Abstract

Senile dementia, a progressive deterioration in intellectual function, is a syndrome with many causes. The commonest is Alzheimer’s disease in which cerebral carbohydrate metabolism is impaired¹ and neurotransmission is defective in cholinergic,² serotonergic³ and peptidergic systems.⁴ Frequently more than one cause is present, for example cerebral infarction and Alzheimer’s disease. The most important principle in the diagnosis of intellectual deterioration in the senium is to identify and remedy any partially reversible factor such as depression, pain (which may be undeclared), hypothyroidism, subdural haematoma and drug toxicity.