Olfactory loss in alcoholics: correlations with cortical and subcortical MRI indices

The relationship between olfactory identification ability and MRI volumetric indices of specific cortical and subcortical brain regions was investigated in 36 recently detoxified male alcoholics. The results of correlational analyses between MRI indices and score on the University of Pennsylvania Smell Identification Test (UPSIT) revealed that impairment in olfactory identification was associated with elevated cortical and ventricular CSF volumes as well as with reduced tissue volumes in the cortical and subcortical grey matter. The volume of the thalamus was found to be a significant unique predictor of UPSIT score, even after accounting for variance shared with other MRI indices. These findings provide the first empirical support for existing hypotheses that olfactory loss in alcoholic subjects may be mediated by both cortical and subcortical structures.