Effect of Prolonged Electrical Stimulation on Neural Plasticity in Spinal Cord Injury
Condition: Spinal Cord Injury
MeSH terms: Spinal Cord Injuries
Study type: Interventional

Summary: 
      Electrical stimulation (pulses of electricity applied over the skin of your wrist) and
      activity-based hand exercise have been shown to improve motor skill and strength in
      individuals with stroke and have recently been shown to also have an effect on individuals
      with spinal cord injury. Therefore, the purpose of this research study is to investigate
      whether electrical stimulation alone or electrical stimulation followed by activity-based
      training produces gains in pinch strength (how hard you can squeeze your thumb and pointer
      finger together) and upper extremity function (how well your arm and hand can perform
      activities) in individuals with spinal cord injury.
    

Detailed description: 
      Spinal cord injury (SCI) affects 10,000 individuals per year in the United States.
      Approximately one half of all individuals with SCI have tetraparesis due to cervical injury.
      Impaired hand function significantly limits the ability of individuals with cervical SCI to
      perform manual activities of daily living which affects these individuals physically,
      psychologically and socially. Preliminary research by this investigator suggests that
      somatosensory stimulation combined with activity-based training improves hand function and
      strength in individuals with incomplete cervical SCI. Further investigations on these novel
      techniques are warranted due to the need to establish proven effective rehabilitation
      techniques that promote recovery of function in individuals with SCI.

      The purpose of this research study is to: 1)determine if somatosensory stimulation in the
      form of prolonged, peripheral nerve electrical stimulation can enhance the effect of an upper
      extremity activity-based training program in individuals with incomplete cervical SCI, and if
      so, 2) identify the operative neural mechanisms underlying the changes induced with the
      application of somatosensory stimulation.

      The hypotheses of this study are that individuals with incomplete cervical SCI:

        1. a 6-week period of somatosensory stimulation of the hand, either alone or combined with
           activity-based training, will produce improvements in behavioral outcomes that are
           significantly greater than those produced by activity-based training preceded by a sham
           stimulation period

        2. this behavioral improvement will be associated with greater changes in cortical
           excitation than will be observed in subjects receiving activity-based training preceded
           by a sham stimulation period.

      The specific objectives of this study are to:

        1. Recruit male and female volunteers with spastic paresis due to incomplete SCI with
           impaired hand function, and randomize subjects into 1 of 3 groups, each of which
           receives 6 weeks of upper extremity training for 3 sessions/week, as follows: a)
           somatosensory stimulation of the median, ulnar and radial nerves at the level of the
           wrist (2 hours/session); SS group b) somatosensory stimulation of the median, ulnar and
           radial nerves at the wrist (2 hours/session) followed by an activity-based upper
           extremity training program (1 hour/session); SS+ABT group and c) sham somatosensory
           stimulation of the median, ulnar and radial nerves at the wrist (2 hours/session)
           followed by an activity-based upper extremity training program (1 hour/session); ABT
           group then carry out training in the 3 subject groups simultaneously, each group
           consisting of 2 subjects at a time, with 2 sets of subjects/year over a 2-year period,
           yielding a target sample of 36 subjects.

        2. Conduct pre-and post-training assessments of behavioral outcomes using Wolf Motor
           Function Test and Jebsen Taylor Hand Function test to measure upper extremity function,
           hand-held dynamometry to measure pinch grip strength, and Semmes-Weinstein Monofilament
           Testing to measure sensory function.

        3. Conduct pre-and post-training assessments of supraspinal motor recruitment, including
           motor evoked potential (MEP) amplitudes in response to transcranial magnetic stimulation
           and extent and duration of cortical silent period in response to transcranial magnetic
           stimulation; and spinal motoneuron excitability measured by F-wave amplitude and
           persistence.
    

Intervention name(s): Somatosensory Stimulation and Massed Practice Training
Intervention type(s): Behavioral
Intervention description(s): a) somatosensory stimulation of the median, ulnar and radial nerves at the level of the wrist (2 hours/session); SS group b) somatosensory stimulation of the median, ulnar and radial nerves at the wrist (2 hours/session) followed by an activity-based upper extremity training program (1 hour/session); SS+ABT group and c) sham somatosensory stimulation of the median, ulnar and radial nerves at the wrist (2 hours/session) followed by an activity-based upper extremity training program (1 hour/session); ABT group then carry out training in the 3 subject groups simultaneously, each group consisting of 2 subjects at a time, with 2 sets of subjects/year over a 2-year period, yielding a target sample of 36 subjects.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Treatment
Keywords: electrical stimulation; hand; Rehabilitation; spinal cord injury