[Clinical diagnosis of frontotemporal dementia]

Frontotemporal dementia (FTD) is poorly recognized clinically. Of the 1,517 patients examined at the Lille Outpatients Memory Clinic data bank (1991-1995), 74 fulfilled the criteria of the Lund and Manchester groups for FTD. They accounted for 5 p, 100 of all patients, 1 for 10 probable or possible Alzheimer's disease. Mean patient age was 63 years, duration of the disease was 5 years, mean Mini Mental State score was 23; 45 p. 100 belonged to the active population. Behavioral disorders occurred before the cognitive decline and remained the major feature. All patients had at least 3 of the following symptoms: self-control impairment, affective disorder, loss of interest and self-neglect. Memory impairment consisted of correct encoding and impaired retrieval processes, without major storage impairment. No patients had spatial disorientation. Language was usually reduced, EEG was normal. Two diagnoses were confirmed by autopsy: both consisted of aspecific frontal and temporal degeneration, 41 p. 100 of the patients were referred by a general practitioner, 30 p. 100 by a psychiatrist, 16 p. 100 by a neurologist, 2 p. 100 by other specialists, and 11 p. 100 following the advice of their relatives. FTD had never been suspected. Alzheimer's disease or non specified degenerative dementia was suspected in 2/3 of patients and a psychiatric disorder in 1/3. With the advent of novel pharmacological agents for the treatment of dementing disorders and for research purposes, the identification and accurate differentiation of FTD from Alzheimer's disease and psychiatric disorder is essential. Therefore, the role of multidisciplinary memory clinic is crucial to differentiate FTD from other degenerative dementias.