Auditory-evoked responses in chronic alcohol and drug abusers

Abstract

Although the effects of alcohol and drug intoxication on auditoryevoked potentials arc well documented, reports on the effects of abstinence or detoxification therapy are still emerging. Stockard and colleagues (1976) first reported reversibility of auditory brainstem response (ABR) I-V latency prolongations with ameliorating clinical manifestations of central pontine myelinolysis in two chronic alcoholics. They suggested edema and demyelination to account for this reversibility. Studies reporting increased ABR variability in newly detoxified atcoholic mid -' coholic/cocaine subjects (Spitzer and Newman 1987; Metz and Adelman 1990), as well as abnormal absolute and interpeak ABR latencies in cocaine babies at birth (Shih et al 1988), but not a few months postpartum (Salamy et al 1990), also allude to reversib!e changes. High correlations between abnormal ABRs and ce.':ebr2 atrephy in ¢e,,~_puterized tomographic scans (Chu et al 1982), and marked interpeak latency prolongations in abstinent alcoholics (Begleiter et al 1981; Diaz et al 1990) indicate that increased incidence of abnormal ABRs may be related to alcoholic neurological diseases. Measurements of middle latency response (MLR) have been reported only by Diaz et al (1990). After 1 month of abstinence, alcoholics in this study si~owed significa.nt decrease in the latencies of the Na and Pa components of the response, without any alteration in the Na-Pa amplitude. These investigators suggested that such changes may be a result of structural degeneration of the auditory neurons and the neuronal connections, and/or neurochemical alterations within the thalamus. The present study documented ABR and MLR changes at the beginning of detoxmCauuu therapy in a group of ,,,u~vmuaa~ . . . . . . . . . . . . . who used alcohol and cocaine concurrently.