Outcome of investigation of patients with presenile dementia.

Of 106 patients admitted for investigation to a neurological hospital with a presumptive diagnosis of dementia, 84 were confirmed to have intellectual impairment or loss of learning and memory function or both. A possible aetiology for the dementia was found in 36 of these 84 patients; the commonest causes discovered were intracranial mass lesions, arterial disease, and alcoholism. Fifteen of the 106 patients were found not to be demented but to have some other illness, most commonly depression. Of the whole series some 15% of the patients suffered from conditions that were amenable to treatment.