[Selective attention disorders associated with a history of occupational exposure to organic solvents]

The cognitive effects of long-term exposure to organic solvents could be similar to those triggered by certain neurodegenerative diseases.

The purpose of this study was to evaluate the effects exerted by accumulated exposure on the cognitive functions.

105 subjects with an average history of exposure of 19.3 years were evaluated using seven computerised cognitive tasks (CPT, digit-symbol substitution, Stroop, memory span, word learning and recognition, and TRD) and results were later compared with the performance of a non-exposure group and with a normative reference. A study was made of the association between the length of exposure and performance in the variables in which the exposed subjects displayed significantly lower values than control subjects. In order to evaluate the effect exerted by age, regression functions between performance and age were calculated for each group.

Only the indicators from the Stroop and digit-symbol tasks correlated with the length of exposure. The regression functions between performance and age for each group showed that the former decreased significantly faster among exposed subjects than among controls.

Findings suggest that, while recent exposure seems to have an effect on a wide range of functions, chronic exposure exerts a selective influence on a smaller group. In this case, only selective attention appears to deteriorate. Similar deficits have been observed in the early stages of patients with Alzheimer's and Parkinson's.