Section 2 Flashcards

Question

A 55-year-old male with altered cognition and right-sided weakness was diagnosed with primary angiitis of the central nervous system (PACNS) following cerebral angiography and stereotactic biopsy. He was promptly started on combination therapy with oral prednisone and cyclophosphamide. During the follow-up visit, the patient had no resolution of prior symptoms and was noted to have developed new-onset blurring of vision, which was also determined to be secondary to PACNS. Which of the following is the next best step in the management of this patient? 1. Increase the dose of cyclophosphamide and prednisone 2. Discontinue both the drugs and start on intravenous methylprednisolone 3. Discontinue both drugs and start infliximab 4. Add infliximab to the current drug regimen

Answer 1

**4. Add infliximab to the current drug regimen** ## Footnote * The patient has features consistent with primary CNS vasculitis refractory to both glucocorticoids and immunosuppressants, and therefore adjunctive therapy is advocated. * Tumor necrosis factor-alpha blockers (infliximab, etanercept) and mycophenolate mofetil can be used as adjunctive therapy along with the standard therapy. * Patients started on tumor necrosis factor-alpha blockers have shown striking resolution of their neurological as well as radiological characteristics. * The evidence of intravenous (IV) steroids being superior to oral regimens has not been noted. The discontinuation of the primary therapy is not advocated in refractory cases of CNS vasculitis.

Answer 2

**1. Genetic counseling should be offered to both son and daughter** ## Footnote * Cavernous malformations can be either sporadic or familial in etiology. * Between 40% to 60% of cases of cavernous malformations are familial. * Familial cases of cavernous malformations are inherited in an autosomal dominant fashion. First-degree relatives of patients with familial type cavernomas should have a screening MRI and genetic counseling. * Familial cases of cavernous malformations tend to present with multiple cavernomas, compared with solitary cavernomas in sporadic occurrences. A higher proportion of Hispanic patients with cavernomas have familial type cavernomas compared with other populations.

Answer 3

**4. Acetazolamide challenge with CT angiogram** ## Footnote * The patient has had recurrent ischemic events related to underlying right Moyamoya disease. * The most definitive therapy is revascularization with direct extracranial to intracranial bypass grafting or indirect revascularization with omental or dural synangiosis. * Angiography with acetazolamide and carbon dioxide reactivity are the best tests to determine vascular reactivity and subsequent response to revascularization. * The patient most likely has terminal right ICA occlusion with Moyamoya collaterals. A neck angiogram will not be helpful at all. Cardioembolism is one of the main causes of stroke in young patients, yet the description of this patient is clearly not embolic. Antiplatelet agents are indicated in secondary prevention of stroke in this patient, yet there is no evidence platelet function tests will help to determine the efficacy of its treatment.

Answer 4

**4. Flaccidity with absent reflexes** ## Footnote * T6-T7 is below the innervation of the upper extremities, so these would not be affected. * Acute VCS will have absent reflexes. However, there is a gradual return of the reflexes with increased tone or spasticity later on. * Position sense is spared throughout the spinal cord. * The acute stages of VCS present flaccidity and loss of deep tendon reflexes. Further, spasticity and hyperreflexia will develop in the following days and weeks.

Answer 5

**2. Ask the surgeon to flood the surgical field with warmed saline** ## Footnote * 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. * Flooding the surgical field with warmed saline would most quickly and effectively warm the components of the sensory pathway being monitored with SEPs, which have likely been exposed to room air and become relatively hypothermic. * Although this would likely increase the patient's body temperature given an adequate amount of time, it is not the fastest way to address the SEP changes, nor is it as effective as applying a warm solution to the surgical field, where the sensory path is likely exposed and vulnerable to being cooled to ambient temperatures. Attempts at directly warming the portions of the sensory pathway that are exposed during surgery, such as flooding the surgical field with warm saline, are likely to be more successful more quickly than attempting to warm only exposed parts of the patient.

Answer 6

**3. Turn the head to the contralateral side** ## Footnote * As endovascular procedures grow in numbers, more complications are coming to light. * During carotid artery stenting, sometimes the anti-embolic device may get stuck, but the device may come loose by altering the head position. * However, there is a risk of a stroke when manipulating this device. * Sometimes one may have to gently extend the neck to dislodge the device. The aim is to straighten the internal carotid artery. If preoperatively the internal carotid artery is tortuous, expect this complication to occur.

Answer 7

**4. Lack of axillary sweating** ## Footnote * In patients with a history of spinal cord injuries, autonomic dysreflexia can lead to increased axillary sweating. Resection of the rami communicantes, transmitting pre- and post-ganglionic sympathetic nerve fibers, would not affect the somatic motor fibers running in the spinal nerves and thus, there would be no paralysis of intercostal musculature. * Hyperhidrosis of the axillary sweat glands might be a result of overstimulation of the sympathetic nervous system via the rami communicantes, therefore a lack of sweating would result from an interruption of this system. Resection of the rami communicantes, transmitting pre- and post-ganglionic sympathetic (visceral efferent) nerve fibers, would not affect the somatic afferent fibers running in the spinal nerves. Thus, there would be no general sensory loss in the affected intercostal spaces or the subjacent parietal pleura. * The superior tarsal muscle receives innervation by sympathetic fibers exiting the spinal cord at T1, synapsing in the superior cervical ganglion, and eventually distributed to the orbit via the oculomotor nerve. The superior tarsal muscle serves to raise the superior eyelid. Its innervation would not be affected by a division of sympathetic innervation below T1, as in this case. * Sympathectomy is surgical resection of the sympathetic nervous innervation to reduce symptoms such as hyperhidrosis (excessive sweating). The thoracic sympathetic outflow to the axillary sweat glands would be disrupted by cutting the rami communicantes at the second thoracic spinal level.

Answer 8

**3. Shining light in left eye leads to constriction of the left pupil without consensual constriction of the right pupil** ## Footnote * Oculomotor nerve palsies are most commonly caused by microvascular complications of hypertension or diabetes, trauma, or compression via aneurysms or neoplasm. * The oculomotor nerve handles most movements of the eye, including adduction in primary position (looking straight ahead). In addition to somatic innervation, the oculomotor nerve controls parasympathetic innervation to the pupil and lens. These fibers are located on the outermost part of the nerve, and are thereby prone to compression from the outside via aneurysms, neoplasm, or increased intracranial pressure. * The pupillary reflex is controlled by the optic nerve (afferent) and oculomotor nerve (efferent). Due to the anatomy at the brainstem, when one optic nerve is stimulated both oculomotor nerves become stimulated. This results in bilateral pupil constriction when light is shined in one eye. * If the light is shined in one eye and neither pupil constricts, this is likely an optic nerve pathology because the stimulus did not reach the brainstem via the afferent pathway. If the light is shined in one eye and the same eye constricts, but there is no consensual constriction of the other eye, the oculomotor nerve on the other side is likely affected. If the light is shined in one eye and only the other eye constricts, the pathology probably lies within the oculomotor nerve on the same side.

