Disturbance of hearing balance and test

Question 1

401. An 89-year-old man has noticed that his hearing has gradually wors-ened with aging. This has probably developed because of which of the fol-lowing?
     a. Calcification of ligaments stabilizing the ossicles
     b. Weakness of the tensor tympani
     c. Neuronal degeneration
     d. Weakness of the stapedius muscle
     e. Granulation tissue in the middle ear

Answer 1

401. The answer is c.( Victor, pp 301–315.) Presbycusis is the most com-mon cause of hearing loss in the elderly. High-frequency perception is
     impaired in this disorder because of sensorineural damage. The neurons
     most likely affected in this degenerative disorder are the spiral ganglion
     neurons of the cochlea.

Question 2

402. A 65-year-old diabetic woman has aphasia secondary to a stroke
     involving the inferior division of the left middle cerebral artery. Her hear-ing is intact. Dominant temporal lobe infarction will not produce complete
     deafness because
     a. There is no temporal lobe representation for hearing
     b. Each cochlear nucleus projects to both temporal lobes
     c. Deafness results with nondominant hemisphere damage
     d. Both thalamic and temporal lobe damage must occur
     e. Both brainstem and temporal lobe damage must occur

Answer 2

402. The answer is b.( Victor, pp 301–304.) Hearing in each ear is repre-sented bilaterally even at the level of the brainstem. Lesions rarely produce
     sufficient damage in the brainstem to cause unilateral deafness unless they
     are so massive that the patient is unlikely to be responsive to most stimuli
     and unlikely to survive. If there is unilateral deafness, the patient should be
     evaluated to determine whether the hearing loss is conductive or sensori-neural.

Question 3

403. A 72-year-old man is having difficulty hearing. He is being tested
     with a tuning fork. If he has disease of the middle ear, sound transmitted
     strictly by air conduction will be perceived as
     a. Louder than that transmitted by bone conduction
     b. Quieter than that transmitted by bone conduction
     c. Lower-pitched than that transmitted by bone conduction
     d. Higher-pitched than that transmitted by bone conduction
     e. Oscillating between high and low pitch

Answer 3

403. The answer is b. ( Victor, p 306.) The traditional test for detecting
     conductive deafness is the Rinne test. The vibrating tuning fork is applied
     to the mastoid process. When the patient can no longer hear the vibration
     of the fork, it is taken off the skull and moved to the external auditory mea-tus. With nerve deafness, acuity may be generally reduced, but perception
     with air conduction will be superior to that with bone conduction. This
     will also be true in normal persons. With conductive hearing loss, the
     sound waves are transmitted more effectively to the cochlea directly
     through the bones of the skull than through the air and along the pathway
     that starts at the external auditory meatus.

Question 4

404. A 13-year-old girl has a severe case of mastoiditis. Despite treatment,
     she develops a fluent aphasia. Her aphasia is most likely the result of exten-sion of the infection into the
     a. Frontal lobe
     b. Parietal lobe
     c. Temporal lobe
     d. Occipital lobe
     e. Cerebellum

Answer 4

404. The answer is c.( Victor, pp 508–509.)Mastoiditis may extend either
     supratentorially into the temporal lobe or infratentorially into the cerebel-lum. Cerebellar involvement is likely to produce ataxia, vertigo, nausea,vomiting, and morning headache. Temporal lobe extension causes a fluent
     aphasia by damaging Wernicke’s area in the superior temporal gyrus. The
     lesion in either the cerebellum or the temporal lobe is usually an abscess
     formed by bacteria responsible for the mastoiditis. Surgical removal of the
     abscess is essential in either location, as progression of the abscess in either
     the cerebellum or the temporal lobe will be lethal.

Question 5

405. A 19-year-old soldier was very close to an exceptionally loud explo-sion. If her hearing has been damaged, it is most likely a
     a. High-tone sensorineural loss
     b. Low-tone sensorineural loss
     c. High-tone conductive loss
     d. Low-tone conductive loss
     e. Central deafness

Answer 5

405. The answer is a.( Victor, p 310.) The principal site of damage with
     acoustic trauma is the cochlea. Mechanical trauma may produce a high-tone conductive loss by perforating the eardrum. A strictly acoustic insult
     would not be expected to convey enough energy to the tympanum to dis-rupt it, but it may convey enough energy to the cochlea to shear off recep-tor filaments from hair cells.

