[Chronic neurological diseases: from the clinical setting to the population clinical setting]

The population aging has produced an increase of chronic neurological disorders (dementia, stroke, Parkinson and so on) of the elderly. These disorders currently account for a substantial part of the neurological consultations, but in the clinical setting these illnesses are not fully attended because many patients do not demand medical care. For this and other reasons the population based study of these disorders might be performed.

This article is an author's review of the medical impact of several elderly chronic neurological disorders. The population based investigations done by the U. H. Doce de Octubre neurologist team in these illnesses are commented.

The epidemiological and clinical aspects of the elderly main chronic neurological disorders are briefly reviewed. The data of the three population based investigations done by the Hospital Universitario Doce de Octubre neurologist team are described: a pilot study in three neighbourhoods of Madrid, the participation in the WHOAAD Project, and the NEDICES (Neurological Disorders in Central Spain) Study. In all of these studies, frequency (prevalence and incidence) data are in agreement with other European and developed countries findings, but the incidence of essential tremor is highest published. Several epidemiologic analytic data of these studies are commented.

The difficulties in performing population based investigations are stressed. The main difficulty is the need of expert diagnosis (neurologist based) in the field study. Some recommendation for new population based studies (biological data, genetic analysis, and brain tissue studies) are commented.