Brain stimulation can improve speech after stroke

Every year, around 250,000 people in this country suffer a stroke. Often patients have to struggle with the consequences throughout their lives. Many sufferers suffer from speech disorders due to the sudden circulatory disorder in the brain. People who used to be able to communicate, read and write in the normal way often have to relearn these skills completely by damaging certain brain areas. However, good help could possibly be provided by electrical brain stimulation. As Berlin researchers in the neurology journal "Brain" report, this language ability can be improved.

Patients lose their ability to speak through brain damage
If the brain, which is responsible for speech, reading and writing, is damaged in a stroke ("speech-dominant hemisphere"), speech disorders (aphasia) often occur. Depending on their extent and localization, they may vary in severity: partially hearing affected persons, e.g. but do not understand the content of the words. Other aphasics, on the other hand, understand the content of what has been said, but can not reproduce it. The majority of patients suffer from word-finding disorders and therefore need to re-learn both language and grammar like a foreign language from scratch.

Brain stimulation can significantly improve speech after a stroke. (Image: psdesign1 / fotolia.com)

In the future, good support could be provided by electrical brain stimulation. This was demonstrated by doctors from the Berlin Charité using a small model study. The neurologists recognized that the speech ability of stroke patients could be improved with the help of external electrical stimuli on the head. The scientists presented their findings at the 60th Annual Scientific Meeting of the German Society for Clinical Neurophysiology (DGKN) in Düsseldorf.

Berlin researchers examine 26 stroke patients
The study involved 26 female and male patients with chronic aphasia ("speechlessness") who were treated with DC stimulation twice daily for 20 minutes each for 8 days. The weak electrical current led the doctors through two externally attached electrodes through the skull bone into the brain. In addition, the subjects completed a language training for about three hours, in order to learn the naming of objects such as "candle" or "balloon" again. While one group received "real" electrical current during the exercises, the other patients were given sham stimulation.

It turned out that initially both groups profited from language training and improved their ability to speak. "But the group with the right stimulation made more progress," said Professor Agnes Flöel, a neurologist at the Berlin Charité, told the news agency "dpa". "In each session, you have a slightly greater learning gain than the group with mock stimulation found." After eight days, the difference was already "quite large" according to Agnes Flöel. According to this, after the therapy, the patients would have made progress in naming objects, but also in everyday activities such as shopping or a conversation with the doctor. The positive effects would last for about half a year, the expert explained. "Our findings provide the first evidence from a randomized, controlled trial that transcranial DC stimulation can improve the functions and action-related outcomes of chronic aphasia," the researchers write in their article.

Speech disorder does not constitute mental retardation
Earlier studies had shown that weak electrical impulses can have a positive effect in stroke therapy, e.g. in patients with motor deficits as a result of the sudden onset of brain disease. The study of aphasia patients, however, is more difficult according to the study director. Because in aphasia, those affected have lost their language, but unless other brain areas are affected, they are in no way mentally disabled. The mind is unimpaired, but patients can no longer establish the connection between an object and its name. "That means they recognize the candle, but they can not find the word," explains Flöel. The DGKN Congress President Alfons Schnitzler, neuroscientist at the University Hospital Düsseldorf, described the study as a "milestone" in the direction of a therapeutic use of non-invasive brain stimulation in stroke patients, according to the announcement of the "dpa". According to Flöel, a larger study with 150 to 200 patients at different locations should now follow. (No)