Answer 9

**2. Supplemental oxygen therapy** ## Footnote * According to current guidelines, if pulse oximetry levels remain persistently below 90% despite the CPAP therapy, supplemental oxygen therapy can be tried. * Weight loss surgery is usually the last resort. * Bi-PAP can also be tried in patients with increasing episodes of apnea or hypopnea on CPAP therapy. * Medroxyprogesterone use is not regularly recommended.

Answer 10

**2. Abducens nerve and sympathetic fibers** ## Footnote * If anisocoria increases and one eye shows minimal dilation with cocaine eye drop, it indicates Horner syndrome. * On examination, he had a right abduction deficit consistent with an abducens nerve palsy. * The combination of an abducens nerve palsy and a Horner syndrome indicated a cavernous sinus localization. The history of slow progression over months indicated a compressive or infiltrative lesion. * The proximity to critical neurologic structures makes it difficult for any invasive procedures like biopsy or excision.

Answer 11

**4. Non-caseating granulomas** ## Footnote * This patient has neurosarcoidosis. Non-caseating granulomas are the hallmark of sarcoidosis. * A lumbar puncture will show elevated protein and mild-to- moderate pleocytosis. * An MRI with contrast may show leptomeningeal enhancement. * A lumbar puncture may help exclude infection of the central nervous system, malignancy, or multiple sclerosis.

Answer 12

**3. Lateral posterior choroidal branch of the posterior cerebral artery** ## Footnote * The lateral posterior choroidal branch of the posterior cerebral artery vascularizes the medial and posterior portions of the lateral geniculate nucleus (LGN). * The only other vascularization of the lateral geniculate nucleus is from the anterior choroidal artery. * Arteriovenous malformation of the lateral geniculate nucleus can produce homonymous hemianopsia. * Damage to the LGN may present without concomitant effects on visual feedback responses, such as some forms of extraocular muscle function or pupillary reflex.

Answer 13

**3. His fracture can be treated with a rigid cervical collar for at least eight weeks, but we will need to acquire further imaging studies to evaluate his vascular structure, and the ligaments in his neck and the fracture has a high chance of healing on its own** ## Footnote * A fracture of the bilateral pars interarticularis of C2 is also known as a Hangman fracture. * Hangman fracture without significant subluxation or angulation has a greater than 90% chance of healing on its own and should be treated with a rigid cervical collar for at least eight weeks. * It is important to obtain a CT angiogram of the neck to evaluate for vertebral artery occlusion or dissection, which could result in more serious neurologic damage. * Additionally, an MRI of the cervical spine is necessary as damage to the ligamentous structures or the C2-3 disc space may require surgical intervention.

Answer 14

**2. Respiratory failure** ## Footnote * Respiratory dysfunction and failure is the most common complication leading to mortality in cordotomy procedures. * The mortality rate among cordotomy patients is documented as high as 6%. * With current improved techniques and advancements in ablation devices, rates of respiratory failure and dysfunction are progressively decreasing. * Poor respiratory function before undergoing percutaneous cervical cordotomy has not been shown to increase rates of respiratory failure.

Answer 15

**2. L5/S1 right paracentral discectomy** ## Footnote * Generalized formal physical therapy should be trialed in patients with symptomatic lumbar disc herniations, however, if failed, other treatment options should be considered. This patient has failed a trial of formal physical therapy, and his pathology is not indicative of predicted responsiveness to any demonstrated specific therapy protocol. Surgical intervention has a higher likelihood of providing a positive outcome. * This patient has a symptomatic lumbar disc herniation, as regarding his right-sided symptoms has failed a trial of conservative therapy. Surgery in the form of discectomy is indicated at this time as it has a relatively higher likelihood of positive outcome when compared to continued nonoperative therapy. Despite pathology at on the left side at L5/S1, symptoms resulting from this specific disc herniation have resolved with physical therapy. When performing discectomy, surgical intervention should be focused only on correlated clinical and radiographic findings to maximize outcome and preserve segmental stability. As such, right paracentral discectomy at L5/S1 is the most appropriate treatment option. * Strict and demonstrable associated clinical and radiographic evidence of pathology should be pursued when planning discectomy. As the symptoms caused by the left-sided far lateral herniation at L5-S1 have resolved and there are no abnormalities on physical exam of the left side, this herniation should not be addressed surgically to maintain segmental stability in the setting of the right-sided partial discectomy for the symptomatic paracentral herniation. * Lumbar fusion is not indicated in the setting of symptomatic disc herniation, despite multiple foci of pathology. This patient's work up is notable for the absence of instability on x-ray. L5/S1 right sided paracentral discectomy is the indicated surgical option to address this patient's pathology.

Answer 16

**2. 2** ## Footnote * This patient presents with sudden onset, severe headache, and neck stiffness. This is concerning for subarachnoid hemorrhage (SAH) from a ruptured cerebral aneurysm. * This patient has a history of polycystic kidney disease, which is a risk factor for cerebral aneurysm formation, and ultimately, rupture. * The Hunt and Hess Classification system can be used to grade patients with subarachnoid hemorrhage from ruptured cerebral aneurysm. The system uses initial neurologic status to determine grade, which can be used to predict overall mortality. * This patient presented with a severe headache, neck stiffness, and a left cranial nerve III palsy. This is consistent with a grade 2 on the Hunt and Hess Classification system.

Answer 17

**3. Opioids** ## Footnote * To decrease use of opioids postoperatively, one single center, randomized, blinded trial studied preoperative diclofenac as a prophylactic agent. It decreased the intensity of headache on postoperative day 1, and up to post-op day 5 for patients with infratentorial surgeries. However, there always remains a risk of bleeding with the use of non-steroidal anti-inflammatory medications. * Long-term use of opioids is not indicated in the treatment of chronic post-craniotomy headaches. One alternative approach is the use of botulinum toxin A, which works presynaptically to block the release of acetylcholine at the neuromuscular junction. * Of particular concern with opioid administration is the possibility of respiratory depression. Therefore, research is now focusing on medications like dexmedetomidine, which is an alpha-2 adrenergic agonist that has the potential for treatment of post- craniotomy headaches and is a sedative agent that does not carry risk of respiratory depression. * In post-craniotomy patients, opioids may obscure physical exam findings and red flag signs that may indicate urgent or emergent work up. Differential diagnoses to keep in mind post-operatively include cerebrospinal fluid leak, intracranial hemorrhage, and meningitis or infection.

Answer 18

**2. Type II: isthmic** ## Footnote * Injury of the pars interarticularis is one of the most common identifiable causes of ongoing low back pain in adolescent athletes; sometimes, this condition is not detected until adulthood, when the injury becomes chronic and symptomatic. * The vast majority of pars defects, also called spondylolysis, occur at L5 (85–95%), with L4 being the next most commonly affected level (5 to 15%). * Although lateral lumbosacral radiographs may show a defect in pars in 80%, the classical oblique X-ray views have been mentioned as essential studies to diagnose this condition. * Type I: dysplastic: congenital abnormalities of L5 or the upper sacrum allow anterior displacement of L5 on the sacrum. Type III: degenerative: secondary to long-standing intersegmental instability with the associated remodeling of the articular processes. Usually, in elderly patients. Type IV: traumatic: acute fractures in the vertebral arch other than the pars.

