Diseases Of Inner Ear Flashcards
Sensorineural hearing loss
Sensorineural hearing loss
Lesions to the cochlea, 8th nerve or central auditory pathway prevent transmission of acoustic vibrations and frequency specific action potentials
Aetiology of SNHL
Congenital or Acquired Unilateral or bilateral
Common causes of unilateral SNHL
Sudden onset SNHL Menieres Vestibular schwannoma Trauma to temporal bone (fractures and head injury) Infections (bacteria. Viral, meningitis, labrynthitis) Iattogenic post OP deafness Acoustic trauma
Common causes of bilateral SNHL
Presbycusis Ototoxicity Familial progressive hearing loss Systemic disease (DM, SLE, hypothyroidism) All unilateral causes affecting both ears Autoimmune inner ear disease Noise induced occupational hearing loss
SNHL clinical fetaures
Hearing loss from birth or gradual. Onset may also be sudden. Difficulty hearing in noisy surroundings and where people are talking from different directions Speech and word discrimination difficult
SNHL rehab
Hearing aid
Presbycusis
Hearing loss condition associated with aging process
The type of hearing loss in SNHL
Bilaterally symmetrical
How to diagnose SNHL
Pure tone audiometry. Showing bilateral hearing loss. Reduction of both air and bone reduction. No air- bone gap
What do you need to rule out in a unilateral hearing loss
Vestibular schwannomas Cerebello Pontine angle tumours
Ototoxicity
The tendency of certain therapeutic agents to damage tissues of inner ear
Clinical features of ototoxicity
Tinnitus Hearing loss Disequilibrium
Tinnitus in SNHL
Initially high pitched, continuous then low pitched when damage continues. Early warning sign of inner ear damage
Hearing loss in SNHL
Often gradual but immediate with loop diuretics
Vertigo in SNHL
True vertigo is rare, as both ears are affected symmetrically
Where does disequilibrium predominantly occur
With vestibulotoxic drugs
Common ototoxic drugs
Aminoglycoside antibiotics Loop diuretics (furosemide) Salicylates (aspirin) Quinine Cisplatin and carboplatin Erythromycin Chloramphenicol Indomethacin Ibuprofen Propranolol Propylthiouracil
Noise induced hearing loss
Decline in hearing acuity due to noise exposure
Acoustic trauma
Single exposure to intense, loud sound from firecrackers, fire arms, blasts
Vertigo
False sense of motion, either of environment or of 8individual when there is nonen
Benign paroxysmal positional vertigo
Spinning sensation when head is placed in certain position