[Consideration on neuroimaging and functional diagnosis in cerebrovascular disorder]

The electroencephalogram(EEG) has been one of the important clinical examination in cerebrovascular disorder(CVD). Since X-ray computed tomography(CT) was introduced in the 1970's, the numbers of EEG examination decreased in Japan. In the present, the diagnosis of acute CVD is done by neuroimaging examinations which generally are CT, magnetic resonance imaging(MRI) and at times, single photon emission computed tomography(SPECT). But EEG examination is necessary for estimate of brain function in acute and/or chronic CVD. Only EEG examination is able to confirm epileptic seizure, sleep-wake disorder and disturbance of consciousness. alpha-coma and spindle coma are peculiar disturbance of consciousness and appear in acute CVD. REM sleep behavior disorder(RBD) sometimes appear in chronic CVD. The characteristic of RBD is violent or injurious behavior during REM sleep. Polysomnography demonstrates abnormal REM sleep without loss of atonia. Both neuroimaging and functional diagnosis have been to perform to estimate in CVD same as in the other central nervous disorders.