Answer 19

**3. Attempt to tap the ventricle** ## Footnote * Intraoperative brain swelling can be managed with an attempt to tap the ventricles and thereby allow egress of some CSF. * Paine's point can be approached intraoperatively during the intraoperative period. * The point of the ventricular tap is through the apex of an isosceles triangle, whose base is 3.5 cm along the Sylvian fissure, and each of its limbs is 2.5 cm. This can lead to temporary laity of the brain, providing time for targeting and then debulking the tumor. * Closing the brain after removing the herniated brain and then keeping the patient ventilated will not prevent the secondary damage and is only undertaken as a last resort in managing such an emergency.

Answer 20

**2. Cement vertebroplasty** ## Footnote * Given the description of the CT findings, the patient has a low thoracic compression fracture with moderate loss of vertebral body height. * Cement augmentation will allow for stabilization of fracture, decreased pain, and increase functionality quickly for this patient. It can be performed as a percutaneous daycare surgery. * She lives independently, so a means of treatment that allows her to improve her functionality and quality of life quickly, such as cement augmentation, is a good choice for her. * While there is level 5 evidence to suggest mobilization without bracing is ok, the published literature supports bracing or cement augmentation as opposed to no immobilization (answers 1 and 4). Based on the clinical vignette, this patient will likely not succeed with an extended period of bracing due to body habitus and pain level. This patient is obese and will not be adequately immobilized with a TLSO. Therefore, cement augmentation will help with improving her pain, function, and quality of life. Pedicle screw fixation is a major procedure and is only advocated in unstable fractures, and in patients with canal compromise.

Answer 21

**3. The RFA needle should be withdrawn slightly and retested; if proper stimulation is achieved, local anesthetic should be injected to anesthetize the area; if the patient does not report a liquid feeling in the back of his throat the radiofrequency ablation should be completed, and the patient should then be monitored for any symptoms such as bleeding or infection.** ## Footnote * The sensation of liquid running down the patient's throat is an indication that the nasopharyngeal space has been entered. * If the needle enters the nasopharyngeal space, the clinician should monitor the patient for bleeding and infection. The patient should also be educated on which signs and symptoms to be aware of and report. * Although aborting the procedure is an option, in most cases it is unnecessary as the procedure can be completed safely. * After puncture of the nasopharyngeal cavity starting the patient empirically on antibiotics is not recommended as this could lead to an antibiotic-resistant infection.

Answer 22

**4. A heart rate of 48 beats per minute, blood pressure of 165/70 mmHg, and respiratory rate of 10 breaths per minute** ## Footnote * Cushing reflex is a physiological response to increased intracranial pressure, which is seen in severe traumatic brain injury. * Cushing triad is a late sign of impending herniation. * Cushing triad includes bradycardia, hypertension, and respiratory depression. In children, it can cause either bradycardia or tachycardia. * The presence of Cushing triad is an ominous condition and requires urgent evaluation and subsequent intervention.

Answer 23

**3. Carotid artery stenting** ## Footnote * It is reasonable to intervene for asymptomatic carotid artery stenosis in 2 to 3 weeks of the cerebrovascular event if the patient is recovering from stroke as expected. * Type 3 aortic arch and aortic calcifications can make a transfemoral approach for stenting difficult. * This patient is a high risk for carotid endarterectomy given his recent myocardial infarction and chronic obstructive pulmonary disease. * Transcarotid carotid stenting with flow reversal represents the next best step along with medical management including aspirin, clopidogrel, and a statin.

Answer 24

**2. Electroneuronography** ## Footnote * Electroneuronography (ENoG) is the gold standard for the evaluation of facial nerve function. The facial nerve can be acutely transected in the setting of a temporal bone fracture. * ENoG is a noninvasive study that utilizes brief electrical stimulation and subsequent recording of propagated action potentials. Amplitude is the key parameter that is compared to the contralateral unaffected side of the face. ENoG provides excellent prognostic value if used after 3-5 days from injury. Prior to this timeframe, the distal portion of a transected nerve still maintains some stimulability. * Because ENoG testing relies on comparison of the injured side of the face to the normal side of the face, it is not applicable for patients with bilateral facial nerve injuries. * A computed tomography (CT) scan with contrast would not be able to identify facial nerve damage in this patient, although it could be used to assess for ischemic stroke. Although strokes can cause facial paralysis, in the setting of acute temporal bone fracture, suspicion for facial nerve injury should be high. Blink reflex testing is based on the corneal reflex. The facial nerve serves as the efferent limb of the corneal reflex, and its function can be assessed by this form of testing. This would not provide any significant diagnostic or prognostic information but may be used to monitor recovery progress. Magnetic resonance imaging may be used to evaluate the intracranial contents in the event of unexplained neurological findings, but the CT obtained originally revealed the etiology of the facial paralysis.

Answer 25

**2. The shunt tap is likely to diagnose the underlying condition** ## Footnote * CSF in ventriculitis may show a raised cell count and protein, with low glucose. * CSF culture may be positive, although this is not always the case, especially if the sample is taken following antibiotic administration. * The presence of oligoclonal immunoglobulin G or M bands, CSF lactate, procalcitonin, and lysozymes help make an early diagnosis. * Non-contrast CT head demonstrates non-specific findings, including dependent hyperdense ventricular debris, hydrocephalus, periventricular low density as well as features of the underlying abnormality. It does not offer a definitive diagnosis. A CSF sample should be obtained. CSF sample can be obtained via a shunt tap, it does not need to be obtained via lumbar puncture. The patient had a plain CT head. Enhancement may be seen on a contrast-enhanced scan. A CSF sample will also be required. A wound infection needs to be considered - an examination of her abdomen and the cranial wound is imperative. A shunt series radiograph may help rule out a blocked shunt. Comparison of the new and previous CT scans may help decide if the patient has hydrocephalus, which may suggest a blocked shunt.

Answer 26

**3. Subarachnoid hemorrhage** ## Footnote * Despite the potential for death, subarachnoid hemorrhage is a very rare occurrence in patients with autosomal dominant polycystic kidney disease. * The aneurysms in the brain do not always rupture, as was once believed. * The major cause of death in these patients is cardiac disease. * Cerebral aneurysms are serious but in fact are very rare. Rupture is most common in patients with uncontrolled hypertension.

Answer 27

**2. The patient has a good prognosis for recovery within 3-4 months, yet with slower conduction velocity than pre-injury** ## Footnote * Neurapraxia is the mildest form of peripheral nerve injury, characterized by local damage to an axon that does not disrupt axonal continuity. Common after a local mechanical compression, a full recovery is usually complete within days to weeks. * Axonotmesis is defined by interruption of the axons, but with preservation of the basal lamina connective tissue that allows axonal regeneration. Regeneration occurs at approximately 1 inch per month. Schwann cells will be remyelinated with thin and nodes more closely spaced, thus decreasing conduction velocity. * Axonotmesis results in interruption of the axon, but with preservation of Schwann cell basal lamina that allows axonal regeneration. In a more severe injury, with poor recovery, one would observe a decrease in conduction velocity or a conduction block. * Neurotmesis, the most severe form of peripheral nerve injury, results in a loss of continuity in both the axon and the surrounding connective tissue. Surgical end-to-end reconnection of the nerve stumps is usually required.