Question 6

406. A 79-year-old woman is brushing her teeth when she has an intense
     sensation that the room is moving as if she were on a ship. Examination
     and testing reveal a cerebellar stroke. Cerebellar damage may be associated
     with severe vertigo if the tissue damaged is in the distribution of the
     a. Superior cerebellar artery
     b. Posterior inferior cerebellar artery (PICA)
     c. Anterior inferior cerebellar artery (AICA)
     d. Anterior spinal artery
     e. Posterior cerebral artery

Answer 6

406. The answer is b. ( Victor, pp 844–845.) The PICA has both medial
     and lateral branches. The medial branches supply the brainstem. With
     occlusion of these, vestibular nuclei in the brainstem are infarcted, and ver-tigo is common. Even with an occlusion limited to the lateral branches,
     vertigo is likely. If no brainstem damage occurs, cerebellar flocculonodular
     lobule injury may induce vertigo.

Question 7

407. A 62-year-old man has started getting a haircut every week. When-ever he lays his head back to have his hair washed, he has the sensation of
     spinning. With vertigo that develops on extreme extension or rotation of
     the head, the patient probably has insufficiency in the
     a. Left subclavian artery
     b. Internal carotid arteries bilaterally
     c. Vertebrobasilar system
     d. Internal maxillary artery
     e. Innominate artery

Answer 7

407. The answer is c.( Victor, pp 842–844.) The vertebral arteries ascend
     through foramens in the transverse processes of the cervical vertebrae.
     With bony spurs on the vertebrae or with severe atherosclerotic disease in
     the vertebral arteries, flow through the vertebrobasilar system may be tran-siently reduced when the head is extended or rotated. Because vertigo may
     be positional without any associated vascular insufficiency, a diagnosis of
     vertebrobasilar ischemia should be reached only after other causes, such as
     cerebellar tumor, have been eliminated.

Question 8

408. Early in the evolution of Ménière’s disease, hearing is lost
     a. Over all frequencies
     b. Primarily over high frequencies
     c. Primarily over middle frequencies
     d. Primarily over low frequencies
     e. In virtually no patients

Answer 8

408. The answer is d.( Victor, pp 319–321.) Unlike the deficit of presby-cusis, lower tones are most susceptible to impaired perception during the
     initial phases of Ménière’s disease. The severity of the hearing loss typically
     fluctuates considerably. As fluctuations in the low-tone loss abate, high
     tones become progressively more involved. The attacks of vertigo associ-ated with Ménière’s disease usually abate as hearing loss in the affected ear
     peaks.

Question 9

409. A 52-year-old diabetic man on multiple medications develops ver-tigo. Which of the following medications may cause a toxic labyrinthitis?
     a. Promethazine
     b. Penicillin
     c. Dimenhydrinate
     d. Acetylsalicylic acid
     e. None of the above

Answer 9

409. The answer is d.( Victor, p 310.) Salicylates, as well as alcohol, qui-nine, and aminoglycoside antibiotics, may produce a toxic labyrinthitis
     with vertigo as a prominent feature. Vertigo is also a common sequela of
     head trauma or whiplash injury. Promethazine (Phenergan), dimenhydri-nate (Dramamine), and meclizine (Antivert) are all commonly used agents
     to reduce symptoms of vertigo.

Question 10

410. A 50-year-old man is being evaluated for tinnitus. It is worse on
     some days than others. Which of the following should he be told may exac-erbate the tinnitus?
     a. Alcohol
     b. Aspirin
     c. Glucose
     d. Diazepam
     e. Steroids

Answer 10

410. The answer is b. ( Bradley, pp 260–261.) Aspirin may produce tin-nitus in persons usually unaffected by this problem. Patients on high
     doses of aspirin for rheumatoid arthritis are especially susceptible to this
     drug-induced tinnitus. Those patients with chronic tinnitus from acoustic
     trauma or Ménière’s disease will find their symptoms worsen with aspirin.

