Background Hyperkinetic dysarthria is a common sign of Huntington’s disease (HD). Although antipsychotic medication alone can induce hyperkinetic dysarthria, its effect on speech in HD remains unknown.

Aim The aim of the current study was to survey if antipsychotic medication can influence speech in HD.

Methods We studied 40 patients diagnosed with HD, 22 of them were treated with antipsychotic medication (HD-AP) whereas 18 patients received no antipsychotic therapy (HD-NoAP). As controls, 40 age- and sex-matched healthy subjects were also investigated. All participants performed short reading passage for subsequent quantitative acoustic analyses of vowel articulation, intensity, pitch, and speech timing.

Results When compared to controls, both HD-AP and HD-NoAP patients demonstrated significantly slower articulation rate and decreased number of pauses (p < 0.001). HD-NoAp group showed significantly decreased pitch variation (p < 0.05) whereas intensity variation was increased in HD-AP group (p < 0.01). Measures of vowel articulation were significantly worsen in both HD-AP and HD-NoAP groups (p < 0.05) but articulation deficits were generally less pronounced in the HD-AP group.

Conclusions Our results demonstrate that antipsychotic medication may evoke excessive pitch and loudness variations, which can together form the perceptual impression of excessive-inefficient-variable patterns of word stress. In addition, antipsychotics may accentuate general problems with speech timing, mainly slowing articulation rate and decreasing number of pauses. Conversely, antipsychotic treatment may induce a slight improvement of vowel articulation in HD speakers. In conclusion, speech may well reflect treatment effects and therefore could be considered as a valuable marker of functional disability in HD.