A study called WAKE-UP conducted by scientists at the University Hospital Hamburg-Eppendorf (UKE) has shown that patients who suffer a stroke while asleep and do not notice the symptoms until they wake up can also benefit from thrombolysis, a press release said Wednesday (May 16, 2018). The results have also been published in the New England Journal of Medicine. Until now, the clogged blood vessel in the brain could only be reopened, if symptoms began no more than 4.5 hours earlier. As part of the study, researchers were able to select patients suitable for thrombolysis using MRI diagnostics, even with an unknown time of symptom onset. The selected patients showed fewer neurological symptoms or disabilities than other patients.
WAKE-UP is a European multicentre investigator-initiated randomized placebo-controlled clinical trial of MRI based thrombolysis in acute stroke patients with unknown time of symptom onset, e.g. due to recognition of stroke symptoms on awakening. The WAKE-UP study included patients with acute ischemic stroke and unknown onset of symptoms between the ages of 18 and 80. Patients were selected for treatment using magnetic resonance imaging (MRI).
Two special examination sequences were used namely diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery imaging (FLAIR). Earlier investigations had shown that if the DWI shows acute stroke damage but FLAIR is unclear (“DWI flair mismatch”), then the patient is still in a time window in which thrombolysis can be effectively and safely applied.
Early therapy protects against disabilities
Stroke is the second leading cause of death and the most common cause of permanent disability in adults in the western world. The cause is usually the occlusion of a blood vessel in the brain (ischaemia) by a blood clot (thrombus). As a result, the brain tissue supplied by the closed vessel dies. The blood clot can be dissolved with medication by treatment with thrombolysis. If this occurs on time, permanent neurological symptoms or disability can be prevented.
Prof. Dr. Götz Thomalla, first author of the study and senior consultant in the Department of Neurology at the UKE, said: “The positive result of the WAKE-UP study is a big step towards improving the treatment of stroke patients, as the study opens up the possibility of treating a large number of patients with thrombolysis, who were previously excluded from it. Treatment based on MRI without knowing when the symptoms start is a paradigm shift for stroke thrombolysis.”