Answer 28

**4. CSF fistula and nerve root injury** ## Footnote * Postoperative weakness of the upper extremities would not be considered to be a primary complication following surgery for a closed neural tube defect involving the lumbosacral spine. Surgical intervention can result in nerve root injury or injury to the conus medullaris. Associated deficits would include motor and/or sensory compromise of the lower extremities in addition to the potential for bowel/bladder compromise. Surgical interventions in the lumbosacral region would not be associated with any abnormalities of the upper extremities. * Postoperative CSF fistulas would be considered to be a primary complication following surgery for a closed neural tube defect involving the lumbosacral spine. The complication of a CSF cutaneous fistula is best prevented by meticulous dural and fascial closure. Nonabsorble monofilament suture is preferred for these layers. * Postoperative nerve root injury would be considered to be a primary complication following surgery for a closed neural tube defect involving the lumbosacral spine. Nerve root damage is avoided by meticulous dissection and the use of intraoperative neurophysiologic monitoring. * As noted above, Postoperative CSF fistulas and postoperative nerve root injury would be considered to be primary complications following surgery for a closed neural tube defect involving the lumbosacral spine. Wound infection would also be considered to be a primary complication following surgery for a closed neural tube defect involving the lumbosacral spine. Wound infection is best addressed in the infant/toddler population by frequent scheduled diaper changes and aggressive family education as to proper wound care.

Answer 29

**2. Add electrocardiogram (ECG) monitoring** ## Footnote * Concomitant electrocardiogram (ECG) monitoring is essential to detect any ECG artifacts in the EEG. * EEG can confirm brain death when it shows no electrical activity of more than 2 microvolts, at a sensitivity of 2 microvolts/mm for at least 30 seconds. EEG sensitivity should be at least 2 microvolts/mm to assess electrocerebral inactivity more accurately. * It should show no reactivity to intense somatosensory stimuli. * Sedation should not be given to the patient as it may affect the EEG. Interelectrode distances should be at least 10 centimeters during testing for electrocerebral inactivity.

Answer 30

**3. 20 degrees of kyphosis at the thoracolumbar junction** ## Footnote * Sagittal imbalance plays a critical role in the causation of a spinal instability and the genesis of chronic low back pain and failed-back surgery syndrome. * The thoracolumbar junction is normally neutral in the sagittal plane, as it is a transition zone from thoracic kyphosis to lumbar lordosis. * Twenty degrees of kyphosis at this region is too much kyphosis and indicates that sagittal imbalance is present. * The sagittal vertical axis, lumbar lordosis, and pelvic incidence are within normal reference values in this patient.

Answer 31

**2. Vitamin C** ## Footnote * Deficiency of dietary vitamin C is called scurvy. * Impaired hydroxylation of proline residues in the nascent procollagen chains leads to weakness of blood vessel walls and is caused by the deficiency of vitamin C. * Scurvy is characterized by splinter hemorrhages, perifollicular hemorrhages, fragmentation of hairs, purpura, ecchymoses, and hemorrhages into muscle. * Ascorbic acid is needed for biosynthetic pathways by accelerating hydroxylation and amidation reactions. In the synthesis of collagen, ascorbic acid is required as a cofactor for prolyl hydroxylase and lysyl hydroxylase. These enzymes are responsible for the hydroxylation of the proline and lysine amino acids into collagen. Hydroxyproline and hydroxylysine help stabilize collagen by cross-linking the propeptides in collagen. Defective collagen fibrillogenesis results in impairment of wound healing. Collagen is part of a bone, so bone formation is affected. Defective connective tissue leads to fragile capillaries, resulting in abnormal bleeding. Untreated scurvy is invariably fatal.

Answer 32

**4. Open endarterectomy** ## Footnote * Currently, the society for vascular surgeons recommends carotid endarterectomy as first-line treatment for most symptomatic patients with stenosis of 50% to 99% and asymptomatic patients with stenosis of 60% to 99%. * The risk of stroke is less with carotid endarterectomy compared to carotid artery stenting. The elevated risk of myocardial infarction in carotid endarterectomy in comparison with stenting may be related to the hemodynamic stress induced on the body by clamping a major artery in the body - this is an essential step in the endarterectomy procedure. * The inferiority of carotid artery endarterectomy in terms of a higher rate of myocardial infarction was not constant among two recently published randomized controlled trials, the carotid revascularization endarterectomy versus stent trial (CREST) and the international carotid stenting Study (ICSS). * Carotid artery stenting should be reserved for symptomatic patients with stenosis of 50% to 99% at high risk for carotid endarterectomy for anatomic or medical reasons. Historically, DSA has been the standard gold test to evaluate the extra- and intracranial circulation. This is an invasive procedure, typically performed via a transfemoral puncture, and involves selective imaging of the carotid and vertebral arteries using iodinated contrast. The risk of stroke during cerebral angiography is generally reported at approximately 1%. It is typically due to chemoembolization related to wire and catheter manipulation in the arch aorta or proximal branch vessels.

Answer 33

**3. Direct cannulation of the superior ophthalmic vein following surgical exposure** ## Footnote * The patient presents with an indirect carotid cavernous fistula and worsening symptoms, which requires intervention. Observation and conservative management would not be appropriate because her symptoms may further worsen and lead to vision loss. * Another attempt at transvenous embolization is unlikely to be successful if two prior attempts have been unsuccessful. * Radiosurgery is not an option for emergency cases because obliteration of the fistula may take weeks to months. * Direct cannulation of the superior ophthalmic vein is an alternative when standard transvenous access to the cavernous sinus through the inferior petrosal sinus is not successful.

Answer 34

**3. Withhold antibiotic therapy until positive cultures are obtained to guide the antibiotic therapy** ## Footnote * The Infectious Diseases Society of America (IDSA) guidelines recommend that in the non-emergent setting (i.e., no signs of sepsis or neurologic compromise) antibiotic therapy can be withheld for up to 1 to 2 weeks. * Every attempt is to be made to obtain positive blood or tissue cultures to identify an offending pathogen and appropriately narrow down antibiotic coverage. * Numerous intravenous therapeutic regimens are recommended by the IDSA for the treatment of vertebral osteomyelitis with options for oral therapies as well. * Antibiotic stewardess as per the culture and sensitivity report is of paramount impotence to prevent antibiotic resistance.

Answer 35

**4. Cobalamin** ## Footnote * A diagnosis of pernicious anemia is made through blood work. Patients usually have a high MCV and a normal MCHC. * Ovalocytes are present on the smear with hypersegmentation of the neutrophils. * The patient may complain of a triad of paresthesias, sore tongue, and weakness. Impaired urination, loss of sensation in feet, unsteady gait, and clumsiness are common in chronic cases. * Repletion of cobalamin is the treatment.