Question 11

411. A 26-year-old man has multiple café au lait spots. Which of the fol-lowing tumors is most likely to occur in this patient?
     a. Medulloblastoma
     b. Acoustic schwannoma
     c. Neurofibroma
     d. Ependymoma
     e. Meningioma

Answer 11

411. The answer is c.( Victor, pp 1073–1077.) Café au lait spots character-istically occur in both type 1 and type 2 neurofibromatosis. Meningiomas,
     acoustic schwannomas, and other types of CNS tumors occur with these
     hereditary disorders, but the neurofibroma is the most common lesion. Type
     1 neurofibromatosis develops with a defect on chromosome 17, type 2 with
     a defect on chromosome 22.

Question 12

412. A 30-year-old woman has progressive hearing loss. An MRI reveals
     bilateral acoustic schwannomas (neuromas). She most likely has which of
     the following?
     a. Type 1 neurofibromatosis (von Recklinghausen’s disease)
     b. Type 2 neurofibromatosis
     c. Meningeal carcinomatosis
     d. Multifocal meningiomas
     e. Disseminated ependymomas

Answer 12

412. The answer is b. ( Victor, p 1076.) Schwannomas most often occur
     on the eighth cranial nerve, but they may also develop on the fifth, seventh,
     ninth, or tenth cranial nerves. With type 2 neurofibromatosis, bilateral
     tumors are more the rule than the exception. The tumors that develop on
     the eighth cranial nerve usually develop on the vestibular division of the
     nerve.

Question 13

413. The olfactory cortex in humans is located in the
     a. Anterior perforated substance
     b. Lateral olfactory gyrus (prepiriform area)
     c. Posterior third of the first temporal gyrus
     d. Angular gyrus
     e. Calcarine cortex

Answer 13

413. The answer is b. ( Victor, pp 238–239.) The olfactory tract divides
     into medial and lateral striae. The medial stria sends fibers across the ante-rior commissure to the opposite hemisphere. The lateral stria terminates in
     the medial and cortical nuclei of the amygdaloid complex, as well as the
     prepiriform area. This primary olfactory cortex is in area 34 of Brodmann
     and is restricted to a small area on the end of the hippocampal gyrus and
     the uncus. This distribution of fibers makes olfaction unique among the
     senses in that it does not send fibers through the thalamus.

Question 14

414. The hypogonadism and anosmia of Kallman syndrome usually attract
medical attention during
a. The newborn period
b. Infancy
c. Childhood
d. Adolescence
e. Adult life

Answer 14

414. The answer is d. (Swaiman, pp 1317–1318.) Development of geni-talia and secondary sexual characteristics during puberty and adolescence is usually negligible in boys affected by Kallman syndrome. The olfactory
     defect is congenital but may be unsuspected until the hypogonadism
     becomes apparent. The defects responsible for both the anosmia and hypo-gonadism are developmental rather than acquired. Until the defect in sec-ondary sexual characteristics becomes apparent, the affected person is
     usually perceived as normal

Question 15

415. A 22-year-old woman is involved in a head-on motor vehicle acci-dent. She was not wearing a seat belt, and she received a skull fracture
     when her head hit the windshield. By what mechanism would this patient
     develop anosmia?
     a. Subarachnoid blood causes pial adhesions on the olfactory nerve
     b. Injury to the temporal tip injuries the olfactory cortex
     c. Torsion on the brainstem injures trigeminal tracts
     d. Shearing forces sever filaments of the receptor cells as they cross the cribriform
     plate
     e. Traction on the chorda tympani damages fibers as they course through the skull415. A 22-year-old woman is involved in a head-on motor vehicle acci-dent. She was not wearing a seat belt, and she received a skull fracture
     when her head hit the windshield. By what mechanism would this patient
     develop anosmia?
     a. Subarachnoid blood causes pial adhesions on the olfactory nerve
     b. Injury to the temporal tip injuries the olfactory cortex
     c. Torsion on the brainstem injures trigeminal tracts
     d. Shearing forces sever filaments of the receptor cells as they cross the cribriform
     plate
     e. Traction on the chorda tympani damages fibers as they course through the skull

