a Hangman fracture due to its close relationship of the C2 transverse foramen and the pars interarticularis. * Often a fracture may extend to the transverse foramen, and thus a CT angiogram of the neck must be obtained for the evaluation of the vertebral artery. * The superior cervical ganglion is located nearby but unlikely to be injured in a Hangman fracture. While not impossible for the V3 segment to be injured, it is more likely for the V2 segment to be injured at the level of the transverse foramen of C2. The cervical internal carotid artery is unlikely to be injured from in the setting of a Hangman's fractures.

Answer 12

**1. Worsening bowel and bladder function** ## Footnote * The child in this vignette is experiencing a well-known complication of spina bifida, a tethered cord. * These patients present with pain in back and legs, increased spasticity, worsening of gait, increased scoliosis, and problems with bowel and bladder function. * Providers should have a high index of suspicion for this complication in patients with a history of spina bifida. * Facial weakness is not a complication of spina bifida. Neck rigidity may be seen with meningitis.

Answer 13

**3. The superior half of the medulla oblongata** ## Footnote * The glossopharyngeal nerve CN IX is responsible for the afferent portion of the gag reflex, taste on the posterior 1/3 of the tongue, and innervation of the stylopharyngeus muscle. * The nucleus ambiguus is located in the superior medulla oblongata and gives rise to the sensory nerves of CN IX and is a synapse point for the motor fibers of CN IX as they descend from the cortex. * The medulla oblongata is the lowest portion of the brainstem and has 4 cranial nerves that arise from it, CN IX-XII. * Only one of the cranial nerve motor nuclei in the medulla oblongata is located medially, the hypoglossal nerve, cranial nerve XII.

Answer 14

**3. Vertebral fusion** ## Footnote * Spinal fusion surgery can loosely be described as the fusing two or more of a patient's vertebral bodies together. Studies have shown patients undergoing surgery have decreased levels of pain in both short and intermediate follow-up after surgery. However, there are limited disability outcomes for patients undergoing vertebral fusion. * There has been a recommendation for patients with low back pain greater than one year in duration and nonradicular in nature, to undergo spinal fusion as a reasonable treatment option, despite having inadequate evidence effectiveness in the long term. * Bracing would be a potential option for the acute or subacute phase of treatment for pain control in an osteoporotic compression fracture. However, this can lead to atrophy of the core musculature with prolonged use. It also shows limited efficacy with long term use compared to a spinal fusion surgery, which has been shown to have some efficacy in the short term and intermediate follow up. * Steroid injections into the facet joint have been shown to have limited evidence for the use. They have not been shown to be effective to treat low back pain secondary to osteoporotic compression fractures. Disc dissection surgery has not been shown to be a reasonable treatment option for osteoporotic compression fractures. There is limited evidence to be beneficial patient's chronic low back pain.

Answer 15

**1. CT of the head, thorax, and abdomen** ## Footnote * The patient has two signs of Waddell triad and has a low hematocrit. The abdomen, especially the retroperitoneum, can be a source of significant bleeding. * The Waddel triad includes trauma to the head, abdomen, thorax, and lower extremities with a car versus pedestrian impact. The full workup includes a whole-body CT scan, which can rapidly identify injuries to the brain (intracranial hemorrhage), chest, abdomen, and presence of any fractures. This is usually done as part of the tertiary trauma survey, which follows the secondary survey (a focused history and physical exam). * If the patient has low hematocrit and there is no fracture, and the chest is clear, think about possible bleeding in the abdomen. * The size of the child and the type of car can help determine injury patterns. Injury patterns will vary depending on the country and what side of the road a driver is on when a pedestrian is impacted by the vehicle. Children ages 1 to 5 years may be knocked down and dragged under the vehicle. The front bumper causes injuries to the femur, chest, abdomen, and pelvis. Children ages 3 to 11 years are prone to bumper impacts that fracture femurs and chest injuries from fenders or the hood. A child may be thrown onto the hood and hit the windshield, causing head and facial trauma. Another insult to the head occurs when the car stops abruptly, and they are thrown off the hood and onto the road striking their head again. Suspect multiple injuries with a car versus pedestrian impact. When taking a history, determine speed, the point of impact, and any safety gear worn at the time.

Answer 16

**1. MRI spine** ## Footnote * MRI is the preferred imaging modality to determine the fracture acuity in terms of bone marrow edema. * MRI will show T2 signal hyperintensities, mostly seen on STIR imaging, in cases of an acute fracture. * MRI also provides the anatomic status of the spine as well as the integrity of the soft tissues, thereby enabling rational therapeutic decision-making. * Elevation of the trabecular attenuation was the only CT spine variable showing high specificity in predicting acute fracture while comparing to MRI spine.

Answer 17

**1. Direct admission to the hospital, urgent spinal surgery consultation** ## Footnote * This case describes cauda equina syndrome. It is a surgical emergency. It is a severe form of lumbar radiculopathy. The patient’s history and physical is consistent with compression of the cauda equina, likely secondary to a bilateral fracture of the pars interarticularis causing significant slippage and compression of the nerve roots, including S1. * For cauda equina syndrome, operative decompression is recommended within twelve hours after the onset of symptoms. * The best results for prevention of neurological sequelae would be surgical intervention within six hours after the onset of symptoms. An urgent spinal surgery consultation is warranted. * Moderate to severe radicular symptoms without concern for cauda equina syndrome does warrant an urgent MRI. However, given the time-sensitive nature of the treatment of possible cauda equina syndrome, immediate consultation of spinal surgery would be the first choice in management. The management of an osteoporotic fracture without neurological symptoms with close follow up would be an acceptable treatment option. Conservative management and a trial of NSAID's would be appropriate for a patient with mild radicular back pain and without neurological symptoms.

Answer 18

**2. Loss of abduction-adduction of fingers** ## Footnote * The clinical vignette describes a case of syringomyelia with type 1 Chiari malformation. The clinical vignette describes a case of syringomyelia with type 1 Chiari malformation. Segmental dissociated sensory loss of pain & thermal sensation with spared tactile, joint position & vibratory sense, leads to frequent finger “burns” as described the question. * Increase in thoracoabdominal pressure (Valsalva maneuver, coughing, straining) causes engorgement of spinal epidural veins leading to “sloshing” of syrinx fluid and expansion of syrinx cavity. This is due to Williams theory of craniospinal pressure dissociation. This is seen clinically as a headache and neck-pain that exacerbates with Valsalva maneuver. * Cerebellar and brain-stem compression also manifests as “down-beat nystagmus” which can be elicited by asking the patient to look down-and-out. A pathological upward drift of gaze followed by corrective downward saccade is seen. Downbeat nystagmus is most commonly due to structural pathology at cervicomedullary junction. Antiepileptic drugs can also cause this. However, the patient has no history of any drug consumption. * Involvement of anterior horn cells leading to paralysis of intrinsic muscles of hands and claw hand deformity is a classic of syringomyelia. Claw hand is due to paralysis and atrophy of interossei muscles responsible for abduction-adduction of fingers. Palmar interossei are responsible for ADduction of fingers (PAD); Dorsal interossei is responsible for ABduction of fingers (DAB). Atrophy of these muscles leads to prominent hollowing between thumb and forefinger.

