Psychometric tests for assessment of brain function after solvent exposure.

Psychometric testing is a key issue in neuropsychological toxicology assessment. Evaluation of methods for assessing general intellectual impairment is necessary as conventional neurology has been shown to be insensitive to the neurotoxic effects of solvents and metals. This study presents an analysis of a psychometric test battery from an investigation of psycho-organic syndrome in a historical cohort of 96 metal degreasers with long-term exposure to solvents, particularly trichloroethylene. The neuropsychological test battery was a combination of Wechsler Adult Intelligence Scale (WAIS), Luria, and tests developed in Scandinavia. Linear regression analysis showed a significant dose-response relation between increasing cumulative solvent exposure and impaired psychometric test performance in 9 out of 15 tests. Multivariate analysis, however, suggests that much of the variance was due to confounding variables, especially age, and to a lesser degree, primary intellectual function and word blindness. After control for confounding factors the strongest association with solvent exposure occurred for the following three tests: acoustic-motor function, Paced Auditory Serial Addition Test (PASAT), and the visual gestalt test.