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Neurology Board Review A 38-year-old woman is evaluated in the office for a 10-month history of increasingly frequent headache. The headache is often worse in the morning on awakening. She has recently started keeping a headache diary, which reveals episodes on approximately 25 days of each month. The headache varies from a near-daily bilateral frontal dull throbbing to a severe left hemicranial throbbing associated with nausea, photophobia, and phonophobia. The patient has a 20-year history of migraine without aura and a history of depression. Her mother also has a history of migraine and depression, and her sister has a history of 25% 25% 25% 25% migraine. The patient has been taking propranolol for 3 months; a mixed analgesic containing butalbital, caffeine, and acetaminophen for mild or moderate headache at least 3 days per week for 9 months; rizatriptan for severe headache at least 2 days per week for 4 months; and citalopram for 1 year. Rizatriptan has become increasingly ineffective over the past month. Physical examination findings, including neurologic examination findings, are normal. Which of the following is the most likely diagnosis for her current symptoms? 1. 2. 3. 4. Chronic migraine Chronic tension-type headache Idiopathic intracranial hypertension Medication overuse headache 1 2 3 4 Headache Symptoms Treatment Prophylactic Only image pt with headache if patient has a “red flag” for Migraine Unilateral, pulsating, Acetaminophen, Beta-blockers, secondary headache: last 4-72hrs + aura Aspirin, NSAIDs and TCAs, triptans anticonvulsants, 1. first or worst headache CCB 2. abrupt onset or thunderclap Cluster 3. progression Unilateral, severe Oxygen and Verapamil or fundamental change in headache pattern pain with vasomotor triptans 4. abnormal physical exam phenomenon 5. neurologic symtoms lasting longer than an hour 6. new headache in pt <5 >50 years old Tension7. new heache Squeezing, bilateral, Aspirin, Amitriptyline, in pt with cancer/pregnant/immunosuppressed chronic, constant, Acetominophen, gabapentin 8. headache with LOC non-pulsating 9. headache triggered by exertion,NSAIDs sexual activity or valsalva Idiopathic In obese womenRepeat LP’s, Weight reduction MRI is study of choice unless there acetazolamide, is a skull fracture, acute SAH or Intracranial morning headaches ICH and paranasal sinus Hypertension worse with incdisease! loop diuretics (Pseudotumor) pressure, papilledema Trigeminal Neuralgia Brief unilateral lancinating pain Carbamazepine, oxcarbazepine A 32-year-old woman is seen for a follow-up evaluation. She had a witnessed generalized tonic-clonic seizure 1 week ago and was evaluated in the emergency department, where results of physical examination, complete blood count, measurement of serum electrolyte levels, and urine toxicology screen were all normal. She is otherwise healthy, has no significant personal or family medical history, and takes no medications. Results of a repeat physical examination are also normal. 25% 25% 25% 25% In addition to electroencephalography, which of the following diagnostic tests should be performed next? 1. 2. 3. 4. Ct of the head Lumbar puncture MRI of the brain Positron emission tomography 1 2 3 4 A 70-year-old man is seen in the office for routine follow-up of partial seizures that began 2 years ago after a stroke. At that time, he was started on phenytoin, 300 mg/d, and has had no subsequent seizures; he tolerates the medication well, with no reported adverse effects. His current medications are phenytoin, an angiotensin-converting enzyme inhibitor, a statin, and aspirin. Results of physical examination, including a neurologic examination, are normal. 25% 25% 25% 25% Laboratory studies show a total serum phenytoin level of 9 mg/L (35.6 µmol/L) (therapeutic range, 10-20 mg /L [39.6-79.2 µmol/L]). Results of a complete blood count and liver chemistry tests are normal. Which of the following is the most appropriate next step in management? 