This study uses a form on non-invasive brain stimulation called transcranial magnetic stimulation to understand 1) understand how the brain learns post-stroke and 2) assess non-invasive brain stimulation as an addition to current stroke rehabilitation approaches. In two study arms the investigators will compare the effect of active transcranial magnetic stimulation paired with motor practice with placebo (or sham) transcranial magnetic stimulation paired with the same motor practice.
Stroke is the leading cause of permanent disability in the United States. In the absence of treatments to restore the lost tissue, clinical scientists have focused upon repetitive forced used of the paretic limb to promote neural reorganization in preserved tissue and reduce disability. However, forced use interventions are time intensive and the extent of functional recovery is variable. One potential contributor to this variability is the potential trade-off between compensatory cognitive motor control strategies and the extent of procedural learning that can occur. Compensatory strategies adopted by patients may produce quick short-term increases in performance but retard slower sustained improvements by interfering with development of procedural learning. Consistent with this hypothesis, the investigators' previous work documents an increased reliance upon dorsolateral prefrontal cortex during performance of learned skills post-stoke. However, the investigators' previous work also demonstrates that the effect of increased activity in dorsolateral prefrontal cortex may limit reorganization in important areas involved in the consolidation of practice thereby limiting functional recovery post-stroke.
Transcranial magnetic stimulation offers a unique opportunity to investigate the relationship between dorsolateral prefrontal cortex activity and consolidation of motor practice/rehabilitaion post-stroke. Here the investigators' objective is to determine whether suppression of the contralesional dorsolateral prefrontal cortex, with continuous theta burst transcranial magnetic brain stimulation (cTBS), a form of transcranial magnetic stimulation, prior to motor practice enhances brain reorganization in critical areas and leads to greater sustained improvements in motor ability over time.
The proposed work will enhance the understanding of motor learning post-stroke and provide preliminary evidence for the benefits of dorsolateral prefrontal cTBS as an adjunct to current rehabilitation interventions.
- Active continuous theta burst stimulation (cTBS) Device
Intervention Desc: Active cTBS over dorsolateral prefrontal cortex that has an effect upon dorsolateral prefrontal cortex brain activity. ARM 1: Kind: Experimental Label: Experimental Description: Application of active continuous theta burst stimulation over dorsolateral prefrontal cortex prior to upper limb motor practice.
- Placebo (Sham) continuous theta burst stimulation Device
Intervention Desc: Sham stimulation over dorsolateral prefrontal cortex that looks and sounds like active cTBS but does not have any effect upon dorsolateral prefrontal cortex brain activity. ARM 1: Kind: Experimental Label: Control Description: Application of sham continuous theta burst stimulation over dorsolateral prefrontal cortex prior to upper limb motor practice.
- Motor Practice Behavioral
Intervention Desc: Upper limb reaching task to be practiced. Practice will be paired with Active/Sham stimulation. Twenty trials will occur before Active/Sham stimulation. 40 trials will be practiced after Active/Sham stimulation. ARM 1: Kind: Experimental Label: Experimental Description: Application of active continuous theta burst stimulation over dorsolateral prefrontal cortex prior to upper limb motor practice. ARM 2: Kind: Experimental Label: Control Description: Application of sham continuous theta burst stimulation over dorsolateral prefrontal cortex prior to upper limb motor practice.
|Type||Measure||Time Frame||Safety Issue|
|Primary||Persistent change in response time||3 weeks|
|Secondary||Transfer to Functional Motor Ability||3 weeks|
|Secondary||Short-term change in response time||60 minutes|
|Secondary||Persistent Motor Cortical Excitability Change||3 Weeks|