[Aging of the central and peripheral nervous system (author's transl)]

In introduction to the symposium devoted to Aging of the Central (C.N.S.) and Peripheral Nervous System, the author deals with certain sociological and medical considerations relating to the influence of neurological aging in the general problems of senescence. He emphasises the interest of neurobiological studies comparing aging of the C.N.S. and that of the Peripheral Nervous System. He indicates the need for distinction to be made between normal and pathological aging, between irreversible lesional deficits and deficits related to poor functional adaptability. This introduction also refers to the importance of methodological problems, in particular relating to the choice of samples, the taking into consideration of reference groups of healthy young individuals, the limitations of transverse studies, the need for multifactorial analyses including psychometric, electrophysiological, morphometric, neurochemical, haemodynamic and metabolic data. The author finishes by a review of classical E.E.G. findings in the elderly subject.