Parietal rTMS Induced Changes in Cortical Excitability in Patients With Minimally Conscious State Using TMS-EEG

Area of Science:

• Neuroscience
• Neurology
• Rehabilitation Medicine

Background:

• Minimally conscious state (MCS) presents significant challenges in diagnosis and treatment.
• Assessing and improving cortical excitability is crucial for consciousness recovery.
• Non-invasive brain stimulation techniques offer potential therapeutic avenues.

Purpose of the Study:

• To evaluate the efficacy of parietal repetitive transcranial magnetic stimulation (rTMS) in MCS patients.
• To utilize TMS-EEG for objective assessment of cortical excitability changes.
• To explore the correlation between clinical outcomes and electrophysiological measures.

Main Methods:

• 10 MCS patients received 10 Hz rTMS on the parietal cortex for 10 days.
• A subsequent 10-day sham stimulation period was administered after a 14-day washout.
• Coma Recovery Scale-Revised (CRS-R) and TMS-EEG were used for assessments before and after stimulation.

Main Results:

• Active rTMS led to significant improvements in CRS-R scores compared to sham stimulation.
• TMS-EEG showed increased amplitude of TMS-evoked potentials and global brain power post-active rTMS.
• Significant differences in PCIst values were observed after active rTMS, correlating with CRS-R scores.

Conclusions:

• Parietal high-frequency rTMS demonstrates therapeutic efficacy in improving consciousness and cortical excitability in MCS.
• TMS-EEG serves as a valuable tool for monitoring treatment response and cortical changes.
• The parietal cortex is a promising therapeutic target for MCS interventions.