A new study says that a drug that dissolves blood clots in the brain can benefit patients up to 4.5 hours after a stroke.
Till date, the useful limit for administering thrombolytic drugs was believed to be just three hours.
"These new insights will benefit tens of thousands of patients whose cerebral circulation could be restored," said the study director, Professor Dr. Werner Hacke, Medical Director of the Neurology Clinic at Heidelberg University Hospital.
In the study, 826 patients in 130 European stroke centres who were treated in the clinic between 3 and 4.5 hours after a stroke were injected with either the thrombolytic drug alteplase or a placebo.
Initially, CT scan ruled out Cerebral haemorrhage as a cause of the stroke.
Almost 52 percent of the patients treated with alteplase responded well to treatment and suffered no or only slight impairment, while in the placebo group, there were only 45 percent responders. The mortality rate was very low and identical in both groups (8 percent).
Thus, researcher suggested that stroke patients could be treated with thrombolytic drugs even after three hours.
"But having more time does not mean that we can take more time", warned Professor Hacke.
He added that patients with signs of a stroke should still be brought to the hospital and treated as soon as possible. Previous analyses clearly showed that patients respond best the earlier they received treatment.
Also, the study will set an important course - there had been no positive study on acute stroke therapy for more than 12 years, and ECASS 3 is just the second acute study ever to have a positive result for strokes.
"This study will have an impact on the entire field of stroke treat-ment. It has finally been demonstrated again that stroke can be treated and this will encourage many researchers and companies to continue to work in this field," said Professor Hacke.
The results of the study, namely "European Cooperative Acute Stroke Study 3" (ECASS 3) have now been published in the "New England Journal of Medicine".