Verbal fluency patterns in mild cognitive impairment and Alzheimer's disease

Verbal fluency patterns can assist in differential diagnosis during neuropsychological assessment and identify individuals at risk for developing Alzheimer's disease (AD). While evidence suggests that subjects with AD perform worse on category fluency than letter fluency tasks, the pattern in mild cognitive impairment (MCI) is less well known.

Performance on the Controlled Oral Word Association Test (COWAT) and Animal fluency was compared in control, amnestic MCI, non-amnestic MCI, and AD groups. The sample included 136 participants matched for age, education, and gender.

Both MCI groups performed similarly with a category > letter fluency pattern rather than a category < letter fluency pattern typically observed in AD. The pattern in MCI, albeit relatively more impaired than in controls, was more similar to healthy controls who exhibited a category > letter fluency pattern.

MCI using a category < letter fluency pattern may not represent AD; however, future research requires longitudinal studies of pattern analysis.