title: Time configuration of combined neuromodulation and motor training after stroke: A proof-of-concept study.
abstract: BACKGROUND
  Intensive motor training is a therapeutic intervention that supports recovery of movement function after stroke by capitalizing on the brain's capacity for neuroplastic change. Peripheral nerve stimulation and transcranial direct current stimulation are neuromodulation techniques that can upregulate neuroplasticity and, in turn, enhance outcomes of motor training after stroke. Few studies have investigated possible adjuvant effects between peripheral nerve stimulation, transcranial direct current stimulation, and intensive motor training.
  
  
  OBJECTIVE
  This proof-of-concept study investigated whether timing variations in neuromodulation paired with robot-assisted motor training effect differential outcomes for subjects with chronic, moderate-to-severe upper extremity impairment after stroke.
  
  
  METHODS
  Ten subjects in the chronic phase (>12 months after stroke) of recovery completed the study. Subjects received 10 daily sessions of transcranial direct current stimulation either at the start (n = 4) or at the end (n = 6) of peripheral nerve stimulation preceding intensive motor training. Pre-post changes in motor function (Fugl-Meyer Assessment; Stroke Impact Scale) and neuroplasticity (transcranial magnetic stimulation) were assessed by condition.
  
  
  RESULTS
  Significant improvement in Stroke Impact Scale (p = 0.02) and no change in Fugl-Meyer Assessment were associated with the start condition. No changes in Stroke Impact Scale and Fugl-Meyer Assessment were associated with the end condition. Only 1 subject in the start group had measurable neuroplastic responses and demonstrated an increase in ipsilesional cortical map volume. Only 1 subject in the end group had measurable neuroplastic responses and demonstrated a decrease in ipsilesional cortical map volume. Opposite shifts in ipsilesional cortical centers of gravity occurred relative to condition.
  
  
  CONCLUSIONS
  In cases of moderate-to-severe impairment after stroke, transcranial direct current stimulation at the start, rather than the end, of peripheral nerve stimulation prior to motor training may effect better functional outcomes. Future research with a larger sample size is needed to validate the findings of this proof-of-concept study.
authors: Department of Physical Medicine and Rehabilitation, University of Kentucky, Lexington, KY, USA.
authors: Elizabeth S
authors: ES
authors: Powell
authors: Department of Physical Medicine and Rehabilitation, University of Kentucky, Lexington, KY, USA.
authors: Cheryl
authors: C
authors: Carrico
authors: Department of Biostatistics, College of Public Health, University of Kentucky, Lexington, KY, USA.
authors: Philip M
authors: PM
authors: Westgate
authors: Department of Physical Medicine and Rehabilitation, University of Kentucky, Lexington, KY, USA.
authors: Kenneth C
authors: KC
authors: Chelette
authors: Department of Physical Medicine and Rehabilitation, University of Kentucky, Lexington, KY, USA.
authors: Laurie
authors: L
authors: Nichols
authors: Department of Physical Medicine and Rehabilitation, University of Kentucky, Lexington, KY, USA.
authors: Lakshmi
authors: L
authors: Reddy
authors: Department of Physical Medicine and Rehabilitation, University of Kentucky, Lexington, KY, USA.
authors: Emily
authors: E
authors: Salyers
authors: Department of Physical Medicine and Rehabilitation, University of Kentucky, Lexington, KY, USA.
authors: Andrea
authors: A
authors: Ward
authors: Department of Physical Medicine and Rehabilitation, University of Kentucky, Lexington, KY, USA.|HealthSouth Cardinal Hill Rehabilitation Hospital, Lexington, KY, USA.
authors: Lumy
authors: L
authors: Sawaki
mesh_terms: D000368:Aged; D001931:Brain Mapping; D002908:Chronic Disease; D004599:Electric Stimulation Therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009068:Movement; D009473:Neuronal Plasticity; D010525:Peripheral Nerves; D012371:Robotics; D000071939:Stroke Rehabilitation / Q000379:methods*; D065908:Transcranial Direct Current Stimulation; D050781:Transcranial Magnetic Stimulation; D004561:Transcutaneous Electric Nerve Stimulation; D016896:Treatment Outcome
keywords: Peripheral nerve stimulation; neuroplasticity; robot-assisted upper extremity motor training; transcranial direct current stimulation; transcranial magnetic stimulation