Answer 36

**1. Cervical collar application** ## Footnote * This patient is demonstrating a classical description of Hirayama disease. While often considered a benign or self-limiting condition with a plateau phase, an increased rate of progression may sometimes be observed. * Conservative management includes therapy to maintain function and strength until the plateau phase of the process is reached. Eary initiation of therapeutic intervention is essential to maintain independence and limit functional deficits. * A neck collar promotes cervical spine stability and avoids further cervical spine atrophy by decreasing microtrauma events. * Surgical management is reserved for patients with rapid progression, extreme limitations in function, or bilateral involvement. This procedure is known to have good results. However, patients may have a limited return of lost functions.

Answer 37

**2. The recurrent course along the first anterior cerebral artery branch (A1) towards the anterior perforated substance** ## Footnote * The RAH has a characteristic course following its origin, which can be of help for its identification intraoperatively. * It always follows a recurrent course along with the first division of the anterior cerebral artery (A1) while transiting towards the anterior perforated substance. * This course is therefore responsible for its latest naming as the Recurrent artery of Heubner. * Orbitofrontal artery is the first division of the anterior cerebral artery. The origin of RAH is variable and can arise from A1, A1- ACOM junction, or A2. It sometimes only form rete communication with branches from other lenticulostriate vessels.

Answer 38

**4. An overweight 25-year-old woman who presents with severe bilateral vision loss, headaches, pulsatile tinnitus, and field constriction with severe bilateral optic disc edema, and an opening pressure of 55 cm H2O by lumbar puncture** ## Footnote * It is important to ensure that patients meet the diagnostic criteria for the diagnosis of PTC syndrome prior to considering surgical intervention. In patients, without optic disc edema or a localizing neurologic deficit the diagnosis of PTC syndrome can only be considered. ONSF is not indicated in the absence of optic disc edema and is not a primary treatment for headache management. * In the setting of secondary intracranial pressure (ICP) elevation from tumors, hydrocephalus, metabolic derangements, venous sinus thrombosis, etc., every effort should be made to directly address the underlying cause of ICP elevation as visual loss from papilledema is secondary to these etiologies. In the setting of brain tumors causing ICP elevation appropriate surgical and medical management should be instituted to address the lesion. * In patients with malignant PTC and severely elevated ICP causing severe vision loss, both ONSF and cerebrospinal fluid diversion procedures are sometimes performed concomitantly in an attempt to maximize the chance of preserving vision. This requires communication between ophthalmology and neurosurgery regarding the severity of the case and coordination of surgical procedures. * This patient has malignant PTC syndrome and is a candidate for ONSF as she has symptoms and signs of ischemic end-organ damage to the optic nerves from severely elevated ICP.

Answer 39

**1. Herniated nucleus pulposus** ## Footnote * Cauda equina lesions which may affect the patellar and Achilles reflexes can be distinguished from lesions to the conus medullaris, which affect the Achilles reflex but spare the patellar reflex. * Cauda equina lesions typically involve a herniated nucleus pulposus but also may occur due to a tumor or abscess. * The nucleus pulposus typically herniates in the postero-lateral direction due to the weak nature of the posterior longitudinal ligament. * Cauda equina syndrome may occur slowly over time but should be quickly addressed to prevent permanent sequelae.

Answer 40

**4. Atlantoaxial facet instability** ## Footnote * This is a variant of Group A Basilar Invagination. * Atlantoaxial facet instability predisposes to odontoid peg migration through the foramen magnum thereby causing brainstem compression. * All other associated anomalies such as the short neck, torticollis, Chiari malformation and syringomyelia is suggested to be secondary to basilar invagination only. * Reversal of this facetal slip and craniovertebral fusion has been shown to reverse such pathological sequelae and improve neurological outcome among patients. Crowded posterior fossa predisposes to Chiari malformations.

Answer 41

**4. CT perfusion studies** ## Footnote * The patient presented with recurrent ischemic events, which are pathophysiologically due to hypoperfusion. * Regular therapies used for stroke prevention, including antihypertensives, statins, and antiplatelets are not effective for moyamoya disease. * Anticoagulation is not effective and may cause an increased risk of bleeding. * It is important to perform perfusion study and acetazolamide challenge to identify the perfusion deficits and reserves, which will help in making decisions regarding revascularization therapy.

Answer 42

**1. Vancomycin 20 mg/kg and cefepime 2 g intravenously** ## Footnote * Cefepime is a fourth-generation cephalosporin with good Pseudomonas coverage. It is recommended in the setting of meningitis with recent neurosurgery or penetrating head trauma. Its structure allows better and more rapid penetration through the cell wall of aerobic gram-negative bacilli. * Ceftriaxone can also be used in basilar fractures at a dose of 2 g IV twice a day. * Ampicillin is primarily used for Listeria coverage. Listeria should be suspected in neonatal and older populations.

Answer 43

**2. Double-stranded DNA virus** ## Footnote * The patient has signs and symptoms of encephalitis, including fever, headache, papilledema, neck stiffness, and a tonic-clonic seizure. She also has an increased opening pressure of CSF with a spinal tap. * The CSF spinal tap findings in this patient suggest a viral cause due to an elevated CSF protein level, elevated leukocytes, of which 85% are lymphocytes and a normal CSF glucose concentration. These findings rule out bacterial or fungal causes and indicate a viral cause of encephalitis. * The most typical cause of viral encephalitis is herpes simplex encephalitis. Herpes simplex virus is a double-stranded linear DNA molecule. * Herpes simplex encephalitis is an acute or subacute illness associated with focal or global cerebral dysfunction caused by herpes simplex viruses belonging to either type 1(HSV-1) or type 2 (HSV-2).

Answer 44

**2. Hypertension** ## Footnote * Charcot-Bouchard aneurysms are microaneurysms that measure 0.8-1.0 mm in diameter. * These tiny aneurysms occur at well-defined anatomical locations like the pons, basal ganglia, subcortical white matter, and cerebellum. * Charcot-Bouchard aneurysms are associated with long-standing hypertension. Over time, the tiny blood vessels are infiltrated with hyaline and fatty substances, a pathological process that is known as hypertensive lipohyalinosis. * Charcot-Bouchard aneurysms are the principal cause of primary intracerebral hemorrhage and commonly arise at the bifurcation of small arteries that lie deep within the brain parenchyma

Answer 45

**3. Macula** ## Footnote * The macula is also called the macula lutea for its yellowish pigmented appearance and offers the greatest visual acuity within the retina. * Light is focused onto the macula which contains a high concentration of cone cells and is located temporally from the optic disc. * The photoreceptor cells within the macula transmit light sensory information onto the bipolar cells and then to the ganglion cells which become the optic nerve. * The symptoms presented are common in retinal detachment which results in vision loss as the macula is displaced and the photoreceptor cells degenerate from ischemia.

