Inner Ear

Question 1

The inner ear Lies in Petrous Portion of Temporal bone and is composed of the

Answer 1

• bony labyrinth
• membranous labyrinth

Question 2

Parts of the BOny Labyrinth
SIZE

Answer 2

• Bony Cochlea 35 mm long, 2.5 turns
• Vestibule
• Bony semicircular canals.

Question 3

Parts of the Membranous labyrinth

Answer 3

• Cochlear duct
• Saccule (inferior) and utricle (superior) > both form the endolymphatic duct extended to the dura laterally
• Membranous semicircular ducts.

Question 4

Fluid in the bony labyrinth which is extracellular-like fluid; found in scala tympani and vestibuli

Answer 4

Perilymph fluid

Question 5

Fluid in Membranous Labyrinth that is intracellular-like fluid; found in scala media

Answer 5

Endolymph

Question 6

Diseases of the inner ear presents with signs and symptoms related to the

Answer 6

Cochlea, Vestibular symptoms, or Both

Question 7

Generalizations of the Diseases of the inner ear

Answer 7

• Sudden onset usually present with vestibular symptoms
• Gradual onset usually present with less or no vertigo
• Etiologic agents may affect
  + Either the cochlear or vestibular system
  + Some affect one rather than both ears

Question 8

Cochlear Diseases that is Gradual in Onset and Bilateral

Answer 8

• Presbycusis
• Systemic Disease

Question 9

Cochlear Diseases that is sudden in onset and bilateral

Answer 9

• Ototoxicity

Question 10

Cochlear Diseases that is fluctuant in onset and unilateral or bilateral

Answer 10

Meniere’s disease

Question 11

Cochlear Diseases that is sudden of onset and unilateral

Answer 11

• Trauma
• Barotrauma

Question 12

Cochlear Diseases that is sudden of onset and uni or bilateral

Answer 12

• Infection

Question 13

Cochlear Diseases that is gradual of onset and uni or bilateral

Answer 13

Noise-induced

Question 14

Vestibular disorders based on dizziness and hearing

DIZZINESS: Episodic
HEARING LOSS: Fluctuant

Answer 14

Meniere’s

Question 15

Vestibular disorders based on dizziness and hearing

DIZZINESS: Acute, aggravated by head movement
HEARING LOSS: No loss

Answer 15

Vestibular neuronitis

Question 16

Vestibular disorders based on dizziness and hearing

DIZZINESS: Recurrent related to position and aggravated by head movement
HEARING LOSS: No loss

Answer 16

Benign Positional

Question 17

Vestibular disorders based on dizziness and hearing

DIZZINESS: Acute
HEARING LOSS: Severe sensorineural hearing loss

Answer 17

Acute labyrinthitis

Question 18

Vestibular disorders based on dizziness and hearing

DIZZINESS: Progressive
HEARING LOSS: Progressive sensorineural hearing loss

Answer 18

Acoustic Neuroma

Question 19

Vestibular disorders based on dizziness and hearing

DIZZINESS: Acute and aggravated by head movement
HEARING LOSS: Compatible with presbyacousis

Answer 19

Vertebrobasilar insufficiency

Question 20

• Temporary or permanent loss of hearing related to a brief exposure to a sudden loud sound (>90dB) ! such as an explosion
• Usually recovers within 2 weeks if temporary

Answer 20

Acoustic trauma

Question 21

• Results from exposure to high level of sound for extended period
  Requires noise level of 90dB continuously for 5 hours a day for 2 years
• Treatment:
  + Prevention is the most important
  + Hearing aid may be used
  + Medical management

Answer 21

Noise induced hearing loss

Question 22

Aminoglycosides that are Vestibulotoxic drugs

Answer 22

• ## StreptomycinGentamycin

Question 23

Aminoglycosides that are Cochleotoxic drugs

Answer 23

• ## DihydrostreptomycinKanamycin
• ## NeomycinTobramycin
• vancomycin

Question 24

Drugs that affects enzyme synthesis of stria vascularis

Answer 24

Diuretics

Question 25

Sensorineural hearing loss associated with systemic disorders

Answer 25

- Congenital syphilis - Diabetes - Collagen diseases - Hypothyroidism - Leukemia - Paget’s disease - Hand-Schuller-Christian disease - Sarcoidosis

Question 26

- Inability of the Eustachian tube to open up and equalize - Occurs with atmospheric pressure increase - Sudden changes in pressure cause rupture of the tympanic membrane

Answer 26

Inner ear/Barotrauma

Question 27

Due to spasm, thrombosis or hemorrhage of the internal auditory artery

Answer 27

Ischemia

Question 28

- hallucination of movement” usually a whirling sensation – a more general term and includes light headedness

Answer 28

- Vertigo - Dizziness

Question 29

Positive test when patient losses balance when eyes closed and do not when eyes open

Answer 29

Romberg's Test

Question 30

- If hot water is irrigated into right ear, px will develop right jerk nystagmus - cold water into the right ear- left ear jerk nystagmus - If both ears are stimulated for + Cold water- upbeat jerk nystagmus + Warm water - downbeat jerk nystagmus

Answer 30

Caloric Test

Question 31

Type of Vertigo Peripheral - Duration: - Ssx: - Eye fixation on an object: - Spontaneous nystagmus: - Induced nystagmus:

Answer 31

- Duration: Intermittent Hours to days - Ssx: negative - Eye fixation on an object: Suppresses nystagmus - Spontaneous nystagmus: fatigable - Induced nystagmus: Fatigable Duration < 1 min Follow COWS

Question 32

Type of Vertigo Central - Duration: - Ssx: - Eye fixation on an object: - Spontaneous nystagmus: - Induced nystagmus:

Answer 32

- Duration: Persistent Weeks to months - Ssx: present - Eye fixation on an object: No effect - Spontaneous nystagmus: Non-fatigable - Induced nystagmus: Non-fatigable Duration < 1 min Doesn’t follow COWS

Question 33

Peripheral causes of vertigo with Hearing Loss - Schwannoma of the eight nerve - SNHL is progressive and persistent - Vertigo less prominent - Unilateral - Tests: + PTA + CT scan (>1.5cm in size) + MRI (<1cm in size) + ABR - Treatment: Surgical excision

Answer 33

Acoustic Neuroma

Question 34

Peripheral causes of vertigo with Hearing Loss - Brief (<1min) of severe vertigo - pathogenesis – otoconia of utricle is loose and moves with changes in position (cupolithiasis) - Etiology – closed head injury, degenerative changes, stapes surgery - Provoked by positional tests

Answer 34

Benign Positional Vertigo

Question 35

Peripheral causes of vertigo with Hearing Loss - Vertigo lasting for days - May or may not have history of viral infection - Clinical exams: normal PTA but decreased calorics

Answer 35

Vestibular neuritis

Question 36

Peripheral causes of vertigo with Hearing Loss - Etiology not known - Due to increased endolymph - Rare in childhood - Triad: intermittent SNHL, tinnitus, vertigo - Severe vertigo in later stages - Patient is normal in between attacks - Treatment Medical, Surgical

Answer 36

Meniere’s disease

Question 37

Central causes of vertigo

Answer 37

- Tumors - Multiple sclerosis - Epilepsy - Vascular problems: + Posterior inferior cerebellar artery occlusion + Basilar migraine + Vertebrobasilar insufficiency