Inclusion Criteria- 18 years of age or older.
- Clinical diagnosis of ischemic stroke defined as acute neurological deficit occurring in one or more major vessels.
- Must arrive at hospital and be able to begin treatment within 2 hours of established eligibility and this must be within 24 hours of symptom onset. - - Patients unable to report symptom onset time or those awakening with symptoms must use the time last known to be well as the onset time.
- Admission plasma glucose of > 110 mg/dL.
Exclusion Criteria- Renal dysfunction as defined by a serum creatinine of >/=2.5 mg/dL at enrollment.
- Substantial pre-existing neurological or psychiatric illness that would confound neurological assessment.
- Patients who have received experimental therapy for the enrollment stroke.
- Pregnant females.
- Patients with other severe life threatening conditions that makes them unlikely to survive 90 days.
- Patients who are unable to follow the protocol or come back for 90-day followup.
- Patient has condition for which insulin infusion is the usual practice or the treating physician feels that there is an indication for insulin infusion.