Neurology Board Review

1. Neurology Board Review Stroke and Spinal Cord Disorders

2. Diagnosis of acute stroke • Head CT without contrast = initial test of choice to identify hemorrhagic stroke. • MRI can identify acute ischemia or a nonvascular cause. • Hemorrhagic stroke cannot be reliably distinguished from ischemic stroke on clinical grounds alone. Coma, meningismus, seizures at onset, vomiting, headache, and a diastolic blood pressure greater than 110 mm Hg makes hemorrhagic stroke more likely. • CT angiography is commonly used to identify patients who may benefit from endovascular treatment or to identify potential sources of hemorrhage.

3. Transient Ischemic Attack • Any focal neurologic deficit caused by impaired cerebral blood flow that lasted <24 hours • The ABCD2 score (based on Age >60, Blood pressure >140/90, Clinical presentation, Duration of symptoms, and the presence of Diabetes) to stratify risk of subsequent stroke. • The risk of subsequent stroke at 90 days approaches 10% in patients who have a TIA, with the highest risk in the first 48 hours • Hospital admission is recommended for all patients seen within 72 hours of initial symptoms whose ABCD2 score is at least 3.

4. Ischemic Stroke • Defined by presence of cerebral infarction on imaging, but may not be seen if the infarct is small or located in the brainstem. • 20% of ischemic strokes are cardioembolic • 20% from large artery atherosclerosis • 25% are small subcortical infarcts • 30% are cryptogenic strokes, for which no cause is identified • 5% have rare causes, such as cerebral artery dissection or vasculitis.

5. Treatment of acute ischemic stroke • Recombinant tissue plasminogen activator (rtPA) is effective within 3 hours of acute ischemic stroke. • National guidelines recommend that treatment be initiated within 1 hour of arrival at the emergency department. • Risk factors for hemorrhage after tPA include large infarct size, poor BP control, hyperglycemia, and treatment after the appropriate time window. • tPA requires ICU x 24 hrs. Avoid surgical procedures and antithrombotic treatment for 24 hours. • Prior to tPA, BP should be <185/110 mm Hg, which can be achieved by labetalol or nicardipine infusions. • After tPA infusion, BP target is <180/105 mm Hg. • In patients ineligible for tPA, blood pressures up to 220/120 mm Hg are permitted with the intention of improving cerebral perfusion

6. tPA Exclusion Criteria • Minor or rapidly improving symptoms • Seizure at stroke onset • Other stroke or trauma within 3 months • Major surgery within 14 days • History of intracerebral hemorrhage • Sustained BP ≥185/110 • Suspicion of SAH • Arterial puncture at noncompressible site within 7 days • Received heparin within 48 hours and PTT elevated • INR >1.7 • Plt <100,000 • Glc <50 or >400

7. Hemorrhagic Stroke • Intracerebral hemorrhage • Use labetalol or nicardipine infusion for aggressive BP control if SBP>200 mm Hg • If SBP >180 mm Hg, target SBP <160 if no elevated ICP or <140 if elevated ICP • Reverse anticoagulation as quickly as possible. The efficacy and safety of platelet transfusions in the setting of antiplatelet-associated ICH have not been established. • If elevated ICP, need medical stabilization followed by surgical evacuation of the hematoma. Intubation and short-term hyperventilation followed by osmotherapy with either mannitol or hypertonic saline. • Cerebral hemorrhage may obscure an underlying tumor, so need repeat imaging 4 to 6 weeks after the initial event.

8. Hemorrhagic Stroke • Subarachnoid hemorrhage • Typically caused by a ruptured cerebral aneurysm • If CT head is negative for SAH but the clinical suspicion remains high, do lumbar puncture to look for erythrocytes and xanthochromia. • Angiography to delineate the anatomy of a ruptured cerebral aneurysm and to rule out other causes of subarachnoid hemorrhage, such as intracranial arterial dissection or mycotic aneurysms. • Causes of decline in neurologic status after SAH are rebleeding and elevated ICP (cerebral edema, hydrocephalus) in the acute setting, and arterial vasospasm 5 days or more after the hemorrhage. • Nimodipine to prevent vasospasm.

