||Presbycusis is a clinical term that describes the progressive high-frequency sensorineural hearing loss that results from age-related degenerative alterations within the auditory system.
In susceptible individuals, the effects of presbycusis are first apparent in early middle age, and the hearing loss worsens progressively with advancing years.
Presbycusis typically appears as a bilateral, symmetrical, sensorineural hearing loss, with absent or partial recruitment, and phonemic regression.
The history in these patients is usually negative for other possible causes of hearing loss, e.g., noise exposure, ototoxic drugs, etc.
The pathologic basis of presbycusis appears to be a gradual devascularization of the cochlea, which may be due in part to those environmental causes (e.g., smoking, diet, and stress) that have been correlated with the development of arteriosclerosis.
These environmental factors appear to accelerate the inevitable underlying aging process. Even in childhood, there is already a histologic loss of the patency of the capillaries in the stria vascularis of the basal turn of the cochlea. This devascularization of the stria vascularis progresses slowly toward the apex of the cochlea over the years, and is closely followed by a dropout of the hair cells along the organ of Corti.