REVERSIBLE DEMENTIA IN ELDERLY PATIENTS REFERRED TO A MEMORY CLINIC

Dementia has a reversible cause in some cases, and these should be dia gnosed without over-investigating the many patients with irreversible disease. We prospectively studied the prevalence of reversible dementi a in a memory clinic, determined the added value of investigations com pared with clinical examination and assessed the outcome of treatment of potentially reversible causes by measuring (1) cognition, (2) disab ility in daily functioning, (3) behavioural changes and (4) caregiver burden. Two hundred patients aged 65 years and over were examined, usi ng the CAMDEX-N. If they were demented, the probable cause was diagnos ed clinically and confirmed or excluded by a standard set of investiga tions, which were done in all patients. Of the patients, 170 (mean age 79.2 years) were demented; 31 were treated for potentially reversible causes. At follow-up after 6 months, no patients showed complete reve rsal of dementia. Five patients improved on clinical impression, but o nly one on clinicial measurement. Thirty patients were cognitively imp aired, but not demented; seven were treated. Judged clinically, three patients improved, but on assessment only one did so; she recovered co mpletely. Blood tests often produced diagnostic results that were not expected clinically, but electroencephalography and computed tomograph y of the brain did not. None of the investigations had an effect on ou tcome of dementia after treatment. We conclude that in elderly patient s referred to a memory clinic, the prevalence of reversible dementia i s of the order of 1%, if outcome after treatment is assessed by a stan dardized measurement. We recommend blood tests in all patients, to det ect not only metabolic causes of dementia but also co-morbidity possib ly worsening the dementia. Other investigations can be performed on cl inical indication. Clinical evaluation remains the mainstay of diagnos is in dementia.