9. Dural Venous Sinus Thrombosis • Venous thrombosis should be considered if there are focal neurologic symptoms; often accompanied by severe headache, a depressed level of consciousness, and seizures. 50% have papilledema. • Most common location is the superior sagittal sinus. • Cavernous sinus thrombosis results in a characteristic neurologic syndrome that includes lesions of cranial nerves III, IV, V (V1 and V2), and occasionally VI. • Risk factors: hypercoagulable disorders, malignancy, trauma, systemic inflammatory disorders, severe dehydration or infection, or pregnancy. • Definitive treatment for venous thrombosis has not been established, but most experts recommend anticoagulation for 6 months, even in the setting of ICH.

10. Carotid and Vertebral Artery Dissection • Rare cause of stroke but should be considered in persons younger than 50 years. • The presence of a partial Horner syndrome (ptosis and miosis without anhidrosis) with head or neck pain should prompt investigation for ICA dissection. • Obtain MRI of the soft tissues in the neck • Anticoagulation for 3 to 6 months is commonly used in treating arterial dissection.

11. Secondary Stroke Prevention • HTN is the greatest risk factor. To prevent recurrent stroke, aim for BP<140/80 • Goal LDL<100 • Symptomatic extracranial ICA stenosis > 70% is a risk factor for recurrent stroke. Carotid endarterectomy (gold standard) has a higher risk of perioperative myocardial infarction, but angioplasty and stenting has a higher risk of perioperative stroke, especially if >70 years old. • No benefit of percutaneous closure of patent foramen ovale for stroke prevention.

12. Secondary Stroke Prevention • Antiplatelet agents are recommended over anticoagulation in patients with stroke who have intracranial atherosclerosis because warfarin was associated with an increase in mortality. • For stroke prevention in patients without atrial fibrillation, the most commonly used aspirin dosage is 81 mg/d. • Clopidogrel is better for stroke prevention in patients with peripheral arterial disease • Clopidogrel or aggrenox for patients with recurrent ischemic stroke despite optimal risk factor management while treated with aspirin. • The combination of aspirin and clopidogrel is not commonly used in patients without cardioembolic stroke unless they have vascular stents or a previous myocardial infarction

13. Compressive Myelopathies • Spinal cord compression is neurologic emergency, can occur in cases of metastatic neoplasm, vertebral fracture (pathologic or traumatic), epidural abscess, or epidural hematoma. • Neck or back pain is often the initial symptom, followed rapidly by weakness, sensory changes, and bowel or bladder dysfunction • Chronic spinal degenerative changes also can cause a compressive myelopathy, with progressive weakness, numbness, spasticity, and bladder impairment • MRI of the spinal cord to diagnose • High-dose corticosteroids, most often dexamethasone, is indicated for traumatic spinal cord injury or epidural metastases. • Decompressive surgery followed by radiotherapy for metastatic tumors. Decompressive surgery provides the best chance for future ambulation. Leukemia, lymphoma, myeloma, and germ-cell tumors are very sensitive to radiation and may not require surgery.

14. Noncompressive Myelopathies • Idiopathic transverse myelitis: postinfectious syndrome (usually after viral gastroenteritis or URI) with a subacute weakness, sensory changes, and bowel or bladder dysfunction and is sometimes preceded by back pain or a thoracic banding sensation. • Dx: clinical features of the syndrome, evidence of inflammation (such as contrast enhancement of the lesion on MRI or leukocytosis in the cerebrospinal fluid), and exclusion of other potential causes. • Tx: Intravenous methylprednisolone (1 g) x 3-5 days. Transverse myelitis that is refractory to steroids may require plasmapheresis or cyclophosphamide. Recurrence of symptoms beyond 30 days of initial onset suggests the presence of other diseases, such as multiple sclerosis.

15. Noncompressive Myelopathies • Infectious causes: HSV, VZV, West Nile virus, Lyme, neurosyphilis, HIV, tuberculosis • Vascular causes: Spinal cord infarction (eg. anterior spinal artery). Acute bilateral weakness, loss of pain and temperature sensation, but vibration and position sense are often spared because of the redundant vascular supply to the posterior aspect of the cord. Diagnose by angiography. • Metabolic causes: • Severe vitamin B12 deficiency may result in a subacute combined degeneration of corticospinal tracts and the dorsal columns. Replacement therapy will usually halt progression of but may not improve symptoms. • Copper deficiency can be clinically indistinguishable from vitamin B12 deficiency.

