PRESBYCUSIS Sensorineural hearing loss associated with physiological aging process in the ear is called presbycusis. It usually manifests at the age of 65 years but may do so early if there is hereditary predisposition, chronic noise exposure or generalized vascular disease. Four pathological types of presbycusis have been identified. 1. Sensory. This is characterized by degeneration of the organ of Coi, staing at the basal coil and progressing gradually to the apex. Higher frequencies are affected but speech discrimination remains good. 2. Neural. This is characterized by degeneration of the cells of spiral ganglion, staing at the basal coil and progressing to the apex. Neurons of higher auditory pathways may also be affected. This manifests with high tone loss but speech discrimination is poor and out of propoion to the pure tone loss. 3. Strial or metabolic. This is characterized by atrophy of stria vascularis in all turns of cochlea. In this, the physical and chemical processes of energy production are affected. It runs in families. Audiogram is flat but speech discrimination is good. 4. Cochlear conductive. This is due to stiffening of the basilar membrane thus affecting its movements. Audiogram is sloping type. Patients of presbycusis have great difficulty in hearing in the presence of background noise though they may hear well in quiet surroundings. They may complain of speechbeing heard but not understood. Recruitment phenomenon is positive and all the sounds suddenly become intolerable when volume is raised. Tinnitus is another bothersome problem and in some it is the only complaint. Patients of presbycusis can be helped by a hearing aid. They should also have lessons in speech reading through Visual cues. Cuailment of smoking and stimulants like tea and coffee may help to decrease tinnitus. Ref : ENT textbook by Dhingra 6th edition Pgno : 37