This is a pragmatic, prospective, multi-center trial with blinded outcome assessment of treatment candidates three months after stroke. Treatment candidates will be defined as patients with final discharge diagnosis of cerebral ischemia, and onset-to-alarm time ≤4 hours, symptoms not resolved at time of ambulance arrival, and able to walk without assistance prior to emergency. These patients will be included if their emergency call from a predefined catchment area in Berlin, Germany, caused a stroke alarm at the dispatch center during STEMO hours (7am-11pm, Monday-Sunday). About 45% of STEMO dispatches will be handled by regular ambulances since STEMO will be already in operation creating the quasi-randomized control group. B_PROUD uses data from the B-SPATIAL registry. The B-SPATIAL registry has started recruitment in January 2016. However, B_PROUD recruits patients with symptom onset October 1st, 2016 or later (because data access at the dispatch center had to be established first).
Inclusion criteria: 1. Suspected acute stroke according to the dispatcher stroke identification algorithm during STEMO hours (7am-11pm, Monday-Sunday) and within the STEMO catchment area Inclusion criteria for primary study population: 2. Final diagnosis of ischemic stroke (ICD 10: I63) or TIA (ICD 10: G45 except G45.4) 3. Confirmed onset-to-alarm time ≤ 4 hours at dispatch 4. Pre-stroke modified Rankin scale ≤ 3 (being able to ambulate, in routine clinical care, patients with mRS up to 3 are usually deemed suitable for tissue plasminogen activator treatment) Exclusion criteria: 1. Symptom remission until arrival of emergency medical service 2. Malignant or other severe primary disease with life expectancy < 1 year Exclusion criteria for primary study population: 3. Major surgery within 4 weeks before study inclusion 4. Confirmed stroke within 3 months before study inclusion 5. Absolute contraindications for thrombolysis AND thrombectomy