Multiple chemical sensitivity: a test of the olfactory-limbic model.

Thus far, no neuropsychological study has examined the cognitive profile of multiple chemical sensitivity (MCS) within the framework of Bell's Olfactory-Limbic Model. It predicts that cognitive weaknesses will be associated more with limbic (ie, frontal and/or temporal lobe) than with non-limbic (ie, posterior cortex) brain regions. Matched MCS, asthma, and healthy control groups (n = 63) were tested on cognitive measures with localizing value. Between-group comparisons found that the MCS group performed as well as controls on all cognitive tasks. Within-group comparisons found that both the MCS and asthma groups performed significantly more poorly on tasks that were sensitive to frontal and temporal regions than to posterior regions. Additional research is needed before concluding that the Olfactory-Limbic Model adequately describes the cognitive strengths and weaknesses of MCS. Confounding factors such as medication use and chronic illness need to be considered.