Inclusion Criteria
All patients transported by EMS in Los Angeles County will be screened for study entry. Study inclusion criteria are:

1. Age 40-95, inclusive
2. Last known well time within 2 hours of treatment initiation
3. Deficit present for > 15 minutes

Exclusion Criteria
Study exclusion criteria are:

1. Coma
2. Rapidly improving neurologic deficit
3. Pre-existing neurologic, psychiatric, or advanced systemic disease that would confound the neurological or functional outcome evaluations
4. SBP < 90 or > 220
5. Known severe renal dysfunction (on dialysis or known chronic creatinine > 3.0)
6. Severe respiratory distress (O2 sat < 90% or respiratory rate < 12 or > 24)
7. Known second or third degree heart block with no pacemaker in place
8. Major head trauma in the last 24 hours
9. Recent stroke within prior 30 days
10. Patient unable to give informed consent and no available legally authorized representative to provide informed consent