Pure tone audiometry in presbycusis shows?
ANSWER: (B) Sensory neural hearing lossREF: Dhingra 4th ed page 38, Otolaryngology Basic science and clinical review by Thomas. R.Va p.327PRESBYCUSIS:Sensory neural 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.Clinical features:Patients of presbycusis have great difficulty in hearing in the presence of background noise though (he may hear well in quiet surroundings).They may complain of speech being heard but not understood.Recruitment phenomenon is positive and all the sounds suddenly become intolerable when volume is raised.Tinnitus is another troublesome problem and in some it is the only complaintCauses: Although the precise etiology of presbycusis is currently not known, the cause of presbycusis is generally agreed to be multifactorial. Proposed causes include the following:Arteriosclerosis:Diabetes accelerates the process of atherosclerosis, diffuse proliferation and hypertrophy of the vascular intimal endothelium and brainstem neuropathyDiets high in antioxidants such as vitamins C and E reduce the progression of presbycusisAccumulated exposure to noiseDrug and environmental chemical exposureStressGeneticsInvestigations: Audiometric testing with pure-tone average and speech discrimination forms the cornerstone of diagnostic testing for presbycusis. Based upon audiometry and histopathology presbycusis is classified asTypeAudiometry SensorypresbycusisSharply down-sloping bilateral symmetrical sensorineural hearing loss. Higher frequencies are affected but speech discrimination remains good.Degeneration of the organ of corti, starting at the basal coil and progressing gradually to the apex.NeuralpresbycusisSlowly descending audiometric pattern, worse in the high frequencies, and a significant decrements in speech discrimination.Degeneration of the coils of spiral ganglion, starting at the basal coil and progressing to the apex.Strial or metabolicAudiomety is flat but speech discrimination is good.Atrophy of the stria vascularis in all turns of cochleaCochlearconductiveSloping type audiogramThis is due to stiffening of the basilar membrane thus affecting its movementsTreatment: Patients of presbycusis can be helped by a hearing aid. They should also have lessons in speech reading through visual cues. Curtailment of smoking and stimulants like tea and coffee may help to decrease tinnitus.
Normal study
Sensory neural hearing loss
Conductive hearing loss
Mixed hearing loss
Ear