Chapter 7: Diseases of the Inner Ear Flashcards
1
Q
Symptoms of inner ear disease
A
- Hearing loss
- Tinnitus
- Disequilibrium
2
Q
Abnormal ringing noise in the ear
Associated most frequently with sensorineural hearing loss
A
Tinnitus
3
Q
Anatomic sources for tinnitus
A
- Vascular problems (aberrant vessels)
2. Middle ear tumors
4
Q
Loss of consciousness or has the sensation that he is about to faint during any attacks of dizziness
A
Nonvestibular etiology of dizziness
5
Q
Creates a sensation of whirling or spinning, either of the patient or the environment
A
Vestibular dizziness
6
Q
In more chronic cases and in bilateral cases of peripheral dizziness, patients may experience only a…
A
Drunken feeling or a feeling of severe unsteadiness
7
Q
Characterized by nausea, spinning sensations, and blurry vision
A
Dizziness caused by vestibular disorder
8
Q
Central dizziness
A
Onset: variable
Nature: unsteady (swimming), lightheaded
Duration: constant, varying
Fatigable: rarely
Visual effects: closing eyes does not alter
Visual symptoms: double vision, blind spot
Auditory symptoms: no
Headaches: yes
Systemic effects: none
ENG results: abnormal saccades; difficulty following a target
9
Q
Peripheral dizziness
A
Onset: sudden
Nature: spinning, turning
Duration: episodic, motion-related, <2-3 days
Fatigable: yes
Visual effects: closing eyes makes symptoms worse
Visual symptoms: blurry vision
Auditory symptoms: yes
Headaches: no (but aural fullness)
Systemic effects: nausea, vomiting
ENG results; decreased unilateral caloric
10
Q
Requires visual tracking, rapid deviation of eye movement and caloric testing
A
Electronystagmography (ENG)
11
Q
Hereditary hearing loss
A
- Diabetes
- Hyperlipidemia
- Otosclerosis
12
Q
Total lack of development of the inner ear
Autosomal dominant
A
Michel’s deafness
13
Q
Partial aplasia of the bony as well as membranous labyrinth
A
Mondini’s deafness
14
Q
Flattened cochlea with development only of the basal turn so that instead of 2 1/2 turns there are only 1 1/2 turns, while the middle and apical turns occupy a common space
Osseous vestibular labyrinth may also be malformed
A
Mondini’s deafness
15
Q
Cause of hearing loss in Mondini’s deafness
A
Dysgenesis of the organ of Corti
16
Q
Type of aplasia, in which the bony labyrinth is fully developed but the pars inferior (saccule and cochlear duct) is represented by mounds of undifferentiated cells
A
Scheibe’s deafness
17
Q
Most common of all inherited congenital deafness
Autosomal recessive
A
Scheibe’s deafness
18
Q
Most severely affected in Scheibe’s deafness resulting in a high frequency hearing loss
A
Organ of Corti and adjacent ganglion cells of the basal coil of the cochlea
19
Q
Features of Waardenburg’s deafness
A
- Lateral displacement of the medial canthi and lacrimal points
- Flat nasal root
- Hyperplasia of the eyebrow
- Partial or total heterochromia of the irides
- Partial albinism in the form of a white forelock
- Congenital deafness
20
Q
May be autosomal dominant, recessive or sex-linked
May be bilateral and severe deafness
A
Albinism
21
Q
- Congenital male dystrophy
- Congenital sensorineural deafness
- Small, short fingernails and toenails and severe high-frequency deafness
A
Onychodystrophy
22
Q
- Abnormal iodine metabolism–>thyroid enlargement
2. Severe hearing loss
A
Pendred’s disease (nonendemic goiter)
23
Q
- Prolongation of the Q-T interval
- Stokes-Adams attacks
- Congenital bilateral severe hearing loss
A
Jervell’s disease (Jervell and Lange-Nielsen disease)
24
Q
- Progressive retinitis pigmentosa
2. Congenital severe to moderate sensorineural hearing loss
A
Usher’s disease
25
1. Low-set ears
2. Undifferentiated pinnae
3. Absence of EAC or middle ear
4. Cleft lip/palate
5. Micropthalmia
6. Coloboma irides
7. Aplasia of optic nerve
Trisomy 13-15 (D)
26
1. Low-set ears
2. Malformed pinnae
3. Micrognathia
4. Flexion of the index finger over the 3rd finger
5. Prominent occiput
Trisomy 18 (E)
27
Most common causes of nongenetic congenital deafness
Rubella (German measles)
28
The probability that the child will suffer some degree of sensorineural hearing loss
1st 3 months of pregnancy
29
Pathologic exam in child infected with rubella
Aplasia of the organ of Corti and saccule (pars inferior)
| Pars superior is normal
30
Kernicterus in the newborn may result from Rh blood incompatibility of the patents
Erythroblastosis fetalis
