TABLE 2

Cohort Studies with Clinical Diagnosis of AD Based on Longitudinal Assessment

Reference and AAN levelDiagnostic standard and study typeSubjectsMajor findings
Dobert et al., 2005 (34), AAN level IILongitudinal clinical diagnosis; prospective cohort study in primary care–like settingTwenty-four patients with initial clinical suspicion of beginning dementia, 12 of whom had mild cognitive impairment, underwent 18F-FDG PET at baseline. Final diagnosis was based on variable longitudinal clinical follow-up (average, 16 ± 12 mo) and included 9 patients with pure AD, 7 with mixed AD and vascular-type dementia, 6 without dementia, and remainder with FTD or pure vascular dementia.For diagnosis of more purely defined AD, 18F-FDG PET had sensitivity of 44% and specificity of 83%. For diagnosis of mixed AD and vascular dementia, 18F-FDG PET had sensitivity of 71% and specificity of 78%. For diagnosis of AD and mixed vascular/AD dementia vs. absence of dementia, 18F-FDG PET had sensitivity of 91.7% and specificity of 88.9%.
Panegyres et al., 2009 (35), AAN level ILongitudinal clinical diagnosis with average clinical follow-up of 5–6 y; prospective cohort study of 18F-FDG PET diagnostic utility in primary care settingCommunity-dwelling subjects presented to primary care center for cognitive complaints. Final clinical diagnosis was early-stage AD (n = 49), non-AD dementia (n = 29), depression (n = 11), or miscellaneous (n = 13).For diagnosis of AD, 18F-FDG PET had sensitivity of 78% and specificity of 81% in this heterogeneous population. For differential diagnosis of other dementias, including FTD, 18F-FDG PET had specificity > 95%.