Classification of organic brain syndromes by cluster analysis.

Cluster analysis was carried out on a sample of 92 patients with behavior disorders caused by degenerative, vascular, (alcohol) toxic, and other diseases of the brain. Rating variables of the AMDP system concerning mental state, social behavior, need for special care, sleep disorders, autonomic, physical, and neurologic symptoms were used in the absence of severe degrees of disordered consciousness such as stupor, coma, delirium tremens, and gross cerebral lesions. Results suggested the existence of four major groups of global cognitive impairment combined with neurasthenia and irritability in the first, hypochondriasis and depression in the second, withdrawal symptoms in the third, and severe disorientation in the fourth. At the seven-group level the groups were further distinguished according to severe withdrawal, amnestic syndrome, and dementia by various social and illness behaviors, sleep-wakefulness pattern, hypo- or hyperactivity, additional physical, and neurologic symptoms. Other minor types of organic brain syndromes were identified as individual cases by hallucinations or other circumscribed cognitive, psychomotor, affect, motivation, personality, and/or behavior disorder, symptomatic manic, or schizophreniform psychosis. The findings lent support to old classifications and new ones of organic mental syndromes (DSM-III).