Systems

(Reproduced, with permission, from Anschel DJ, Romanelli P, Mazumdar A. McGraw-Hill Specialty Board Review: Clinical Neuroimaging. New York: McGraw-Hill; 2008:45.)

a. A stroke involving the right anterior cerebral artery

b. A stroke involving the right middle cerebral artery

c. Occlusion of the right anterior communicating artery

d. Occlusion of the right posterior communicating artery

e. A stroke of the posterior cerebral artery

392. A 50-year-old man presents with dizziness, headaches, and ataxia of the limbs. He is given an MRI, shown in the figure here, and a hemangioblastoma is noted (indicated by the white arrow). Where is the tumor most likely located?

(Reproduced, with permission, from Anschel DJ, Romanelli P, Mazumdar A. McGraw-Hill Specialty Board Review: Clinical Neuroimaging. New York: McGraw-Hill; 2008:79.)

a. Midbrain

b. Cerebellum

c. Rostral pons

d. Caudal pons

e. Medulla

393. A patient who suffered a stroke presents with a paralysis of the right side of the lower face, right spastic paralysis of the limbs, deviation of the tongue to the right with no atrophy, and no loss of taste from any region of the tongue. Which of the following structures is most likely affected by the stroke?

a. Internal capsule of the right side

b. Internal capsule of the left side

c. Right pontine tegmentum

d. Base of the medulla on the right side

e. Base of the medulla on the left side

394. A 74-year-old woman is brought to the hospital after she suffered a stroke. Several days later, a neurological examination reveals that she is unable to perform certain types of learned, complex movements (referred to as apraxia). Which of the following regions of the cerebral cortex is most likely affected by the stroke?

a. Precentral gyrus

b. Postcentral gyrus

c. Premotor cortex

d. Prefrontal cortex

e. Cingulate gyrus

395. A 47-year-old man is admitted to a hospital after he presents with writhing, wild, flinging-like movements of his left arm that became progressively worse over time. An MRI reveals the presence of a tumor present over the caudate and putamen on the right side of the brain. The neurologist concludes that the tumor caused significant damage to neurons in this region, thus disrupting their normal functions. Which of the following best characterizes neurons in the neostriatum that were disrupted by the tumor?

a. Inhibited by γ-aminobutyric acid (GABA) released at corticostriate terminals

b. Inhibited by GABA released at nigrostriatal terminals

c. Inhibited by substance P released at corticostriate terminals

d. Excited by acetylcholine (ACh) released from hypothalamic-caudate terminals

e. Excited by glutamate released at corticostriate terminals

396. A child is suffering from a developmental abnormality that affects the primary transmitter released from terminals of both neostriatal and paleo-striatal neurons. Which neurotransmitter is most likely affected by this abnormality?

a. Glycine

b. Enkephalin

c. Dopamine

d. GABA

e. Glutamate

397. A 46-year-old woman receives a diagnosis of having a movement disorder associated with disturbances of the basal ganglia. In particular, she presents with writhing, uncoordinated movements at rest of her left arm and leg. An MRI reveals the presence of a tumor affecting mainly the right caudate nucleus and putamen. Which of the following best explains why the dysfunction is expressed on the side of the body contralateral to the region of the basal ganglia directly affected by the stroke?

a. Fibers from the basal ganglia to the spinal cord are crossed.

b. Fibers from the basal ganglia project to motor nuclei of the brainstem whose axons then project to the contralateral spinal cord.

c. Fibers from the basal ganglia project to the ipsilateral motor cortex.

d. Axons from the basal ganglia project to the cerebellum, whose outputs are known to modulate the contralateral side of the body.

e. Fibers from the basal ganglia project directly to the contralateral motor cortex.

398. A 43-year-old man who began to display marked involuntary movements at times of rest is seen by a neurologist, who concludes that he is suffering from Huntington disease. Which of the following neurotransmitters is lost or reduced in this individual?

a. Dopamine in the neostriatum

b. Substance P in the substantia nigra

c. ACh and GABA in intrastriatal and cortical neurons

d. Serotonin in the neostriatum

e. Histamine in subthalamic nucleus

399. A patient is admitted to the local hospital for treatment of a vascular occlusion within the forebrain. An MRI indicates that the damage is limited to the subthalamic nucleus. As a result of this lesion, which of the following disorders is likely to be present in the patient?

a. Torsion dystonia

b. Tremor at rest

c. Hemiballism

d. Spastic paralysis

e. Tardive dyskinesia

400. A patient presents with a movement disorder, which includes most prominently chorea-like symptoms. In treating this patient, the neurologist adopts a strategy based upon our current level of knowledge of neuroscience of this region of the brain. Which of the following strategies is the neurologist most likely to apply?