1. 2. 3. 4. Continue the phenytoin at the current dosage Increase the phenytoin dosage Measure the free serum phenytoin level Substitute gabapentin for the phenytoin 1 2 3 4 Partial Seizures • Simple partial- focal seizure that does not impair awareness • Complex partial- involves an alteration of consciousness that typically occurs when the seizure spreads to involve one or both temporal lobes • Secondarily generalized- when a partial seizure spreads to involve both hemispheres diffusely and results in a generalized convulsion Generalized Seizures • Generalized tonic-clonic • Absence- momentary lapse of consciousness (typically less than 5 seconds) • Myoclonic- brief shocklike muscular contractions that can occur in rapid succession and usually are not associated with an impairment of consciousness Diagnostic Evaluation of Seizures and Epilepsy • Head CT in the acute setting • MRI brain • EEG • Inpatient video EEG monitoring should be considered in any patient whose seizures have not responded to two or more antiepileptic drugs or require further characterization Increased Risk of Seizure Recurrence • • • • • • • Age > 65 years Abnormal EEG History of prior neurologic injury Postictal Todd paralysis Family history Partial seizure as first seizure MRI with abnormality • The presence of one or more of these risk factors justifies the institution of AED treatment, even after a single seizure. Treatment Pearls • Monotherapy preferred over polytherapy • Uptitrate medication until seizure free or develop adverse side effects • Make dose adjustments based on clinical seizure control and drug side effects moreso than based on therapeutic levels. • Consider slowly tapering AEDs off after being seizure free for 2 years. • Juvenile myoclonic epilepsy requires lifelong treatment. • Continue therapy: abnormal neuro exam or underlying structural abnormality. • IV lorazepam followed by phenytoin (fosphenytoin if available) is first-line management of status epilepticus A 75-year-old woman is evaluated 1 day after experiency a 60-minute episode of right arm weakness and dysarthria. The symptoms have not recurred. She has hypertension and type 2 diabetes mellitus. Medications are aspirin, metoprolol, enalapril, and metformin. On physical examination, blood pressure is 156/94 mm Hg, pulse rate is 62/min and regular, and respiration rate is 16/min. No carotid bruits are noted. Neurologic examination findings are normal. 25% 25% 25% 25% Results of laboratory studies obtained 3 weeks ago show a hemoglobin A1c value of 7.1% and a serum LDL cholesterol level of 68 mg/dL (1.76 mmol/L). Which of the following is the most appropriate next step in management? 1. 2. 3. 4. Addition of clopidogrel Immediate hospital admission Outpatient MRI of the brain 24-Hour ECG monitoring 1 2 3 4 TIA • Transient neurologic deficit without acute infarction – Risk of stroke at 90 days is 10% – Most stroke risk within first 48 hours, 5.3% patients at risk – Identify patients at highest risk of stroke with ABCD2 score. Hospitalize patients seen within 72hours of initial symptoms and whose score is at least 3. 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 25% 25% 25% 25% 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? 1. 2. 3. 4. Percutaneous patent foramen closure Prolonged cardiac rhythm monitoring Surgical closure of patient foramen ovale Warfarin 1 2 3 4 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 20% 20% 20% 20% 20% 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? 1. 2. 3. 4. 