Answer 19

**3. Cavernous sinus** ## Footnote * This patient's history and physical exam findings are suggestive of trochlear and oculomotor nerve involvement. * The only answer choice that supports involvement of multiple cranial nerves is cavernous sinus. This patient most likely has cavernous sinus syndrome due to mass effect from a pituitary tumor. * The cavernous sinus is home to CN III, IV, V1, V2, and VI. In a patient presenting with a constellation of cranial nerve dysfunctions, involvement of the cavernous sinus should be considered. * Lesions at the trochlear nucleus, decussation of the trochlear nerves, or below the inferior colliculus will most likely result in isolated trochlear nerve palsy.

Answer 20

**3. The stage of the injury** ## Footnote * Morita et al. and Katoh et al. attempted to assess the relationship between bony healing and the radiographic stage of the pars lesion. They classified the pars lesions into early, progressive, and terminal stages based on either plain radiographs or CT. They found much higher healing rates in early-stage lesions with very little or no healing in terminal-stage defects. * The early stage was defined as a hairline defect of focal bony absorption. The progressive stage was defined as a wide defect with the presence of small fragments. The terminal change was defined as sclerotic change. * Healing was noted in 73% of the early stage, 38.5% of the progressive stage, and none of the terminal defects. * A higher prevalence of spondylolisthesis was found in white adolescent gymnasts at the L5 level. But neither of these characters is relevant in predicting bony healing capacity.

Answer 21

**2. The 24 hour Glasgow coma scale score** ## Footnote * The prognosis of patients with closed head trauma is dependent on many factors including 1) severity of injury 2) type of injury 3) age of the patient and 4) comorbidity. * The Glasgow coma score (GCS) score at 24 hours is the strongest predictor of cognitive recovery at 24 months after injury, especially in patients with severe head injury, * Other factors that can predict prognosis include the use of antithrombotics, the need for surgery during admission, and neurological status on admission. * Pupillary function before and after the injury can also predict prognosis. Those who do not regain pupillary function usually remain in a vegetative state. Duration of fever is also noted to be associated with a negative prognosis.

Answer 22

**3. Patient’s has a surgical history of transplant and is receiving immunosuppressive therapy** ## Footnote * Surgery and antibiotics are the mainstays of treatment for intracranial abscesses. However, according to the Undersea and Hyperbaric Medical Society, adjunct hyperbaric therapy can be used in poor surgical candidates, patients where surgery is contraindicated, and in patients who deteriorate despite antibiotic and surgical therapy. * Past medical history can play a role in the decision to use adjunct hyperbaric therapy for the treatment of intracranial abscesses. According to the Undersea & Hyperbaric Medical Society, hyperbaric therapy should be considered in immunocompromised patients. * Imaging can play a role in deciding if hyperbaric oxygen therapy should be used to treat an intracranial abscess. According to the Undersea and Hyperbaric Medical Society, adjunct hyperbaric therapy can be used in patients with multiple abscesses or if the abscesses are located in a deep or dominant location. * Lab values, microbiology results, and neurologic function should not be used in a clinician's decision to use hyperbaric oxygen therapy for the treatment of intracranial abscesses.

Answer 23

**1. Reduced hippocampal volume with increased T2 signaling** ## Footnote * Reduced hippocampal volume and increased T2 signaling are often seen in mesial temporal lobe epilepsy (m-TLE), the most common form of refractory epilepsy. Mesial TLE with hippocampal sclerosis (mTLE-HS) is a subtype of mTLE, affecting the hippocampus primarily and neighboring limbic (or mesial) structures. It is the most common source of focal epilepsy and possesses distinctive EEG and neuro-imaging characteristics. About 48-56 percent of cases of mTLE-HS are bilateral, and volumetric analysis by experienced interpreters may be necessary for diagnosis. * Hippocampal sclerosis is often refractory to the use of antiepileptic drugs (AEDs). * Amydalohippocampectomy and anterior temporal lobectomy are the two most common surgical procedures performed for m- TLE. * Although mesial temporal lobe epilepsy with hippocampal sclerosis is often refractory to multiple AEDs, it has a higher relative risk reduction with temporal lobe surgery.

Answer 24

**2. Metastatic workup and spine surgery consultation** ## Footnote * In patients with a history of cancer and acute back pain, metastasis should be considered as one of differential diagnosis. * Metastasis spine tumors are the most common cancer in the spine. * X-ray findings for concern for metastasis should be further investigated using CT, PET scan, or MRI. * An isolated vertebral mass should be biopsied prior to definitive treatments.

Answer 25

**4. Phenol is hyperbaric relative to cerebrospinal fluid, and if using 7% phenol, the painful side should be dependent** ## Footnote * Phenol is hyperbaric in relation to cerebrospinal fluid (CSF), and this principle can be utilized by positioning patients with the painful side dependent. * Alcohol is hypobaric in relation to CSF; hence, to facilitate the spread of alcohol to the target area, the patient should be positioned lateral decubitus with the painful side uppermost. * The concentration of alcohol should be at least greater than 33%, but clinically mostly 80% alcohol is used. * Typically, alcohol causes a burning sensation on injection, while phenol has local anesthetic properties and often causes a warm sensation. The total volume of alcohol to be administered should not exceed about 1.0 ml.

Answer 26

**1. Fluid supplementation with isotonic saline** ## Footnote * Cerebral salt wasting syndrome is characterized by hyponatremia with elevated urine sodium in a hypovolemic state, as evidenced by decreased skin turgor, hypotension, decreased central venous pressure, and elevated hematocrit. * Syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is characterized by hyponatremia with elevated urine sodium in a hypervolemic to euvolemic state. * Cerebral salt wasting syndrome can be differentiated from SIADH by fluid status. In cerebral salt wasting, the patient is hypovolemic. In SIADH, the patient is hypervolemic to euvolemic. * Cerebral salt wasting syndrome is treated with fluid resuscitation. SIADH is treated with fluid restriction.

Answer 27

**3. Anterior inferior cerebellar artery (AICA)** ## Footnote * The posterior cerebral artery (PCA) is the last branch of the basilar artery, and it becomes part of the circle of Willis. Any infarction or aneurysms affecting the PCA will affect the occipital lobe of the cerebral cortex leading to contralateral hemianopia with macular sparing. * The posterior inferior cerebellar arteries (PICA) which supply the rostral lateral medulla, is one of the major branches of the vertebral arteries. Infarction or an aneurysm involving the PICA will lead to a lateral medullary syndrome. While these patients may present with vomiting and vertigo due to the involvement of the vestibular nuclei, they may also have dysphagia, hoarseness, and decrease gag reflex due to the involvement of the nucleus ambiguus. * This patient presentation is consistent with an aneurysm in the cerebellopontine angle and the compression adjacent nerve nucleus. As reported in the literature, aneurysms of the posterior fossa account for 8% to 12% of all a cerebral aneurysm, with aneurysms of anterior inferior cerebellar artery accounting for about 1% to 2% of all aneurysms. The most common site of an aneurysm formation is the basilar (BA)-anterior inferior cerebellar artery junction, with rare cases reported to originate from the distal anterior inferior cerebellar artery. Majority of mass effects seen clinically in the cerebellopontine angles are due to acoustic schwannoma. Patients with an anterior inferior cerebellar artery aneurysm located peripherally may have a cerebellopontine angle mass effect. These patients may present with a sudden hearing loss, tinnitus, vertigo due to the involvement of the labyrinthine artery or vestibular nerve, facial paresis due to the involvement of the facial nerve, gait ataxia, dysmetria due to the involvement of the middle cerebellar peduncle. The spinal trigeminal nucleus and spinothalamic tract may also be affected leading to decrease pain and temperature from the contralateral body and ipsilateral face. A complication of this condition may be subarachnoid hemorrhage, acute severe headache, nausea, vomiting, or sudden coma. * Lesions involving the anterior spinal artery will lead to medial medullary syndrome, with mostly the lateral corticospinal tract, the hypoglossal nerve, and the medial lemniscus affected.

