"Stroke is one of the most common causes of death and functional impairment in Western nations. It usually occurs when a blood clot obstructs a blood vessel in the brain. This blockage restricts the blood supply to the brain, causing oxygen deficiency — ischaemia — in the area around the clot."
"In Sweden, as in the USA and much of Europe, we have introduced thrombolytic treatment in patients with ischemic stroke by injecting tPA enzyme into the blood. This enzyme is normally found in blood, but by supplying extra we can accelerate the degradation of blood clots.
"However, fewer than 5% of patients with ischemic stroke actually receive this treatment. The reason is because treatment must begin within three hours of the initial symptoms; otherwise it could lead to haemorrhaging and cause further damage to the brain. "
"Previous research has shown that tPA can evoke opening in the blood-brain barrier, a barrier that normally protects the brain from harmful substances. This could possibly explain the adverse effects of tPA treatment."
"The same blocking also limits the side effects after thrombolytic treatment using tPA in mice with stroke. We are currently following up the results to better understand the role that these signals normally play, and can play under diseased conditions."

Linda Fredriksson. Photo: Jyrki Siikanen, Voff Media.