Dichotic Listening Performances of Patients with Chronic Exposure to Organic Solvents

Abstract

The present study was concerned with the clinical utility of dichotic listening in the examination of individuals with “intermediate” levels of organic solvent exposure (i.e., exposure sufficient to cause peripheral neurological symptoms and mental status complaints, but not manifest solvent encephalopathy). Neuropathological studies on animals and humans have indicated that organic solvents often caused injury to subcortical white matter. Because other studies involving patients with relatively specific white matter disease have found these patients to be impaired in dichotic listening, it seemed logical to investigate dichotic listening in solvent-exposed workers. Among solvent-exposed workers, dichotic listening was frequently impaired in relation to previously established norms or a control group matched for age, education, and stability of employment. Dichotic listening proved far more sensitive than other neuropsychological measures administered. Results have implications for both the neuropsychological assessment of solvent-exposed patients and for the pathophysiology of multiple ''peak exposures'' to organic solvents in humans.