TMSSA was found in 51 (4.7%) of 1091 psychiatric patients, with a higher incidence found in the older group (40 years of age or over). Although TMSSA was found in various disorders, a close association with cerebrovascular dementia was suggested. It was uncommon in patients with primary degenerative dementia. No increase of TMSSA was noted in cerebrovascular disorders without dementia. TMSSA was found fairly often in patients with affective disorders, neurosis, and other functional disorders, suggesting underlying mild cerebral dysfunction in some. TMSA, a variant of TMSSA, was very similar to TMSSA except for its greater frequency in cerebrovascular disorders without dementia.