473. A 55-year-old alcoholic man is brought in to the emergency room in a confused but nonagitated state. Significant examination findings include ophthalmoparesis, nystagmus, and ataxia. Emergency administration of which of the following medications is appropriate in the treatment?
a. Glucose
b. Magnesium sulfate
c. Pyridoxine
d. Cyanocobalamin
e. Thiamine
474. A 66-year-old woman presents with weakness worsening over the past 3 hours. The weakness began in her face, but now involves most of her body. She had made her own jam several months before and tasted a sample of it early this morning prior to discarding it because it smelled rancid. On further electrophysiologic testing, which of the following abnormalities would be most characteristic of this patient’s illness?
a. Abnormal visual evoked responses (VERs)
b. Abnormal brainstem auditory evoked potentials
c. Posttetanic potentiation of the compound muscle action potential
d. Conduction block
e. Fibrillation potentials
475. A 6-month-old child is brought to the emergency room after having a generalized seizure at home. She is found to have a temperature of 102.5°F (39.16°C). Which of the following correctly reflects why this patient should be investigated with a spinal tap?
a. All febrile seizures justify spinal taps.
b. Most febrile seizures are due to bacterial infections.
c. Febrile seizures cause increased intracranial pressure that must be relieved by withdrawing cerebrospinal fluid (CSF).
d. Intrathecal antiepileptics must be given.
e. Children this age may have meningitis with no manifestations other than fever and seizures.
476. A 17-year-old girl presents with subacute mental status change and left arm weakness. She had a viral illness 1 week ago, and now a diagnosis of acute disseminated encephalomyelitis (ADEM) is made. ADEM is a white matter disease that is distinguishable from multiple sclerosis (MS) by its being which of the following?
a. Monophasic
b. Rapidly lethal
c. Associated with brainstem and spinal cord disease
d. Associated with magnetic resonance imaging (MRI) lesions, which may resolve
e. Associated with inflammatory changes in the brain
477. A 26-year-old woman with low back pain is seen in the clinic. She states that her pain began acutely 2 weeks ago while lifting a couch. An MRI was performed in the emergency room and she was told that she has a “slipped disk” and sent home. The patient wants to know why surgery was not done immediately to correct the problem. Acute herniation of an intervertebral disk will require emergency surgery in which of the following circumstances?
a. The disk is laterally herniated at C7.
b. The disk is causing radicular pain.
c. The cauda equina is being crushed.
d. A thoracic disk is involved.
e. The filum terminale is displaced.
478. A 57-year-old man has been having nightly, unilateral, throbbing headaches. They have been occurring daily for the past week. The patient recalls having had a similar headache 5 years ago that lasted for several weeks. The patient has noticed that the headache is associated with lacrimation and a “stuffy nose.” Ergotamine prophylaxis has been partially successful. Which of the following is the most effective means of aborting this type of headache?
a. Inhaled 100% oxygen
b. Sublingual nitroglycerin
c. Oral methysergide
d. Oral propranolol
e. Dihydroergotamine suppository
479. A 32-year-old woman with alcoholism and cocaine use dating back at least 10 years comes to the emergency room after 48 hours of recurrent vomiting and hematemesis. She reports abdominal discomfort that preceded the vomiting by a few days. For at least 36 hours, she has been unable to keep ethanol in her stomach. Intravenous fluid replacement is started while she is being transported to the emergency room, and while in the emergency room she describes progressive blurring of vision. Over the course of 1 hour, she becomes increasingly disoriented, ataxic, and dysarthric. Which of the following is the most likely explanation for her rapid deterioration?
a. Dehydration
b. Hypomagnesemia
c. Wernicke encephalopathy
d. Hypoglycemia
e. Cocaine overdose
480. A 27-year-old man undergoes general anesthesia for a hernia repair. As the anesthesia begins, his jaw muscles tense and he becomes generally rigid. He becomes febrile, tachycardic, and tachypneic. Intravenous administration of which of the following agents may be lifesaving?
a. Suxamethonium
b. Nitrous oxide
c. Succinylcholine
d. Dantrolene
e. Phenobarbital
481. A 57-year-old woman with a history of diabetes mellitus and hyper-thyroidism presents to the emergency room with a history of 2 days of vertical and horizontal diplopia. There is moderate orbital pain. On examination, her left eye is deviated downward and outward. It can be passively moved medially and upward. The pupils both react normally. Which of the following is the most likely etiology of her diplopia?
a. Hyperthyroidism
b. Diabetes mellitus
c. Cerebral aneurysm
d. Orbital pseudotumor
e. Orbital infection
482. A 33-year-old operating room nurse accidentally has blood splashed in her eyes during a procedure. The surgical resident who examines her immediately afterward notices that she has 2-mm anisocoria and sends her to the emergency room. She feels well, is alert and talkative, and has no motor dysfunction. On examination, the emergency room physician recognizes that the iris of the eye with the smaller pupil is pale blue, whereas that of the other eye is brown. Which of the following is the most likely etiology of the woman’s anisocoria?
