Closed-Loop Real-Time TMS-EEG in Humans

Transcranial Magnetic Stimulation (TMS) enables non-invasive perturbation of brain activity in humans. Its repeated application over the left prefrontal cortex is effective for the treatment of depression. However, there is significant variability in treatment outcomes across patients. We hypothesize that aligning TMS pulses to the "context" of the ongoing brain activity (EEG) using a closed-loop real-time approach will improve the effectiveness of the stimulation.

(Left.) Real-time closed-loop phase detection. EEG is recorded and streamed to the computer. The alpha band from the region of interest is extracted by bandpass filtering. The signal is forward predicted. TMS is delivered at the upcoming peak (excitable brain state). (Right.) Experimental setup for real-time closed-loop TMS-EEG.

Neurophysiological Assessment in Stroke

Using the closed-loop approach described above, we combine real-time EEG analysis with online phase-specific TMS. By measuring cortical excitability with TMS at different brain oscillation phases in stroke patients, high and low excitability states can be identified, which may be beneficial for stroke rehabilitation.