Comparison of electrical and pneumatic somatosensory evoked fields - A MEG Study

Abstract

Somatosensory evoked fields (SEFs) can be recorded following either electrical or mechanical stimulation, allowing for the investigation of brain responses to different somatosensory pathways. This study compares SEF components elicited by electrical and pneumatic stimulation to assess whether pneumatic stimulation could serve as an alternative to electrical stimulation, particularly for reducing patient discomfort. Recordings of the M20 and M37 components were obtained from 10 subjects under both types of stimulation. The analysis focused on signal-to-noise ratio (SNR), SEF waveform characteristics, topographical differences, and correlations. The results demonstrated that: (1) Electrical stimulation produced clearer SEF waveforms, shorter latencies, and higher SNR compared to pneumatic stimulation; (2) After normalizing stimulus intensity, the topographies of M20 and M37 components were highly correlated between electrical and pneumatic stimulation. In conclusion, while electrical stimulation remains the preferred method in clinical settings due to its superior SNR, clearer SEF waveforms, and shorter latencies, pneumatic stimulation offers potential as a research tool in neuroscience, particularly for exploring natural tactile mechanisms and minimizing subject discomfort.