Objective: To treat hypokinetic dysarthria (HD) in PD patients using multiple sessions repetitive transcranial magnetic stimulation (rTMS)

Background: Based on results from our rTMS exploratory study [1] we hypothesized that multiple sessions rTMS over the right posterior superior temporal gyrus (STG; i.e. the voice feedback area) will induce long-lasting improvement of HD in PD.

Method: A parallel groups sham stimulation-controlled trial (clinicaltrials.gov NCT04203615). Altogether 39 PD patients with mild to moderate HD were randomly assigned to 10 sessions of real/ sham rTMS (1 Hz, 100% RMT, 1,800 pulses per session) over the right STG.  All subjects were evaluated at baseline (T0) and at follow up visits after 2 weeks (T1), 6 weeks (T2) and 10 weeks (T3), including Phonetics Score (PS) of the 3F Test – Dysarthric Profile, and a reading task and resting state fMRI. We were specifically interested in hemodynamic response and resting state functional connectivity (rs-FC) changes in regions engaged in the dorsal language pathway. Linear mixed models (LMM) with post-hoc pairwise comparisons were used to evaluate effects of rTMS on PS and brain activation/ rs-FC changes.

Results: Altogether 33 patients completed the study (20 in the real rTMS group and 13 in the sham rTMS group). Regarding PS, we found significant effect of time (F(3, 88.1) = 22.7, p < 0.001) and a significant time-by-treatment group interaction (F(3, 88.0) = 2.8, p = 0.040). In the real rTMS group, PS significantly improved at T1 (T0 vs T1, mean diff. = -2.5, p < 0.001), and further improved at follow-up visits (T1 vs T3, mean diff.= -1.8, p=0.029). In the sham rTMS group, PS significantly improved only at T1 (T0 vs T1, mean diff.= -1.6, p= 0.038). Moveover, time-by-treatment group interaction was found for the orofacial sensorimotor cortex [OFSM1] activation (F(3,34.4)=2.9,p=0.045) and caudate head [CN] activation (F(3,36.2)=2.8, p=0.048). The task-induced activation increased across T0-T1-T2 after the real rTMS while it decreased after the sham rTMS. The time-by-treatment group interactions were also found for the rs-FC between STG and OFSM1 (F(3,21.1)= 3.1, p=0.045) and between STG and CN F(3,25.4)=2.8, p=0.059).

Conclusion: We showed that multiple sessions rTMS over the right STG may have long-lasting positive effects on HD in PD. We observed changes in rTMS-induced activation and rs-FC of areas engaged in voiced articulation.

References: [1] L. Brabenec, P. Klobusiakova, M. Barton, J. Mekyska, Z. Galaz, V. Zvoncak, T. Kiska, J. Mucha, Z. Smekal, M. Kostalova, I. Rektorova, Non-invasive stimulation of the auditory feedback area for improved articulation in Parkinson’s disease, Parkinsonism & Related Disorders. 61 (2019) 187–192. https://doi.org/10.1016/J.PARKRELDIS.2018.10.011.

« Back to MDS Virtual Congress 2020

MDS Abstracts - https://www.mdsabstracts.org/abstract/noninvasive-brain-stimulation-to-treat-hypokinetic-dysarthria-in-pd-a-sham-stimulation-controlled-trial/