1. The results of brain mapping had been studied in 27 patients with different stages of ischemic stroke and in 20 patients with dementia, ten of SDAT and ten of vascular type. 2. It has been shown that in ischemic stroke the mapping correlates better with the severity of clinical symptoms than with anatomical and hemodynamic imaging methods. For the differentiation of SDAT and VD the mapping showed a clear cut possibility of differentiation.