5. Add clopidogrel Add ticlopidine Add warfarin Substitute clopidogrel for aspirin Substitute warfarin for aspririn 1 2 3 4 5 Ischemic Stroke • Cardioembolism – Most common etiology is a. fib – Multiple infarcts or infarcts involving the surface of the brain • Large artery atherosclerosis – Risk of recurrence is highest with >70% occlusion • Subcortical infarcts (lacunae) – Commonly occur in setting of HTN – Cause pure motor or pure sensory strokes • Cryptogenic Stroke Location Symptoms Notes Anterior Cerebral Artery Weakness and sensory loss in contralateral leg Middle Cerebral Artery Contralateral weakness (hemiplegia), sensory loss and homonymous hemianopsia If dominant hemisphere affected aphasia If nondominant changes in spatial perception Posterior Cerebral Artery Contralateral homonymous hemianopsia; mild contralateral sensory loss; may have color blindness NO motor deficits Lacunar infarcts Either pure motor or sensory loss Treatment TPA BP TPA: goal BP <180/105 Anti-thrombotic Goal BP <140/80 No TPA goal BP <220/120 Secondary Prevention Goal LDL <100 Antithrombotic Aspirin Warfarin Clopidogrel Aspirin and Dipyridamole *If this is the only contraindication, try to reduce BP and then give tpa Hemorrhagic Stroke • Intracerebral hemorrhage – Deep location hemorrhage most likely due to HTN and originates in basal ganglia or cerebellum – Lobar hemorrhage more likely related to cerebral amyloid angiopathy – Differential: • Vascular malformation • Infection • Brain tumor with hemorrhage – Higher mortality rate than ischemic stroke • Subarachnoid hemorrhage – Typically caused by rupturued cerebral saccular aneurysm – Rarer causes include AVMs and mycotic aneurysms – “Worst headache ever” Hemorrhagic Stroke • 17% strokes, with 50% intracerebral hemorrhage and 50% subarachnoid hemorrhage • Diagnosis: non-contrast CT; if negative and high suspicion for SAH LP (erythrocytes and xanthrocromia) ICH • Complications – Hematoma expansion – Elevated ICP • Lower BP with IV labetalol or nicardipine if sBP >200 or MAP > 150 • Target BP 160/90 or MAP 110 – Hyperventilation, mannitol and Surgical evacuation for elevated ICP SAH • “Worst headache ever” • Complications: • Rebleeding • Vasospams • Hydrocephalus Dural Sinus Venous Thrombosis • Risk factors include venous hypercoagulable disorders, systemic malignancy, trauma, systemic inflammatory disorders (i.e. ulcerative colitis), severe dehydration, infection, pregnancy • Head CT with contrast may show “empty delta sign” • MRV is the diagnostic exam of choice • Treat with anticoagulation A 64-year-old woman is evaluated for a 1-year history of increasing difficulty finding the right word in conversation and completing sentences; she sometimes says the wrong word accidentally. Her family now has difficulty understanding her, and she no longer has any interest in speaking on the telephone. Her ability to drive, shop, pay bills, and cook seems unimpaired. She has no other relevant personal or family medical history. Her only medication is aspirin, 81 mg/d. On physical examination, temperature is 36.6 °C (97.9 °F), blood pressure is 122/78 mm Hg, pulse rate is 80/min, respiration rate is 14/min, and BMI is 23. The patient is right-handed. Her level of alertness is normal, and her comprehension appears to be intact, with her correctly executing the commands to show the right thumb and two fingers on the left hand. Spontaneous speech is effortful, and she talks in short, telegraphic sentences filled with many mispronunciations (such as “posital” for “hospital”). She makes similar errors when trying to write words rather than speak them, can repeat no more than two words or four numbers at a time, and can repeat essentially no sentences. 20% 20% 20% 20% 20% Results of a complete blood count, a basic metabolic panel, a serum vitamin B12 measurement, and thyroid function tests are normal. An MRI of the brain without contrast shows mild atrophy but is otherwise unremarkable. This patient’s impairment in speech and writing is most likely due to which of the following disorders? 1. 2. 3. 4. 