Background and aims: Frontal lobes and executive functions appear to be more vulnerable to normal aging than other cerebral regions and domains. The aim of the study was to evaluate executive functions by the Frontal Assessment Battery (FAB) in healthy oldest old subjects free of dementia.
Methods: Thirty-two healthy oldest old subjects (age range 85-97 yrs) and 32 young old subjects (aged 61-74 yrs) were studied. All subjects were living with their families or alone and were considered normal, since they were fully independent in their activities of daily living and without signs or symptoms characteristic of any type of dementia. Mental status was assessed by the Mini- Mental State Examination (MMSE) and executive functions by the FAB.
Results: Mean MMSE scores were 23.12 ± 4.68 in oldest old and 26.78 ± 2.60 in young old subjects (p<0.005). Delayed recall was the most impaired domain, followed by executive (Serial 7). Mean FAB scores were 9.37 ± 4.14 in the oldest old and 13.53 ± 2.12 in the young old (p<0.0001). Among the FAB subtests, conceptualization was the most impaired in both groups, with sensitivity to interference and inhibitory control exhibiting higher discrimination between the oldest old and young old. Education influenced performance on MMSE and FAB in both groups.
Conclusions: On the FAB test, healthy oldest old subjects showed executive impairment with respect to the young olds, due to the involvement of functions depending on activities of different regions of the frontal lobes. FAB results were consistent with the hypothesis that frontal lobes have a high vulnerability to normal aging. Short composite batteries like the FAB are suitable for rapid and reliable description of patterns of executive functioning in the oldest old.