Cortical Enhancement of Posture, Movement Planning, and Execution of Upright Reaching Following Stroke
Cortical Enhancement of Posture, Movement Planning, and Execution of Upright Reaching Following Stroke
Stroke is the leading cause of disability and diminished quality of living that frequently
 includes impairments of postural control and upper extremity (UE) function. The interaction
 of posture and UE coupling in terms of movement planning, initiation, and execution is not
 well understood. StartReact responses triggered by a loud acoustic stimulus (LAS) during the
 planning and preparation of goal intended actions has been used to probe the state of
 brainstem neuronal excitability related to posture and movement sequencing. The purpose of
 this study is to examine posture and goal-directed movement planning and execution using
 startReact responses and to evaluate posture and UE movement sequence during reaching while
 standing in individuals with chronic hemiparesis and healthy controls. Secondly, the
 investigators will determine the modulatory role of the cortical premotor areas (PMAs) in
 startReact responses in healthy controls and in persons with stroke by using transcranial
 direct current stimulation (tDCS) to up- or down-regulate PMAs excitability.
Inclusion Criteria for stroke:

 -  Unilateral cortical or white matter subcortical stroke

 -  Age 40 yrs and older

 -  ≥ 6 months post ischemic stroke or ≥ 12 months post hemorrhagic stroke

 -  Residual arm hemiparesis as indicated by Fugl-Meyer Upper Extremity score between
 20-65

 -  Having the ability to perform reaching movements with the paretic arm in standing
 without an assistive device.

 Exclusion Criteria for stroke:

 -  Stroke involving bilateral hemisphere, brainstem or cerebellum

 -  Any medical condition precluding participation in testing

 -  Other health conditions affecting balance and upper extremity movement function beyond
 the effects of stroke.

 Inclusion Criteria for healthy controls:

 -  Age-matched to the stroke subjects

 -  Without a history of stroke or any known neurological conditions

 -  Having the cognitive ability to follow two-step commands and give informed consent

 Exclusion Criteria for healthy controls:

 -  Any medical condition precluding participation in testing

 -  Other health conditions affecting balance and upper extremity movement function beyond
 the effects of stroke.

 Participants were also excluded if they did not meet the TMS safety criterion including
 having implantable medical devices, history of seizures, taking medications to reduce
 anxiety, sedatives, and seizure, and pregnancy.