5. Alzheimer dementia Creutzfeldt-Jakob disease Dementia with Lewy bodies Frontotemporal lobar degeneration Vascular dementia 1 2 3 4 5 An 81-year-old man is evaluated for the gradual onset and progression of memory loss over the past year. He says he has difficulty recalling the names of familiar people, has misplaced his wallet on numerous occasions, and is slower to find his car in large, crowded parking lots. He continues to manage his finances, travel with his wife, and perform the activities of daily living without difficulty. He has borderline hyperlipidemia that is managed by diet alone. A paternal uncle developed Alzheimer dementia at age 74 years. His only medications are aspirin and a daily multivitamin. On physical examination, temperature is 36.7 °C (98.1 °F), blood pressure is 126/82 mm Hg, pulse rate is 68/min, respiration rate is 14/min, and BMI is 26. His level of alertness, speech, and gait are 20% 20%losing 20%all three 20% points 20%on normal. He scores 26/30 on the Folstein Mini–Mental State Examination, the recall portion and one point on the orientation section for incorrectly stating today’s date. Results of a complete blood count, serum vitamin B12 measurement, thyroid function tests, and a basic metabolic panel are normal. An MRI of the brain without contrast shows no abnormalities. Which of the following is the most likely diagnosis at this time? 1. 2. 3. 4. 5. Alzheimer dementia Dementia with Lewy bodies Frontotemporal dementia Mild Cognitive impairment Vascular dementia 1 2 3 4 5 Dementia • MMSE < 22 indicates dementia • Alzheimer Disease: Insidious, progressive disease with significant impairment of normal daily functioning. Persistent forgetfulness is hallmark. • Cholinesterase inhibitors: donepezil, rivastigmine, galantamine • N-methyl-d asparte R antagonist: memantine Dementia Dementia with Lewy bodies Dementia, hallucinations, REM sleep disorder, parkinsonism Vascular Abrupt onset with stepwise decline Frontotemporal Rapid onset dementia with change in personality- disinhibition, impulsivity, loss of verbal fluency CJD Rapid dementia with startle myoclonus NPH Dementia, gait ataxia, incontinence Additional Dementia Treatments A 62-year-old woman is evaluated for a 1-year history of tremor that affects both upper extremities. She says that her handwriting has become sloppier since she first noticed the tremor and that she occasionally spills her morning coffee because of it. Although she feels otherwise healthy, she is concerned that she may have Parkinson disease. The patient has a history of hyperlipidemia controlled by diet and exercise but is otherwise healthy. Her mother, who died at age 79 years, had a similar tremor. Her only medication is a daily multivitamin. 25% 25% 25% 25% On examination, she has a mild tremor in the upper extremities that is present with the arms extended and during finger-to-nose testing. No resting tremor is apparent. Muscle tone and gait and limb coordination are normal. Administration of which of the following drugs is the most appropriate treatment of this patient? 1. 2. 3. 4. Carbidopa-Levodopa Clonazepam Propranolol Ropinirole 1 2 3 4 A 53-year-old woman is evaluated in the office for a 4-month history of tremor. The tremor affects both upper extremities and is present “most of the time.” She has a 15year history of type 2 diabetes mellitus; she also has a history of hypertension, gastroparesis, and chronic kidney disease. Medications are insulin glargine, insulin lispro, lisinopril, hydrochlorothiazide, and metoclopramide. On examination, she has diminished pedal pulses. Speech, language, and mental status are normal. Cranial nerve function is normal, although a paucity of facial expression is noted. Movements are slow, and there is mild bilateral upper and lower extremity rigidity. Deep tendon reflexes are normal, as are results of manual muscle strength testing. Sensory examination reveals distal sensory loss. She had a mildly stooped 25% 25% 25% 25% posture but no postural instability. A 4-Hz resting tremor in both upper extremities is noted, as is a prominent postural tremor. Which of the following is the most likely diagnosis? 1. 2. 3. 