Answer 28

**4. Revision surgery should be expected to have an equal likelihood of improving radicular pain and postoperative functional status as compared to primary surgery** ## Footnote * Severe radicular leg pain is, in many cases, what causes functional impairment in patients with lumbar disc herniation. Thus, a higher likelihood of improvement in radicular symptoms, though the lower likelihood of improved functional status, makes this a poor choice. Furthermore, recent studies have demonstrated that primary and revision discectomy have similar outcomes improvement of radicular leg pain and postoperative functional status. * Revision discectomy has equal outcomes to primary surgery with regards to postoperative functional status. * In general, discectomy has a lower likelihood of improving back pain than radicular pain. Revision surgery outcomes have not been proven to be superior to primary surgery with regards to functional status. * High-quality data demonstrate that primary and revision surgery have similar outcomes with respect to improvement in radicular leg pain and postoperative functional status.

Answer 29

**3. Endoscopic third ventriculostomy** ## Footnote * The patient with ventriculitis will have a high risk of shunt failure following shunt infection. Endoscopic third ventriculostomy is advantageous to the fact that there is no need for shunt placement. * Endoscopic third ventriculostomy creates a new channel between the floor of the third ventricle and the pre-pontine cisterns, thereby ideal for the management of obstructive hydrocephalus. * The patency of the endoscopic third ventriculostomy depends upon the size of the stoma and the flapping pattern of the stomal margins. * The antibiotic-impregnated shunt has minimal risk of shunt infection compared to other normal shunts. The colonization of the shunt by the slime formed by the bacteria is higher in patients previously treated for ventriculitis.

Answer 30

**3. Spinal dural arteriovenous fistula** ## Footnote * Spinal dural arteriovenous fistulas are the most common vascular malformation of the spinal cord and are thought to be an acquired disease. They predominantly affect middle-aged males, are unrelated to trauma, and usually present as progressive myelopathy worsened by prolonged standing, exercise, singing, or position changes. * They are not located within the cord parenchyma, rather they tend to form on the dorsal surface of the spinal cord between branches of a radicular artery and a radicular vein. They do not frequently cause hemorrhage. * With the feeding artery directly draining into the radicular vein, the vein becomes arterialized and tortuous with increased venous pressure and hyalinized thickened walls. This pressure backs up into the perimedullary venous plexus on the surface of the cord and ultimately within the intramedullary radial veins. Venous hypertension results over time, causing decreased perfusion of the cord parenchyma, cord edema, decreased arterial perfusion, ischemia, and hypoxia. Over time, this manifests as progressive myelopathy. * MRI is diagnostic and usually shows hyperintensity with peripheral sparing (representing cord edema), serpentine and dilated intervertebral veins, along with flow voids within engorged perimedullary venous plexus. Flow voids are seen with T2 weighted images and refer to the loss of MRI signal in flowing fluids such as blood, CSF, and urine. It is related to the velocity of moving protons within the flowing fluid.

Answer 31

**2. Atlanto-axial subluxation** ## Footnote * Atlanto-axial subluxation (Grisel syndrome) is a rare but extremely important complication of adenoidectomy that carries significant morbidity if not promptly recognized and treated. * Although its pathogenesis is not fully understood, one widely accepted hypothesis is that the spread of infection from the posterior pharynx through the periodontoid venous plexus produces pathological laxity of the supporting atlantoaxial ligaments. This ultimately leads to atlantoaxial joint instability and subluxation. * Risk factors include pre-existing atlantoaxial instability, more commonly seen in individuals with Down syndrome, and excessive use of monopolar suction diathermy. * Severity is graded using the Fielding classification with stepwise management ranging from bedrest and analgesia to immobilization and neurosurgical intervention. A neurosurgical opinion must always be sought.

Answer 32

**1. Anterior cingulate cortex** ## Footnote * Anterior cingulate cortex infarction produced by injury or vasospasm of the anterior cerebral artery is the most common cause of abulia minor. * Unilateral anterior cerebral artery lesions produce transient abulia often associated with contralateral motor neglect (because of damage to the medial premotor area). * Bilateral lesions in the medial frontal lobes, basal ganglia, supplementary motor areas, caudate nuclei, and cingulate gyri lead to persistent abulia. * Bilateral lesions at or rostral to the meso-diencephalic junction or bilateral damage to the frontal lobes can lead to abulia major.

Answer 33

**4. 24 mm colloid cyst with large lateral ventricles** ## Footnote * A patient with hydrocephalus from a colloid cyst should receive treatment. * Small colloid cysts which are asymptomatic may be watched with serial imaging in certain circumstances. * Larger colloid cysts are more difficult to remove via an endoscopic approach and can lean the surgeon to chose an open approach. * A patient with ventriculomegaly provides a larger working corridor (the enlarged ventricles) and thus can make transcortical or endoscopic approaches easier for removel of the colloid cyst.

Answer 34

**4. Extramedullary hematopoiesis** ## Footnote * Extramedullary hematopoiesis occurs in patients with thalassemia and chronic hemolytic anemias as a compensatory mechanism. It typically occurs in sites such as the spleen, liver and adrenal glands. It has been reported to occur in the spinal canal, causing compression of the spinal cord and its associated structures. * A high index of suspicion must be kept for cauda equina and conus medullaris syndromes (CES/CMS) in patients presenting with urinary or bowel retention or incontinence, as these can be the only presenting complaints. * Laminectomy with evacuation of the hematopoietic tissue would be the appropriate treatment to decompress the cauda equina in this case. * Fungal abscesses have also been reported as rare causes of CES/CMS.

Answer 35

**3. 97%** ## Footnote * The intracerebral hemorrhage (ICH) score predicts 30-day mortality based on patients with non-traumatic intracerebral hemorrhage. * The score is based on Glasgow coma score (GCS), age, the volume of hemorrhage, intraventricular hemorrhage, and infratentorial origin of hemorrhage. * The point distribution is GCS 13 to 15 is 0 points, GCS 5 to 12 is 1 point, GCS 3 to 4 is 2 points; age 80 or greater is 1 point, ICH volume 30 mL or more is 1 point, intraventricular hemorrhage is 1 point, and infratentorial origin of hemorrhage is 1 point. * 30-day mortality is 0% for 0 points, 13% for 1 point, 26% for 2 points, 72% for 3 points, 97% for 4 points, 100% for 5 points, and assumed to be 100% for 6 points.

