Feasibility and safety of magnetic resonance imaging-based thrombolysis in patients with stroke on awakening: initial single-centre experience

Background Up to 25% of all acute ischaemic strokes occur during sleep. Because of the unclear time window, patients with stroke on awakening are usually not considered for acute therapy and excluded from most acute treatment trials. Aim To evaluate the feasibility of magnetic resonance imaging-based intravenous thrombolysis in patients with stroke on awakening in a routine clinical setting. Methods Forty-five patients with stroke on awakening clinically qualifying for intravenous thrombolysis and presenting within 6 h after symptom recognition were admitted to our institution between October 2006 and May 2008. Following an institutional protocol, patients received magnetic resonance imaging as a first-line imaging modality and were offered mismatch-based thrombolysis whenever possible. Baseline demographic data, clinical, laboratory and imaging findings were analysed. Outcome was assessed using the modified Rankin Scale score at 3 months. Results Magnetic resonance imaging screening was feasible in 43/45 patients (96%). After screening, 10 patients (22%) were treated with intravenous thrombolysis. There were no differences between treated and untreated patients regarding cardiovascular risk factors, stroke aetiology, previous prophylactic treatment and symptom recognition to door time or door to imaging time. Outcome was comparable in both groups despite a trend towards more severe strokes in the intravenous thrombolysis group. Only one asymptomatic and no symptomatic haemorrhage were observed. Conclusion Our data demonstrate that magnetic resonance imaging-based thrombolysis is feasible and possibly safe in patients with stroke on awakening (SOA). Randomised clinical trials for patients with stroke on awakening are needed to further test the safety and efficacy of intravenous thrombolysis in this patient group. The results of our study may help to initiate and design such studies.