Conditioning Neural Circuits to Improve Upper Extremity Function
Condition: Spinal Cord Injury; Tetraplegia
MeSH terms: Spinal Cord Injuries; Quadriplegia
Study type: Interventional

Summary: 
      Non-invasive brain stimulation has gained increasing popularity and research support over the
      past several years. Recent research indicates that it might have benefits for improving hand
      function in people with spinal cord injury. The purpose of this study is to evaluate the
      effects of a type of non-invasive brain stimulation, known as tDCS, on hand function.
    

Detailed description: 
      Transcranial direct current stimulation (tDCS) is a technique in which low intensity
      electrical current is applied over the skull in order to excite the underlying brain tissue.
      It has been studied in many populations (stroke, spinal cord injury, learning disability,
      migraine, memory) and may be a useful counterpart to traditional rehabilitation of
      neurological injuries. Preliminary studies from members of the investigator's lab group have
      indicated beneficial, single-session effects of tDCS on hand function in people with spinal
      cord injury. Longer-term, multi-session trials are now warranted.

      Another approach that has research support for augmenting the effects of hand function
      training is peripheral nerve somatosensory stimulation (PNSS). Unlike tDCS, which excites
      brain tissue directly, PNSS excites the brain via an indirect approach. Members of the
      investigators' lab have found the combination of PNSS and fine motor training to be more
      effective in improving hand function than either intervention alone. Multi-session trials of
      PNSS have been conducted; however it has not yet been compared with another clinically
      accessible adjunctive therapy, like tDCS, in a multi-session trial.

      The investigators plan to study the comparative effects of tDCS and hand function training to
      PNSS and hand function training and hand function training alone in people with neck-level
      spinal cord injuries. People with both acute/subacute (<6 months post-injury) and chronic (>1
      year post-injury) injuries will be enrolled, in order to look at responses to tDCS at
      different stages of recovery.

      Before beginning training, participants will complete approximately three hours of testing of
      their arm/hand function and self-reported perception of their overall function. Participants
      will then be randomly assigned to receive either tDCS, PNSS, or sham tDCS in combination with
      personalized fine motor training. This training will take place 3 times/week, for a total of
      3 hours of training/week, for 4 weeks. Fine motor training will be based on principles that
      have been shown to optimize neuroplasticity (changes in the brain and/or spinal cord), yet
      customized, in order to allow participants to work towards individualized goals. At the end
      of 4 weeks, participants will complete a three-hour post-test using the same measures as
      before to examine any changes in arm and hand function. Participants will be asked to return
      to Shepherd Center 4 - 6 weeks following the post-intervention assessment to complete the
      post-intervention assessment.
    

Intervention name(s): transcranial direct current stimulation; peripheral nerve somatosensory stimulation; sham transcranial direct current stimulation
Intervention type(s): Other; Other; Other
Intervention description(s): High-definition transcranial direct current stimulation is applied over the hand area of the primary motor cortex (M1). Parameters= 2mA for 20 minutes. Functional task practice will be completed concurrently with tDCS and for approximate 40 minutes after the stimulation stops.; Electrical stimulation will be applied to the median nerve of the primary hand being trained at parameters that elicit a sensory but not motor response (called "peripheral nerve somatosensory stimulation"). Stimulation parameters are 100Hz with a 250uS pulse width. Stimulation intensity will vary between 1-10mA per participant. Stimulation will be applied for 1 hour and functional task practice will be completed concurrent with the stimulation.; During sham transcranial direct current stimulation (tDCS), a sham tDCS device will be used along with functional task practice. The sham tDCS unit will be used for the first 20 minutes of FTP, followed by an additional 40 minutes of FTP.
Other intervention name(s): tDCS
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment