Validity of the ischemic score in degenerative and vascular dementia and depression in old age.

Thirty six male and 45 female patients (mean age 66 years) suffering from either dementia of Alzheimer type (DAT) or dementia of vascular type (DVT) with comparable severity and suffering from depression in old age were included in the investigation. The study was performed to evaluate the diagnostic value of Ischemic Score, EEG and CT scan of the brain in differentiating dementia types and depression in old age. The patients underwent physical, psychiatric, psychometric, neurological, neurophysiological and CT scan examinations. Clinical diagnosis and diagnosis related to Ischemic Score were consistent in 86% of DAT and in 65% of DVT. Patients suffering from DVT showed significantly higher incidence of distinct Ischemic Scale items than was found in DAT patients. The Ischemic Scale items were found to be of major importance in differentiating vascular dementia from both DAT and depression. However, it was insufficient to distinguish between the latter two. In EEG, general slowing predominated in DAT (68%), and focal disturbances in DVT (71%). Patients with DAT and depression could not be differentiated on the basis of their EEG findings. CT scans of the brain yielded a higher incidence of brain atrophy in patients with DAT (71%) and DVT (70%) as compared to depressive patients (37%). In DAT, ventricular enlargement seems to be rather disease- than age-related. Psychological testing showed abnormalities in attention and memory performance in DAT and DVT to a significantly greater extent as compared to depression. This study demonstrated that the combination of Ischemic Score and EEG was found to be most valid in differentiating DAT from DVT. Additional cranial computerized tomography and the psychological testing of attention and memory were able to confirm the diagnosis of dementia and to differentiate dementia from depression in old age.