Apoplectic stroke
Time equals brain cells

<b>When the head breaks down</b> Despite improved possibilities for treatment, a stroke is still one of the most common causes of death. Image: Simone Golob/Corbis
After a stroke has occurred, every minute counts. The new ray of hope is a so-called micro-catheter, with which doctors manually remove the dangerous blood clots from the blocked vessel. But it will take time before this treatment is available to every patient.
Behind cancer and heart attacks, strokes rank among the three most common causes of death in Germany. About 270,000 individuals are affected every year, and one out of three remains disabled or is in need of care for the rest of his life. “Without blood and oxygen supply, roughly 2 million out of a total of 100 billion nerve cells in the brain die per minute,” says Martin Ebinger, senior physician at the Charité Klinik für Neurologie. He has been conducting research for many years on how the supply chain during a stroke – from emergency phone call to successful rehabilitation of the patient – can be improved. Physicians differentiate between two kinds of strokes, Ebinger explains: the haemorrhagic stroke triggered by cerebral haemorrhage and the ischemic stroke, which is caused by the occlusion of a cerebral vessel, at 90% the most commonly occurring stroke – as in the case with Thomas E. “We only have a window of a few hours until it becomes too late to carry out targeted measures,” says Martin Ebinger. He can still remember Thomas E quite well; not only because he is still relatively young. “When the patient arrives here within four-and-a-half hours after an ischemic stroke, we execute the standard method – the thrombolysis. This involves injecting a drug that inhibits coagulation within the body, thus dissolving the blood clot,” explains the neurologist. “In Thomas E’s case, this was unfortunately not enough for successful removal of the entire massive thrombus. The situation was extremely threatening to him.”
But Thomas E is fortunate enough to experience his second blessing in disguise: He is still within the perimeters of the time window in which a different treatment is still possible, and thanks to the fast supply, tissue damage within the brain has not advanced too far. These are the exact conditions required by the doctors for a second intervention. Starting at the femoral artery, they push a micro-catheter – a so-called stent retriever – up through the carotid artery to the cerebral artery. Attached to its tip is a wire-mesh net, which can be folded out to capture the thrombus. In the latest models, negative pressure in the catheter sucks it up and prevents the escape of very small pieces of the clot up into the brain, which would initiate a new stroke. This method, which the physician controls with the aid of a contrast medium and imaging techniques, is now celebrated all over the world as the ray of hope in the war against strokes. But the procedure is so complicated that it demands extensive experience and can only be deployed by specially-trained physicians.
<b>Lebensretter auf Rädern</b> Ein Berliner Rettungswagen, das Stroke-Einsatz-Mobil, ist speziell für Schlaganfall-Patienten ausgestattet – selbst ein Computertomograph ist an Bord. Bild: Charité UniversitätsmedizinBerlin
“We now know for certain that this therapy with modern stent-retrievers increases by 20 to 30 percent the chances for our patients of surviving a severe stroke with only limited adverse effects. These are spectacular results,” says Matthias Endres, Director of the Charité-Klinik für Neurologie and member of the executive board for the Deutsche Schlaganfall-Gesellschaft. For him the biggest challenge now is to improve the structures in such a manner that every patient who comes into consideration is allowed to receive the therapy – regardless of whether he lives in the country or in a metropolitan area.
During the acute phase, the principle is still nonetheless valid – what the physicians refer to as “Time equals brain cells” – the faster the blood supply in the brain is re-established, the bigger the chances of survival are during an ischaemic stroke. It is important to establish the time of the stroke as precisely as possible because, after a specific amount of time has elapsed certain therapies, such as this one involving the stent-retriever, can even cause more damage.
The emergency response physician must therefore decide whether a detour must be taken to a hospital with a catheter laboratory, and whether respective expertise is advisable. If the patient is non-responsive, medical practitioners can only ascertain this with the aid of imaging technology such as computer tomography (CT), or magnetic resonance tomography (MRT).
“Some patients seem to regenerate better than others after a stroke”
A normal ambulance is not equipped for this eventuality. For this reason since 2011, the Berlin Fire Department operates the “Stroke-Einsatz-Mobil” (STEMO) in mutual cooperation with the Center for Stroke Research Berlin of the Charité. “On board we can make a diagnosis and already initiate thrombolysis in transit,” explains Senior Physician Martin Ebinger. He coordinates the neurologists specialised in stroke treatment during the medical procedures and has gained considerable experience with the STEMO. There is also telemedical equipment on board, through which CT images can be discussed with a neuroradiologist, and further interventions planned efficiently.
<b>Was danach passiert</b> Holger Gerhardt erforscht die Gefäßneubildung nach einem Schlaganfall. Bild: David Ausserhofer
“Some patients seem to regenerate better than others after a stroke. In the event of vessel occlusion as well as stroke, the vessel network in these patients is able to more quickly manufacture a detour for the blood and oxygen supply. Thus they are better protected in case of a stroke. We have found out that endothelial cells that line the inner wall of vessels are capable of moving dynamically and modifying a vessel. Here there are genetic interrelationships that we would like to take a closer look at,” the expert for blood-vessel regeneration explains. But he also mentions that it is too early for a molecular therapy approach with human beings. Cooperation plans are currently being made.
It was three weeks ago that the stroke occurred. Thomas E is in a rehabilitation clinic in Berlin – he is sitting in a wheelchair. He was able to speak again already after three days in the Charité. His quick admission into the stroke unit and treatment with the stent-retriever saved his life and saved him from an even worse fate, he believes. “I have been here two weeks now, and have learned quite a bit. Previously, I wasn’t able to do anything. In the beginning they put me into a bed or sat me down in the wheelchair. And now I am able to go to the toilet alone and stand in front of the sink to brush my teeth,” he says. Then he laughs: “But I’m not able to dance yet!” Whether he will completely relearn all of his skills, he doesn’t know. But he does know that the odds are good
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