[Three cases of clinically diagnosed corticobasal degeneration--neuroimaging studies with MRI, SPECT and PET].

We report three cases of clinically diagnosed corticobasal degeneration: a 63-year-old male, a 63-year-old female and a 62-year-old female. All the three patients exhibited asymmetric limb-kinetic apraxia and extrapyramidal signs. Neuroimaging studies with MRI, 123I-IMP SPECT and FDG-PET were performed in each of the three cases and FDOPA-PET was performed in patient 1. MRI analysis showed asymmetric cortical atrophy, especially in the parietal cortex, in all the three cases. 123I-IMP SPECT analysis revealed asymmetric reduction of the cerebral blood flow, in accordance with the MRI findings. FDG-PET analysis showed marked asymmetric reduction (> or = 10%) of cerebral metabolic rates for glucose (CMRGlc) in the lateral frontal cortex, lateral posterior frontal cortex and primary motor and sensory cortex in all the patients, although the asymmetry in the thalamus which had been described as a characteristic CBD finding in previous reports was not observed in any of the patients in our study. FDOPA-PET analysis revealed reduction of uptake in both the putamen and caudate nucleus, predominantly in the caudate nucleus, which suggests that the FDOPA-PET findings correlate with the extrapyramidal signs observed in the case of the 63-year-old male.