Three of the 18 participants were found to be carriers of the ε4 allele, while the other 15 did not have the allele. Carriers were of similar age than noncarriers (26 vs 23 years, P=.07), education (17.3 vs 16.5, P=.56) and sex (P=.13). Neuropsychological performance did not differ between the groups for the Mini-Mental State Examination (29.2 vs 28.9, P=.46), Nelson Adult Reading Test intelligence quotient (121.3 vs 119.9, P=.60), Wechsler Adult Intelligence Scale-Revised vocabulary subtest (12.0 vs 12.8, P=.51), digit symbol subtest (11.7 vs 12.7, P=.62), and Selective Reminding Test delayed recall score (9.7 vs 10.5, P=.35).
Compared with individuals without the ε4 allele, ε4 carriers exhibited significantly lower resting rCBF in the left and right inferior temporal gyri, while resting rCBF was higher in the left insula, right supramarginal gyrus, and the inferior occipital gyrus (). The results were unchanged after controlling for age.
Resting Relative Cerebral Blood Flow (rCBF) in Individuals With and Without an Apolipoprotein ε4 Allele