16. A 37-year-old woman presents with 1-week history of headache. The headache is constant, worse when she first awakens, and characterized by a feeling of increased pressure. She reports no other focal neurologic symptoms. The patient has a 10-pack-year history of smoking. Her only medication is a low-dose estrogen oral contraceptive. On physical examination, temperature is normal, BP 112/78 mm Hg, pulse 62/min and regular, RR 16/min; BMI is 37. Bilateral papilledema is noted. The Valsalva maneuver increases the headache pain. All other general and neurologic examination findings are unremarkable. Laboratory studies show a normal leukocyte count, a platelet count of 322,000/µL (322 × 109/L), an INR of 1.1, and an activated partial thromboplastin time of 36 s. An MRI of the brain without contrast is normal. Which of the following is the most appropriate next diagnostic test? • Cerebral angiography • Lumbar puncture • Magnetic resonance venography • Measurement of serum lupus anticoagulant level

17. This patient should next undergo magnetic resonance venography. Her headache, (worse in AM and with Valsalva) is consistent with elevated ICP. Combined with her history of tobacco and oral contraceptive use, and the presence of papilledema, she most likely has dural sinus venous thrombosis. Dural sinus venous thrombosismay also present with focal neurologic findings, seizures, and mental status changes. • Risk factors include conditions that predispose to spontaneous thromboses (inherited or acquired thrombophilia, pregnancy, OCP use, malignancy, sepsis, head trauma). • Magnetic resonance venography is the most sensitive imaging modality for detecting the thrombus and the occluded dural sinus or vein. • The recommended treatment is smoking cessation, discontinuation of oral contraceptives, and systemic anticoagulation to prevent sequelae related to elevated intracranial pressure for 6 months if no hypercoagulable disorder is found.

18. A 71-year-old woman is evaluated in the emergency department 90 minutes after onset of left-sided weakness and slurred speech. She has a history of type 2 diabetes mellitus. Medications are glyburide and metformin. On physical examination, blood pressure is 178/80 mm Hg, pulse rate is 60/min and regular, and respiration rate is 16/min. No carotid bruits are heard. On neurologic examination, left facial weakness and left arm and leg weakness are noted; weakness is more pronounced in the left arm than left leg. Labs: aPTT 36s Platelet count 410,000 INR 0.9 Creatinine 1.1 CT scan of the head without contrast is normal. Six hours after tPA infusion, her blood pressure is 190/90 mm Hg and pulse rate is 68/min; the neurologic examination findings are unchanged except for increasing anxiousness. Which of the following is the most appropriate next step in treatment? • Aspirin • Cryoprecipitate • Diazepam • Nicardipine • Nitroprusside

19. Treatment guidelines indicate that after tPA infusion, BP should be <180/105 mm Hg. Nicardipine and labetalol are options to reduce the blood pressure to avoid intracerebral hemorrhage. • Aspirin should be avoided. Treatment antithrombotic and antiplatelet medications must be withheld for at least 24 hours after tPA administration • Intracerebral hemorrhage due to thrombolytic therapy presents with headache, nausea, vomiting, and a worsening of the neurologic exam. If clinically suspected, tPA infusion should be stopped and a repeat CT of the head obtained. If ICH present, consider cryoprecipitate and platelet infusion. However, in the absence of documented intracerebral bleeding, the administration of these agents is not indicated. • Diazepam also should not be administered. Although the patient's hypertension may be anxiety induced, treatment of the hypertension to prevent intracerebral hemorrhage is the priority. Additionally, benzodiazepines in the setting of acute stroke may impair recovery from neuronal injury and thus should be avoided. • Nitroprusside is relatively contraindicated in patients with acute ischemic stroke or hemorrhage because of the possibility of increasing intracranial pressure.

