The material in this study guide, as well as the study questions that go with the material, has thus far been parceled out into (I hope) easy-to-digest chunks. This parceling out, however, is only meant to be a stepwise approach to reaching a broader understanding of the overall organization of the central nervous system. This chapter is a series of questions designed to cover all material in the book. Some of them are simple review questions referring to individual chapters, whereas others require the integration of material from several chapters. Some have more than one correct answer.
- 1.
Sensory information arriving from one side of the body or head typically reaches the cerebral cortex of the contralateral side. The axons that cross the midline to accomplish this are the axons of
- a.
primary sensory neurons
- b.
second-order or higher-order neurons in the sensory pathway
- c.
thalamic neurons
- d.
Could be any of the above, depending on the sensory pathway
- a.
- 2.
Arachnoid villi are
- a.
the sites at which cerebrospinal fluid (CSF) is secreted
- b.
the sites at which CSF is filtered out of blood
- c.
the sites at which CSF is pumped out of subarachnoid space and into the venous circulation
- d.
the sites at which CSF is pushed passively by hydraulic pressure into the venous system
- e.
small vacation homes for spiders in southern France a
a Thanks to Dr. Tom Finger.
- a.
- 3.
As CSF is being withdrawn during a lumbar puncture, the tip of the needle is located in the
- a.
epidural space
- b.
subarachnoid space
- c.
subdural space
- d.
subpial space
- a.
- 4.
Medial medullary syndrome (the name says something about the location of the lesion) refers to a condition in which a patient has spasticity and diminished proprioception and tactile sensation on one side of the body, combined with weakness and atrophy of the contralateral side of the tongue. Which way would the tongue deviate when protruded? What structures would have been damaged to account for these findings? Occlusion of which artery or arteries would be most likely to cause such a syndrome?
- 5.
A left-handed 65-year-old butterfly collector complains that he has been having more and more difficulty lately collecting butterflies because he “sees double,” which confuses him. Your examination reveals a drooping right eyelid, lateral strabismus of the right eye, and a moderately dilated right pupil. He is completely unable to move his right eye to the left past midposition. You can find absolutely no other neurological disturbances. Following angiography, the radiologist announces that the patient has a large intracranial aneurysm. You immediately say, “Aha! I knew it! It’s an aneurysm of the…”
- 6.
A 39-year-old handball hustler, in an apoplectic rage over a referee’s call, suddenly lost consciousness and fell to the floor. He was rushed to an emergency department and treated for an intracranial hemorrhage. When you examine him several days later, you find weakness of his right arm and leg. Stroking the sole of his right foot causes its big toe to turn up and its others to fan. The patient looks at you with his head turned to the left because he says that in any other position he sees double. When you ask him to look straight ahead, his left eye is deviated medially. When you ask him to look to the right, his right eye moves normally and his left eye moves farther medially. When you ask him to look to the left, his right eye again moves normally and his left eye moves laterally almost, but not quite, to midposition. The sensory examination is normal and there are no other cranial nerve findings. Where is the damage? Which artery, or a branch of which artery, caused it?
- 7.
A 33-year-old, right-handed roller derby skater comes to you complaining of periodic attacks of tinnitus (“ringing” or “buzzing”) in her left ear and vertigo (the sensation that she and her surroundings are moving relative to one another, when she is standing or sitting still). She says these attacks have been becoming more frequent over the past year or so, and now, between attacks, she feels as though she can’t hear as well with her left ear as she can with her right. Your examination reveals that the auditory threshold is indeed elevated in her left ear, whether you use air conduction or bone conduction. You also notice that touching either cornea with a wisp of cotton causes her right eye to blink briskly and her left eye to blink somewhat sluggishly. Then you notice that she seems to have a somewhat asymmetrical smile: the right side of her face moves more than the left. What is the most likely cause of this patient’s problems?
- 8.
A 57-year-old, right-handed topologist, while discussing the various routes out of Klein bottles, suddenly became dizzy and tumbled to the floor. She did not lose consciousness but was mildly confused and complained of a severe headache for several days after the fall. Following hospitalization and partial recovery, some symptoms and signs persisted. The patient was referred to you, an eminent neurologist, for diagnosis and treatment 2 weeks after the episode. Your examination revealed the following:
- a.
The patient was alert, oriented, intelligent, and showed no sign of confusion.
- b.
She no longer complained of headache.
- c.
There was complete loss of pain and temperature sensation on the right side of her body.
- d.
Her voice seemed hoarse and somewhat abnormal, and her left vocal cord and left soft palate appeared paralyzed.
- e.
There was loss of pain and temperature sensation on the left side of her face.
- f.
She complained of often feeling dizzy.
- g.
Her left arm and leg were mildly ataxic. For example, if she tried to reach for something with her left hand, the hand would oscillate as it approached the object.
- h.
Her history revealed that she had enjoyed generally excellent health but had gradually developed hypertension over the previous few years.
- a.
Could a single lesion account for all these findings? What structures were damaged? What was the most likely cause?
- 9.
Are there places in the brainstem where a single reasonably discrete lesion could cause
- a.
bilateral Babinski signs?
- b.
bilateral loss of tactile and proprioceptive sensation in the entire body?
- c.
bilateral loss of pain and temperature sensation in the entire body?
- d.
bilateral signs of cerebellar dysfunction?
- a.
- 10.
Arrange the following fibers in order of conduction velocity, with the fastest first: afferents from muscle spindles, afferents from temperature receptors, axons of gamma motor neurons.
- a.
Gamma, temperature, spindle
- b.
Gamma, spindle, temperature
- c.
Spindle, gamma, temperature
- d.
Temperature, gamma, spindle
- e.
Spindle, temperature, gamma
- a.
- 11.
A middle-aged neurologist was walking through City Park late one night wearing a peculiar hat and laughing to himself (as he often did) when he was mistaken for a moose by an overeager bowhunter. The left half of his spinal cord was severed at T12. What neurological problems would you expect him to have a month later?
- 12.
Endolymph
- a.
fills the bony labyrinth
- b.
fills a restricted part of the membranous labyrinth
- c.
has a high [K + ] relative to ordinary extracellular fluid
- d.
None of the above
- a.
- 13.
Deafness of the left ear would be caused by damage to the
- a.
left cochlear nuclei
- b.
right cochlear nuclei
- c.
left lateral lemniscus
- d.
right lateral lemniscus
- e.
Either (a) or (c)
- f.
Either (a) or (d)
- a.
- 14.
The visual field deficits shown below (shaded area = defective) could best be explained by