Answer 36

**1. The consolidation of memory, and the procession of emotional responses** ## Footnote * Mesial temporal lobe epilepsy is often refractory to the use of antiepileptic drugs. In these instances, a surgical evaluation may be considered. The two more common surgical procedures performed for mesial temporal lobe epilepsy are anterior temporal lobectomy (ATL) and amygdalohippocampectomy (AH). ATL involves the resection of a significant portion of the anterior temporal lobe in addition to mesial structures, whereas AH offers a more selective approach, preserving a greater volume of cortical tissue. * An amygdalohippocampectomy involves the resection of the amygdala and part of the hippocampus; these structures are mesial structures which are considered to be components of the limbic system. The amygdala and hippocampus are involved in emotional perception as well as the consolidation of memory. * There are electrophysiological and functional imaging data that support the proposal that the majority of temporal lobe seizures originate from mesial temporal lobar structures. Although ATL is successful at reducing the ictal frequency, the greater cortical volume resected in this procedure increases the likelihood of resultant neurocognitive dysfunction, whereas, in comparison, AH may provide equal rates of ictal control, with lesser neurocognitive decline. * There are three major approaches to amygdalohippocampectomy are transylvian, transcortical, and subtemporal. These procedures require expertise in microsurgical techniques, as well as familiarity with the complex anatomy in this region.

Answer 37

**4. IV metronidazole and cefepime** ## Footnote * With any infection, the appropriate antibiotic choice is based on the most likely organism implicated in the infection, bioavailability, and tissue penetration. Chronic otitis media can be caused by Pseudomonas aeruginosa or anaerobes. * Of the choices listed, only metronidazole has adequate penetration into the cerebrospinal fluid and it covers penicillin- resistant anaerobes. Cefepime or ceftazidime is administered to treat for P. aeruginosa. Brain abscess is a serious infection and requires parenteral administration. * The concentration of metronidazole in the cerebrospinal fluid is similar to that in plasma. * Common side effects including headache, metallic taste, nausea, vomiting, and diarrhea. Uncommon side effects include peripheral neuropathy or a disulfiram-like reaction with alcohol.

Answer 38

**3. Immediate incision and drainage and spinal decompression** ## Footnote * Given that the patient is experiencing symptoms of spinal cord compression, treatment with intravenous antibiotics alone is not appropriate. * It would not be appropriate to wait for the drainage of this abscess. * This patient warrants emergent surgical incision and drainage and spinal decompression. * Oral antibiotics are not the appropriate management for any patient with a spinal epidural abscess

Answer 39

**3. Decreased nerve conduction velocities on electromyography** ## Footnote * In those with Duchenne muscular dystrophy, serum creatine kinase (CK) levels are elevated before the development of clinical symptoms and signs and may be elevated in newborns. Levels peak by 2 years of age and can be more than ten to twenty times above the upper limit of normal. As age and the disease progress, serum CK levels decrease because muscle is progressively replaced by fibrosis and fat. In this 3-year-old patient, increased creatine kinase levels can be expected. * A muscle biopsy will demonstrate endomysial connective tissue proliferation; scattered degeneration and regeneration of myofibers; muscle fiber necrosis with mononuclear cell infiltrate; and replacement of muscle with adipose tissue and fat. * Calve hypertrophy can be expected in a 3-year-old with Duchenne muscular dystrophy. Motor and sensory nerve conduction velocities are normal, and denervation is not present. * Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are highly concentrated in muscle cells. Duchenne muscular dystrophy can lead to an elevation in ALT and AST. The elevation is most striking during the early stages of the disease.

Answer 40

**1. Hypertonic saline** ## Footnote * Osmolar therapy is used to reduce the space-occupying effects of hemorrhage and edema by increasing the serum osmolality and facilitating the osmotic movement of water into the vasculature with reactive vasoconstriction. * Either hypertonic saline or mannitol may be utilized and there is no superiority of one over the other. * Corticosteroids have not demonstrated any benefit in the treatment of cerebellar hemorrhage. Current evidence does not support hypothermia for cerebellar hemorrhage. * There is no need for prophylactic hyperventilation except in extreme cases of impending brainstem herniation as above.

Answer 41

**2. Brain magnetic resonance imaging (MRI) with and without intravenous enhanced gadolinium contrast** ## Footnote * Magnetic resonance imaging (MRI) with intravenous contrast- enhanced gadolinium shows an enhancing lesion usually extending from the jugular bulb to the middle ear, but posterior fossa and cervical extension are common in untreated tumors. It is the gold standard study for identifying glomus jugulare tumors. * Vascular flow voids are described with the characteristic “salt- and-pepper” appearance on T1 and T2 weighted images. MRI images depict the tumor vascularity, extension along neural foramina and multicentricity, and should be the first imaging study when evaluating a patient with a suspected glomus jugulare. * Glomus jugulare grows large and may grow into the mastoid or through the wall that divides the middle ear from the mastoid, and they may then deeply infiltrate the bone. The tumor may also wrap around and infiltrate areas around the facial nerve. The tumor may become attached to the jugular vein and carotid artery. With the invasion, the tumor is more difficult to remove. If the tumor fills the middle ear space, hearing loss will occur. * Head computed tomographic (CT) scan with fine cuts at the temporal bone demonstrates bone destruction. Bone eroded is sometimes called moth-eaten appearance.

Answer 42

**1. Central canal stenosis-lumbar** ## Footnote * Central Canal Stenosis is seen in patients when neurogenic claudication is seen bilaterally, and not unilaterally. Radiologic imaging shows ligamentum flavum hypertrophy, which contributes to central canal stenosis. Central canal stenosis is a narrowing of the spinal canal which causes compression of the cord, usually leading to bilateral symptoms of pain, paresthesias, and weakness which is termed neurogenic claudication. Vascular claudication is ruled out as the patient has strong, palpable pulses and no skin discolorations when walking. Also, patient states it takes some resting time for his symptoms to resolve, whereas in vascular claudication, the symptoms are immediately resolved with rest. * Central stenosis is usually bilateral and worsens with extension and walking downhill. This patient's symptoms are relieved when walking with lumbar flexion posture while using his walker. * Foraminal and lateral stenosis are not consistent with the radiologic findings and symptoms the patient is experiencing. Hypertrophy of the ligamentum flavum and symptoms of bilateral buttock pain and paresthesias are more indicative of central canal stenosis. * Cauda equina syndrome is a surgical emergency. This patient does not have any acute sensory, motor, bowel, or bladder changes and also denies saddle anesthesia. Cauda equina is not the primary diagnosis in this case as radiologic imaging confirms ligamentum flavum hypertrophy, which points to the more likely diagnosis of central canal stenosis.

Answer 43

**3. Stretching hamstrings, adductors, and gastrocnemius** ## Footnote * This more invasive tactic should not be the initial approach to initiating treatment for spasticity. * Ankle splints would not help with the ankle clonus this patient is experiencing, and would deter in minimizing her progressing spasticity. * Stretching hamstrings, adductors, and gastrocnemius is a more conservative approach. It would be a reasonable start to this patient's management, as it is non-invasive, and stretching would potentially help with her spastic diplegia. * Though baclofen is a reasonable choice as far as pharmacological treatment for spasticity, this should not be the initial approach, and physical therapy modalities should be the first choice.

