hile promising therapeutic strategies
are beingexplored, our capacity to diagnose
dementias early intheir evolution remains poor. Degenerative
dementiasare insidious and progressive in nature. It
is thereforeconceivable that a dementia picture
is preceded by apreclinical state (ie, pathognomonic
cerebral lesionscoexisting with normal cognition) as described inAlzheimers disease (AD),1,2 followed
by mild deficitsfirst experienced by patients themselves, then
suspectedby their family members, and eventually
demonstratedthrough neuropsychological examination.It is generally assumed that normal
aging involves cogni-tive changes, displaying large
inter- and intraindividualvariability.3 Some
studies challenged this common view,showing that the use of strict criteria
for the inclusion ofcognitively normal subjects in longitudinal
studies demon-Keywords: aging;
cognition; dementia; Alzheimers disease; treatmentAuthor affiliations: Director of Research and Development, FORENAP,Rouffach,
FranceAddress for correspondence: FORENAP,
Institute for Research in Neuroscienceand Neuropsychiatry, BP29, 68250 Rouffach,
France(e-mail: christian.gilles@forenap.asso.fr)C l i n i c a l r e s e a r c h6 1Age-related mild cognitive deficit:a ready-to-use concept?Christian Gilles, MDWFor better management of mild cognitive
impairment in elderly patients, clinicians should be provided with instrumentsto detect early changes and predict
their progression. To define this cognitive status between optimal and pathologicalaging, many concepts have been proposed,
which actually describe various conditions and provide more or less precisecriteria, leaving room for variable
implementation. As a consequence, application of these criteria gave highly variableprevalence rates. Neuropathological
studies indicate that the different criteria have variable power in detecting
incipi-ent Alzheimers disease (AD)
and suggest that the transition between mild cognitive impairment and AD is not
merelyquantitative. Follow-up studies have
produced, according to the criteria used, a 2.5% to 16.6% annual rate for pro-gression toward dementia, and have
also shown that the criteria differ in their stability and predictive power.
Baselinecognitive performances have some predictive
value, but are difficult to apply in first-line medicine. Investigational tech-niques (structural and functional
imaging, magnetic resonance spectroscopy, magnetization transfer imaging, cerebrospinalfluid neuro-chemistry, and apolipoprotein
E genotype) are promising tools in the early diagnosis of AD, which remainsthe most frequent type of dementia
in elderly people and probably the most frequent type developed by patients withmild cognitive deficit. The final
goal is to offer early treatment to those patients who will evolve towards dementia,
oncethey can be identified. In the case
of AD, recent findings question the adequacy of cholinergic replacement therapies.
Inits current state, the criteria for
mild cognitive deficit are hardly transferable to first-line medicine. However,
dissemi-nating the concept could help increase
the sensitivity of general practitioners to the importance of cognitive complaintsand signs in their elderly patients.Dialogues Clin Neurosci.
2003;5:61-76.