[Ageing and cerebral vascular sclerosis: myth or reality? (author's transl)].

The most important aspects of normal and pathological brain ageing are considered from a structural, cellular, hemodynamical, chemical and clinical point of view. It seems admitted that cerebral blood flow and cerebral consumption for oxygen decrease with age but when severe health criteria are used to select normal old subjects, no significant differences exist between normal young and optimally healthy elderly. The question arises whether the blood flow reductions are responsible for the alterations in metabolism, or whether it is simply an auto-regulatory response to the lesser metabolic demands of the tissue. The part of cerebral arteriosclerosis is questioned on cerebral flow drop accompanying clinical signs in senile mental impairment. Among some cardiovascular risk factors, hypertension seems to play a leading part in acute and chronic neurological diseases associated with age and with certain types of senile dementia (multi-infarct). However in all other cases, hypertension and cerebral vascular insufficiency, for all that this syndrome exists, seem to have been overestimated to explain chronic senile brain deterioration.