20. A 57-year-old man has a follow-up evaluation 3 months after discharge from the hospital, where he was treated for an ischemic stroke. He has a history of hypertension, dyslipidemia, and peripheral arterial disease for which he has required no revascularization procedures. Medications are enalapril, hydrochlorothiazide, rosuvastatin, and aspirin. On physical examination, blood pressure is 138/68 mm Hg, pulse rate is 68/min and regular, and respiration rate is 16/min. Cardiac examination reveals no carotid bruits. Neurologic examination shows only a right pronator drift. Results of laboratory studies show a platelet count of 340,000/µL (340 × 109/L), a serum creatinine level of 1.1 mg/dL (97.2 µmol/L), and an LDL cholesterol level of 68 mg/dL (1.76 mmol/L). A head CT scan and a brain MRI show a left pontine infarct. An electrocardiogram shows normal sinus rhythm with no ischemic changes. A transthoracic echocardiogram and a magnetic resonance angiogram of the head and neck are normal. Which of the following is the most appropriate treatment? • Add clopidogrel • Add ticlopidine • Add warfarin • Substitute clopidogrel for aspirin • Substitute warfarin for aspirin

21. This patient should receive clopidogrelinstead of aspirin. He has a small subcortical infarction and a history of peripheral arterial disease. The Clopidogrel versus Aspirin in Patients at Risk of Ischemic Events (CAPRIE) study showed that clopidogrel was superior to aspirin in preventing ischemic stroke, MI, and death, with the benefit being greatest among participants with peripheral arterial disease. The combination of aspirin and dipyridamolecould be another appropriate option for secondary stroke prevention. • The combination of aspirin and clopidogrel for ischemic stroke prevention was associated with a slight reduction in risk of ischemic stroke, but this was offset by hemorrhagic complications. • Although ticlopidine has been shown to be superior to aspirin in preventing recurrent stroke, it can cause agranulocytosis and thrombotic thrombocytopenic purpura. • For noncardioembolic ischemic strokes, aspirin and warfarin were shown to be equivalent in the Warfarin-Aspirin Recurrent Stroke Study (WARSS). This patient has no evidence of atrial fibrillation or other high-risk cardioembolic symptoms that necessitate treatment with warfarin or direct thrombin inhibitors. • The combination of aspirin and warfarin does not provide any additional protection against recurrent ischemic stroke and is associated with greater rates of hemorrhagic complications.

22. A 34-year-old woman is evaluated in the emergency department for acute onset of a severe headache. She has hypertension treated with lisinopril. On physical examination, blood pressure is 160/100 mm Hg, pulse rate is 78/min, and respiration rate is 12/min. General medical examination findings are normal. Neurologic examination shows that she is somnolent but readily arousable, with symmetric and briskly reactive pupils and a left arm drift. Results of routine laboratory studies are normal. A CT scan of the head shows a subarachnoid hemorrhage, with a thick clot in the right sylvian fissure, but no hydrocephalus or cerebral edema. Angiography shows a 10-mm right middle cerebral artery aneurysm. The patient undergoes urgent aneurysmal clipping with no complications and is started on nimodipine. She is transferred to the intensive care unit and has no further symptoms until 6 days after initial evaluation, when she is less responsive and has new left arm paralysis on neurologic examination. Which of the following is the most appropriate next diagnostic step? • CT angiography of the head • Electroencephalography • Lumbar puncture • MRI of the brain

23. The patient with subarachnoid hemorrhage should undergo CT angiography of the head. The complications after SAH are classified as early vs late. In the first 48 hours after hemorrhage, aneurysm rerupture and hydrocephalus are the principal causes of neurologic deterioration. Starting at day 5, the risk of cerebral arterial vasospasm emerges. • CT angiography can diagnose cerebral vasospasm. Treatment includes induced hypertension. Intra-arterial therapy with calcium channel blockers or angioplasty of the artery in spasm may be performed. • Convulsive and nonconvulsive status epilepticus, which is associated with poor neurologic outcome, is common and underdiagnosed after hemorrhagic stroke. If neuroimaging does not find a cause of neurologic decline, EEG may be an appropriate next step. • Lumbar puncture may be useful to measure intracranial pressure and diagnose postoperative meningitis. Repeat imaging, however, is first required to ensure that no mass effect is present that could precipitate cerebral herniation. • MRI may provide information on cerebral infarction but is less accurate than other means for determining vasospasm.

