HEAD-INJURY AS A RISK FACTOR IN ALZHEIMERS-DISEASE

Several case-control studies have reported head injury to be more comm on among patients with Alzheimer's disease (AD) than healthy elderly c ontrols. The present study sought to determine whether milder head inj ury is also a risk factor for AD. Furthermore, it was hypothesized tha t head injury would be more common among AD patients without a genetic risk for the disease. History of head injury in 68 consecutive cases of probable or definite AD and 34 non-demented control subjects was as certained from their spouses. Head injury was reported in 20 of the AD patients (29%), and in only one control subject (2.9%) (odds ratio = 13.75). Twenty per cent of the familial and 43.5% of the sporadic AD c ases reportedly had a premorbid head injury (odds ratio = 3.08). Head injury had no effect on age of dementia onset. The results indicate th at head trauma may be a predisposing factor to AD, particularly in the absence of a clear genetic contribution.