Data from the literature have suggested that a longer time of thrombolysis might be more effective in ischemic stroke. We, the investigators at Hospices Civils de Lyon, have designed a randomized protocol to test this hypothesis. Moreover, the therapeutic window is 7 hours.

Rt-PA (alteplase) is injected intravenously in the 2 arms of the study for a duration of 60 minutes in the arm with a "classical dose" and 90 minutes in the arm with a "low dose-longer infusion".

This is a study of the outcome at 90 days.

• Drug: alteplase 0.9mg/kg over 60 minutes
• Drug: alteplase 0.8mg/kg over 90 minutes

Inclusion Criteria:

• Symptoms of ischemic stroke
• Presence of a deficit measurable with National Institutes of Health Stroke Scale (NIHSS)
• Lack of any hemorrhagic lesion on the computed tomography (CT) scan at entry
• Time of therapy less than 7 hours after onset of stroke
• Permanent or aggravating symptoms
• Ages 18-81

Exclusion Criteria:

• Lack of cerebral infarction or of cranial trauma within 3 weeks before therapy
• No surgery within 14 days before therapy
• History of cerebral bleeding
• Blood pressure: systolic >185 mmHg and/or diastolic >110 mmHg
• Minor symptoms or symptoms rapidly improving
• Gastro-intestinal or urinary hemorrhage within 21 days
• Arterial puncture within 7 days before therapy
• Epileptic seizure at the beginning of stroke
• Patients under oral anticoagulants or having received heparin within 48 hours, and with elevated activated partial thromboplastin time (aPTT)
• Patients with elevated International Normalized Ratio (INR) or thrombocyte count < 100 x 10^9
• Blood glucose value < 2.7 mmol/l or > 22.2 mmol/l
• Cardiac, pulmonary, hepatic or renal failure, not allowing a study over 3 months
• History of gastric ulcer within 15 days; gestation and menstruation