a. Conjunctivitis
b. Traumatic third-nerve palsy
c. Carotid artery dissection
d. Pupillary sphincter injury
e. Congenital
483. A 26-year-old man is brought into the emergency room after a motorcycle accident in which he was not wearing a helmet. The computed tomography (CT) scan shows bifrontal hemorrhagic contusions. The Glasgow Coma Scale (GCS) score is 6. He has no verbal response, opens his eyes to painful stimulation only, and shows a flexion response to pinch of the extremities. Which of the following is the most appropriate classification of this patient’s head injury?
a. Minimal
b. Mild
c. Moderate
d. Severe
e. Vegetative
484. Two days after a motor vehicle accident, you are examining a 19-year-old right-handed man. He has a severe headache and “raccoon eyes.” The presence of periorbital ecchymosis in a patient with traumatic head injury should be considered a sign of which of the following?
a. Subdural hemorrhage
b. Parenchymal hematoma
c. Ocular injury
d. Retinal detachment
e. Basilar skull fracture
485. MRI scan of a 19-year-old woman after a motor vehicle accident shows multiple foci of punctate hemorrhage. These are most likely indicative of which of the following?
a. Diffuse axonal injury
b. Uncontrolled hypertension
c. Amyloid angiopathy
d. Ischemic infarction
e. Coagulopathy
486. Which of the following treatments should be recommended to improve the outcome of a patient with a severe traumatic head injury?
a. Corticosteroids
b. Prophylactic hyperventilation
c. Hyperthermia
d. Hypothermia
e. Prophylactic anticonvulsants
487. A 47-year-old woman begins to have difficulty swallowing food at dinner. Over the following 3 hours, she develops diplopia, dysarthria, and ultimately anarthria. She has a history of hypothyroidism and is on thyroid hormone replacement. There is no history of exposure to ticks or recent travel. On examination, she nods her head appropriately to questions, and she can write. Forced vital capacity is 500 mL, and she is intubated. She is afebrile, tachycardic, and normotensive. Bilateral ptosis and ophthalmoparesis are present; pupils are 6 mm in diameter and minimally reactive. Facial sensation is intact. Bifacial paresis is present, and the tongue is weak. Extremity muscle bulk and tone are normal, and proximal strength is 4/5 in her arms and legs. Finger and toe movements are rapid and symmetric. Plantar responses are flexor. Blood tests are normal. Motor nerve conduction studies (NCS) show low-amplitude compound muscle action potentials with normal velocities. Sensory nerve action potentials are normal. Which of the following organisms is most likely responsible for this woman’s syndrome?
a. Cytomegalovirus (CMV)
b. Treponema pallidum
c. Chlamydia pneumoniae
d. Clostridium botulinum
e. Campylobacter jejuni
488. A 66-year-old woman presents with fever and a generalized convulsion. MRI shows high T2 signal in the medial temporal lobes (R > L). Lumbar puncture is performed and routine CSF analysis indicates 100 lymphocytes/μL, 15 red blood cells (RBCs), xanthochromia, and a mildly elevated pressure. Which of the following is the most appropriate treatment for this patient?
a. Dexamethasone
b. Amphotericin B
c. Gamma globulin
d. Methotrexate
e. Acyclovir
489. A 41-year-old right-handed woman has had 1 day of progressive weakness. The symptoms began in her extraocular muscles and then spread quickly to involve other muscles in her face before her entire body felt weak. The history is significant for the recent ingestion of home-canned fruit. The underlying mechanism of this disease is which of the following?
a. Antibodies to the acetylcholine receptor
b. Antibodies to the calcium receptor
c. Depolarizing blockade of the potassium channel
d. Impaired formation of acetylcholine-laden vesicles
e. Toxic muscle necrosis
f. Demyelination
490. A 22-year-old woman presents to the emergency room with an episode of acute painful loss of vision in the right eye. On examination, there is a right afferent pupillary defect and papillitis on funduscopic examination. She has no history of neurological symptoms. An MRI shows a few foci of T2 signal increase in a periventricular distribution. Which of the following is the most appropriate treatment for presumed optic neuritis in this patient?
a. Oral prednisone
b. Intravenous methylprednisolone
c. Cyclophosphamide
d. Plasma exchange
e. Intravenous gamma globulin
491. A previously healthy 23-year-old woman has had 2 weeks of blurry vision in her left eye. Multiple tests, including visual evoked potentials, are performed. The diagnosis of optic neuritis is made. What is the approximate likelihood that this patient will eventually develop MS?
