Non-invasive stimulation of the auditory feedback area for improved articulation in Parkinson's disease

Abstract

Introduction: Hypokinetic dysarthria (HD) is a common symptom of Parkinson's disease (PD) which does not respond well to PD treatments. We investigated acute effects of repetitive transcranial magnetic stimulation (rTMS) of the motor and auditory feedback area on HD in PD using acoustic analysis of speech. Methods: We used 10 Hz and 1 Hz stimulation protocols and applied rTMS over the left orofacial primary motor area, the right superior temporal gyrus (STG), and over the vertex (a control stimulation site) in 16 PD patients with HD. A cross-over design was used. Stimulation sites and protocols were randomised across subjects and sessions. Acoustic analysis of a sentence reading task performed inside the MR scanner was used to evaluate rTMS-induced effects on motor speech. Acute fMRI changes due to rTMS were also analysed. Results: The 1 Hz STG stimulation produced significant increases of the relative standard deviation of the 2nd formant (p = 0.019), i.e. an acoustic parameter describing the tongue and jaw movements. The effects were superior to the control site stimulation and were accompanied by increased resting state functional connectivity between the stimulated region and the right parahippocampal gyrus. The rTMS-induced acoustic changes were correlated with the reading task-related BOLD signal increases of the stimulated area (R = 0.654, p = 0.029). Conclusion: Our results demonstrate for the first time that low-frequency stimulation of the temporal auditory feedback area may improve articulation in PD and enhance functional connectivity between the STG and the cortical region involved in an overt speech control.

Neurobehavioral Effects of LSVT® LOUD on Auditory-Vocal Integration in Parkinson’s Disease: A Preliminary Study

“…It is thus suggested that impairments in auditory-vocal integration in individuals with PD may be attributed to hyperactivity in their cortical speech motor networks (Huang et al, 2016). This idea is supported by one recent study showing that improved speech articulation in individuals with PD after brain activity in the right STG was depressed by low-frequency repetitive transcranial magnetic stimulation (rTMS) (Brabenec et al, 2019).…”

High-Frequency rTMS of the Motor Cortex Modulates Cerebellar and Widespread Activity as Revealed by SVM

“…The motor cortex is one of the most frequently reported stimulation targets for rTMS modulation in both healthy populations (Hartwigsen and Siebner, 2015;Cona et al, 2017) and those with brain disorders including movement disorders (Wagle Shukla et al, 2016;Brabenec et al, 2019), stroke rehabilitation (Ludemann-Podubecka et al, 2016;Lee et al, 2019), and other disorders (Siebner et al, 2003;Odorfer et al, 2019;Pei et al, 2019;Zhang et al, 2019). Some of these studies performed RS-fMRI before and after modulation and analyzed the network changes.…”

“…However, there is large variation in the analytical methods applied from study to study. These included voxel-to-voxel based dynamic FC , graph theory using 24 ROIs (Lee et al, 2019), whole-brain graph theory (Pei et al, 2019), and seed-based FC (Brabenec et al, 2019). While it could be concluded that rTMS of the motor cortex modulates the motor network, such a conclusion appears too general since it is difficult to identify which specific brain areas are modulated.…”

Biofeedback as a form of neurorehabilitation in Parkinson's disease

“…Hypokinetic dysarthria (HD) is a common symptom of PD which does not respond well to PD treatments. Brabenec et al (20) investigated acute effects of repetitive transcranial magnetic stimulation (rTMS) of the motor and auditory feedback area on HD in PD using acoustic analysis of speech. The results demonstrated that low-frequency stimulation of the temporal auditory feedback area may improve articulation in PD and enhance functional connectivity between the superior temporal gyrus ST and the cortical region involved in an overt speech control.…”