A multimodal approach using TMS and EEG reveals neurophysiological changes in Parkinson's disease

Maidan I, Zifman N, Hausdorff JM, Giladi N, Levy-Lamdan O, Mirelman A

Key finding

Patients with Parkinson's disease showed lower early phase deflection, lower inter-trial adherence and lower connectivity between homologous areas than healthy controls.

Study design

Case-control study, TMS-EEG

Participants

32 patients with Parkinson's disease and 21 healthy controls

Summary

This study examined how the brain responds to targeted magnetic stimulation in Parkinson's disease (PD). Combined transcranial magnetic stimulation and electroencephalography (TMS-EEG) was used to compare the electrical responses of patients with PD and healthy controls to stimulation of four cortical areas.

Study design

Participants: 32 patients with PD and 21 healthy controls.
Stimulation sites: left and right primary motor cortex (M1) and left and right dorsolateral prefrontal cortex (DLPFC).
Six measures of the TMS-evoked potential (TEP): waveform adherence, late phase deflection, early phase deflection, short-term plasticity, inter-trial adherence, and connectivity between right and left M1 and DLPFC.
Analysis: linear mixed model comparing groups and stimulated areas.

Key findings

Compared with healthy controls, patients with PD showed lower early phase deflection (p = 0.009), lower inter-trial adherence (p < 0.001) and lower connectivity between homologous areas (p = 0.050). Waveform adherence showed a trend in the same direction (p = 0.052).
Late phase deflection and short-term plasticity did not differ between the groups.
Lower inter-trial adherence correlated with longer disease duration (r = −0.355, p = 0.050).

Authors' conclusions

The authors report several alterations in neurophysiological measures in patients with PD. They suggest that higher cortical excitability, greater variability and less widespread evoked potentials may help explain different aspects of the pathophysiology of the disease.

Read the full article

Maidan I, Zifman N, Hausdorff JM, Giladi N, Levy-Lamdan O, Mirelman A. A multimodal approach using TMS and EEG reveals neurophysiological changes in Parkinson's disease. Parkinsonism & Related Disorders. 2021;89:28–33. doi:10.1016/j.parkreldis.2021.06.018

Summary prepared by QuantalX from the published abstract. All results are as reported by the authors. The full text is available from the publisher.

Bring brain function data into your practice

Talk to the QuantalX team about Delphi-MD™ in your clinical setting.

Request a demo