225. A 75-year-old woman with suspected normal-pressure hydrocephalus undergoes lumbar puncture. Forty milliliters of fluid are removed. Three hours later, she is able to walk unassisted and turns well. Spinal fluid would be expected to show which of the following?
a. No abnormalities
b. Elevated protein
c. Low protein
d. Atypical lymphocytes
e. Low glucose
226. A physician believes that her patient has Alzheimer disease. Which of the following is most characteristic of the brain in patients with Alzheimer disease?
a. Neuronal loss in the cerebral cortex
b. Demyelination in the cerebral cortex
c. Posterior column degeneration
d. Neuronal loss in the cerebellar cortex
e. Pigmentary degeneration in the hippocampus
227. An 80-year-old man has had a gradual memory decline over the past 10 years. A reversible cause of dementia cannot be found, and positron emission tomography scan supports the diagnosis of Alzheimer disease. In the dementia associated with Alzheimer disease, the electroencephalography (EEG) will usually show which of the following?
a. Spike-and-wave discharges
b. Periodic frontal lobe discharges
c. Focal slowing
d. Generalized background slowing
e. An isoelectric record
228. A 55-year-old man has a steep decline in his cognitive abilities over a 3-month period. Initial testing is nondiagnostic. He continues to progress and develops myoclonus and a left hemiparesis. Eventually, he dies of an aspiration about 8 months after the onset of symptoms. In the diseases that cause dementia, myoclonus is usually most evident in which of the following?
a. Alzheimer disease
b. Creutzfeldt-Jakob disease
c. Parkinson disease
d. Huntington disease
e. Pick disease
229. A 29-year-old mentally retarded woman living in an institution has had a subacute to chronic decline in memory. Testing for reversible causes of dementia is nondiagnostic. The brain of the adult with trisomy 21 (Down syndrome) exhibits many of the histopathologic features of which of the following?
a. Tay-Sachs disease
b. Friedreich disease
c. Pick disease
d. Parkinson disease
e. Alzheimer disease
230. An 80-year-old man has a history of 2 years of progressive gait disturbance and incontinence, which had been attributed to old age and prostatism. Within the past 3 months, he has been forgetful, confused, and withdrawn. His gait is short-stepped, and he turns very slowly, almost toppling over. He has a 30-year history of head trauma. His computed tomography (CT) scan is shown below. Which of the following is the most likely diagnosis?
a. Alzheimer disease
b. Creutzfeldt-Jakob disease
c. Progressive multifocal leukoencephalopathy
d. Normal-pressure hydrocephalus
e. Chiari malformation
231. An 82-year-old man has 6 months of worsening memory loss. His family is concerned, and he is taken to a physician. After an extensive evaluation and neuropsychological testing, he is diagnosed with dementia. Which of the following is the most common cause of dementia in the general population?
a. Epilepsy
b. Vascular disease
c. Alzheimer disease
d. Parkinson disease
e. Head trauma
232. A patient undergoes ventriculoperitoneal shunt placement for hydrocephalus. He is discharged 2 days later, his gait and cognition much improved. The following morning, his wife finds him lying in bed, very confused and complaining of a headache. He is unable to walk. The surgeon who performed the procedure is concerned that these new symptoms are owing to which of the following?
a. Chemical meningitis
b. Subdural hematoma
c. Epidural hematoma
d. Seizures
e. Bacterial ventriculitis
233. A 67-year-old man has a history of progressive memory loss for 2 years. His examination is otherwise normal. A diagnosis of Alzheimer disease is made. Which of the following medications may result in some cognitive improvement?
a. Donepezil
b. L-Dopa
c. Risperidone
d. Prednisone
e. Vitamin B12
234. Language testing is most likely to uncover which of the following deficits in a patient with Alzheimer disease?
a. No abnormalities
b. Mutism
c. Conduction aphasia
d. Transcortical sensory aphasia
e. Transcortical global aphasia
Questions 235 to 240
For each clinical scenario, choose the most likely diagnosis. Each lettered option may be used once, more than once, or not at all.
