Effect of Speech Therapy in Combination With Non-invasive Brain Stimulation on Speech of Patients With Parkinson's Disease

Home-based Non-invasive Brain Stimulation in Combination With Lee Silverman Voice Treatment on Hypokinetic Dysarthria in Parkinson's Disease

Up to 90% of patients with Parkinson's disease (PD) have hypokinetic dysarthria (HD) in the early phase of the illness. HD is characterized by a harsh breathy voice quality, reduced variability of pitch and loudness and imprecise articulation. This project investigates the novel combination of speech therapy and home-based non-invasive brain stimulation (tDCS) treatment in order to increase overall positive effects on HD in PD. Using a novel multimodal analysis approach based on functional magnetic resonance and acoustic signal processing, we will be able to monitor changes in different domains of speech, as well as associated changes in brain plasticity.

Study will investigate the long-term effects of repeated (20) sessions of home-based tDCS as an add-on to well-established remote LSVT (i.e. the gold standard procedure for HD treatment) as compared to LSVT alone (coupled with sham stimulation) in patients with PD in their "on" dopaminergic condition without dyskinesias.

A two parallel-group, double-blinded, randomized, sham-stimulation-controlled design will be used. Forty PD patients will be randomized into two parallel groups by independent researcher by a computer-generated random number list, 20 subjects in each arm. Participants in the real tDCS group and the sham tDCS group will undergo a baseline assessment (V0), a follow-up assessment after four weeks of combined tDCS and LSVT treatments (V1) and another follow-up assessment 8 weeks after the baseline assessment (V2). Each visit will consist of EEG, speech tasks recording and speech evaluation by a speech therapist; MR scanning will be done at V0 and V1. Both groups will undergo the same speech therapy (LSVT) via telepractice as the gold standard treatment for HD, in combination with real or sham tDCS.

Inclusion Criteria:

• patients with clinically established PD (Postuma et al. 2016)

Exclusion Criteria:

• psychiatric disorders, including major depression, hallucinations
• any MRI-incompatible metal in the body
• epilepsy
• lack of cooperation
• presence of dementia