4. Dementia with Lewy bodies Drug-induced parkinsonism Multiple system atrophy Parkinson disease 1 2 3 4 Parkinson’s Disease Symptoms: (the 4 R’s) initially unilateral disease 1. Resting tremor and cogwheeling 2. Rigidity and flexed posture 3. Retarded movement (brady and hypokinesia) 4. Loss of postural Reflexes Drug Mechanism Adverse effect Levodopa-carbidopa Dopamine replacement DOC for older patients 1. Motor fluctuations: dopamine agonist or amantadine 2. Wearing off: inc dose or frequency Ropinirole, Pramipexole Dopamine receptor agonist DOC for <65yo Impulse control disordershypersexual and gambling Amantadine NMDA receptor antagonist Mild symptoms, tremor AMS and psychosis Selegiline, Rasagiline MAO-B inhibitor May delay need for L-dopa Seratonin syndrome if with SSRIs or tricyclics **Acutely discontinuing dopa therapy may cause NMS. Treat with a dopamine agonist: bromocriptine, amantadine or dantrolene Movement Disorders Disorder Key Points Essential Tremor Fine tremor that impairs manual tasks and is present with action. Treat with propranolol or primidone. Dystonia Torsional, twisting movement. Focal dystonia should be treated with injections of botulinum toxin A or B. Huntington disease Neurodegenerative choric disorder. Generalized chorea, dysarthria, parkinsonism, psychiatric disease, dementia, and death Tardive Dyskinesia Choreiform movement of the face. Caused by D2 blocking agents. May persist when offending agent is withdrawn. Myoclonus Single, rapid, shocklike muscle jerk. Seen in CJD, anoxic brain injury, stroke. Treat with anticonvulsant. Wilson Disease Curable metabolic disease due to irreversible copper deposition in the basal ganglia and cerebellum. Kayser-Fleischer rings, “wing-beating” tremor, young adults. Confirm diagnosis with low ceruloplasmin level. Treat with penicillamine or liver transplantation. NMS Hyperthermia + extrapyramidal signs + delirium. D2 receptor blockers can induce syndrome. Bromocriptine and dantrolene to reverse. Restless Leg Syndrome Associated with IDA, uremia, DM, RA, fibromyalgia. Treat with bromocriptine or pramipexole. A 33-year-old man is evaluated for a 3-day history of worsening weakness and numbness of the right arm and leg. He has a 5-year history of multiple sclerosis. His only current medication is glatiramer acetate. On physical examination, temperature is 36.5 °C (97.7 °F), blood pressure is 105/75 mm Hg, pulse rate is 68/min, and respiration rate is 14/min. Moderate right arm and leg weakness, hyperreflexia, an extensor plantar response, and vibratory sense impairment are 20% 20% 20% 20% 20% noted. Which of the following should this patient receive to treat his acute relapse? 1. 2. 3. 4. 5. Empiric antibiotic therapy Immune globulin, intravenously Methylprenisolone, intravenously Plasmapheresis Prednisone only 1 2 3 4 5 Multiple Sclerosis Presenting Signs and Symptoms • Optic neuritis- acute loss of vision and pain with eye movement • Myelitis- inflammation of the spinal cord that causes sensory or motor symptoms below the involved spinal cord level • Brainstem involvement- diplopia, sensations of oscillopsia, internuclear ophthalmoplegia • In contrast to cerebrovascular disease, cortical syndromes, such as aphasia and neglect, do not often occur in MS. Multiple Sclerosis Diagnosis • Demyelinating disease of CNS beginning at 20-30 yo; CNS lesions disseminated over time and space • Dx with brain MRI ovoid white matter lesions in periventricular and posterior fossa regions and perpendicular to lateral ventricles • Do LP if MRI inconclusive CSF with lymphocytic pleocytosis; oligoclonal bands and elevated IgG Multiple Sclerosis Treatment Acute Relapse: distinguish between pseudo (infection) or true • Observe if minimal symptoms • IV methylprednisolone or plasmapheresis Disease Modifying Therapies (relapsing remitting disease): • Interferon beta 1a/b • Glatiramer • Natalizumab (assoc with PML) • Fingolimod (only oral agent) • Mitoxantrone No therapies for primary progressive 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. The patient developed a malabsorption syndrome 3 years ago after 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. Laboratory studies: Hemoglobin 12.9 g/dL (129 g/L) Mean corpuscular volume 102 fL Vitamin B12 590 pg/mL (435 pmol/L) Rapid plasma reagin Nonreactive 20% 20% 20% 20% 20% 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? 