a. ACh blockers because there is an excess of this transmitter in the caudate nucleus

b. Dopamine blockers because there is too low a ratio of ACh to dopamine in the neostriatum

c. Serotonin blockers because there is too low a ratio of serotonin to ACh and dopamine in the neostriatum

d. Substance P antagonists because the ratio of substance P to ACh is too high in the neostriatum

e. Norepinephrine antagonists because the ratio of norepinephrine to ACh is too high in the subthalamic nucleus

401. A 65-year-old man has been under long-term treatment for an anxiety disorder. Recently, the psychiatrist observed that he began to develop symptoms of tardive dyskinesia. This disorder is most likely the result of which of the following alterations?

a. A reduction in serotonin receptors in the neostriatum

b. A change in ACh receptors that causes a hypersensitivity to ACh

c. A change in enkephalin receptors that causes a hypersensitivity to enkephalin

d. A change in GABA levels in the basal ganglia

e. A change in dopamine levels in the limbic system

402. Two 18-year-old boys were experimenting with designer drugs and after they took the drugs, each of them presents with a movement disorder associated with basal ganglia dysfunction. The drug is later identified as the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and has recently been applied experimentally with considerable success as a model for the study of which of the following diseases?

a. Huntington disease

b. Hemiballism

c. Parkinson disease

d. Tardive dyskinesia

e. Dystonia

403. A 25-year-old man, who began to have difficulty in walking, is examined by a neurologist and neurosurgeon. They conclude that a tumor is compressing upon the lateral aspect of his spinal cord, affecting primarily the spinocerebellar tracts. Which of the following structures is the principal region within the cerebellum that receives these fibers?

a. Anterior lobe

b. Posterior lobe

c. Flocculonodular lobe

d. Fastigial nucleus

e. Dentate nucleus

404. A 23-year-old woman is exposed to a neurotoxin that selectively destroyed the Purkinje cell layer of the cerebellum, resulting in loss of balance and coordination. Of the structures or regions indicated below, which one is most directly affected by the loss of Purkinje cells?

a. Red nucleus

b. Deep cerebellar nuclei

c. Reticular formation

d. Ventrolateral (VL) nucleus (thalamus)

e. Spinal cord

405. A 64-year-old man who had been an alcoholic patient for many years dies from a myocardial infarction. A CT scan of his brain is taken through the level of the cerebellum as well as one showing the hemispheres and sulci. Which of the following clinical signs would this patient be most likely to display?

(Reproduced, with permission, from Ropper AH, Samuels MA. Adams & Victor’s Principles of Neurology. 9th ed. New York: McGraw-Hill; 2009.)

a. Intention tremor

b. Spasticity

c. Rigidity

d. Ataxia of legs

e. Movement disorder at rest

Questions 406 and 407

406. A previously healthy 62-year-old man is brought to a neurologist because of increasing difficulty in walking. For the past year, he had difficulty getting out of a chair and took a lot of time to begin to walk. When he did walk, he walked with a slow, shuffling gait. There were also changes in his face, and that he had been drooling excessively. His signature on checks became progressively smaller from the beginning of his name to the end, and he had developed a new tremor. The neurologist examines the patient and notices that his facial expression is masklike, with few eye-blinks. When asked to write a sentence, the letters become progressively smaller toward the end of the sentence. His speech is soft and monotonous, and he has a slow, resting pill-rolling tremor in both of his hands. He has very little spontaneous movement, and his arms, legs, and trunk are stiff. When the neurologist tries to flex his arm, he feels many catches, similar to a cog-wheel. There is no weakness, sensory problems, or abnormalities in his reflexes. When asked to walk, the patient takes many tries to rise from his chair. When he finally stands up, his posture is stooped and flexed. His gait is slow, his feet shuffle when he walks, and his arms do not swing with his steps. The neurologist concludes that this his condition is not just aging. Damage to which of the following structures most likely caused this patient’s problem with movement?

a. Substantia gelatinosa

b. Substantia nigra, pars reticularis

c. Substantia nigra, pars compacta

d. Caudate nucleus

e. Thalamus

407. In the patient in Question 406, which of the following is damaged?

a. Lenticulostriate branches of the middle cerebral and anterior cerebral arteries

b. Perforating branches of the basilar and vertebral arteries

c. Anterior choroidal artery and anterior cerebral artery

d. Branches of posterior cerebral and posterior communicating arteries

e. Anterior cerebral and anterior communicating arteries

408. A 65-year-old man is informed by his neurologist that he has Parkinson disease. Which of the following neurotransmitters is deficient in this patient?

