Mild cognitive impairment (MCI) and pre-MCI are stages which precede Alzheimer’s Disease (AD) dementia. The authors assessed descendants of individuals with a mutation in presenilin 1 (PSEN1) which causes familial Alzheimer’s Disease, hoping to identify distinct stages in the clinical progression to Alzheimer’s Disease. Between 1995 and 2010, 1784 patients were initially identified, 449 of whom were PSEN1 E280A carriers.
Pre-dementia cognitive impairment was subdivided as follows:
Asymptomatic pre-MCI: defined by an absence of memory complaints and no effect on activities of daily living.
Symptomatic pre-MCI: defined by measurable subjective memory complaints, but no effect on activities of daily living.
MCI: defined by a score on the subjective memory complaints checklist higher than the mean, with no effect on basic activities of daily living and little or no effect on complex daily activities.
Dementia: was defined according to the diagnostic and statistical manual of mental disorders, fourth edition.
The researchers used the Turnbull survival analysis method to identify ages at onset of each stage of the disease.
The median age at onset was 35 years for asymptomatic pre-MCI, 38 years (37-40) for symptomatic pre-MCI, 44 years (43-45) for MCI, and 49 years (49-50) for dementia. The median time of progression from asymptomatic to symptomatic pre-MCI was 4 years, from symptomatic pre-MCI to MCI was 6 years, from MCI to dementia was 5 years, and from dementia to death was 10 years (9-12).
Clinical deterioration can be detected as measurable cognitive impairment about two decades before dementia onset in PSEN1 E280A carriers.
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Acosta-Baena, N. Sepulveda-Falla, D. [and] Lopera-Gómez, CM. [et al] (2011). Pre-dementia clinical stages in presenilin 1 E280A familial early-onset Alzheimer’s disease: a retrospective cohort study. Lancet Neurology, March 2011, Vol.10(3), pp.213-20. (Click here to view the PubMed abstract).