31
1. Deposition of bilirubin in the CNS
2. Jaundice
3. Mental retardation
4. Cerebral palsy
5. Deafness
Erythroblastosis fetalis
32
Treatment of erythroblastosis fetalis
Postpartum exchange transfusion
33
Thyroid disease may be associated with deafness (mixed)
Cretinism
34
Nongenetic deafness occuring alone
1. Premature birth
2. Hypoxia
3. Prolonged labor
4. Mother received ototoxic drugs
35
1. Bilateral
| 2. Flat or basin-shaped sensorineural configuration on the audiogram with fairly good discrimination
Genetic progressive deafness
36
1. Autosomal dominant
2. Primarily a conductive hearing loss
3. May be associated with a progressive sensorineural hearing loss
Otosclerosis
37
1. Progressive renal disease
2. Progressive sensorineural hearing loss (increases as renal malfunction worsens, bilateral, symmetric, greater in the high frequency)
Alport's disease
38
1. Localized form of neurofibromatosis
2. Bilateral acoustic tumors
3. Hyperpigmented spots on the skin
Von Recklinghausen's disease
39
1. Skeletal deformity
2. Dwarfism
3. Mental retardation
4. Enlargement of the spleen and liver
5. Blindness
6. Profound sensorineural hearing loss
Hurler's syndrome
40
1. Fusion of the cervical vertebrae
2. Spina bifida
3. Scoliosis
4. Torticolis
5. Vestibular dysfunction
6. Profound sensorineural deafness
Klippel-Feil syndrome
41
1. Retinitis pigmentosa
2. Ichthyosis
3. Polyneuropathy
4. Ataxia
5. Progressive sensorineural hearing loss
Refsum's disease
42
1. Retinitis pigmentosa
2. Diabetes mellitus
3. Obesity
4. Progressive deafness
Alstrom's disease
43
Skeletal deformities of the skull and long bones of the legs
Paget's disease (Osteitis deformans)
44
1. Mental deficiency
2. Ataxia
3. Hypogonadism
4. Severe deafness
Richards-Rundle syndrome
45
1. Premature synostosis of the cranial suture
2. Exophthalmos
3. Parrot or hook nose
4. Short upper lip and protruding lower lip
5. Atresia of the auditory meatus
6. Mixed hearing loss
Crouzon's disease (Craniofacial dysostosis)
46
Leading cause of unilateral acquired hearing loss
Mumps
47
Leading cause of bilateral hearing loss
Measles
48
Major cause of hearing loss in children
Bilateral
Occurs in patients who are comatose for some period of time
Not be aborted even with appropriate antibiotic therapy
Meningitis
49
Considered as a cause for acquired sensorineural hearing loss
Fluctuating unilateral or bilateral hearing loss with changes in balance
Congenital syphilis
50
Infectious process involving the middle layer of the TM
| Painful process associated with high-tone sensorineural hearing loss
Bullous myringitis
51
When using any ototoxic agent:
1. Get baseline hearing levels
2. Test for balance
3. Warn the patient of the potential toxicity
52
Ototoxic agents (antibiotics)
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Streptomycin
Dihydrostreptomycin
Neomycin
Gentamicin
Tobramycin
Amikacin
Vancomycin
Erythromycin
Chloramphenicol
Ristocetin
Polymyxin B
Viomycin
Pharmacetin
Colistin
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53
Ototoxic agents (diuretics)
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Furosemide
Ethacrynic acid
Bumetanide
Acetazolamide
Mannitol
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54
Ototoxic agents (analgesics and antipyretics)
Salicylates (reversible)
Quinine
Chloroquine
55
Ototoxic drugs (antineoplastics)
Bleomycin
Nitrogen mustard
cis-Platinum
56
Ototoxic agents (miscellaneous)
Pentobarbital
Hexadine
Mandelamine
Practolol
57
Ototoxic agents (chemicals)
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Carbon monoxide
Oil of chenopodium
Nicotine
Aniline dyes
Alcohol
Potassium bromate
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58
Ototoxic agents (heavy metals)
Mercury
Gold
Lead
Arsenic
59
Most common inner ear tumor causing hearing loss
Acoustic neuroma
60
Benign tumors of the Schwann cells covering the 8th nerve
Acoustic neuroma
61
Other causes of hearing loss by tumors in the internal auditory canal
1. 7th nerve neuromas
2. Meningioma
3. Hemangioma
4. Aberrant vessels
62
Causes all cases of bilateral acoustic neuromas
Von Recklinghausen's disease
63
Course of an acoustic neuroma
Patient develops a unilateral sensorineural hearing loss
| Mild at 1st but as the tumor continues to grow, it slowly crushes the nerves of the internal auditory canal
64
Any unilateral or asymmetric hearing loss is an...
