Objective: The objective of this study was to assess the possible changes in acoustic speech parameters in a cohort of PD patients after acute levodopa challenge.

Background: Hypokinetic dysarthria (HD) is a common motor feature reported in 70–90% of Parkinson’s disease (PD) patients. Studies on the effect of dopaminergic stimulation on the overall speech performance in PD have produced contradictory findings. The fact that treatment-related improvement differed in various aspects of speech for PD patients may be explained by different pathophysiological mechanisms of the different speech parameters.

Method: We prospectively conducted 38 patients with PD followed up at the Neurology department of the Habib Bourguiba hospital in Sfax, Tunisia. The patients’ speech was evaluated before (“OFF” condition) and after (“ON” condition) Levodopa treatment by analysing the different speech parameters in sustained phonation of the vowel /a/ and syllable repetition tasks /pΛtΛkΛ/. We calculated the Unified Parkinson’s Disease Rating Scale (UPDRS) in the “OFF” and in the “ON” conditions.

Results: The mean age of our patients was 57.84 years old (21 males, 17 females). Most of the patients had mild to moderate stage of PD. Levodopa improved significantly the motor performances of our patients with an average rate of 49.22%. We found a significant improvement in most phonatory parameters between the OFF and ON conditions including mean standard deviation of F0 in semitones (F0 SD), jitter, shimmer, amplitude perturbation quotient (APQ), pitch perturbation quotient (PPQ) and mean noise-to-harmonics ratio (NHR) of sustained phonation. There was no significant difference in maximum phonation time (MPT) and the fraction of locally unvoiced frames of sustained phonation (degree U). Articulation parameters including diadochokinetic (DDK) rate, DDK regularity and average duration of each syllable were also significantly improved after Levodopa intake, unlike silence rate.

Conclusion: Our data underlines that usage of Levodopa has beneficial effect on most of the phonatory and articulation speech parameters. Further research is needed to understand better the levodopa’s actions on the voice production in PD and the underlying mechanisms.

« Back to 2024 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/effect-of-levodopa-therapy-in-hypokinetic-dysarthria-in-parkinsons-disease/