a. Transient global amnesia (TGA)
b. Normal-pressure hydrocephalus
c. Alzheimer disease
d. Parkinson disease
e. Creutzfeldt-Jakob disease
f. Vitamin B12 deficiency
g. Hypothyroidism
h. Huntington disease
i. Rett syndrome
j. Multi-infarct dementia
k. General paresis
l. Temporal lobe epilepsy
235. A 73-year-old man steps out of the shower on a Saturday evening and is unable to remember that he and his wife have tickets to a play. He asks her repeatedly, “Where are we going?” He appears bewildered, but is alert, knows his own name, speaks fluently, and has no motor deficits. He has no history of memory disturbance and after 8 hours returns to normal.
236. A 50-year-old woman began having double vision and blurry vision 3 months ago and has since had diminishing interaction with her family, a paucity of thought and expression, and unsteadiness of gait. Her whole body appears to jump in the presence of a loud noise. A magnetic resonance imaging (MRI) scan and routine cerebrospinal fluid (CSF) examination are unremarkable.
237. A 2-year-old girl developed normally until the past year. She has since become unable to speak or otherwise communicate with her parents, sits in a chair, and makes nearly continuous wringing movements with her hands. She also has episodes of breath holding alternating with hyperventilation.
238. A 17-year-old girl develops mild dementia, tremor, and rigidity. Her father died in his fourth decade of life of a progressive dementing illness associated with jerking (choreiform) limb movements. On exposure to L-dopa, she becomes acutely agitated and has jerking limb movements.
239. A 62-year-old man has had 2 years of progressive memory loss and inappropriate behavior. He has been delusional. More recently, he has developed tremors, myoclonus, dysarthria, and unsteadiness of gait. The CSF shows a lymphocytic pleocytosis, protein of 150, and positive VDRL.
240. A 44-year-old woman from Africa presents with inattentiveness, poor concentration, and lethargy. She has paranoid delusions. There is mild proximal weakness and ataxia. On general examination, she has edema, coarse and pale skin, and macroglossia. On reflex examination, she has delayed relaxation of the ankle reflexes.
Questions 241 to 243
For each patient, select the likely organism that caused the disease. Each lettered option may be used once, more than once, or not at all.
a. HTLV-I
b. Tropheryma whippeli
c. Treponema pallidum
d. JC virus
e. Prion protein
f. Cytomegalovirus
g. Herpes simplex virus
h. Taenia solium
241. A 54-year-old woman presents with 6 months of progressive memory loss. She has limited vertical eye movements, and on examination, she has rhythmic, synchronous grimacing and eye closure movements (oculomasticatory myorhythmia). Jejunal biopsy reveals periodic acid–Schiff (PAS)–positive cells.
242. A 35-year-old intravenous drug abuser presents with inability to control his left hand. He reports that at times he will button his shirt with his right hand, only to find that his left hand is unbuttoning the shirt against his control. He has a history of thrush. He is alert and oriented. MRI shows an increased T2 signal affecting the subcortical white matter of the right parietal lobe without enhancement.
243. A previously healthy 24-year-old man presents with 3 days of headaches and fever, followed by hallucinations, speech disturbance, and lethargy. He has a mild right hemiparesis. Spinal fluid is bloody, and MRI shows abnormal signal, with enhancement, in the left anterior temporal lobe.
244. A 78-year-old retired electrical engineer has had a progressive cognitive decline over the past 10-to-15 years. His wife reports that every 6-to-8 months she will notice another significant decrease in his functioning. It is now at the point where he is belligerent and has little short-term memory. There is a history of hypertension and cardiac stenting after a myocardial infarction at age 65. Examination findings include poor attention and memory, mild left hemiparesis (face, arm, and leg), and brisk reflexes throughout with upgoing toes. Which of the following is most likely to prevent further deterioration in this patient?
a. Deep brain stimulation of subthalamic nucleus
b. Control of hypertension
c. Ventriculoperitoneal shunt
d. Carbidopa/levodopa
e. Psychotherapy
225. The answer is a. (Ropper, pp 535-538.) The CSF in patients with normal-pressure hydrocephalus (NPH) is typically normal. Abnormalities in protein or cellularity should suggest an alternative diagnosis. The pressure of the CSF is also usually normal, although studies using long-term pressure monitoring in these patients have shown that they have periods of pressure elevation, often at night.
