Data acquisition
peripheral sensory nerve impairment
SENSORY DISTURBANCE
We recorded the SEF responses using a whole-head 306-channel sensor array (Vectorview, ELEKTA Neuromag, Helsinki) that comprises 204 planar gradiometers and 102 magnetometers. We analyzed the MEG data recorded by 204-channel planar-type gradiometers. Before the recording, three anatomical fiducial points (nasion and bilateral preauricular points) and four head position indicator coils on the scalp were digitized using a 3D digitizer. The sampling rate was set at 5,000 Hz, and the recording bandpass ranged from 0.03 to 1,500 Hz. We collected 80–91 responses per each median nerve stimulation, and 62–91 artifact-free trials were used for the analyses. Further, we recorded the orthodromic median nerve SNAPs from the surface electrodes placed on the elbow to estimate the contribution of peripheral sensory nerve impairment to the sensory disturbance in chronic MD.