Answer 44

**2. The dosage of ATT in patients with liver cirrhosis is modified on the basis of underlying liver function (Child-Turcotte-Pugh score)** ## Footnote * Guidelines have been proposed on the modifications of ATT dosage based on the Child-Turcotte-Pugh (CTP) score. Patients with stable liver function (CTP score 8) should not be treated with more than 2 hepatotoxic drugs, while patients with CTP between 8 and 10 should be treated with only a single hepatotoxic drug. Those with CTP > 10 or severe liver dysfunction should not be treated with any hepatotoxic drug. Pyrazinamide (PYZ) is the most hepatotoxic drug. * Isoniazid (INH) causes idiosyncratic-type hepatotoxicity. Both rifampicin (RMP) and pyrazinamide cause both idiosyncratic and dose-dependent hepatotoxicity. * In patients receiving combination therapies involving INH, but not RMP, the incidence of hepatotoxicity is around 1.6%. When regimens involving both INH and RMP are employed, the incidence of hepatotoxicity is increased to 2.5%. Elderly patients have a higher incidence of liver decompensation following ATT.

Answer 45

**4. The spinal trigeminal nucleus, chief sensory nucleus, and facial nerve nucleus** ## Footnote * This is the corneal reflex, which is sensed by the chief sensory nucleus and the spinal trigeminal nuclei, is then relayed to cranial nerve VII nucleus in order to facilitate the closure of orbicularis oculi. * While the chief sensory nucleus is partially responsible for this reflex, the spinal trigeminal nucleus and facial nerve (CN VII) nucleus is also integral to the reflex. * The trigeminal motor nucleus is not involved in this reflex. Rather sensory information from the eye is conveyed via the spinal trigeminal and chief sensory nuclei to the bilateral facial nerve nuclei (cranial nerve 7). Each nucleus then stimulates its ipsilateral orbicularis oculi muscles, which shut the eyes. * When the bright light shines into the patients left eye that stimulus is conveyed first to the spinal trigeminal and chief sensory nuclei and then to the bilateral facial nerve nuclei (cranial nerve 7). Each nucleus then stimulates its ipsilateral orbicularis oculi muscles, the result of which shuts both eyes.

Answer 46

**2. Subarachnoid hemorrhage** ## Footnote * Ehlers-Danlos syndrome (EDS) is a collection of genetic mutations that affect the collagen matrix of various tissues, including blood vessels. * Aneurysms discovered in a patient with EDS can be detected throughout the arterial system, including the intracranial vasculature, which can predispose the patient to subarachnoid hemorrhage. * EDS has known associations with dysautonomias (including orthostatic intolerance potentially from postural orthostatic tachycardia syndrome), chronic fatigue, and transient headaches. * Vascular dilation and rupture can occur anywhere in the arterial system with or without predisposing trauma. Vascular rupture occurs most commonly in the thorax and abdomen but can also occur intracranially.

Answer 47

**2. Consult an oncologist** ## Footnote * This patient has paraneoplastic limbic encephalitis (PLE). Symptoms include memory loss, confusion, personality or behavioral changes, seizures, and sleep disturbances. Because the CT and MRI are negative except for the hyperintense lesions in the medial temporal lobe, the diagnosis should be made after excluding other possible causes. One of the most common causes of PLE is occult cancer of the breast, lung, or ovary, which may be diagnosed after symptom onset. * MRI is superior to CT scan in infratentorial lesions and some early manifestations of stroke. Also, brain parenchyma may be evaluated better with MRI. * Aspirin should be used in a patient who has suffered or is susceptible to a stroke, such as a previous myocardial infarction or very high LDL cholesterol. * A PET scan should be considered to find occult malignancies. This step would be reasonable if the oncologist does not find a tumor or to confirm the diagnosis.

Answer 48

**3. 0-degree, 10 lb (4.5 kg)** ## Footnote * The patient's symptoms suggest a diagnosis of C1-C2 subluxation which is more common in certain syndromes (e.g. trisomy 21) and types of arthritis (e.g. rheumatoid arthritis). * Mechanical cervical traction of any cervical pathology at the levels of C1 and/or C2 should be done at a 0-degree angle level that would provide the best pull to this region. * The weight of traction should be limited to 10 lb (4.5 kg) to avoid any complication at the upper cervical level, which is already unstable in patients with C1-C2 subluxation. Any worsening of symptoms should warrant termination of the procedure. * Cervical pathologies below C2 require traction at a 20-degree angle or higher to optimize spinal pull. The load applied in patients who are undergoing traction for indications other than C1-C2 subluxation can be set to up to 45 lb (20.4 kg).

Answer 49

**1. Administer IV tPA and admit the patient to the hospital’s stroke unit** ## Footnote * The American Heart Association and American Stroke Association 2018 guidelines state IV tPA should be administered to all eligible patients as quickly as possible within 3 hours of last known normal with an extended window of 4.5 hours in a more selective group of patients. * Patients without large vessel occlusions do not require mechanical thrombectomy. * Patients with small vessel ischemic stroke can be admitted to a Primary Stroke Center for IV tPA and further care. * Every 15-minute delay in IV tPA administration is associated with worse functional outcomes, including having 4% worse odds of walking independently at discharge; 3% worse odds of being discharged to home (instead of an institution); 4% greater odds of death before discharge; and 4% greater odds of experiencing symptomatic hemorrhagic transformation of the infarct.

Answer 50

**1. Occipital neurolysis** ## Footnote * Occipital neurolysis is the preferred treatment for this patient. It is done by releasing the greater and lesser occipital nerves from semispinalis capitis muscle and fascia around the nerve. * It is done by either making a midline suboccipital incision or by making two incisions medial and caudal to the mastoid. * Fat is wrapped around the nerve to prevent retethering. * The C2 ganglion can also be cut if occipital nerves cannot be identified intraoperatively.

Answer 51

**1. The patient must be extra cautious when working near an open flame or hot objects** ## Footnote * The lateral spinothalamic tract is the target of the cordotomy. * The lateral spinothalamic tract is responsible for transmitting temperature sensation as well as pain and coarse touch. * Depending on the characteristics of pain, unilateral and bilateral cordotomy are both options for consideration. * Other cordotomy side effects include dysesthesia, urinary retention, ataxia, paresis, sympathetic dysfunction, sexual sensitivity impaired or lost, and a form of sleep apnea.

Answer 52

**3. Papez circuit** ## Footnote * The classic patterns of evolution of symptoms in cases of CTE are closely related to the involvement of the Papez circuit on the brain. * The first stage begins with affective disturbances followed by the stage of social instability, behavioral changes, with subtle features of early Parkinsonism which eventually progresses to the third stage of cognitive dysfunction, dementia, and full-blown Parkinsonism. * This circuit which governs emotional experience has been closely linked to the pattern of evolution of symptoms in CTE. * The involvement of other regions in the brain seems to be the collateral damage owing to repeated head impacts.

