Verbal working memory and solvent exposure: A positron emission tomographystudy

Neuropsychological studies have documented frontal dysfunction in patients with a history of exposure to organic solvents. The deficits typically obse rved in these patients appear to be related to working memory (WM). This st udy used [O-15] water positron emission tomography (PET) to examine the pat tern of neural activation during verbal working memory in patients with a h istory of exposure to solvents. Six individuals with solvent exposure were compared with 6 age- and education-matched controls. On the 2 WM tasks exam ined with PET, with equivalent task performance, participants with solvent exposure demonstrated frontal peaks that were atypical for the tasks, where as the posterior peaks were typical for the tasks. The results support fron tal dysfunction and compensatory use within anterior regions of the WM syst em in patients with solvent exposure.