Answer 15

415. The answer is d.( Victor, p 240.) Anosmia is most likely to develop
     with head trauma if the trauma is sufficient to cause a skull fracture. If
     anosmia does occur in the setting of a skull fracture, it is likely to be per-manent. With head trauma that does not cause a fracture, anosmia will per-sist in about 75% of cases.

Question 16

416. A 45-year-old man has noticed over the past 6 months that his sense
of smell is not as sensitive as it used to be. On examination he has unilat-eral anosmia, ipsilateral optic atrophy, and contralateral papilledema. He
most likely has which of the following?
a. Pseudotumor cerebri
b. Multiple sclerosis (MS)
c. Olfactory groove meningioma
d. Craniopharyngioma
e. Nasopharyngeal carcinoma

Answer 16

416. The answer is c.( Victor, p 231.) Ipsilateral optic atrophy and con-tralateral papilledema in association with an intracranial tumor constitute
     the Foster-Kennedy syndrome. A meningioma of the olfactory groove may
     produce this syndrome if it extends posteriorly to involve the ipsilateral
     optic nerve. Compression on the optic nerve by the tumor produces atro-phy and interferes with transmission of the increased intracranial pressure
     down the optic sheath. The increased intracranial pressure is reflected in
     the papilledema apparent in the contralateral eye.

Question 17

417. A 60-year-old woman complains of feeling dizzy intermittently dur-ing the day. Her symptoms are worse when she turns her head to the left,
     to the point that she tends to keep her head stiff, looking forward. She
     becomes particularly dizzy when she lies down in bed at night or turns
     onto her left side. She occasionally wakes up in the middle of the night feel-ing dizzy. She had a similar experience 2 years ago, which lasted for 2
     weeks and then spontaneously resolved. She has otherwise felt well, and
     her hearing is normal. On examination, putting her head back and the left
     ear down elicits a feeling of dizziness and nausea associated with rotatory
     nystagmus, which lasts for 15 s and then resolves. (SELECT 1 CONDI-TION)
     a. Ménière’s disease
     b. Cholesteatoma
     c. Vestibular schwannoma
     d. Benign positional vertigo (BPV)
     e. Aminoglycoside toxicity
     f. Salicylate toxicity
     g. Vestibular neuronitis
     h. Posttraumatic vertigo
     i. Vertebral artery occlusion
     j. Bilateral vestibular hypofunction
     k. Bell’s palsy

Answer 17

417. The answer is d.( Bradley, pp 242–243, 741.) Benign positional ver-tigo commonly affects people in middle age or older. It is characterized by
     recurrent attacks of rotational vertigo occurring on changes in head posi-tion, typically lying down or turning onto the side of the affected ear. The
     symptoms may persist on standing as well, leaving the patient with a con-tinuous sense of disequilibrium. Provocative maneuvers (Nylan-Barany or
     Hallpike maneuver) are used to confirm that the patient’s complaint is due
     to a peripheral cause of vestibulopathy rather than a central process affect-ing the brainstem. In a peripheral vestibulopathy, putting the patient’s head
     in a position hanging at 45° off the end of the examining table, with the
     head turned to the affected side, will produce rotatory nystagmus with a
     latency of up to 40 s, a brief duration (generally less than 1 min), and fatig-ability (a decrease in symptoms and signs with successive maneuvers). The
     cause of BPV is thought to be related to a calcified piece of otolithic mate-rial moving within the posterior semicircular canal. Treatment may include
     vestibular exercises, which entails the maneuvers at home, or a maneuver designed to free the otolith from the
     posterior semicircular canalpatient performing provocative

