Subjects underwent longitudinal neuropsychological assessment
in order to retrospectively determine which measures of cognitive
function best predicted later development of dementia of the
Alzheimer type (DAT). Three groups of subjects were studied:
normal controls, patients with early DAT, and questionable dementia
subjects (QD). All subjects were assessed using a battery of
standard neuropsychological measures and two subtests from the
Cambridge Neuropsychological Test Automated Battery (CANTAB),
paired associate learning and delayed matching to sample. A
structured interview was also used to elicit a profile of the
subject's daily functioning. Subjects were assessed every
6 months for 2 years. At the 6 month assessment, almost half
of the QD group exhibited significant deterioration in scores
on the computerized paired associate learning subtest, while
maintaining their scores on standard measures. At the conclusion
of the study, all of this QD subgroup fulfilled the
NINCDS–ADRDA criteria for probable DAT pertaining to
significant cognitive and functional deterioration. Performance
on the CANTAB paired associate learning subtest identified the
onset of progressive memory deterioration in a subgroup of QD
subjects. In almost all cases this was well before significant
deterioration was noted on standard neuropsychological measures.
Paired associate learning performance may therefore be a valuable
tool for the early, preclinical detection and assessment of
DAT. (JINS, 2002, 8, 58–71.)