Answer 53

**2. Ask the surgeon to pause and release any retractors that are in place** ## Footnote * Releasing the retractors in place is the first step that should be taken when such SEP changes are noted; * If surgical dissection, use of electrocautery, or retraction is causing these changes, this should be identified as soon as possible to avoid irreversible injury to the involved neurologic structure. * Many surgical factors can alter SEPs, though the most time- sensitive of these are ischemia, surgical manipulation of structures, cautery, and dissection. Ischemia could be caused by pressure, retraction, clipped vessels, etc. Manipulating structures and dissecting in certain areas may compromise neurologic structures and/or tracts, leading to a loss or distortion of evoked potential signals that, if not corrected, could result in permanent neurologic deficits. Cautery, if used too liberally, could compromise blood flow and/or directly injure a nerve or spinal tract. * Changes in temperature, namely hypothermia, can increase the latency of SEPs, though this is not the first step that should be taken if such changes were noted on SEPs intraoperatively. Drops in MAP that compromise perfusion pressure to the involved sensory pathways can lead to the listed changes in SEPs. Ensuring the MAP is adequate is a critical step in addressing SEP changes, but it is arguably less important than notifying the surgeon and asking that they momentarily pause while attempts are made to return the SEPs to baseline. Volatile agents can affect the SEP waveform and complicate the picture when trying to identify the cause of changes. Discontinuing or decreasing a volatile agent is a reasonable thing to do, but should not be the first step in addressing these changes.

Answer 54

**2. Cement extravasation** ## Footnote * The predominant reaction associated with both kyphoplasty and vertebroplasty is extravasation of the injected cement. This potentially leads to increased pain and or damage to the underlying nerve root. * Extravasation of the injected cement can potentially lead to increased pain and or damage to the underlying nerve root. * Reports have been shown that cement embolization can occur following procedures. This can potentially occur due to extravasation of the injected cement. Regarding a pulmonary embolism secondary to extravasation of the injected cement, no adverse reactions have been documented, regardless of radiological evidence of embolization. * Recent studies have shown vertebral cement to be associated with bone necrosis. There has also been an association of new fractures in many randomized control trials after patients received vertebroplasty when compared to controls. These potential side effects are much less common compared to extravasation of the injected cement.

Answer 55

**3. Plan for cranioplasty and then monitor for the progression of hydrocephalus** ## Footnote * In patients with decompressive hemicraniectomy, hydrocephalus can be seen due to altered CSF dynamics and the sinking skin flap syndrome. * In such cases, early cranioplasty would reverse the CSF dynamics with no need for any diversion procedure in large subsets of such patients. * This approach will prevent the concurrent risks and complications of shunt surgeries. Therefore, there has been an agreed consensus on planning for early cranioplasty following decompressive hemicraniectomy (DHC) to minimize such complications. * Shunt and cranioplasty in the same setting have associated risks. Shunt first would cause a risk of hematoma beneath the cranioplasty due to the failure of brain expansion. Cranioplasty first would complicate the tapping of the ventricles due to shifting in their anatomical position following bone replacement.

Answer 56

**1. Shortness of breath** ## Footnote * Complications from ESP are very rare because the site of injection is far from the pleura, major blood vessels, and the spinal cord. * Infection at the needle insertion site, local anesthetic toxicity/allergy, vascular puncture, pleural puncture, pneumothorax, and failed block are the primary complications of ESP. * Symptoms of a pneumothorax caused by unintentional needle intrusion into the pleural space during ESP could include sharp chest pain or mild-to-severe shortness of breath. * Care should be taken during ESP to visualize the needle using an in-plane ultrasound approach. This visualization will decrease the chance of unexpected pleural puncture and pneumothorax.

Answer 57

**1. Observation** ## Footnote * In a glomus tumor, conductive hearing loss is seen in addition to tinnitus. Observation provides an excellent treatment alternative, as 65% of tumors remained stable or even regressed in size. For her age, this is the best treatment modality. * They are slow-growing, rare, and hypervascular. It is most common in women in their fifth and sixth decades of life. * They originate from the chief cells of the paraganglia of the jugular bulb. Glomus tumors of the middle ear are more common than glomus tumors of the jugular vein and result from abnormal growth of a single glomus body. They appear as a red ball behind the eardrum. The eardrum may pulsate if the tumor is touching the intact eardrum and is called pulsatile tinnitus. * Pulsatile tinnitus may get worse as the tumor enlarges. Glomus tumors grow large and may grow into the mastoid or through the wall that divides the middle ear from the mastoid, and they may then deeply infiltrate the bone. With the invasion, the tumor is more difficult to remove. If the tumor fills the middle ear space, hearing loss will occur.

Answer 58

**2. Atlantoaxial instability** ## Footnote * Twenty-five percent to 80% of patients with rheumatoid arthritis may develop atlantoaxial instability. * Symptoms can include decreased range of motion, brainstem signs, and myelopathy. * Excessive movement can compress the spinal cord or brainstem. * The cervical spine is frequently involved in patients with rheumatoid arthritis. Cervical involvement tends to be asymptomatic. The flexion-extension moment exerted on the spine can cause ligamentous disruption with subsequent atlantoaxial instability.

Answer 59

**4. Indefinite anticoagulation** ## Footnote * The duration of anticoagulant therapy should be individualized. Indefinite anticoagulation is highly advisable in those with unprovoked thrombosis, life-threatening venous thromboembolism (VTE), more than one episode, or thrombosis at an unusual site, such as cerebral veins, mesenteric veins, or portal veins. * For individuals with heterozygous factor V Leiden mutation and a single provoked VTE, 3 to 6 months of anticoagulation is sufficient. * The choice of anticoagulant usually is based on a number of factors, including patient preference, the severity of thrombosis, adherence to therapy, and possible drug and dietary interactions. * For asymptomatic individuals who are heterozygous for factor V Leiden, anticoagulation is recommended in some high-risk situations, such as surgery or pregnancy.

Answer 60

**2. Physical examination** ## Footnote * The patient has a chronic, post-craniotomy headache (PCH), defined as headaches occurring within 7 days of a craniotomy and which persist for greater than 3 months. * The first step in evaluation is a good history and physical examination, remembering to build a broad differential, and searching for any red flags that may need emergent management. Physical examination should include evaluation of surgical scar, musculoskeletal exam of the cervical spine, and neurological exam for focal neurological signs. Part of the diagnostic criteria according to the International Classification of Headache Disorders 3-beta (ICHD-3) is that a headache is not better accounted for by another ICHD-3 diagnosis. * Currently, research is lacking in regards to current strategies to treat post-craniotomy headaches. Therefore, options for consideration in the acute phase include the use of typical medications seen in the treatment of headaches with similar phenotypes. Although opioid analgesics are indicated for the treatment of moderate to severe pain, caution is advised as they have addictive potential, can cause respiratory depression, and may obscure the ability to monitor neurologic responses. * In the chronic phase, a shift to more non-pharmacological adjuncts may be ideal. Alternatives to consider include physical therapy, acupuncture, transcutaneous electrical nerve stimulation, hot or cold packs, massage, or bio-behavioral interventions. A small case series of four patients demonstrated benefit with the use of Botulinum toxin-A to treat delayed onset PCH, but similar to the other approaches, more research is needed.

Answer 61

**1. Frequent MRI scans as a follow-up** ## Footnote * The main concern with tectal gliomas is occlusion of the cerebral aqueduct and the increase in intracranial pressure that develops. The tumor itself is often low-grade with slow growth. * Following treatment to relieve the increased pressure, most patients remain asymptomatic and require no further treatment. * Frequent monitoring of the tumor for growth is recommended with chemotherapy if necessary. * In this case, the child has no further symptoms and further treatment would only induce unnecessary side-effects. Monitoring with MRI scans every 3 months is sufficient.

