Explorer of the brain

They are called ‘neuro diseases’: Parkinson's disease, as well as incontinence problems (urinary or faecal) and chronic pain. They are the result of brain or nerve cells that communicate with each other poorly or not at all. This communication is controlled by electric currents in our body. By placing an electrode in a given area of the brain or spinal cord, where our movements are controlled, you can administer extra current and improve the communication between the cells. The result: Parkinson's patients stop shaking and incontinent patients can be rid of their unpleasant problem. The electrodes are connected via subcutaneous wires connected to a subcutaneous pacemaker with a battery that delivers continuous power. The properties of the current (quantity, frequency, etc.) can be set from outside. That is, quite simply explained, the principle of 'neuromodulation’.

Emotional moment
Parkinson patients who receive the electrodes are conscious during the first part of the operation, so that it can be determined if the neurosurgeon has arrived at the correct area of the brain. “That's often an emotional moment for the patient”, says Yasin Temel. “The trembling stops suddenly, and they haven’t experienced that for a long time.” He is proud of the Neuro Intervention Centre at the Maastricht hospital, where all of the knowledge about neuromodulation comes together. Urologists who treat incontinence, psychiatrists who treat and refer patients, surgeons who perform the operation and many more. In addition to patient care, the team also does scientific research—because although the technique achieves amazing results and its use is expected to double over the next five years, there is still a lot of room for improvement.

One prescription
“For instance, we can’t yet help every Parkinson's patient. And our prescription for neuromodulation for the disease is basically the same as our prescription for urinary incontinence; only the place where we implant differs. In the future, we would like to have a specific neuromodulation prescription for each illness and each patient that is most effective for that one target group.” Next to this, it is true that a brain pacemaker currently delivers power continuously, not only when symptoms occur like a cardiac pacemaker already can. “We are developing a tremor-watch here, which we will soon start testing in Parkinson's patients. This device continuously records if and the extent to which someone shakes, and eventually we want the pacemaker to react.” The professor and his team do other research with the high-value fMRI scanners in Maastricht. “We want to better understand which areas of the brain are involved in Parkinson's and how they react to certain stimuli.” But he also dreams of deep brain stimulation without surgery, for example using nanoparticles injected into the blood. “Contrast dye that is injected in patients for MRI scans is an example of a nanoparticle. These are iron oxides that we want to bring to the right place in the brain using magnets, after which we can use stimulation. The effect should be the same, but the administration of it would be less of a burden for patients.”

Limburg players
The professor is, in any case, certain that neuromodulation will really take off in the coming years. “Preventing Parkinson’s, for example through lifestyle modifications, still appears to be difficult and new drugs haven’t been discovered for years for this disease. But this part of healthcare is growing rapidly.” He gladly contributes to its further development. “Two of the three major players in the field are located in Limburg: Medtronic and Boston Scientific. An the third is located very close, St. Jude in Brussels. We hope to work together more intensively in the coming years. Here at MUMC+ we have patients, and in our neuromodulation lab we have a lot of knowledge and models in which we can develop and refine new technology.”
The cooperation within the team of many different specialists is one of the secrets of Maastricht’s success as a neuromodulation centre, he believes. In collaboration with the ENT specialists, for the last four years he did research into tinnitus, chronic 'ringing in the ears'. “We have discovered the brain region that we can stimulate, with a particular pulse, so that the tinnitus signal can be completely suppressed. We want to research the first patients soon. The translation to humans is always a little bit stressful, but I’m hopeful that it will be successful, given previous experiences with brain research.”

Traveling
Since he began his brain research in 1999 in Maastricht, he has acquired more than four million euros in research grants with his team. “Looking back on these seventeen years, I’ve been able to make a kind of journey through the brain. I have visited various regions and have seen things that had never been seen before.” With his PhD research, he was the first in the world to establish why the stimulation of a brain region to improve a patient’s motor skills also resulted in mood swings. The stimulation not only affected the motor skills area, but it also inhibited the area which produces serotonin, thereby affecting our mood. “We discovered a brain region where we could cause acute panic through stimulation, and one that could improve our memory processes tremendously.” Still, not all results are translated into human studies—a matter of time and research money. “I feel like a kind of traveller in the brain and the journey is not over yet.”

By Femke Kools