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

OBJECTIVE

To verify the effectiveness of the parietal repetitive transcranial magnetic stimulation (rTMS) and take advantage of TMS-EEG to assess cortical excitability in patients with minimally conscious states (MCS).

METHODS

We enrolled 10 MCS patients who received 10 sessions of 10 Hz rTMS on the parietal cortex for 10 consecutive days and then 10 days of sham stimulation after a 14-day wash-out period. The Coma Recovery Scale-Revised (CRS-R) and TMS-EEG were used to assess the levels of consciousness and cortical excitability before and after active and sham stimulation, respectively.

RESULTS

Compared to sham stimulation, the CRS-R revealed a significant improvement after receiving active rTMS. The amplitude of components of TMS-evoked potential after active stimulation significantly increased at 30, 60, and 180 ms, respectively; global brain power increased significantly. The PCIst values had a significant difference after active rTMS stimulation, and the CRS-R scores showed a significant correlation with PCIst values before and after active stimulation.

CONCLUSION

High-frequency rTMS on the parietal cortex has therapeutic efficacy and can improve cortical excitability in MCS patients.

SIGNIFICANCE: Our results provide preliminary evidence to support the use of the parietal area as a potential therapeutic target for MCS patients in clinical practice.