Answer 62

**2. MRI lumbar spine without contrast** ## Footnote * Among the answer choices, an MRI of the lumbar spine gives the best visualization of nerve root compression and or disc herniation. Lumbosacral radiculopathy is a diffuse disease process that affects more than one underlying nerve root, causing pain, loss of sensation, and motor function depending on the severity of nerve compression. * The most common origin of lumbar radiculopathy is nerve root compression. It commonly results from either disc herniation or spondylosis. A disc herniation can be either due to an acute injury or secondary to chronic degeneration of the spine. * MRI of the lumbosacral spine is the most useful imaging to identify underlying pathology and the need for surgical intervention. CT myelography is used when a patient has either a contraindication for an MRI, such as having a pacemaker device or defibrillator or when a standard CT or MRI is negative or equivocal. A CT myelogram is also used when direct visualization of the nerve root sleeve is required. * Plain radiographs of the patient's lumbar spine offer limited value in the evaluation of underlying radiculopathy. A CT is a poor test for the visualization of nerve roots, making it challenging to diagnose radicular disease. Standard CT scans are better than MRI for assessing bony structures.

Answer 63

**3. Difficulty with initiating deglutition** ## Footnote * In the percutaneous cervical cordotomy, the lateral spinothalamic tract anterolateral column is destroyed most often at the level of C1-C2. * With the disruption of the lateral spinothalamic tract at C1-C2, the aim is for a contralateral disruption of painful sensations beyond C4. * The geniohyoid muscle is innervated by fibers from the first cervical nerve. * The geniohyoid muscle moves the hyoid bone up and forward facilitating the initiation of deglutition and also assisting respiration.

Answer 64

**3. Metastatic compression fracture** ## Footnote * Studies that have shown the greatest evidence for the use of vertebral augmentation has been shown for patients with metastatic fractures secondary to multiple myeloma. Multiple studies have been done on patients suffering from multiple myeloma with metastatic pathological compression fractures. In this select group of patients, kyphoplasty has been found to significantly decrease the need for patient requirement of walking aids post augmentation as well as a decrease in analgesic medication use. There was also found to be decreased patient requirement of bedrest secondary to pain. * Furthermore, in an uncontrolled study, kyphoplasty was shown to have significant decreases in patient's pain, improvement in their underlying physical and social functioning, and reported vitality. Over 80% of patients have reported pain relief following kyphoplasty in patients with metastatic multiple myeloma who suffer from vertebral compression fractures. * A separate study also showed in a group of 57 patients with pathological fracture secondary to malignancies either a complete or significant resolution of pain in over 84% of patients who underwent kyphoplasty or vertebroplasty. The pain scores remained significantly decreased at one year following the procedure. * Multiple systematic reviews of vertebral augmentation for patients with underlying cancer have been reported. In over half of these studies, patients reported significant improvement in pain following vertebral augmentation. Similar scores were shown for decreases in pharmacological analgesia and disability scores. A traumatic fracture of the lumbar spine would not be an indication for vertebroplasty. However, patient with a traumatic fracture may require spinal surgery consultation depending on the severity of the injury or if the patient is experiencing any neurological sequelae. Osteoporotic compression fractures have had mixed results regarding the efficacy for patients undergoing kyphoplasty or vertebroplasty. If a patient failed conservative management and continues to have prolonged and severe pain secondary to an osteoporotic compression fracture, some experts consider vertebroplasty as a reasonable second-line treatment. However, the evidence is limited regarding its effectiveness. Degenerative osteoarthritis of the spine would not be an indication for kyphoplasty. Patients with degenerative osteoarthritis of the spine may suffer from spinal stenosis. It is unlikely that a patient would experience point tenderness over the vertebrae in degenerative osteoarthritis, but they could experience radicular symptoms if there were a narrowing of the spinal canal. First-line management after the onset of pain secondary to spinal stenosis would be conservative management. For patients who are suffering from lumbar spinal stenosis after the initial six weeks of symptoms, they may benefit from a lumbar epidural for symptomatic relief, as long as their neurological symptoms were not progressing or were not severe. Traumatic fracture of the lumbar spine will need to be evaluated by spinal surgery if there is concern for spinal cord compression. The patient may require emergency decompression if a fracture was severe enough.

Answer 65

**2. If the decision were made to proceed to lumbar provocative discography, this patient is at a high risk for a false positive result** ## Footnote * Provocative discography is a diagnostic procedure that is not indicated in the routine evaluation of chronic lower back pain. There is nothing in this patient's history to suggest that she has features of discogenic lower back pain, such as focal pain at the midline, flexion and sitting intolerance, and pain aggravated by Valsalva maneuvers. Further, there is no mention of how results, if believed, will be used to guide treatment. * This patient has an abnormal, non-anatomic pain map, a history of widespread chronic pain, and probable somatization, which puts her at a very high risk of a false positive result. Other common causes of false positive results include a history of prior back surgery and failure to utilize manometry or a control disc during the performance of the test. * Given her clinical presentation, including severe psychosocial pathology, widespread chronic pain, and radiographic findings that do not correlate well with history and physical examination, the performance of any diagnostic test to attempt to determine a 'pain generator' is probably unwise. This usually will fail to accurately uncover a pain etiology or may produce a false positive result that may lead to further, unhelpful procedures or surgery. * This patient is at high risk for iatrogenic injury and will almost certainly not improve with her current treatment regimen of medications and procedures. Even if her L5 to S1 protruded disc were symptomatic, it does not explain the balance of her symptoms, and so treatments aimed at it will fail to improve her overall function. This patient may do better in a functionally- based rehabilitative program that includes education, physical therapy, and behavioral health. In her case, the biomedical model (i.e., continuing to search for a 'pain generator'), reliance on medications, and procedural or surgical interventions should be de-emphasized.

Answer 66

**3. Continued intracranial pressure elevation causing optic nerve compression and axonal loss producing optic atrophy** ## Footnote * The rate at which optic disc edema resolves after treatment depends upon the length and severity of preoperative perioptic intracranial pressure (ICP) and the method of ICP lowering. However, improvement in disc edema can represent either reduction of axoplasmic stasis or continued axonal loss from persistent ICP elevation. * It is important to check visual fields and visual acuity at each postoperative visit in addition to examining the optic nerve for the status of edema. Patients with an improvement of disc edema from ICP lowering should demonstrate visual acuity stability while those with continued optic nerve damage will demonstrate a decline of their visual function. * Signs of continued ICP elevation after optic nerve sheath fenestration include continued headaches, transient visual obscurations, and cranial nerve VI palsies with associated diplopia. * An important sign of continued ICP elevation is causing a reduction in optic disc edema from axonal loss is the development of optic atrophy. These patients should be strongly considered for a cerebral spinal fluid diversion procedure for global ICP control.

Answer 67

**1. Klumpke palsy with associated Horner syndrome, refer out for CT myelography and surgical consult** ## Footnote * Klumpke palsy is a brachial plexus lesion of the C8 and T1 spinal roots and can sometimes also avulse the cervical sympathetic ganglia. In these cases, the patient will present with a "claw" hand deformity and associated ptosis, miosis, and anhydrosis. * Statistically surgical correction in severe cases of brachial plexus injuries shows the best prognosis. * In severe brachial plexus injuries where there might be suspected avulsion, like in the case presented, CT myelography would be the best imaging option. * Young males post motorcycle accidents have the highest incidence of brachial plexus injuries.

