Risk factors associated with persistence of neuropsychological deficits in persons with organic solvent exposure

This study examined neuropsychological prognosis following organic solvent exposure. Twenty-seven persons with evidence of "mild toxic encephalopathy" were evaluated on two separate occasions with a standard neuropsychological test battery and the Minnesota Multiphasic Personality Inventory. Ratings by experienced clinicians revealed that 50% of exposed persons had improved neuropsychological performance at the second evaluation. The other 50% were rated as having no change or a decline in neuropsychological tests scores. While the majority of persons in the good-outcome group were working at the time of the follow-up evaluation, none of the persons in the poor-outcome group was actively employed. Persons rated as having shown no improvement were significantly more likely to have had a peak exposure--an episode in which they were briefly exposed to a larger than normal amount of solvent. In addition, persons in the poor outcome group reported higher levels of psychological distress, both initially and at the follow-up evaluation. Results from this study suggest that the presence of certain risk factors, namely a peak exposure and psychological distress, may be particularly detrimental for long-term neuropsychological outcome in persons with a history of organic solvent exposure.