Acoustic neuroma until proved otherwise
65
Requires further work-up with ABR, CT or MRI
Any asymmetric hearing loss
66
Acoustic tumors may be removed surgically by 3 major routes
1. Middle fossa
2. Posterior fossa
3. Across the labyrinth
67
Trauma to the inner ear can be divided into 2 primary forms
1. Acoustic energy
| 2. Mechanical energy
68
Is made of some of the densest bone in the human body
Temporal bone
69
Temporal bone fractures are possible
Mechanical trauma to the temporal bone
70
Temporal bone fracture causes
Loss of consciousness
Subdural or epidural hematoma
Concussion
71
Temporal bone fractures are divided into 2 general groups
1. Longitudinal (80%)
| 2. Transverse (20%)
72
1. Begin at the foramen magnum
2. Travel out to the EAC
3. Ear usually bleeds
4. Conductive hearing loss
Longitudinal fractures
73
1. Account for high proportion of injuries to the labyrinth and facial nerve
2. Fracture line travels through the petrous apex or the labyrinth
Transverse fractures
74
Can be less severe, causing a concussion phenomenon with recovery of balance and hearing, or more severe, with total loss of hearing
Labyrinthine injuries
75
Cause a concussion wave that does more damage to the middle ear
High-tone sensorineural hearing loss
Blast injuries
76
Loss of hearing over time due to the aging mechanism in the inner ear
Presbycusis
77
4 pathologic types of presbycusis classified by Schuknecht
1. Sensory presbycusis
2. Neuropresbycusis
3. Strial presbycusis
4. Cochlear-conductive hearing loss
78
1. Hair loss on the basal turn of the cochlea
| 2. High-tone hearing loss
Sensory presbycusis
79
1. Primary loss of cochlear neurons with relative preservation of the hair cells
2. Greater loss of word discrimination
3. Gradual loss of hair cells over time
Neuropresbycusis
80
1. Excellent word discrimination
2. Moderate to severe hearing loss
3. Stria vascularis appears to degenerate and shrink
Strial presbycusis
81
1. Normal neuronal and hair cell population without damage to the stria vascularis
2. Hearing loss that is thought to be related to a limitation of movement in the basilar membrane
Cochlear-conductive hearing loss
82
1. Swelling of the endolymphatic space
| 2. Fluctuation in hearing loss with a low-tone tinnitus
Meniere's disease
83
Is thought to be caused by thromboembolic or immune events
Idiopathic sudden hearing loss
84
Balance depends upon 4 separate and interdependent systems
1. Vestibular system
2. Proprioceptive
3. Visual
4. Brain stem and cerebellum
85
Nonvestibular causes of dizziness
1. Hyperventilation
2. Hypoglycemia
3. Vascular causes
4. Cervical vertigo
86
1. One of the more common causes of nonvestibular dizziness
2. Lightheadedness and paresthesia in the distal extremities occur with rapid ventilation
3. Circumoral area is prone to sensation of paresthesia
4. Associated with hysterical types of personalities
Hyperventilation
87
1. Transient reduction in blood glucose
2. Accompanied by nausea and vomiting
3. Symptoms of unsteadiness and lightheadedness and severe sweating and pallor
Hypoglycemia
88
Most common form of vascular cause of dizziness
Migraine
89
1. Certain position of the head causes attacks of transient dizziness
2. Accompanied by nystagmus that fatigues on repeated testing
3. 1st attack is usually the most severe and repeated attacks become less severe
4. Calcified cupula
Benign position vertigo (cupulolithiasis)
90
Treatment of BPPV
Symptomatic relief
| Reassurance that the process resolves spontaneously
91
1. Severe dizziness with intractable vomiting, nausea and inability to stand or walk
2. No change in hearing
Vestibular neuritis
92
Inflammatory process involving the inner ear mechanism
Labyrinthitis
93
Caused by an infection of nearby structures, whether it be the middle ear or the meninges
Acute toxic labyrinthitis
94
1. Resolves with some loss of hearing and vestibular function
2. Caused by toxic products from an infection
Toxic labyrinthitis
95
Occurs with an acute bacterial infection that extends into the structures of the inner ear
Acute suppurative labyrinthitis
96
1. Caused by swelling of the endolymphatic compartment
2. Reissner's membrane ruptures, mixing endolymph and perilymph
3. Temporary hearing loss that resolves when the membrane reseals and the the chemical composition of the endolymph and perilyphm returns to normal
4. Low-tone sensorineural hearing loss followed by symptom of low-pitched tinnitus
5. Aural fullness and acutely vertiginous
Meniere's disease
97
Treatment of Meniere's disease
1. Limitation of salt in the diet
2. Diuretic
3. Symptomatic treatment: vestibular suppressants
4. Medical failure: surgery-improving the flow of endolymph
98
Disruption of the round or oval window membrane, allowing perilymph to leak into the middle ear space
Perilymph fistula
99
Management of Perilymph fistula
Sealing a leak with fat grafts
100
Severe and persistent cases of vestibular vertigo can be treated with vestibular nerve sections through
1. Nerve can be sectioned through the middle fossa (limited to patients under 60 years of age in good health and those willing to accept a half-head shave)
2. Posterior fossa, a suboccipital craniectomy is performed and the nerve is identified in the internal auditory canal ( carries some risk to the facial nerve as well as the cochlear nerve)
3. Translabyrinthine, removal or destruction of the entire vestibular system (high degree of success, all patients will lose hearing in the affected ear)
