Hypothermia in Acute Ischemic Stroke - Surface Versus Endovascular Cooling (HAIS-SE)

Inclusion Criteria: * Ischemic stroke * Intravenous thrombolysis within 4.5h from symptom onset * Informed consent of the patient * NIHSS score ≥ 2 and ≤ 20 * Age ≥ 18 and ≤ 90 years * Placement of cooling catheter / cooling pads within 6h from symptom onset Exclusion Criteria: * (Expected) intubation (e.g. for interventional treatment) * Pregnancy * Body weight \> 120kg * Body height \< 150cm * Life-expectancy \< 3 months * Fever \> 38.5°C at screening * Known hematologic disease with increased risk of thrombosis (e.g. cryoglobulinemia, cold agglutinins, sickle cell anemia) * Known vasospastic vascular disorder (e.g. Raynaud's phenomenon or thromboangiitis obliterans) * Possible compression of the inferior vena cava (e.g. due to tumor) or vena cava filter * Acute pulmonary embolism * Acute myocardial infarction * Severe cardiac insufficiency (NYHA ≥ III) * Threatening ventricular dysrhythmia * QTc-interval \> 450ms * Bradycardia \< 50/min * Sick-Sinus-Syndrom * AV-block \> I° * Severe infection with bacteremia or sepsis ≤ 72h * Severe renal (GFR \< 30ml/min) or liver insufficiency (Child-Pugh C) * Myopathy * Known intolerance or allergy against acetaminophen, buspirone, clonidine, magnesium sulphate or pethidine. * Treatment with MAO-inhibitors ≤ 14 days * Acute closed-angle glaucoma