[A case of corticobasal degeneration--the usefulness of surface anatomy scatomy scanning image by MRI].

We experienced usefulness of surface anatomy scanning (SAS) image by weight-summation technique using MRI in corticobasal degeneration. The patient was a 73-year-old right-handed woman who had progressive dysarthria and clumsiness of the right hand. Neurological examination revealed mild dementia, dysarthria, buccofacial apraxia, rigidity and dystonic movement of the right upper limb. Dysarthria was guessed to be caused by buccofacial apraxia. Brain CT and MRI demonstrated atrophy of the left frontoparietal lobes, and hypoperfusion was shown in their areas by 123I-IMP SPECT. Clearly, SAS image disclosed the atrophy of the left pre- and post-central gyri that were surrounded by enlarged sulci. SAS was recently designed in Japan as a technique for visualization of brain surface structures. It is difficult to observe surface structures of cerebral gyri and sulci by conventional neuroradiological slice image, so SAS is useful for analysis of disorders affecting cerebral cortex as corticobasal degeneration.