24. A 78-year-old woman is evaluated in the emergency department 12 hours after onset of left-sided weakness and slurred speech. She reports being unable to swallow water at home. She has a history of hypertension and type 2 diabetes mellitus, both of which she tries to control with lifestyle modifications. On physical examination, blood pressure is 190/90 mm Hg, pulse rate is 68/min and regular, and respiration rate is 16/min. Cardiac examination reveals no carotid bruits. Neurologic examination reveals facial weakness on the left side, severe dysarthria, left-sided hemiplegia, left-sided sensory loss, and normal mental status. Results of laboratory studies show a serum creatinine level of 1.1 mg/dL (97.2 µmol/L) and no serum troponins; urinalysis findings are normal. A CT scan of the head shows a faint hypodensity in the right posterior limb of the internal capsule. An electrocardiogram shows normal sinus rhythm with no ischemic changes. A chest radiograph is normal. Which of the following is the most appropriate treatment of this patient's elevated blood pressure? • Intravenous hydralazine • Oral candesartan • Oral labetalol • Oral nitroglycerin • No treatment is required

25. This patient does not require treatment of her elevated blood pressure (190/90 mm Hg) at this time. Because her initial evaluation occurred 12 hours after her acute ischemic stroke, she is not a candidate for tPA. The American Heart Association guidelines allow blood pressures of up to 220/120 mm Hg in patients with ischemic stroke who are ineligible for tPA, unless evidence of end-organ damage (active ischemic coronary disease, heart failure, aortic dissection, hypertensive encephalopathy, acute kidney failure, or preeclampsia/eclampsia) exists. Treatment with antihypertensive agents in the acute setting may lead to neurologic worsening due to a decline in cerebral perfusion in the area of the tissue at risk. • The blood pressure target of less than 220/120 mm Hg is maintained until hospital discharge to home or a rehabilitation facility, at which time patients can begin or resume taking antihypertensive medication.

26. A 76-year-old man is evaluated for an episode of left-handed weakness involving all five digits that occurred yesterday and gradually subsided over 3 hours. He has had two similar episodes in the past 2 weeks. He reports no other problems and has no pertinent personal or family medical history. An exercise stress test performed 1 year ago had normal results. His only medication is aspirin, 81 mg/d. On physical examination, blood pressure is 156/78 mm Hg and pulse rate is 76/min and regular. Cardiac examination reveals a right carotid bruit. Other physical examination findings are normal. Results of laboratory studies show a serum LDL cholesterol level of 156 mg/dL (4.04 mmol/L). An electrocardiogram shows normal sinus rhythm with no evidence of ischemia. A carotid duplex ultrasound shows 80% to 99% stenosis of the right internal carotid artery, which is confirmed by CT angiography. An MRI of the brain shows a 5-mm infarct in the right middle cerebral artery distribution. Which of the following will have the greatest impact in reducing the risk of recurrent stroke in this patient? • Carotid endarterectomy • Carotid stenting • Clopidogrel • Simvastatin

27. This patient should be referred for immediate R ICA carotid endarterectomy. He has had an acute ischemic stroke caused by symptomatic high-grade carotid stenosis. Carotid endarterectomy has been shown to be highly effective in reducing the risk of recurrent stroke (number needed to treat, 17) in the immediate poststroke period. With symptomatic carotid stenosis, the risk of recurrent stroke is 1% per day for the first 2 weeks after a stroke or transient ischemic attack, which indicates that the greatest benefit is gained when the procedure is performed early. • Endarterectomy was superior to stenting because stenting poses a greater risk of perioperative stroke than does endarterectomy. • No evidence supports the use of clopidogrel in the acute poststroke period in patients with symptomatic high-grade carotid stenosis. Antiplatelet agents generally provide only a marginal benefit in reducing the risk of stroke compared with surgery. • Statins have yet to be established as safe or efficacious in the immediate poststroke setting.

