Inclusion criteria:

1. Age > 18
2. For cases, admission to the Stroke Inpatient Service with a diagnosis of acute ischemic stroke. NIHSS≥1, including at least 1 point for limb weakness.  At least half of the stroke patients must have at least 2 points on the NIHSS for limb weakness.
3. For controls, admission to the hospital with a TIA, normal MRI, and normal neurologic exam, admission to the Epilepsy Monitoring Unit for differential diagnosis of transient neurologic spells with a normal MRI and normal neurologic exam, or recent cardiac surgery.

Exclusion criteria:

1. Any medical or psychological conditions that, in the opinion of the investigator, would compromise the subject’s safety or successful participation in the study.
2. A limb amputation above the wrist in the upper extremities and the ankle in the lower extremities.
3. For controls:
   • History of prior stroke
   • Evidence of prior brain injury on MRI when this data is available, excluding mild small vessel ischemic disease
   • Evidence of any focal neurologic findings on exam including asymmetric limb weakness or neglect