• Modified Rankin Scale (MRS) score [ Time Frame: at 3 months ] [ Designated as safety issue: Yes ]
• Symptomatic intracranial hemorrhage [ Time Frame: for the initial 3 weeks ] [ Designated as safety issue: Yes ]

• Modified Rankin Scale score at 3 months
• Symptomatic intracranial hemorrhage for the initial 3 weeks

• NIHSS score, JSS score, Barthel Index, modified Rankin Scale score [ Time Frame: at various time-points ] [ Designated as safety issue: Yes ]
• Various adverse effects [ Time Frame: for the 3 months ] [ Designated as safety issue: Yes ]

• NIHSS score, JSS score, Barthel Index, modified Rankin Scale score at various time-points
• Various adverse effects for the 3 months

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.

• Active Comparator: The patients who are allocated to Argatroban monotherapy
• Active Comparator: The patients who are allocated to Edaravone-Argatroban combination therapy

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