Distinct patterns of imprecise consonant articulation among Parkinson's disease, progressive supranuclear palsy and multiple system atrophy

- Distinctive speech patterns in atypical Parkinsonian syndromes are very rare.
- We investigated consonant articulation across Parkinsonian and healthy speakers.
- Voice onset time of voiceless plosives was related to overall dysarthria severity.
- Duration of pre-voicing was significantly shorter only in multiple system atrophy.
- Voiced plosives in multiple system atrophy tended to be misclassified as voiceless.

Distinct speech characteristics that may aid in differentiation between Parkinson's disease (PD), progressive supranuclear palsy (PSP) and multiple system atrophy (MSA) remain tremendously under-explored. Here, the patterns and degree of consonant articulation deficits across voiced and voiceless stop plosives in 16 PD, 16 PSP, 16 MSA and 16 healthy control speakers were evaluated using acoustic and perceptual methods. Imprecise consonant articulation was observed across all Parkinsonian groups. Voice onset time of voiceless plosives was more prolonged in both PSP and MSA compared to PD, presumably due to greater severity of dysarthria and slower articulation rate. Voice onset time of voiced plosives was significantly shorter only in MSA, likely as a consequence of damage to cerebellar structures. In agreement with the reduction of pre-voicing, MSA manifested increased number of voiced plosives misclassified as voiceless at perceptual evaluation. Timing of articulatory movements may provide important clues about the pathophysiology of underlying disease.