Background Verbal fluency tasks have been identified as important indicators of executive functioning impairment in patients with Huntington’s disease (HD). The F.A.S. test has been widely used to assess phonological fluency in Anglo-Saxon people, because these three letters are the most frequent in English language. In the contrast, normative data have been developed for the letters P, M and R since they are more frequent in the Spanish population.

Aims To compare the performance in phonological verbal fluency (F.A.S vs P.M.R) in a sample of HD participants and their correlation with the global cognitive status.

Method Pilot, cross sectional study. The F.A.S. and P.M.R fluency tests were administered to a sample of patients with HD (2 pre-manifests, 4 manifests). Scores in terms of correct words for each letter, perseverations and intrusions were collected. The global cognitive status was assessed by the Mini-mental State Examination (maximum score 35). Data were analysed using non parametric tests.

Results The F.A.S and P.M.R fluency testes were comparable (total score p = 0.24, intrusions score p = 0.31, perseveration score p = 0.08). However, there was a higher correlation of P.M.R with MMSE (r_s = 0.81, p = 0.05) compared to F.A.S. (r_s = 0.60, p = 0.20).

Conclusions F.A.S and P.M.R provided an equivalent measure of phonological verbal fluency in our sample. However, P.M.R seems to be a better predictor of global cognitive status. Based on these preliminary results, the phonological verbal fluency should be analysed based on the patient’s mother tongue. Further studies including a higher sample size and group differences (manifest vs. pre-manifest) are needed to confirm these preliminary results.