Dissociation of neuropathologic findings and cognition: case report of an apolipoprotein E epsilon2/epsilon2 genotype.
BACKGROUND
The apolipoprotein E (APOE) epsilon2 allele has been suggested as having a protective effect and delaying the age at onset of Alzheimer disease.


OBJECTIVE
To describe a dissociation between neuropathologic findings with normal cognition in a woman with severe Alzheimer disease with the APOE epsilon2/epsilon2 genotype.


METHODS
Case report from a community-based prospective study of persons 90 years or older (The 90+ Study).


METHODS
A 92-year-old woman without dementia with the APOE epsilon2/epsilon2 genotype who lived independently without significant cognitive or functional loss and was a participant in The 90+ Study. She died in December 2004, and postmortem examination of her brain was performed.


METHODS
Neurologic examination and a battery of neuropsychological tests were performed 6 months and 1 month before death. Neuropathologic examination included Braak and Braak staging for senile plaques and neurofibrillary tangles.


RESULTS
Neuropathologic examination of the brain revealed advanced senile plaque and neurofibrillary tangle disease consistent with a high likelihood of Alzheimer disease. At clinical evaluation, the participant demonstrated no dementia and only mild cognitive deficits.


CONCLUSIONS
The APOE genotype may have contributed to maintenance of cognition despite advanced neuropathologic findings of Alzheimer disease. This case suggests that the APOE epsilon2 isoform may have a protective effect against cognitive decline in Alzheimer disease that may be independent from senile plaques and neurofibrillary tangles.
Berlau
Daniel J
DJ
Institute of Brain Aging and Dementia, University of California, Irvine, 1515 Hewitt Hall, Irvine, CA 92697-1400, USA. danb@uci.edu
Kahle-Wrobleski
Kristin
K
Head
Elizabeth
E
Goodus
Matthew
M
Kim
Ronald
R
Kawas
Claudia
C
D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology / Q000523:psychology*; D053329:Apolipoprotein E2 / Q000235:genetics*; D001921:Brain / Q000473:pathology*; D003071:Cognition; D005260:Female; D005838:Genotype; D006801:Humans; D016874:Neurofibrillary Tangles / Q000473:pathology; D009460:Neurologic Examination; D009483:Neuropsychological Tests; D058225:Plaque, Amyloid / Q000473:pathology
D053329:Apolipoprotein E2
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