a. 0%
b. 5%
c. 25%
d. 40%
e. 75%
492. A 27-year-old man, who 6 months ago had optic neuritis, presents to the emergency room describing a brief, sharp pain radiating into the left side of his face. The vision in his eye has largely recovered, and there is no evidence of sensory loss on the right side of his face. He describes the pain as ice pick–like and grimaces with each attack. He is most likely to have symptomatic relief from his facial pain if he is managed with which of the following drugs?
a. Aspirin
b. Acetaminophen
c. Ibuprofen
d. Carbamazepine
e. Codeine
493. A patient who has been diagnosed with MS has had recurrent episodes of bed wetting (enuresis) over the preceding month. This should decrease with the administration of which of the following drugs?
a. Oxybutynin
b. Phenytoin
c. Carbamazepine
d. Baclofen
e. Methacholine
494. Over the course of a few months, a patient with MS develops painful spasticity in her left leg that interferes with extension of her leg. The spasticity progresses to the point of interfering with her sleep. Which of the following is the most appropriate treatment for this patient?
a. Imipramine
b. Phenytoin
c. Carbamazepine
d. Baclofen
e. Methacholine
495. A 47-year-old man arrives at the emergency room in a coma. His wife reports that he developed shaking movements and abnormal breathing sounds in the middle of the night. His shaking and the sounds woke her, but she was unable to wake him. He has been somewhat forgetful over the prior 3 months, but has seemed well otherwise. Examination in the emergency room reveals an unresponsive man who exhibits generalized convulsions every 10 minutes. He is afebrile and incontinent of urine. The physician on call believes the patient is in status epilepticus and should consequently immediately order which of the following?
a. An intraventricular drain to monitor intracranial pressure
b. Lorazepam for intravenous administration
c. Carbamazepine by nasogastric tube
d. Phenytoin by nasogastric tube
e. Gabapentin by nasogastric tube
496. During the initial treatment of a patient with status epilepticus, a nurse reports that the patient has just lost bladder control and that the urine appears darker than normal. The responsible physician examines the bed sheets and agrees with the nurse’s assessment. The physician should immediately institute which measure?
a. Order placement of an indwelling urinary catheter.
b. Order methacholine to regulate bladder emptying.
c. Request a surgical consultation in anticipation of an exploratory laparotomy.
d. Order placement of a condom catheter.
e. Request a urologic consultation to assess the incontinence.
497. A 64-year-old man presents to the emergency room with convulsive seizures. A precontrast CT of the brain reveals a hemorrhagic mass in the left frontal lobe, but there is little apparent shift of brain structures and no ventricular enlargement. Two hours after the patient’s seizures have stopped, his blood pressure is still elevated at 180/100 mm Hg, and his pulse is slow at 50 beats per minute. Although the patient is still unconscious, he appears to have decreased tone on the right side of his body. The physician should request which of the following interventions?
a. Intravenous clonidine to lower the blood pressure
b. Placement of a cardiac pacemaker to manage the bradyarrhythmia
c. Neurosurgical consult
d. Placement of a ventriculoperitoneal shunt
e. Intravenous tissue plasminogen activator (TPA)
498. A 52-year-old woman presented to the emergency room with a new-onset aphasia. A hemorrhagic left frontal mass is apparent on head CT. The neurosurgical consultant decides to explore the site of the hemorrhage and evacuate the mass that has collected there. He sends tissue from the margin of the blood clot for a frozen section analysis by the pathologist. The tissue is felt to be Kernohan grade IV astrocytoma. Which of the following postoperative therapies is most reasonable?
a. Cranial radiotherapy
b. Intravenous methotrexate
c. Intravenous fludarabine
d. Intravenous cyclophosphamide
e. Intravenous daunorubicin
499. A 56-year-old man is brought into the emergency room after having collapsed at work 30 minutes ago. He has no medical history and takes no medications. He is alert and speaking but has no awareness of any deficit. He has a right gaze deviation, dense left face and arm plegia, and mild left leg weakness. When asked to raise his legs, he lifts only the right leg. He has reduced blink to threat from the left side. Which of the following is the most appropriate initial diagnostic step?
a. Head CT
b. Cerebral angiogram
c. C-spine MRI
d. Positron emission tomography scan
e. Skull x-rays
500. A 63-year-old man presents to the emergency room with a right hemiparesis and nonfluent aphasia that began acutely 45 minutes ago. Blood pressure is 160/80 mm Hg, coagulation studies are normal, and there is no recent history of bleeding. A head CT scan shows no evidence of intracranial hemorrhage. Which of the following is the most appropriate therapy at this point?
a. Intravenous rTPA
b. Intravenous streptokinase
c. Oral aspirin
d. Intravenous heparin
e. Intravenous mannitol