Shinotoh_2013_Rinsho.Shinkeigaku_53_1029

Recently, several attempts have been made to characterize clinical symptoms and brain atrophy patterns in pathology-proven corticobasal degeneration (CBD) and corticobasal syndrome (CBS). Voxel-based morphometry (VBM) analysis of MRI revealed that frontal lobe involvement is characteristic of CBD. CBS was associated with perirolandic atrophy irrespective of underlying pathology. In CBS due to frontotemporal lobar degeneration (FTLD), atrophy extended into prefrontal cortex, striatum, and brainstem, whereas in CBS due to Alzheimer's disease (AD), atrophy extended into temporoparietal cortex and precuneus.No functional imaging study in pathology-proven CBD or CBS with known histopathology has been published today. PET and SPECT studies demonstrated that decreased glucose metabolism and cerebral blood flow in the fronto-parietal cortex, especially contralateral to the dominant symptoms in patients with CBS. [(18)F]6-fluorodopa PET and dopamine transporter SPECT studies demonstrated dysfunction of nigrostriatal dopaminergic function in CBS. A PET study showed decreased acetylcholinesterase activity (AChE) in the fronto-parietal cortex, and a correlation between cortical AChE activity and mini-mental state examination score in patients with CBS.Amyloid imaging agent is useful for detection of AD pathology in CBS. The recent development of tau imaging agent has made it possible to image distribution of neurofibrillary tangles in the brain in vivo.