Edaravone, a free radical scavenger, is a novel neuroprotective agent, and argatroban is a selective thrombin inhibitor. Both the drugs were approved by the Japanese Government, and have frequently been used for the treatment of acute brain infarction in Japan. The effect of combination therapy of these drugs, however, has not yet been elucidated. This study will test the safety and efficacy of the combination therapy with these agents in patients with acute non-cardioembolic and non-lacunar ischemic stroke.

Inclusion Criteria:

• Acute ischemic stroke < 24 hours of onset
• Measurable neurological deficits caused by the present attack, ranging from 1 to 22 of NIHSS score on admission

Exclusion Criteria:

• Definite or possible cardiogenic brain infarction
• Definite lacunar infarction
• Prior ischemic stroke within 6 months
• Evidence of hemorrhagic brain infarction, epidural hematoma, intracerebral hematoma, or intraventricular hemorrhage
• Severe consciousness disturbances (semicoma to deep coma)
• Neurological signs clearing spontaneously
• Disability of 2 or more on mRS score before the index stroke aPTT being out of the normal range or 1.5 times longer than the pretreatment value
• If taking an oral anticoagulant, INR being 1.6 or more, or no INR data
• Treatment with urokinase, t-PA, heparin, ozagrel sodium, warfarin, or antiplatelet except for aspirin before enrollment
• Intravascular surgery, surgical operation, hyperbaric oxygen therapy, or hypothermia therapy before enrollment
• Serum creatinine >1.5 mg/dL
• Severe hepatic or cardiac disorders, infectious disorders, dehydration, etc.
• Neoplasm
• Pregnancy
• Hypersensitivity to test drugs