Answer 46

**2. Cervical spine radiographs** ## Footnote * Rheumatoid arthritis is a disease of the synovium. At the spine, C1 and C2 are the only vertebral bodies that have synovium. Hence, the only vertebral bodies which RA involves are C1 and C2. When RA affects the synovium tissue between these C1 (atlas) and C2 (axis), it may result in abnormal movement of the atlas relative to the axis. This abnormal movement may result in injury to the spinal cord. * The involvement of the atlantoaxial joint generally occurs in patients with long-standing RA. These patients often have severe peripheral disease, joint deformities of the hands as a result of RA. Erosion might be present on radiographs. * Most of the time, these patients have not been adequately managed for RA. This may be due to a lack of regular follow up for RA due to nonadherence or other reasons. * When RA patients are about to undergo general anesthesia, it is best to have an X-ray of cervical spine to evaluate for atlantoaxial instability to prevent any damage to the spinal cord at the time of intubation.

Answer 47

**3. At 12 hours** ## Footnote * LP is often negative when done within the first 2 hours after the bleed. * LP is most sensitive at about 12 hours after symptoms occur. * Noncontrast CT is usually diagnostic and done before LP. * An LP is usually performed to assess for presence of RBCs and xanthochromia. Unlike a traumatic tap, the number of RBC in subarachnoid hemorrhage will remain elevated in all tubes. The fluid can also be spun down. Xanthochromia of the supernatant is usually seen in subarachnoid hemorrhage.

Answer 48

**2. 30 mg** ## Footnote * Intraventricular instillation of antibiotics is a valid option in treating patients with ventriculitis. * The dose of amikacin through the intraventricular route is 1/20th of the intravenous dose. * The average daily dose of amikacin through the intraventricular route is 30 mg. The maximum daily dose of amikacin should not exceed 50 mg. * The dosage of amikacin in excess of 30 mg daily has shown to be associated with a high incidence of adverse effects, including choroid plexitis and the risk of an intraventricular bleed.

Answer 49

**3. Repeat the medial branch block with a longer-acting local anesthetic** ## Footnote * There is a 25% to 40% false positive rate with medial branch blocks. Thus, a second block is necessary to establish a diagnosis of facetogenic pain. * If the patient's pain is truly facetogenic, a second diagnostic block should produce pain relief for a longer duration than the lidocaine block. Bupivacaine is a longer-acting agent that is commonly utilized. * Since only lidocaine was used, the pain relief obtained should be transient. * The goal of medial branch radiofrequency ablation is to provide six or more months of relief. It can be repeated.

Answer 50

**3. Grade III** ## Footnote * Moderate disability comes under Grade III of MIDAS score. * Grade I shows little or no disability, grade II mild disability, and grade IV severe disability. * The need to take medicines everytime is also an indicator of moderate to severe disability. * This patient will require prophylactic treatment of migraine.

Answer 51

**4. Craniotomy with drainage of the subdural hematoma** ## Footnote * Surgery is generally recommended for subdural hematomas which are either symptomatic, 1 cm or more in greatest thickness, or causing 5 mm or more of midline shift. * A twist drill hole for subdural hematoma evacuation has the lowest operative complication rate and highest recurrence rate. * A burr hole evacuation of subdural hematoma has an intermediate operative complication rate and intermediate recurrence rate. * A craniotomy for subdural hematoma evacuation has higher operative complication rate than twist drill hole or burr hole evacuation but also has a lower recurrence rate than either two procedures.

Answer 52

**3. Nasal, lacrimal, ethmoid, maxillary, and frontal bones** ## Footnote * The nasoorbitoethmoid (NOE) is the confluence of the frontal sinus, ethmoid sinuses, anterior cranial fossa, forehead, orbits, and nasal bones. * The NOE encompasses the vertical and horizontal buttresses of the central face. * Nasoorbitoethmoid fractures are caused by high impact anterior force to the nose and then transmitted posteriorly towards the ethmoid. This can result in telecanthus, nasofrontal duct disruption, orbital injuries, and rhinorrhea. * A thorough understanding of NOE anatomy is critical to avoid complications and obtain an aesthetic surgical result.

Answer 53

**1. There is no convincing evidence for closing an annular fissure** ## Footnote * There is no convincing evidence for closing an annular fissure. * Many surgeons consider a fusion if there are three or more recurrent disc herniations at the same level although some would consider fusion after the first recurrence. * Some patients may need fusion with the first disc herniation depending on other radiologic and anatomic factors. * Many different devices have been developed for closing an annular fissure but robust data for their use is still pending.

Answer 54

**3. Rocuronium** ## Footnote * Conditions that can cause resistance to non-depolarizing neuromuscular blockers include cerebral palsy, burn injuries, hemiplegia, peripheral nerve injuries, chronic infections of botulism, and tetany. * Rocuronium dosing for intubation is IV 0.45 to 0.90 mg/kg and maintenance with 0.15 mg/kg boluses. * In this patient, non-depolarizing neuromuscular blockers may not be effective because the patient was administered a combination of two anticonvulsants (valproic acid, carbamazepine). Anticonvulsants can cause increased resistance to blockade activity. * Other agents that cause resistance are the anticholinesterase inhibitors neostigmine and pyridostigmine.

Answer 55

**1. Conus medullaris syndrome presents with upper motor neuron signs like spasticity and hyperreflexia** ## Footnote * Because CMS always involves the terminal end of the spinal cord at around T12/L1, while CES can involve the conus or only involve the L1-L5 nerve roots, it is much more likely to present with upper motor neuron signs. CES usually presents with lower motor neuron signs only, such a hypotonia, hyporeflexia due to the termination of the upper motor neurons synapsing into the cord above the cauda equina nerve roots. * Saddle anesthesia is neither sensitive not specific for the CES/CMS syndromes and does not carry a high positive predictive value for the diagnosis. * The bladder receives innervation from both the parasympathetic and sympathetic systems and loss of either or both systems can lead to urinary retention in CES/CMS. * Surgical decompression is commonly done through the posterior midline approach to the lumbar spine.

Answer 56

**1. Recommend surgical biopsy of the area for definitive diagnosis** ## Footnote * This patient's MRI is compatible with tumor recurrence; glioblastoma multiforme commonly shows a palisading pattern. * When symptoms plus an MRI is not diagnostic for radiation necrosis, it is best to biopsy for definitive diagnosis and treatment. * The underlying pathologic process for radiation necrosis is ischemia due to endovascular breakdown. * Subjecting the patient to inappropriate therapeutic trials of hyperbaric oxygen therapy would delay definitive diagnosis and treatment. Further radiation therapy could cause worsening of the patient's condition if the underlying problem is radiation necrosis.

Answer 57

**2. Lysis of left zygomaticotemporal nerve** ## Footnote * This patient has a refractory migraine. The trigger site is at the left temporal region, which has been confirmed by botulinum toxin. Repeat injections of botulinum toxin lead to the development of antibodies to the toxin, which leads to the development of resistance, decreasing its effects. * The zygomaticotemporal nerve is the sensory supply to the temporal region. Lysis of this nerve can lead to relief of her symptoms. * The incision is made at the superior temporal line. * It can be performed through either open or endoscopic routes.