226. The answer is a. (Ropper, pp 1014-1023.) The most prominent characteristics of Alzheimer disease are neuronal loss, fibrillary tangles, loss of synapses, and amyloid (or neuritic) plaque formation. These histopathologic features are evident throughout the cerebral cortex, but the neurofibrillary tangles and neuronal loss are most prominent in the hippocampus and adjacent structures of the temporal lobe. The tangles and loss of synapses are most closely linked to the development of dementia. The cell loss may be so substantial that the patient develops marked compensatory enlargement of the ventricles, a condition called hydrocephalus ex vacuo.
227. The answer is d. (Ropper, pp 1014-1023.) The background posterior-dominant rhythm on the normal adult EEG is α activity at 8-to-12 Hz. With Alzheimer disease, the frequency of this rhythm may be slow, and the amount of time in which this rhythm is evident when the patient is lying relaxed with eyes closed may drop substantially. Periodic discharges in the form of sharp waves or spikes may develop during Creutzfeldt-Jakob disease. EEG is otherwise not especially helpful in distinguishing between the common causes of dementia.
228. The answer is b. (Ropper, pp 738-741.) Creutzfeldt-Jakob disease is a spongiform encephalopathy that produces dementia over the course of months. It is caused by the accumulation within the brain of an abnormal form of a normal protein that resists degradation by proteinases (a proteinase-resistant protein, prion protein). Myoclonic jerks—abrupt involuntary muscle contractions that may produce brief limb or facial movements—usually appear at some time in the course of this disease. These are often stimulus-sensitive, such that loud noises may provoke them. Similar movements may develop with Huntington disease, but these patients usually develop more constant and fluid limb movements, called chorea.
229. The answer is e. (Ropper, p 974.) Up to 90% or more of patients with trisomy 21 who die after age 30 have Alzheimer-type changes in the brain. The histopathologic features of Alzheimer disease may be evident in the person with Down syndrome at any age. That a hereditary form of Alzheimer disease was found linked to chromosome 21 raised hopes that a single mutation was the cause of the problem, but this was subsequently negated by the finding of hereditary forms of Alzheimer linked to chromosome 19 and sporadic Alzheimer associated with defects on neither of these chromosomes. Aside from persons with Down syndrome, Alzheimer disease only rarely develops in relatively young people.
230. The answer is d. (Ropper, pp 598-601.) NPH is a chronic, communicating form of hydrocephalus affecting elderly adults. The cause is unknown, but it may relate to prior episodes of trauma, infection, or subarachnoid hemorrhage. The clinical picture typically includes a triad of gait disturbance, dementia, and incontinence. The gait disorder, which may be difficult to distinguish from that of Parkinson disease, has been labeled an apraxic gait, as patients often have difficulty even lifting their feet off the floor, though they have no weakness and may perform motor tasks well with the legs when seated. CT or MRI in these patients usually shows enlargement of the temporal and frontal horns of the lateral ventricles out of proportion to the degree of cortical atrophy. There may also be a squaring off or blunted appearance of the frontal horns, and increased signal on T2-weighted images may be seen in the periventricular regions, consistent with the presence of fluid related to transependymal flow of CSF.
231. The answer is c. (Ropper, pp 1014-1023.) Alzheimer disease accounts for as much as 50% of the dementia in the general population confirmed at autopsy; Parkinson disease accounts for only about 1%. Only 80 years ago, neurosyphilis was the most common cause of dementia, but the introduction of penicillin reduced—though it did not eliminate—this spirochetal disease as a cause of dementia. As the population ages, the incidence and prevalence of Alzheimer disease are increasing. The dementia caused by Alzheimer disease is progressive over the course of years. Language disturbances may appear even before memory problems.
