Disturbance of hearing balance and test Flashcards
1
Q
- 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
A
- 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.
2
Q
- 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
A
- 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.
3
Q
- 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
A
- 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.
4
Q
- 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
A
- 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.
5
Q
- 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
A
- 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.
6
Q
- 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
A
- 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.
7
Q
- 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
A
- 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.
8
Q
- 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
A
- 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.
9
Q
- 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
A
- 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.
10
Q
- 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
A
- 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.
11
Q
- 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
A
- 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.
12
Q
- 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
A
- 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.
13
Q
- 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
A
- 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.
14
Q
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
A
- 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
15
Q
- 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
A
- 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.
16
Q
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
A
- 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.
17
Q
- 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
A
- 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
18
Q
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
A
- 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
19
Q
- 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
A
- 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
20
Q
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
A
- 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.