28. A 62-year-old woman is evaluated in the stroke unit for a 2-day history of difficulty speaking and right arm weakness. She has a history of hypertension and dyslipidemia and a 35-pack-year smoking history. Medications are lisinopril, atenolol, simvastatin, and aspirin. On physical examination, blood pressure is 148/78 mm Hg, pulse rate is 84/min and regular, and respiration rate is 12/min. Other general medical examination findings are normal. Neurologic examination shows mild sensory aphasia and right arm drift. An MRI of the brain shows an acute infarct in the left middle cerebral artery distribution that appears embolic. A magnetic resonance angiogram of the head and neck is normal. An electrocardiogram shows sinus rhythm and is normal. Telemetry performed over the next 3 days shows occasional premature ventricular complexes. A transesophageal echocardiogram shows no intracardiac thrombus, normal left atrial appendage velocities, and a patent foramen ovale with an atrial septal aneurysm. No evidence of deep venous thrombosis is found. Which of the following is the most appropriate next step in management? • Percutaneous PFO closure • Prolonged cardiac rhythm monitoring • Surgical closure of the PFO • Warfarin

29. This patient's condition should be managed with prolonged cardiac rhythm monitoring. She has infarcts that appear embolic on an MRI and no evidence of proximal arterial disease. As such, her stroke is classified as a cryptogenic ischemic stroke. According to data from recent studies, up to 25% of patients with cryptogenic ischemic stroke have paroxysmal atrial fibrillation on prolonged cardiac monitoring. • A diagnosis of atrial fibrillation would be the only reason for this patient to start warfarin for stroke prevention, and this patient has not yet been demonstrated to have atrial fibrillation. No clinical trials have shown the superiority of warfarin compared with aspirin in the prevention of recurrent cryptogenic stroke, even in the presence of a PFO. • The risk of recurrent stroke in patients with a PFO is low. Percutaneous or surgical closure of a patent foramen ovale has not been shown to reduce the risk of ischemic stroke in patients with an otherwise cryptogenic stroke.

30. A 56-year-old man is evaluated in the emergency department 7 hours after onset of right-sided weakness. He has a history of hypertension and osteoarthritis. Medications are hydrochlorothiazide and daily aspirin. On physical examination, the patient is fully awake and interactive. Blood pressure is 220/110 mm Hg, pulse rate is 86/min and regular, and respiration rate is 16/min. No papilledema is detected. Neurologic examination findings include slurred speech, a lack of movement in the right arm, trace antigravity movement in the right leg, and profound sensory loss to all modalities on the right side. Results of laboratory studies show an INR of 1.2, a platelet count of 375,000/µL (375 × 109/L), and a serum creatinine level of 1.4 mg/dL (124 µmol/L). Urine toxicology results are positive for cocaine. A CT scan of the head without contrast shows a right thalamic intracerebral hemorrhage with intraventricular extension and mild enlargement of the ventricles Which of the following is the most appropriate treatment? • External ventricular drain placement • Labetalol infusion • Metoprolol intravenously • Platelet transfusion

31. The patient should receive an infusion of labetalol. He has an intracerebral hemorrhage likely due to HTN, cocaine, and (possibly) aspirin. Hematoma expansion is an important predictor of a poor outcome in intracerebral hemorrhage, and HTN is one of the principal risk factors for expansion. In this patient, SBP should be lowered by an intravenous infusion of antihypertensive medication, with monitoring of vital signs every 5 minutes, particularly because the systolic blood pressure is greater than 200 mm Hg. Because labetalol is unlikely to interact with cocaine and cause an increase in blood pressure, it is the appropriate option. • In patients whose systolic blood pressure is greater than 180 mm Hg, a target blood pressure of 160/90 mm Hg is reasonable as long as there are no signs of elevated intracranial pressure; if intracranial pressure is elevated, a target systolic blood pressure of 140 mm Hg appears to be safe, according to recently published guidelines. • External ventricular drain placement is inappropriate in this awake and interactive patient, despite the hydrocephalus seen on imaging. If the patient were to develop impaired consciousness, then CSF shunting may be necessary to reduce elevated intracranial pressure. • Metoprolol is contraindicated in patients with cocaine intoxication because of unopposed α-activity potentially leading to coronary, and potentially cerebrovascular, vasoconstriction. • Whether platelet transfusions improve outcomes in patients with intracerebral hemorrhage or prevent hematoma expansion in patients taking antiplatelet agents remains unknown.