232. The answer is b. (Ropper, pp 599-600.) Up to 28% of patients who undergo ventriculoperitoneal shunting for NPH may suffer major complications, including subdural hematoma and infections. Subdural hematoma occurs because the reduction in intracranial pressure brought on by the reduction in CSF volume may cause the brain to pull away from the covering meninges, stretching and potentially rupturing the bridging veins.
233. The answer is a. (Ropper, p 1022.) Recognition of the fact that there is a cholinergic deficit in the brains of patients with Alzheimer disease has led to the development of acetylcholinesterase inhibitors designed to augment the cholinergic neurotransmitter system. Several different agents are available, including donepezil, galantamine, rivastigmine, and tacrine. Another drug with a different mechanism of action (memantine) is available. The effects are modest and act to slow cognitive decline as assessed by scales of cognitive function. There is still no cure for Alzheimer disease.
234. The answer is d. (Ropper, pp 1014-1023.) The major clinical features of Alzheimer disease are memory impairment, aphasia, apraxia, and neuropsychiatric impairment, including mood disturbances, delusions and hallucinations, personality changes, and behavior disturbances. The language disturbance may take the form of decreased fluency, dysnomia, and transcortical sensory aphasia, which refers to a reduction in the ability to understand complex linguistic structures. Repetition of verbal material is intact.
235. The answer is a. (Ropper, pp 424-425.) TGA refers to an episode of complete and reversible anterograde and retrograde memory loss lasting up to 24 hours. Patients have a persistent loss of memory for the time of the attack. During the episode, patients often appear bewildered and ask repeated questions. They retain personal identity (unlike characters suffering from transient amnesia in television shows) and can perform complex cognitive and motor tasks. TGA usually affects middle-aged or older men and often occurs in the setting of an emotional or other stressor, such as physical or sexual exertion. Although it shares features of transient ischemic attack, it is not associated with an increased risk of stroke. Nonetheless, a vascular evaluation is often appropriate, particularly in atypical or repeated cases and in the presence of risk factors for stroke. Most patients experience only a single episode. Some have stressed TGA’s similarity to migraine and hypothesized that it is related to migrainous ischemia of the medial temporal lobe structures.
236. The answer is e. (Ropper, pp 738-741.) The neurological symptoms occurring early in the course of Creutzfeldt-Jakob disease are often cerebellar or visual. Patients may have ataxia, clumsiness, or dysarthria, as well as diplopia, distorted vision, blurred vision, field defects, changes in color perception, and visual agnosia. Ultimately, cortical blindness may occur. The diagnosis may be supported by the finding of periodic sharp waves at a 1-to-2 Hz frequency on EEG and the finding of elevated protein 14-3-3 in CSF. The typical EEG pattern is found in up to 80% of patients at some point during the course of the illness. An MRI may show a pattern of increased T2 signal in the basal ganglia or other gray matter in many, but not all, cases.
237. The answer is i. (Ropper, pp 1003-1004.) Rett syndrome is a presumed X-linked genetic disorder that affects only girls; the homozygous version is thought to be fatal in male offspring. Usually the prenatal, perinatal, and early childhood development appear normal or nearly so, and then the girl undergoes rapid regression in cognitive status in early childhood, generally during the second year of life. There is loss of previously acquired language skills and effective eye contact, as well as purposeful hand movement. Stereotypic hand movements develop, usually taking the form of hand wringing, but also including tapping, patting, and at times hand-mouth movements. Seizures may also occur. Etiology is unknown, and there is no treatment.
238. The answer is h. (Ropper, pp 1027-1031.) Dementia is a prominent feature of Huntington disease. Apathy and depression occur commonly, and a schizophreniform illness may be the presenting manifestation at times. The dementia itself is subcortical, characterized by impairment in executive function and concentration, without the classic cortical features of Alzheimer disease, such as aphasia, apraxia, and amnesia.