a. Norepinephrine

b. Glutamate

c. Dopamine

d. ACh

e. GABA

409. A patient suffers from Parkinson disease. His neurologist prescribes a drug, which constitutes a precursor to the neurotransmitter deficient in this individual, as a medication for his disorder. Which of the following precursors to the deficient neurotransmitter is administered as a medication to improve the condition of this patient?

a. Tyrosine

b. Choline

c. Acetyl-CoA

d. Tryptamine

e. L-dihydroxy phenylalamine (L-DOPA)

410. A 67-year-old man has been suffering from Parkinson disease for a number of years and every current drug administered to the patient ultimately was unsuccessful in alleviating the symptoms. Since drug treatment with this patient is typical of the unsuccessful treatment given to many other patients, a pharmaceutical company attempts to develop a new drug for the treatment of Parkinson disease. The approach utilized by this company involves the application of a drug that will block the action of a certain enzyme that normally functions to destroy a specific neurotransmitter. Such a drug would effectively increase the amount of the deficient neurotransmitter in the brain. Which of the following enzymes would be targeted by this drug?

a. Choline acetyltransferase

b. Monoamine oxidase

c. GABA transaminase

d. Acetylcholinesterase

e. Tyrosine hydroxylase

411. A 57-year-old man who has always been a very heavy drinker, often consuming two pints of whiskey per day, for many years, notices that he now needs to stand with his feet far apart in order to maintain his balance and that he waddles when he walks. The doctor who evaluates him tests his memory and speech carefully, as well as his cranial nerves, and is unable to find any deficits. There is no weakness, sensory loss, or abnormalities in his reflexes. When asked to touch the doctor’s finger and then his nose, the patient misses his nose slightly, but rapidly corrects the movement on both sides. When asked to slide his right heel down his left shin, his heel slides sideways and clumsily across the bone until it reaches his ankle. The response with the left heel is similar. When asked to walk, the patient walks with his feet very far apart. If he tries to walk in a tandem fashion, with one heel in front of the other toe, he begins to fall, and the doctor has to catch him. The doctor orders an MRI of the patient’s head. Which of the following terms best describes the patient’s gait?

a. Stiff

b. Festinating

c. Ataxic

d. Spastic

e. Shuffling

412. A patient presents with nystagmus and a gait ataxia. An MRI detects the presence of a lesion in the region of the cerebellum. With which functional division of the cerebellum is most likely the affected region associated?

a. Cerebrocerebellum

b. Spinocerebellum

c. Dentate nucleus

d. Middle cerebellar peduncle

e. Interposed nuclei

413. A patient presents with cerebellar ataxia and nystagmus. An MRI later identifies the site of the lesion. To which of the following deep cerebellar nucleus or related structure do the neurons in the damaged region project?

a. Globose nucleus

b. Emboliform nucleus

c. Fastigial nucleus

d. Dentate nucleus

e. Superior cerebellar peduncle

414. A patient with a long history of alcoholism with a dramatic gait ataxia and nystagmus dies 2 months after he is admitted to a local hospital. Following an autopsy, the neuropathological examination reveals significant loss of which of the following cells?

a. Schwann cells

b. Pyramidal cells

c. Spindle cells

d. Anterior horn cells

e. Purkinje cells

Questions 415 and 416

415. An 86-year-old woman has had difficulty with high blood pressure, high cholesterol, diabetes, strokes, and blood clots in her legs for many years. One day, her grandson arrives at her apartment in a senior citizen center for his weekly visit and finds her lying unconscious on the floor. He immediately calls an ambulance. The paramedics in the ambulance give her some medications, including glucose, but she does not awaken. She is taken to the nearest emergency room, where a physician is called to evaluate her. She is breathing on her own and has a pulse, but could not be aroused to any stimulus. Her arms and legs are stiff and would not move in response to a painful stimulus. Her eyes move in response to moving her head. Finally, in response to a very loud shout and pinch on the arm, she briefly opens her eyes; however, she immediately shut them again. Further attempts to arouse the patient are unsuccessful. She is taken for a CT scan of her head, and then taken to an intensive care unit. An acute stroke in which portion of the central nervous system (CNS) would most likely cause this scenario?

a. Right frontal lobe

b. Left frontal lobe

c. Right temporal lobe

d. Pons and midbrain

e. Right occipital lobe

416. In the patient in Question 415, which of the following is the most likely cause of the stiffness in her arms and legs?

a. Infarction of the corticospinal tracts bilaterally in the pons

b. Damage to the basal ganglia

c. Infarction of the precentral gyrus

d. Infarction of the internal capsules bilaterally

e. Thalamic infarction

417.