1. 2. 3. 4. 5. Copper Folate 25-hydroxyvitamin D Thiamine Vitamin A 1 2 3 4 5 Diseases of the Spinal Cord • • • • Subacute Combined degeneration of the spinal cord Viral infection, Autoimmune dz or MS Leg weakness, numbness, sensory level at trunk. Dx: MRI, CSF with inc protein and lymphocytosis Tx: plasmapheresis or cyclophosphamide • B12 deficiency (even without anemia), copper deficiency, nitrous oxide exposure • Gradual weakness, paresthesias, spastic paresis, loss of proprioception and ataxia. • Dx: MRI, check MMA and HC (both inc with B12 def) • Tx: replacement therapy will usually halt progression of but may not improve symptoms • Back Pain, fever, local tenderness, radicular pain + neuro deficits • Dx: MRI, blood cultures • Tx: laminectomy, drainage and antibiotics Epidural Abscess A 34-year-old woman is evaluated in the office for right-sided facial paralysis that she noticed on awakening 1 hour ago. She has a 10-pack-year smoking history. Personal and family medical history is noncontributory. Her only medication is a daily oral contraceptive. On physical examination, temperature is 36.5 °C (97.7 °F), blood pressure is 110/70 mm Hg, pulse rate is 82/min, respiration rate is 14/min, and BMI is 26. Limb strength, reflexes, and tone are normal bilaterally. Findings from a sensory examination, which included her face, are also normal. When asked to raise her eyebrows, the patient does not elevate the right side. When asked to shut her25% eyes, she the 25%cannot 25%close25% right one, but the globe rotates upward, partially covering the iris. When asked to smile, the patient does not move the right side of her face. Which of the following is the most likely diagnosis? 1. 2. 3. 4. Graves opthalmopathy Left cerebral infarction Right facial nerve (Bell) palsy Right trigeminal neuralgia 1 2 3 4 Mononeuropathies Radial neuropathy: acute wrist drop. Compression, diabetes, lead. Wrist splints, PT Bell’s Palsy: ipsilateral facial paralysis • Treat with prednisone if within 7 days of symptom onset to shorten course and improve function.. • Cortical lesions spare forehead and eyelid Median nerve entrapment: CTS. Entrapment at wrist Splints, steroids, surgery Ulnar neuropathy: Lesion at elbow or cubital tunnel in wrist elbow pads, splints, Peroneal nerve compression: Foot drop Lesion at fibula head **L5 radiculopathy also causes foot drop, but cannot invert OR evert foot. Also weak thigh muscles. Polyneuropathies Guillain Barre Syndrome Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) Critical Illness Neuropathy Ascending paralysis of muscles with areflexia; usually with preceding Campylobacter infection Symmetric sensorimotor loss for > 8 weeks Unable to wean from vent and generalized weakness with flacdid paralysis. Sparing of cranial nerves. CSF with normal cell count and high protein; monitor inspiratory force and expiratory vital capacity CSF with normal cell count and high protein Serum CK and CSF protein levels are normal Plasmapheresis and IVIG Steroids, plasmapheresis, IVIG Supportive treatment with PT/OT; AVOID steroids A 56-year-old man is evaluated in the office for a 1-month history of intermittent weakness of the left foot, a 6-month history of progressive right arm weakness, and 1-year history of muscle cramps. He says he feels lately as if he is “catching” his foot on things when ambulating. He has noticed no shortness of breath, dysphagia, or other bulbar symptoms and reports no other pain, sensory loss, or bowel or bladder impairment. The patient is otherwise healthy, has no history of disease, and is unaware of any family history of neurologic disorders. He takes no medications. Results of a general medical examination are normal. Neurologic examination reveals normal speech, language, and mental status. His tongue appears atrophic with fasciculations. He has diffuse weakness and atrophy of the proximal muscles in