Study of Botulinum Toxin and Recovery of Hand Function After Stroke

Hemiparesis is the most common motor impairment after stroke that frequently leads to persistent deficits in hand function. This study investigates whether the application of botulinum toxin to a set of synergistically-acting hand muscles, in conjunction with task-specific therapy, will lead to reorganization and improved motor function in the stroke-involved hand. The investigators will use objective psychophysical measures of hand function and hand function rating scales to investigate if Botox in conjunction with task-specific therapy will lead to: * improved motor execution, * improved motor planning during a psychophysical two-finger grasping and lifting task with varying object weight, and * increased hand function as assessed by the time taken to complete fine motor tasks.