Cortical excitability effects of stimulation intensity change speed during NMES.

Rehabilitation method of motor dysfunction is a challenging issue of neural rehabilitation. Neuromuscular electrical stimulation (NMES) has been frequently used in rehabilitation therapy to improve neural recovery such as stroke and spinal cord injury. Stimulus, acting on sensorimotor neural system components, resulted in the increased cortical excitability which accompanied with motor performance improvement. Stimulus information conveyed by sensory system included below four elementary attributes: modality, location, intensity, and timing. But, few works has been reported about effect of the stimulation intensity change speed (SICS). In this paper, we studied the effects of SICS by event-related desynchronization (ERD) or event-related synchronization (ERS) and EEG source analysis by exact low resolution brain electric tomography (eLORETA). The results suggested that brain function areas were sensitive to SICS. Using fast SICS could evoked more significant cortical excitability than the slow one. We demonstrated the availability of an efficient NMES method, additionally implied the rehabilitation potential of cortical excitability enhancement in sensorimotor cortex for motor dysfunction.