Envejecimiento cerebral normal y patológico …
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terrenos donde la investigación podría hacer avanzar nuestros conocimientos en
el envejecimiento cerebral, especialmente en el estudio pormenorizado de los
individuos controles sanos de entre 30 y 60 años, en el de los “centenarios” con y
sin demencia y en grupos con características diferenciales neuropsicológicas
(posibles estadíos intermedios de EA según el nuevo “lexicón”). También sería de
gran interés estudiar comparativamente el envejecimiento cerebral humano con
el de otras especies de mamíferos que no presentaran patología amiloide o tau y
con los primates que pueden presentar patología amiloidea. En este último
sentido, los animales transgénicos con patología inducida amiloide o/y tau
también serían importantes fuentes de información.
Palabra clave:
Senilidad cerebral normal; senilidad cerebral patológica;
continuum
; Enfermedad de Alzheimer.
ABSTRACT
Normal and pathological brain aging: a physiopathological
continuum
or an
involutive duality
For years, there is a controversy whether there is a two-‐way (involutive duality)
of senile involution of the brain, which may be called, respectively, pathway to the
physiological or " normal" senility, without signs of dementia but with neuronal
adaptative responses, and pathway to "pathological " senility or Alzheimer's
Disease (AD), which is characterized by the appearance of a progressive dementia,
or, conversely, a single way (continuum) leading from the first morphological or
functional signs of senile involution until the final stage of AD dementia in all
individuals. Moreover, in recent years, a thorough review of the concepts of the
pathological senility / EA is producing, so that is not now considered necessary to
have dementia to diagnose a pathological aging process because it is considered
that the pathological aging / EA is started at the time that a disturbance in
cognitive brain circuits and / or neuropathological changes occurs. With these
new criteria different clinic-‐pathological stages are supposed from normal senility
to terminal pathological senility / EA, without dementia (prodromal or
asymptomatic) and with varying degrees of dementia. In this review the reasons
given in defense of one or another theory are analyzed, as well as the
morphofunctional features of normal and pathological senile brains. Most studies
indicate that there are very marked differential characteristics between normal
brains without dementia and senile pathological brains with dementia, but in
other, large discrepancies exist between the presence or absence of dementia and
the existence or not of neuropathological signs. The existence or not of the
continuum also has a very important practical implication for both prevention and
care of the elderly, because the possible number of individuals affected: the entire