Answer 68

**4. Injury to the right stellate ganglion** ## Footnote * Horner syndrome is a disorder characterized by a constricted pupil (miosis), drooping of the upper eyelid (ptosis), absence of sweating of the face (anhidrosis), and sinking of the eyeball into the bony cavity that protects the eye (enophthalmos). * Injury to the right stellate ganglion would result in Horner’s syndrome on the right side of the face, consistent with this patient’s symptoms. * Injury to the left C-5 nerve root would result in left deltoid weakness. A post-operative retropharyngeal hematoma will most likely cause difficulty swallowing, and if severe difficulty breathing/airway collapse. * Injury to the right recurrent laryngeal nerve could result in hoarseness if the patient has a competent left vocal cord, or in difficulty breathing/airway collapse if the patient has an incompetent left vocal cord.

Answer 69

**1. Near the fornix** ## Footnote * Alzheimer's patients show decreases in the rate of brain atrophy with deep brain stimulation treatments. * An optimal location for placement of a deep brain stimulator is near the fornix. The fornix is a unidirectional projection of the hippocampus to the mammillary bodies. * The fornix is a part of the Papez circuit. It carries information about memory from the hippocampus to the mammillary bodies. This information moves through the mammillary bodies to the anterior thalamus, cingulate cortex, and entorhinal cortex before looping back to the hippocampus. * Stimulation of the mammillary bodies through fornix afferents will influence reciprocal projections between the mammillary bodies and the tegmentum. These circuits help to influence goal-oriented movement and reward circuits within the brain. Patients with deep brain stimulation of the fornix show decreased incidences and degrees of depression. Stimulation of the reward centers of the brain causes this beneficial side effect.

Answer 70

**2. Klumpke palsy and follow up with nerve conduction velocity** ## Footnote * The patient is stable so a nerve conduction velocity (NCV) test can help to locate where the lesion is. MRI is useful, but this patient does not show signs of serious brachial plexus injury and can be managed conservatively. * The patient likely has Klumpke palsy based on history and examination, but the nerve could also be entrapped at a distal location and an NCV would help to rule that out. * Klumpke palsy classically presents with a claw hand deformity, compared to preacher's hand with ulnar palsy, and waiter's tip with Erb palsy. * Klumpke palsy if severe enough can show signs of Horner syndrome and in that case, more intrinsic examinations are needed, along with a surgical consultation.

Answer 71

**4. Ptosis of the ipsilateral eye** ## Footnote * Concern at this time is for extension of his syrinx cephalad into the C8-T1 dermatomes, as evidenced by loss of pain and temperature sensation and risk for thermal injury. Syrinx cavities are often centrally situated and can affect crossing spinothalamic fibers unilaterally or bilaterally, resulting in loss of pain and temperature sensation. * Involvement into the T1 level of the spinal cord can cause a complete or partial Horner syndrome. Sympathetic fibers descend in the spinal cord and exit with the T1 nerve root. Horner syndrome includes partial ptosis (eyelid drooping), anhidrosis (decreased sweating), miosis (constricted/smaller pupil), and the enophthalmos (eyeball being inset). * Intrinsic atrophy occurs with the involvement of T1 innervated muscles, whether from a spinal cord or peripheral cause. A "claw hand" with flexion of the 4th and 5th digits would point to significant ulnar nerve injury. * Ulnar neuropathy at the elbow or cubital tunnel is associated with Tinel's sign in that location. Median neuropathy in the carpal canal is associated with Tinel's sign in that location. The ulnar nerve is served by C8-T1 nerve roots, and injury to the nerve could occur separately or together with spinal cord damage at these levels.

Answer 72

**2. C1-C2 instability** ## Footnote * The patient has a history of os odontoideum and has symptoms related to spinal cord compression, therefore, a C1-C2 instability must be ruled out. The os odontoideum is often attached to the anterior arch of C1 through an intact transverse ligament. One of the main risks of this anatomical entity is the association of anterior atlantoaxial subluxation. * 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. * Posterior atlantoaxial subluxation is extremely rare in os odontoideum. Instability is mainly anterior. In the presence of symptoms or radiographical evidence of instability, surgery is indicated. * A subaxial cervical fracture-dislocation is the most common cause of neck pain and neurological symptoms after cervical trauma. However, knowing the presence of os odontoideum, the main diagnosis is cervical instability. Isolated spinous process fracture may be a differential diagnosis but neurologic symptoms are not usually associated. Atlas fracture usually results from axial compression forces, it is not the mechanism in this case.

Answer 73

**2. Amyloid light-chain amyloidosis** ## Footnote * Amyloid light-chain (AL) amyloidosis is one of the most common differential diagnoses in an elderly patient with spontaneous "raccoon eyes." * They are formed due to bleeding under the skin (bruising) around the eyes. * AL amyloidosis can affect a wide range of organs, kidneys being the most commonly affected. * Subarachnoid hemorrhage (SAH) from an ophthalmic artery aneurysm has been reported to be associated with raccoon eyes as well, but the patient will present with a severe headache. Sweet syndrome or acute febrile neutrophilic dermatosis is a skin disease characterized by the sudden onset of fever, an elevated white blood cell count, and tender, red, well-demarcated papules, and plaques that show dense infiltrates by neutrophil granulocytes on histologic examination. Raccoon sign in this condition is due to secondary vascular damage caused by prolonged exposure to matrix metalloproteinases. Sarcoidosis is not associated with raccoon eyes.

Answer 74

**2. Temporary relief and screening tool** ## Footnote * Patient has failed conservative measures for her migraine. She needs either botulinum toxin or surgery to treat her condition. * Botulinum toxin has efficacy lasting only up to 3 to 6 months. It cannot be labeled as a definitive treatment. * It is instilled at suspected trigger sites. Succesful abolition of pain is a marker of good prognosis after neurolysis of nerves supplying that area. * Cosmetic use of botulinum toxin in this patient is not rational.

Answer 75

**3. The patient is unlikely to have a herniated nucleus pulposus** ## Footnote * Criteria for a true positive straight leg raise (SLR) test are as follows: radicular leg pain should occur (radiating below the knee) when the leg is lifted between 30 and 70 degrees from horizontal. * Pain occurring at an angle greater than 70 degrees from the horizontal is most likely due to tight hamstring or gluteal muscles. * Pain occurring at an angle less than 30 degrees may indicate non-organicity. * Herniated nucleus pulposus is the most common cause of a true positive SLR test.

Answer 76

**2. Full-strength aspirin therapy** ## Footnote * Blunt cerebrovascular injury (BCVI) is a concern when there is a significant mechanism of injury with high energy transfer, eg. strangulation. The Denver criteria have been adopted as screening metrics for who should undergo additional imaging to evaluate for BCVI. * The gold standard four-vessel cerebrovascular angiogram is an invasive, expensive test which has complications Thus, computed tomography with angiography (CTA) is routinely used to evaluate for these injuries. * Full strength aspirin therapy has been found to have a better risk profile as compared to anticoagulants. * For grade 1 injuries, full-strength aspirin therapy alone is the mainstay of treatment.