32. A 76-year-old woman is evaluated in the emergency department for a 2-week history of difficulty walking and four episodes of falling backward. The patient was previously mobile and independent with the use of a walker. She has an 8-year history of Parkinson disease characterized by bilateral tremors at rest, generalized bradykinesia and rigidity, start hesitation and freezing, postural instability, and a tendency to retropulse. She also has osteoarthritis of the knees and spine but no dementia. Medications are levodopa-carbidopa and acetaminophen. Physical examination reveals a thin, alert patient with a kyphotic posture. Vital signs are normal. Bilateral mild hand tremors at rest, neck flexion, and a markedly increased neck tone are noted. The legs are stiff, with three beats of clonus elicited by ankle dorsiflexion, and the toes are upgoing. The arms and hands have normal strength. Sensory examination shows decreased vibration perception to the mid-shins. Her deep tendon reflexes are brisk, with spread, and the plantar responses are extensor. She has difficulty lifting her legs off the gurney and is unable to stand because of leg weakness. Gait and balance cannot be tested because of her inability to stand. Which of the following is the most appropriate next step in management? • CT myelography • Head CT • Increased dosage of levodopa-carbidopa • Lumbar puncture • MRI of the cervical spine

33. An MRI of the cervical spine should be obtained. Acute onset of leg weakness and an inability to walk suggest a cause other than Parkinson disease, and could be caused by compressive cervical myelopathy. Her physical exam is notable for increased tone with ankle clonus, hyperreflexia, extensor plantar responses, and profound leg weakness. Her arm strength and reflexes are normal, which suggests the possibility of spinal cord compression from a combination of cervical arthritis, stenosis, and trauma. • Although CT myelography can also establish the diagnosis of cervical myelopathy and may be needed in patients in whom MRI is precluded, this technique is difficult to perform on an emergent basis and does not produce images of the spinal cord parenchyma. • A CT of the head will not show compression of the cervical spine. • This patient's symptoms are not consistent with a worsening of her Parkinson disease, and thus increasing her dosage of levodopa-carbidopa is unlikely to be helpful. • A lumbar puncture with CSF examination would help diagnose Guillain-Barré syndrome, which can cause a rapidly progressive subacute paraplegia. However, the clinical scenario and examination findings make this diagnosis unlikely

34. A 59-year-old woman is evaluated in the emergency department for a 4-day history of low back pain, leg weakness, and urinary incontinence. She was discharged from the hospital 1 week ago after undergoing a lumbar diskectomy as treatment for lumbosacral radiculopathy. Additional history includes nonvalvular atrial fibrillation with good systolic function and hypertension. Medications are warfarin, metoprolol, and acetaminophen as needed. On physical examination, temperature is 36.6 °C (97.9 °F), blood pressure is 145/65 mm Hg, and pulse rate is 68/min. Strength testing reveals 3/5 weakness in the right leg and 4/5 weakness in the left leg. Reflexes are 2+ in the arms, 1+ in the left patellar region, and 0 in the right patellar region and bilateral Achilles tendons. Laxity of the anal sphincter is noted. Laboratory studies show an erythrocyte sedimentation rate of 3 mm/h, a leukocyte count of 5800/µL (5.8 × 109/L), and an INR of 3.0. MRIs of the lumbosacral spine show a compressive epidural lesion at L2 through L5. Which of the following is the most appropriate management? • Add high dose methylprednisolone • Add vancomycin and ceftazidime • Discontinue warfarin and reverse the anticoagulation • Perform a lumbar puncture

35. The most appropriate management for this patient is discontinuation of warfarin and reversal of the anticoagulation. She most likely has cauda equina syndrome secondary to external compression of the spinal cord by a spinal epidural hematoma. Her recent surgery is a risk factor, which was likely exacerbated by early reinitiation of warfarin after the procedure. Stopping the warfarin and reversing the anticoagulation should be performed in preparation for subsequent surgical decompression. • Adding high-dose methylprednisolone to her treatment regimen is inappropriate because none of the clinical, laboratory, or imaging findings suggests the presence of an inflammatory disorder. • Although an epidural abscess is part of the differential diagnosis in this patient, the lack of fever, elevated leukocyte count, or elevated erythrocyte sedimentation rate makes the diagnosis highly unlikely and intravenous administration of antibiotics inappropriate • Lumbar puncture in this patient in her current state of anticoagulation is likely to exacerbate the underlying epidural hematoma.