Answer 58

**1. Magnetic resonance imaging (MRI) of the cervical spine to evaluate for cervical pathology** ## Footnote * Due to its high specificity, a positive Spurling test is highly indicative of cervical radiculopathy, and further imaging of the cervical spine is often warranted. To perform the Spurling test, the examiner turns the patient's head to the affected side while extending and applying downward pressure to the top of the patient's head. A positive sign is if the pain starts in the neck and radiates in the direction of the corresponding ipsilateral dermatome. * In patients with cervical radiculopathy, MRI is the imaging study of choice. X-ray is an excellent first choice in the case of trauma, but in non-traumatic cervical radiculopathy, it is rarely diagnostic. * In patients with atypical presentation of carpal tunnel syndrome such as neck pain or hand pain not limited to median nerve distribution, cervical pathology should be considered. * In patients with moderate to severe carpal tunnel syndrome, a surgical referral is appropriate, but cervical radiculopathy should be ruled out in patients with atypical presentation.

Answer 59

**3. Plan for eventual ventriculoperitoneal (VP) shunting** ## Footnote * Early VP shunting is justified in post TB meningitis communicating hydrocephalus who show significant recovery following EVD placement. * Early shunt minimizes the risk of infection and meningitis following prolonged days of EVD placement. * There is also no added risk of the shunt being obstructed and nonfunctioning since the tubercular bacilli cannot colonize the shunt tube since they don't form the slime layer. * ETV shows a low success rate in communicating hydrocephalus secondary to tuberculosis. It is also not possible in all centers. However, it has been suggested in patients with chronic illness and VP shunt is suggested in the acute phase of illness. Only ATT therapy would not counteract the hydrocephalus part in TB meningitis. They invariably require permanent CSF diversion

Answer 60

**2. MRI without contrast** ## Footnote * MRI without contrast is necessary to see the spinal cord, ligaments, soft tissue, and disc spaces in this patient. * X-ray is a good imaging modality for initial diagnosis of Klippel- Feil syndrome but is not adequate in this case. * CT scan is an appropriate imaging modality for the evaluation of bony fusion for possible operative planning. * CT scan without contrast is a good imaging platform to evaluate cervical spine fracture in this population as well.

Answer 61

**1. 36-inch standing films** ## Footnote * For imaging, 36-inch standing films are the mainstay of spinal alignment imaging. * A standard 36-inch, two-view x-ray is crucial to evaluate the global spine and lumbopelvic relationships. Sagittal alignment parameters such as pelvic tilt (PT) and sagittal vertical axis (SVA) are measured on these images, and preoperative planning requires these values. * New biplanar x-ray with 2D to 3D reconstruction systems allow standing evaluation of the global spine and pelvis, which provides the benefits of both plain film and CT scan. The main advantage over traditional CT is the lower dose of radiation, which may be 800 to 1000 times less. However, this is a new technology and is only used at select centers at the current time. * MRI is useful for the examination of soft tissue deformities and neural elements. This patient does not exhibit any signs of stenosis or radiculopathy. It is important to remember the CT/MRI modalities are recombinant imaging platforms, not standing.

Answer 62

**1. 26%** ## Footnote * The intracerebral hemorrhage (ICH) score predicts 30-day mortality based on patient with non-traumatic intracerebral hemorrhage. * The score is based on Glasgow coma score (GCS), age, 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 63

**4. Failed back surgery syndrome** ## Footnote * This patient presents with low back pain despite surgical intervention. Her presentation is concerning for failed back surgery syndrome (FBSS). Numerous factors are associated with the development of FBSS despite surgical intervention. This includes history of multiple spine or back surgeries, psychiatric comorbidities such as depression, and the presence of ongoing litigation or worker’s compensations claims. This patient presents with persistent low back pain despite conservative and surgical intervention. Her persistent low back pain despite multiple prior back surgeries suggests a clinical diagnosis of failed back surgery syndrome. * Patients with fibromyalgia present with multiple tender areas that are may respond to neuropathic medications. The history of persistent low back pain despite surgical intervention and conservative management suggests failed back surgery syndrome. * This patient's hypertension is currently well controlled by her primary care physician. It is very unlikely that low back pain with radiculopathy could be explained by a hypertensive emergency. * Failed back surgery syndrome (FBSS) is a very difficult condition to treat. FBSS should be high on the differential for patients with persistent low back pain after surgical and conservative interventions. Appropriate diagnosis can result in appropriate treatment with modalities like spinal cord stimulator implantation. Spinal cord stimulator implants have been shown to reduce low back pain among patients with FBSS dramatically

Answer 64

**2. Computed tomography with angiography of the head and neck** ## Footnote * Blunt cerebrovascular injury (BCVI) is very common in patients who are subjected to high energy transfers during an accident. The Denver criteria was established to define screening parameters for patients who are susceptible to BCVI and who should undergo formal testing for diagnosis and treatment. * Even with appropriate screening parameters, as suggested by the Denver or modified-Memphis criteria, 20% of patients are missed who have clinically significant BCVI. * Multi-slice, high-resolution computed tomography with angiography of the head and neck has become as close to the gold standard of formal four-vessel cerebrovascular angiogram as possible. It is considered the test of choice to evaluate patients for blunt cerebrovascular injury. Its downsides are potential additional radiation dosage (especially in children) as well as an increase in dye load which can lead to contrast nephropathy. Furthermore, for low-grade injuries, Biffl grade I, it has a high false-positive rate, which approaches 48%. * Magnetic resonance angiography is a useful alternative to evaluate for blunt cerebrovascular injury, especially in patients with acute kidney injury as it doesn't utilize IV contrast. However, it has less sensitivity than formal computed tomography with angiography. Furthermore, it does have additional downsides such as it takes longer to perform, the patient must remain still (difficult in children or intoxicated/uncooperative patients), removes a potentially sick patient from a monitored setting. To evaluate for BCVI, MRA should be done for the head and neck and not just for the head as the answer states. Carotid duplex angiography is able to evaluate the carotid arteries well but has very low sensitivity evaluating the posterior circulation consisting of the vertebral arteries which are enclosed within a bony canal. It is not considered adequate as a screening tool to evaluate for BCVI.

Answer 65

**4. STAT Thoracolumbar MRI** ## Footnote * An intrathecal granuloma is a non-infectious mass of fibroblasts, collagen and a few inflammatory cells that usually arise from the arachnoid layer of the meninges as a result of an inflammatory reaction near the site of the catheter tip. * Risk of granuloma development appears to correlate directly with duration if IT therapy, daily dose and rate of drug titration. * Patients who present with increasing pain and change in their neurologic function should be evaluated for granuloma formation. * If granuloma is suspected the diagnosis should be confirmed with an MRI with or without contrast to assess the catheter tip.