the right arm; fasciculations are noted. Left arm strength and muscle bulk are normal. Moderate weakness of the distal muscles in the left leg is noted, with fasciculations present in both lower extremities. Deep tendon reflexes are brisk in the upper and lower limbs, the plantar 25% 25% and 25% 25% response is extensor bilaterally. Sensory examination reveals no abnormalities, and there is no appendicular ataxia. Laboratory studies show a serum creatine kinase level of 602 U/L. Results of a complete blood count; measurement of serum creatinine, electrolyte, and vitamin B12 levels; and liver chemistry studies are normal. A radiograph of the chest shows no abnormalities. Which of the following is the most likely diagnosis? 1. 2. 3. 4. Amyotrophic Lateral Sclerosis Cervical Myelopathy Chronic Inflammatory Demyeliting Polyradiculoneuropathy 1 Primary Lateral Sclerosis 2 3 4 A 56-year-old man is evaluated for a 6-month history of generalized fatigue, slowly progressive weakness in the legs, difficulty climbing stairs and raising his arms above his head, and a 2month history of dry mouth and impotence. He reports that on two occasions in the past month he almost lost consciousness when rising quickly from a sitting position. The patient has a 38pack-year smoking history. On physical examination, blood pressure in the right arm is 130/80 sitting and 100/60 standing and pulse rate is 80/min and regular sitting and 84/min and regular standing. Muscle strength testing reveals moderate weakness in the arms and proximal legs, especially when the patient rises from a low chair. Repeated testing slightly improves strength. Stretch reflexes are diffusely reduced or absent but increase to normal after brief exercise. Results of cranial nerve testing, cerebellar function testing, and sensory testing are normal. Results of laboratory studies show an erythrocyte sedimentation rate of 75 mm/h and a serum creatine kinase level of 120 units/L. A chest radiograph is suspicious for left hilar lymphadenopathy. Which of the following diagnostic tests should be performed next? 1. Acetylcholine receptor antibody assay 2. Lumbar puncture 3. Muscle biopsy 4. Nerve conduction studies Neuromuscular junction disorders Myasthenia Gravis Lambert Eaton Autoantibodies Post synaptic AchReceptor MuSK Receptor Voltage gated calcium channels DTRs Normal Absent Symptoms Improve with rest Improve with movement Associated with Thymoma Small Cell lung cancer Weakness Descending Proximal lower ext Bulbar Present Less common Treatment Pyridostigmine Pyridostigmine and treat underlying malignancy A 71-year-old man is evaluated in the intensive care unit 11 days after undergoing surgery to relieve a bowel obstruction. His postoperative course has been complicated by septic shock and multiorgan failure, for which he has received intravenous fluids, broad-spectrum antibiotics, vasopressors, corticosteroids, and insulin. He has been on mechanical ventilation for 10 days. For the past 72 hours, he has been hemodynamically stable, but attempts at weaning him from the ventilator have been unsuccessful. The patient previously was given muscle relaxants and neuromuscular junction–blocking agents, but these have been withheld for the past 4 days. On physical examination, the patient is alert, follows commands, and cooperates with the examiner. Vital signs are stable. Cranial nerves are intact. Flaccid quadriparesis of the upper and 25% 25%is present. 25% 25% lower extremities is noted that is greater proximally than distally. Areflexia Results of laboratory studies show a serum creatine kinase level of 850 units/L and a plasma glucose level of 200 mg/dL (11.1 mmol/L). Results of electromyography show absent sensory responses in the legs and low amplitudes in the hands. Short duration, low-amplitude motor units consistent with myopathy are noted. Which of the following is the most likely diagnosis? 1. 2. 3. 4. Corticosteroid myopathy Critical illness myopathy Guillain-Barre syndrome Myasthenia gravis 1 2 3 4