Auditory detection and perception in normal man and in patients with adrenal cortical insufficiency: effect of adrenal cortical steroids.

Abstract

Auditory detection thresholds for sinusoidal tones and various tests of auditory perception were determined in 12 patients with adrenal cortical insufficiency (seven with Addison's disease and five with panhypopituitarism) and compared to those in normal volunteers. In adrenal cortical insufficiency auditory detection sensitivity was significantly more acute than normal, and judgments of loudness and of the contralateral threshold shift were made at levels more than 20 db below those of normal subjects. Thus both the lower and the upper limits of the dynamic auditory range are significantly decreased in these patients. Speech discrimination ability of the patients was significantly impaired as was their difference limens, their alternate binaural loudness balances, and their ability to localize tones in space. Treatment of the patients with deoxycorticosterone acetate decreased serum potassium concentration, raised serum sodium concentration, and produced gains in body weight but did not alter auditory detection or perception. Treatment with prednisolone or with maintenance doses of carbohydrate-active steroids returned auditory detection and perception to normal in every patient tested. The inability of the untreated patients to perform the various auditory perception tasks indicates that they have a defect in their ability to integrate incoming sensory stimuli. This defect may be related to the alteration in the timing of transmission of neural impulses along axons and across synapses which occurs in these patients when their carbohydrate-active steroid is removed. This decreased integrative capacity occurs at the same time that they are able to detect many types of sensory stimuli significantly better than normal subjects. This interrelationship between increased detection sensitivity and decreased perceptual ability is dependent upon the absence of carbohydrate-active steroids, for when these steroids are replaced both detection sensitivity and perceptual ability revert to normal.