[Computer tomography contribution to the differential diagnosis of dementia of vascular origin (multi-infarction type) and primary degenerative dementia (Alzheimer type)].

Studies of computed tomography were performed in 367 patients diagnosed as dementia clinically. The mean age was 70.1 years. By the clinicians 240 were classified as senile dementia of Alzheimer's type, 79 as multiinfarct dementia, and 48 were not determined definitely. In 3%, the CT studies did detect treatable causes like tumors, subdural hematomas and communicating hydrocephalus. In about 57% was found by CT a diffuse brain atrophy without focal tissue changes as to expect if occurring a cerebrovascular disease. In 25% there were focal changes of the brain tissue in CT to define as residuals of infarctions in addition to the signs of cerebral atrophy. The results of the CT studies were normal in 15% despite of the evidence of dementia clinically. The analysis of the material did show that a cerebrovascular disease as a cause of dementia is suspected clinically in much more cases than CT studies are able to prove focal pathological changes of the brain tissue due to disorders of cerebral blood flow really.