36. A 63-year-old man is evaluated in the emergency department for a 2-day history of mid-back pain, leg weakness, and urinary incontinence. He was treated with surgical resection for prostate cancer 1 year ago. He has no other medical history of note. On physical examination, temperature is 36.8 °C (98.2 °F), blood pressure is 138/60 mm Hg, and pulse rate is 94/min. Bilateral leg weakness, decreased sensation to pinprick below the T9 level, and mild laxity of the anal sphincter are noted. Laboratory studies show a PSA of 34 ng/mL (34 µg/L) and a normal CBC. An MRI of the thoracic spine shows a contrast-enhancing epidural lesion causing spinal cord compression. In addition to starting intravenous corticosteroids, which of the following interventions is likely to provide the best chance for future ambulation in this patient? • Androgen-deprivation therapy • Chemotherapy • Decompressive surgery • Radiation therapy

37. This patient should next undergo decompressive surgery which provides the best chance for future ambulation. The most common cause of spinal cord compression is tumor metastasis to a vertebral body, which results in direct extension into the epidural space or a pathologic fracture. Pain is the most common initial presenting symptom, with neurologic symptoms typically evolving later. Corticosteroids should be administered immediately in patients with suspected spinal cord compression for improved pain management and prevention of further neurologic impairment. When feasible, decompressive surgery should be performed next, followed by radiation therapy. • Although radiation therapy does provide benefit for most tumor types, evidence from clinical trials shows that the addition of surgical decompression before radiation therapy is superior to radiation therapy alone, and direct head-to-head comparisons show more long-term benefit from surgery than radiation therapy. • Androgen-deprivation therapy (with a GnRH agonist or surgical castration) is used as adjuvant therapy in patients with high-risk disease and as first-line treatment in patients with an increasing PSA after initial definitive therapy for prostate cancer or in those with metastatic disease. It is not an effective treatment for spinal cord compression. • Chemotherapy is not an effective treatment for metastatic cancer causing spinal cord compression unless the tumor is highly sensitive to chemotherapy, such as lymphoma.

38. A 54-year-old man is evaluated for a 9-month history of progressively worsening paresthesia in the legs that has recently spread to the hands and a 6-month history of an ataxic gait. 3 years ago he had gastric bypass surgery. He takes a daily multivitamin, iron, ascorbic acid, calcium, and vitamins D, B6, and B12. On physical examination, temperature is 37.2 °C (99.0 °F), blood pressure is 110/60 mm Hg, and pulse rate is 70/min; BMI is 31. Neurologic examination shows decreased vibratory sensation in the hands and feet and decreased position sense in the feet. Hip flexion strength is 4/5 bilaterally, and reflexes are 3+ throughout with upgoing toes. Labs: Hgb 12.9 MCV 102 Vit B12 590 RPR nonreactive T2-weighted MRIs of the cervical and thoracic spines show slight hyperintensity in the posterior columns from approximately C4 through T9 with no contrast enhancement. Which of the following serum levels should be measured next? • Copper • Folate • 25-OH vitamin D • Thiamine • Vitamin A

39. This patient's serum copper level should be measured next to detect copper deficiency. The Roux-en-Y gastric bypass is a dual-mechanism bariatric surgery combining a small gastric reservoir, which restricts oral intake, with a small-bowel bypass, which induces mild malabsorption. Nutritional deficiencies of vitamin B12, iron, calcium, folate, and 25-hydroxyvitamin D are common in patients after gastric bypass. Less frequently, deficiencies of magnesium, copper, zinc, vitamin A, other B-complex vitamins, and vitamin C may occur. • This patient has a myelopathy (as evidenced by the hyperreflexia and upgoing toes) localizing to the posterior columns and bilateral corticospinal tracts. Common entities that cause dysfunction in this pattern are vitamin B12 deficiency, neurosyphilis, and copper deficiency. • Folate, vitamin D, thiamine, and vitamin A deficiencies are not associated with myelopathy.