title: Closed-loop afferent electrical stimulation for recovery of hand function in individuals with motor incomplete spinal injury: early clinical results.
abstract: Afferent electrical stimulation is known to augment the effect of rehabilitative therapy through use-dependent cortical plasticity. Experiments pairing transcranial magnetic stimulation (TMS) with peripheral nerve stimulation (PNS) have shown a timing-dependent effect on motor evoked potential (MEP) amplitude suggesting that PNS applied in closed-loop (CL) mode could augment this effect through positive reinforcement. We present early results from a clinical trial in which an EEG brain-machine interface (BMI) was used to apply PNS to two subjects in response to motor intent detected from sensorimotor cortex in a cue-driven hand grip task. Both subjects had stable incomplete cervical spinal cord injury (SCI) with impaired upper limb function commensurate with the injury level. Twelve sessions of CL-PNS applied over a 4-6 week period yielded results suggesting improved hand grip strength and increased task-related modulation of the EEG in one hand of both subjects, and increased TMS-measured motor map area in one. These observations suggest that rehabilitation using such interactive therapies could benefit affected individuals.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Schildt
authors.forename: Sarah H
authors.initials: SH
authors.lastname: Thomas
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: Powell
authors.forename: Lumy
authors.initials: L
authors.lastname: Sawaki
authors.forename: Sridhar
authors.initials: S
authors.lastname: Sunderam
mesh_terms: D004558:Electric Stimulation; D019054:Evoked Potentials, Motor; D018737:Hand Strength; D006801:Humans; D009044:Motor Cortex; D013119:Spinal Cord Injuries; D050781:Transcranial Magnetic Stimulation