Hearing loss

Hearing loss

A full or partial decrease in the ability to detect or understand sounds .

Types:

Conductive. Sensorineural. Mixed.

Conductive hearing loss

Tympanic membrane conditions: 1- perforation 2- myringitis bullosa haemorrhagica

C- middle ear:

Haemotympanum Ossicular chain dislocation Baratrauma O.m. O.m. / effusion Otosclerosis Tumour Eust. Tube dysf.

otosclerosis

Autosomal dominant / unknown etiology Pathology: * absorption of a normal bone & replacement by vascular spongy osteoid tissue which becomes thicker later on & stapes ankylosed in advanced cases * the most common site is promontory// anterior margin of the oval window.


Clinical features
Female 18-30 yrs 50% +ve family history Gradually increasing hearing difficulty & tinnitus are the main symptoms Hearing better in noisy surrounding( paracusis willisii) Speak in low tone voice.

Examination:

Normal otoscopical ex. Unless in early stage which shows flamingo ting appearance Hearing assessment reveals * usually CHL in PTA unless cochlear otosclerosis is existing which shows SNHL * tympanometric study reveals type As

treatment

Hearing aids stapedectomy

Sensorineural hearing loss

SNHL is due to insensitivity of the inner ear or to impairment in the function of the auditory nervous pathway including the auditory centre.

Causes : VIINDICTM

Vascular : e.g; arterial occlusion , thrombosis of the internal auditory a., thrombocytopenia , SCA. Inflammatory disease e.g; - measles , mump , meningitis, syphilis , AIDS chlamydial inf. /infected mother

Immune complex dis. ; rh. Arth. Neoplasm e,g; vestibular schwannoma Noise induced hearing loss / 4kH dip Degenerative / presbyacusis Iatrogenic causes / ototoxic drugs e.g; * aminoglycosides * cytotoxic drugs * aspirin , frusamide , ciprofloxacin >> reversible <<


Congenital / waardenburg syndrome , pendred syndrome Trauma h. inj. Surgery, loud sound Miscellaneous - M.S. - DM. - meniere`s dis. - cochlear otosclerosis