Intelligence quotient-adjusted memory impairment is associated with abnormal single photon emission computed tomography perfusion.
Dorene M Rentz,Terri J Huh,Lisa M Sardinha,Erin K Moran,John A Becker,Kirk R Daffner,Reisa A Sperling,Keith A Johnson
Cognitive reserve among highly intelligent older individuals makes detection of early Alzheimer's disease (AD) difficult. We tested the hypothesis that mild memory impairment determined by IQ-adjusted norms is associated with single photon emission computed tomography (SPECT) perfusion abnormality at baseline and predictive of future decline. Twenty-three subjects with a Clinical Dementia Rating (CDR) score of 0, were reclassified after scores were adjusted for IQ into two groups, 10 as having mild memory impairments for ability (IQ-MI) and 13 as memory-normal (IQ-MN). Subjects underwent cognitive and functional assessments at baseline and annual follow-up for 3 years. Perfusion SPECT was acquired at baseline. At follow-up, the IQ-MI subjects demonstrated decline in memory, visuospatial processing, and phonemic fluency, and 6 of 10 had progressed to a CDR of 0.5, while the IQ-MN subjects did not show decline. The IQ-MI group had significantly lower perfusion than the IQ-MN group in parietal/precuneus, temporal, and opercular frontal regions. In contrast, higher perfusion was observed in IQ-MI compared with IQ-MN in the left medial frontal and rostral anterior cingulate regions. IQ-adjusted memory impairment in individuals with high cognitive reserve is associated with baseline SPECT abnormality in a pattern consistent with prodromal AD and predicts subsequent cognitive and functional decline.
KEYWORDS:
| Humans or Animals | Humans |
| Ages | Middle Aged: 45-64 years; Aged: 65+ years |
| Type of Article | Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't |
| Periodical |
Journal of the International Neuropsychological Society : JINS
| Publication Date |
Sep 2007
|
| Volume |
13
| Issue |
5
|
| Start Page |
| End Page |
31
|
| Vernacular Title |
| Abstract Copyright Info |
|
| ISSN |
| ISSN Type |
|
| NLM ID |
9503760
| PubMed ID |
17697413
|