ogy and Medical Psychology, Faculty of Psychology, University of Bergen, and collaborates closely with the academic departments at Haukeland University Hospital. He is involved in several of the projects under the auspices of the research group for Functional magnetic resonance imaging (fMRI), which is headed by Professor Karsten Specht.
…not Jack Nicholson There is a whole arsenal of methods that use an electric current to stimulate the brain. “But don’t think of Jack Nicholson’s rebellion against the treatment in One Flew Over the Cuckoo’s Nest". That type of treatment is now only used for severe depression and only under a general anaesthetic. Hirnstein and his colleagues use a much weaker electric current that only affects one specific, small area in the brain. The current is about the same as that in a small battery, and it is not painful. The patient does not need an anaesthetic, and does not even notice it. “Using these methods, we can “modulate” the selected area so that something in the brain is changed. Then we can help those who do not benefit from medication, as is the case for some patients with depression,” continues Hirnstein.
A brain with two halves Hirnstein started this research because he was curious as to why our two brain hemispheres are so specialized. He explains that the left hemisphere controls our ability to write and to speak, while the right governs our ability to understand spatiality and to navigate. “We discovered that using electrical brain stimulation we could distinguish between the two hemispheres. It is actually a very convenient method to “reset” one half. That was when I became even more interested in the field. We can use the method to diagnose, treat and conduct research,”
comments Hirnstein, who also collaborates with the neurologist Tom Eichele in this field.
Targeting the correct area If a tumour is located in the part of the brain that controls movement, surgeons must be certain when they operate that they know the location of the tumour as accurately as possible. This means the patient can avoid injury or paralysis. When Hirnstein has determined where the tumour is located and what surrounds it, the surgeon can feel more secure that he will hit the target correctly. By using electrical brain stimulation Hirnstein maps the precise areas that controls body movements. And with this method you don’t have to open up the skull. This information is then sent to the neurosurgeons. “We determine which part of the body is controlled by precisely this area of the brain”. The location of the area associated with a particular function of the body varies from person to person. The surgeon also performs his own tests during the operation, when the skull is open. “This means that the accuracy increases for these extremely demanding operations,” says Hirnstein.
Re-finding words Hirnstein uses a method called transcranial magnetic stimulation (TMS) to make the measurements with his device. When the researcher places the device on the head and presses the button, the brain receives a very mild form of electrical stimulation. About 12,000 people in Norway have a stroke every year, and about a third of them subsequently have problems speaking (aphasia). This method can help patients with stroke to regain speech. “Some studies show that the patients who receive this treatment benefit more from language therapy,” states Hirnstein. Using TMS together with speech
therapy is completely new in Norway and researchers need to find out more about this treatment. Therefore, together with colleagues Karsten Specht and Eike Wehling, he wants to introduce TMS also in Norway. The treatment is time consuming for the patient and researcher, and the outcome is still uncertain for some of these patients. Hirnstein explains that there are two ways to do this: Either stimulate the area around the part that is damaged, as our language centre is located in the left hemisphere, or attempt to dampen activity in the right hemisphere because this part of the brain will often strive to compensate for the injury.
Not a cure for everything “Electrical brain stimulation using a weak electric current is without doubt very beneficial in many disciplines. But we must also be clear that this is not a miracle therapy for all disorders,” states Hirnstein. Researchers still does not know enough about what exactly happens in the brain during treatment with weak electric current. Moreover, studies that use this method often have too few participants. That makes it difficult for the researchers to determine for whom this therapy will work. “There is therefore still a lot that needs to be researched in this aera in the future,” concludes Hirnstein enthusiastically.
Marco André Hirnstein. Photo: Eivind Senneset
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