We report a case of clinically diagnosed corticobasal degeneration, in whom neuropsychological testing was performed along with functional imaging with IBZM SPECT. HM-PAO SPECT showed marked perfusion asymmetry in parietal cortical regions, lower to the right, contralateral to the most affected side. IBZM SPECT, which gives information about postsynaptic dopaminergic D2 receptors, showed severe reduction of tracer uptake in the right basal ganglia. Our findings suggest that a postsynaptic lesion in the basal ganglia might account for the lack of response of extrapyramidal motor symptoms to dopaminergic agonists in corticobasal degeneration.
