Neuropsychological deficits in patients diagnosed with chronic toxic encephalopathy: which tests are most discriminative?

Chronic toxic encephalopathy (CTE), a syndrome affecting the central nervous system, has been associated with long-term occupational exposure to organic solvents. We studied the discriminative power of a series of cognitive tests in separating 20 patients exposed to organic solvents, diagnosed with CTE, from 27 non-CTE patients with similar symptoms and exposure, and 19 healthy referents. All subjects were examined with a test battery assessing various cognitive and psychomotor functions. The groups were comparable with regard to age and level of schooling. Stepwise discriminant analyses indicated that tests assessing perceptual speed and attention were the most sensitive in distinguishing the CTE patients from the other patients as well as from the healthy referents. The CTE patients performed worse than the two other groups not only in tests assessing perceptual speed and attention, visual memory, and visuo-spatial skill but also, contrary to expectation, in a test of verbal ability.