Brain Stimulation and Robotics in Chronic Stroke Motor Recovery
Brain Stimulation and Robotics in Chronic Stroke Motor Recovery
Motor skill training and transcranial direct current stimulation (tDCS) have separately been
 shown to alter cortical excitability and enhance motor function in humans. Their combination
 is appealing for augmenting motor recovery in stroke patients, and this is an area presently
 under heavy investigation globally. The investigators have previously shown that the timing
 of tDCS application has functional significance, that tDCS applied prior to training can be
 beneficial for voluntary behavior, and that tDCS effects may not simply be additive to
 training effects, but may change the nature of the training effect. The investigators have
 separately reported in a randomized-controlled clinical trial, that upper limb robotic
 training alone over 12 weeks can improve clinical function of chronic stroke patients. Based
 on our results with tDCS and robotic training, the investigators hypothesize that the same
 repeated sessions of robotic training, but preceded by tDCS, would lead to a sustained and
 functional change greater than robotic training alone. The investigators will determine if
 clinical function can be improved and sustained with tDCS-robotic training and cortical
 physiology changes that underlie functional improvements.
The primary aim of this study is to evaluate whether multiple sessions of combined tDCS and
 robotic upper limb training in chronic hemiplegia, leads to clinical improvement in upperlimb
 motor impairment. In chronic stroke patients (>6months post-injury, stable unilateral motor
 deficit) using a within-subjects repeated-measures design we will evaluate the effects of 12
 weeks of robotic upperlimb training (3x/week, 36 sessions, shoulder/elbow/wrist in each
 session) with real or sham tDCS before the robotic training. Clinical improvement will be
 determined by a change in upper-limb Fugl-Meyer (primary), the Medical Research Council motor
 power score (MRC), Wolf Motor Function Test, Barthel Index, and Stroke Impact Scale
 (secondary) outcome measures following the training, and assessed again six months later.

 The investigators further aim to identify and compare the neurophysiological characteristics
 between intervention groups. The relationship between clinical improvement and
 neurophysiological measures pertaining to robotic motor training following stroke are
 presently not described in the literature. By measuring the EMG response from forearm
 musculature to Transcranial Magnetic Stimulation the investigators will establish: (i)
 plasticity associated with training, and (ii) the neurophysiological characteristics of
 patients who respond to training. By understanding how brain excitability changes underpin
 motor dysfunction, and motor recovery, interventions can be more effectively prescribed and
 prognoses established.
Inclusion Criteria:

 -  A first single focal unilateral lesion with diagnosis verified by brain imaging (MRI
 or CT scans) that occurred at least 6 months prior;

 -  Ability to follow 1-2 step commands

 -  Fugl-Meyer assessment of 7 to 58 out of 66 (neither hemiplegic nor fully recovered
 motor function in the muscles of the shoulder and elbow and wrist).

 Exclusion Criteria:

 -  A fixed contraction deformity in the affected limb;

 -  A complete and total flaccid paralysis of all shoulder and elbow motor performance;

 -  A hemorrhagic stroke

 -  Presence of tDCS / TMS risk factors

 -  Presence of an electrically, magnetically or mechanically activated implant (including
 cardiac pacemaker), an intracerebral vascular clip, or any other electrically
 sensitive support system

 -  A history of medication-resistant epilepsy in the family

 -  Past history of seizures or unexplained spells of loss of consciousness