Question 18

418. A 34-year-old investment banker complains of intermittent episodes
of vertigo associated with a feeling of fullness in his right ear. These last for
several hours. He has had progressive hearing loss in the right ear. There
are no other symptoms. He takes no medications and has no history of
head trauma. (SELECT 1 CONDITION)
a. Ménière’s disease
b. Cholesteatoma
c. Vestibular schwannoma
d. Benign positional vertigo (BPV)
e. Aminoglycoside toxicity
f. Salicylate toxicity
g. Vestibular neuronitis
h. Posttraumatic vertigo
i. Vertebral artery occlusion
j. Bilateral vestibular hypofunction
k. Bell’s palsy

Answer 18

418. The answer is a.( Bradley, pp 245, 741.) Ménière’s disease is charac-terized by repeated brief episodes of fullness in the ear, tinnitus, hearing
     loss, and severe vertigo. The episodes may last from hours to days. Attacks
     may be so severe as to cause the patient to fall to the ground due to severe
     disequilibrium. The cause is generally idiopathic, but is thought to relate to
     distension of the semicircular canal and an increase in the volume of the
     endolymphatic fluid. For this reason, the condition has been called endo-lymphatic hydrops. Treatment is generally with salt restriction and diuret-ics. Surgery with endolymphatic shunts is of unproven value

Question 19

419. A 47-year-old woman with a history of orthotopic heart transplanta-tion 6 months ago has had a complicated postoperative course and was
     readmitted 3 months ago with pneumonia. She was treated with genta-micin, vancomycin, and clindamycin, as well as her usual regimen of
     immunosuppressant medications, lipid-lowering drugs, and aspirin. Since
     then, she has had severe but stable disequilibrium, with inability to walk
     without a cane. There has been no hearing loss or weakness. (SELECT 1
     CONDITION)
     a. Ménière’s disease
     b. Cholesteatoma
     c. Vestibular schwannoma
     d. Benign positional vertigo (BPV)
     e. Aminoglycoside toxicity
     f. Salicylate toxicity
     g. Vestibular neuronitis
     h. Posttraumatic vertigo
     i. Vertebral artery occlusion
     j. Bilateral vestibular hypofunction
     k. Bell’s palsy

Answer 19

419. The answer is e.( Bradley, p 244.) Aminoglycoside antibiotics may
     cause vestibulopathy and ototoxicity. The vestibular end organ is affected
     by streptomycin and gentamicin; kanamycin, tobramycin, and neomycin
     tend to have a greater effect on the cochlea. Disequilibrium may progress
     after exposure. The cause is probably related to the fact that these drugs are
     concentrated in the endolymphatic fluid, exposing the cochlear hair cells
     to high levels of the drug. Renal disease may exacerbate the effects of the
     drugs

Question 20

420. A 72-year-old man awakens with severe vertigo associated with nau-sea and vomiting. He is ataxic. Over the next several days, he develops
numbness of the left side of his body, dysphagia, and hiccups. On exami-nation he has a left homonymous hemianopsia, left-sided sensory loss, dys-metria with the right hand, and no weakness. He has had intermittent
episodes of dizziness for the past month.  (SELECT 1 CONDITION)
a. Ménière’s disease
b. Cholesteatoma
c. Vestibular schwannoma
d. Benign positional vertigo (BPV)
e. Aminoglycoside toxicity
f. Salicylate toxicity
g. Vestibular neuronitis
h. Posttraumatic vertigo
i. Vertebral artery occlusion
j. Bilateral vestibular hypofunction
k. Bell’s palsy

Answer 20

420. The answer is i.( Victor, pp 842–846.) This patient has a history of
     progressive vertigo, ataxia, sensory loss, dysphagia, and hiccups, all symp-
     toms of the lateral medullary syndrome, usually due to distal vertebral
     artery occlusion. This patient’s hemianopsia reflects the probable occur-
     rence of occipital lobe infarction, perhaps related to embolism from the
     occluded vertebral artery. This could have occurred at the time of the lat-
     eral medullary stroke or at an independent time. The preceding history of
     dizzy episodes is indicative of the importance of a thorough evaluation for
     the cause of dizziness in the elderly patient, particularly when other symp-
     toms occur as well.