Answer 66

**2. MR angiogram or CT angiogram** ## Footnote * CT angiogram or contrast MR angiogram are best in visualizing the vertebrobasilar system to define stenosis or occlusions. The studies also can be performed when the patient is asked to extend his or her neck to reproduce the symptoms. * Duplex ultrasound may also be used to visualize the vertebral artery, but the images generally are not good enough for the diagnosis. * MRI is a better imaging modality for brainstem and posterior fossa problems, especially acute brainstem infarction with diffusion-weighted imaging. However, MRI cervical spine will not show stenosis or occlusion of the vertebral arteries which are the presenting symptoms of this patient. * If a patient with vertebrobasilar insufficiency is younger than 45 years of age, further workup is indicated to rule out a cardioembolic cause, hypercoagulable states, vertebral dissection, and fibromuscular dysplasia.

Answer 67

**4. Gradual challenging of the EVD up to 15 cm above the tragus for 24 hours, followed by removal and stitching of the exit wound** ## Footnote * Removal of EVD in cases of hydrocephalus sometimes poses a risk of progression of the hydrocephalus and clinical deterioration following its removal. * It has been found that a gradual rise in the EVD draining height without closing the drain system (training the EVD) would prevent the risk of an inadvertent rise in ICP by the egress of CSF only at high-pressure points. * Clamping the EVD is an option, but there can be sudden deterioration due to the progression of hydrocephalus and can be missed or diagnosed late based on clinical examination only. * Repeat images to assess any progression in hydrocephalus are valid only in cases of chronic and slowly progressive hydrocephalus. Sudden deterioration following acute hydrocephalus requires either reinserting the EVD or opening the clamped drainage system.

Answer 68

**4. The patient is not a surgical candidate for the intervention which would meet her needs** ## Footnote * Cordotomy leads to the nociceptive pathways in the lateral spinothalamic tract anterolateral column being destroyed in the cervical spinal cord at the level of C1-C2. * Percutaneous cordotomy is contraindicated in patients with a coagulation disorder, such as patients with liver failure. * Patients must be at level 3 of pain on the World Health Organization (WHO) cancer ladder with a prognosis of under six months to be a candidate for cordotomy. * In otherwise healthy patients without contraindications, the risk of severe complications with unilateral cordotomy is low.

Answer 69

**2. Inflicted traumatic brain injury** ## Footnote * The findings of an irritability high-pitched cry and bulging fontanelle are suggestive of inflicted traumatic brain injury, also known as abusive head trauma, non-accidental head trauma, or shaken-baby-syndrome. * The lucencies of the posterior ribs are suggestive of posterior rib fractures. Posterior rib fractures are suggestive of child abuse. * The inflicted traumatic brain injury occurs due to the rapid acceleration-deceleration caused by shaking and direct impact to the head causing tearing of the bridging veins. * Inflicted traumatic brain injury can be manifested with nonspecific symptoms such as fussiness, altered mental status, and vomiting. Head CT scan is the next diagnostic study.

Answer 70

**4. Posterior fossa and foramen magnum decompression** ## Footnote * The case depicts Group B basilar invagination with Chiari malformation. * The current recommendation is posterior fossa and foramen magnum decompression only. Since dura is expansile there is no need for performing duroplasty. * Since basilar invagination and resulting crowing of the posterior fossa predisposes to Chiari malformation, standalone surgical decompression is justified since there is a reversal in the Chiari process following the same. * Transoral decompression is now not advocated even for Group A Basilar Invagination. Duroplasty predisposes to a pseudomeningocele formation as well as added risk of CSF leak and meningitis.

Answer 71

**2. Posterior columns of the spinal cord** ## Footnote * Deficiency of vitamin B12 causes damage to both the posterior and lateral columns of the spinal cord. * There is gliosis, demyelination, and vacuolar degeneration predominantly of the upper thoracic and lower cervical regions. * There is a subsequent axonal loss. * A positive Romberg indicates impaired position sense, carried by the posterior columns.

Answer 72

**2. 0.9 percent** ## Footnote * As per the revised cardiac risk index, this patient has only one risk factor for possible life-threatening complications. * The planned surgical intervention (carotid endarterectomy) is the only risk variable in the patient. * This one point gives a risk of 0.9% for any major complications in the patient. * 2 points have a risk of 6.6% whereas 3 or more points have a risk of 11%.

Answer 73

**3. Intravenous desmopressin** ## Footnote * insipidus (DI) is a common complication following pituitary surgery. DI is a disease process that results in either decreased release of or response to antidiuretic hormone (ADH, also known as vasopressin or AVP), which can cause electrolyte * Most cases of diabetes insipidus following transsphenoidal hypophysectomy are transient. About 20% of patients who undergo neurosurgery will present with diabetes insipidus. * Treatment is with fluid replacement and desmopressin. The most common findings in patients with diabetes insipidus are polydipsia, polyuria, and nocturia. * Risk factors for developing diabetes insipidus due to transsphenoidal hypophysectomy include craniopharyngioma or extensive intraoperative handling of the pituitary gland. Hydrochlorothiazide is used for resistant DI.

Answer 74

**4. Resection of granulation tissue at the affected level** ## Footnote * For patients who fail conservative treatment, resection of granulation tissue at a chronic annular disc tear can be considered. * Granulation tissue of an annular disc tear shows some contrast enhancement on T1 MRI sequencing. * First line treatment for symptomatic annular disc tear is non- steroidal anti-inflammatory medications and low-impact physical therapy. * Transforaminal lumbar steroid injections can be considered in patients with annular disc tears who fail non-steroidal anti- inflammatory medications and low-impact physical therapy.

Answer 75

**4. Stork test** ## Footnote * Spondylolysis usually remains asymptomatic with only 10% of affected individuals manifesting symptoms. * For symptomatic spondylolysis, patients' typically present with an insidious, recurrent, achy low back pain which radiates to the buttocks and posterior thighs and is exacerbated by lumbar hyperextension activities. * On physical exam patients' with spondylolysis will commonly demonstrate increased lumbar lordosis, tight hamstrings, and tenderness to palpation overlying the pars interarticularis fracture site. * The stork test involves the patient performing a single leg hyperextension and rotation of the spine and if this maneuver reproduces the patients pain it is considered diagnostic of spondylolysis until proven otherwise.

Answer 76

**1. Skin- superficial fascia- thoracolumbar fascia- lamina portion of the L3/L4 vertebrae** ## Footnote * The outermost layers involve the skin and superficial fascia. The thoracolumbar fascia is a deep investing fascia surrounding the posterior thorax and abdomen. This fascia of the lumbar spine assists in supporting the vertebral column when it is in a flexed position. The vertebral bodies can be found deep to the thoracolumbar fascia. This must be penetrated to reach the lamina of the vertebral bodies. * The transverse process of the vertebral bodies is not involved in the laminectomy procedure. It is the lamina portion of the vertebral body that is removed to allow space for the nerves to pass without compression. * The posterior longitudinal ligament is deep to the spinous process, transverse process, and lamina parts of the vertebral bodies. The laminectomy procedure would not require exposure of the posterior longitudinal ligament. * The spinous process of the lumbar vertebral bodies is superficial to the posterior longitudinal ligament. It also should be noted that the spinous process of the vertebral body is not involved in a laminectomy.