239. The answer is k. (Ropper, pp 694-695.) General paresis is one of the manifestations of neurosyphilis. It is a chronic, often insidious meningoencephalitis that may be delayed up to 20 years after the original spirochetal infection. Clinically, it manifests as dementia, delusions, dysarthria, tremor, myoclonus, seizures, spasticity, and Argyll Robertson pupils. Diagnosis is based on the findings of a monocytic pleocytosis and positive serological tests for syphilis. When caught early and treated with penicillin, the prognosis for independence may be good in up to 40% of cases. Neurosyphilis may be asymptomatic. Its other symptomatic forms include meningitis, meningovascular syphilis causing infarcts, optic atrophy, tabes dorsalis (characterized by ataxia, urinary incontinence, and lightning pains caused by degeneration of the posterior spinal roots), and other forms of spinal syphilis.
240. The answer is g. (Ropper, pp 1103-1105.) Hypothyroidism in adults may present with headache, dementia, psychosis, and decreased consciousness. Neuromuscular findings are also common, and they include a myopathic weakness and a delay in the relaxation phase of reflexes (the hung-up reflex). Percussion of muscles may also cause a mounding of the muscle, called myoedema. Cerebellar ataxia may also occur. In severe cases, myxedema coma may occur, characterized by hypothermia, hypotension, and respiratory and metabolic disturbances. This requires emergent replacement of thyroid hormone.
241. The answer is b. (Ropper, pp 679-680.) Whipple disease is a rare multisystem disorder caused by T whippeli. Gastrointestinal complaints, such as steatorrhea, abdominal pain, and weight loss, reflect bowel infection. Central nervous system (CNS) infection, which may occur in the absence of gastrointestinal disease, may produce seizures, myoclonus, ataxia, supra-nuclear gaze disturbances, hypothalamic dysfunction, and dementia. Oculomasticatory myorhythmia (pendular convergence movements of the eyes in association with contractions of the masticatory muscles) may occur and is considered pathognomonic. At times, other muscles of the body may be involved. Diagnosis can be made by biopsy of the jejunum, though sometimes brain biopsy may be required and may show PAS-positive cells. Treatment with antibiotics may be curative, and, for this reason, the diagnosis is important to remember in unusual cases of dementia with movement disorders.
242. The answer is d. (Ropper, p 711.) Progressive multifocal leukoencephalopathy is a progressive leukoencephalopathy seen in immunocompromised patients, most notably those with AIDS. It is caused by the JC virus. The disease affects subcortical white matter, particularly in the occipital or parietal regions, leading to visual complaints or phenomena such as the alien hand syndrome, as in this patient. Cerebrospinal fluid is usually normal, and the lesions do not enhance on imaging studies. There are usually several foci of abnormality seen on MRI, which can be used reliably to make the diagnosis. In some cases, polymerase chain reaction detection of JC virus in the CSF can be used to make the diagnosis.
243. The answer is g. (Ropper, pp 719-721.) Herpes simplex virus (HSV) encephalitis is the most common form of sporadic encephalitis in the United States. Mortality approaches 70% without treatment, making early diagnosis crucial. Patients may present with acute onset of seizures or with a subacute course characterized by deficits referable to temporal lobe structures, such as amnesia, aphasia, or psychosis. Motor deficits also often occur. Headaches and fever are usually present. Eventually, declining levels of consciousness and even coma may occur, and patients are at risk of uncal herniation from massive swelling of the temporal lobes. Electroencephalography, MRI, and CSF analysis help to confirm the diagnosis. Only in rare cases is biopsy needed. Mortality may be reduced to 20% with acyclovir.
244. The answer is b. (Ropper, p 413.) The history and findings are most suggestive of a vascular dementia caused by multiple strokes. The best way to prevent further cognitive loss is to prevent strokes. Deep brain stimulation of subthalamic nucleus and carbidopa/levodopa are treatments for Parkinson disease. Ventriculoperitoneal shunting is a treatment for normal pressure hydrocephalus. Psychotherapy may improve a pseudodementia by treating underlying depression.