Treating Parkinson’s and tinnitus with electric current
More than 3.000 people work at the Faculty of Health, Medicine and Life Sciences. Some work on bioprinting kidney models in the lab, others are investigating organ blood flow in heart surgery. In 'Nice to meet you', these individuals introduce themselves and share their work within FHML.
During Mark Janssen’s medicine studies, he attended a lecture on deep brain stimulation (DBS). Mark was mesmerised by how surgeons could immediately relieve symptoms with it, and he decided to pursue research in this field. Currently, he is working as an associate professor at the Mental Health and Neuroscience Research Institute (MHeNs), as well as a neurologist and clinical neurophysiologist at Maastricht UMC+ (MUMC+). He is researching how DBS can be used to treat Parkinson's disease and tinnitus. "Every time I am present at such an operation, I see its immediate effect, which is truly wonderful."
Mark studied medicine in Maastricht and started his doctoral research under the guidance of professor Veerle Visser-Vandewalle, who performed the first DBS operation at MUMC+ 25 years ago. "I did my PhD on DBS in Parkinson's disease," Mark says. "Then, I began my training to become a neurologist, also in Maastricht. Now I have been working in the Department of Clinical Neurophysiology and also in Neurology, doing brain recordings (EEG) and nerve conduction studies on patients, for example. Specifically, I focus on DBS, especially in people with Parkinson’s disease and tinnitus. I spend three days a week on patient care, one day on research, and one day on teaching."
Thermostat
In DBS, the surgeon drills a hole about the size of a fingernail in the skull. An electrode is inserted through this hole, aimed at a specific area of the brain. The electrode is connected to a battery, which generates electric pulses and is placed under the collarbone or in the abdomen. The doctor and patient can adjust the electric current using a tablet or phone and thus influence brain activity in that area. The latest batteries are also able to measure brain signals.
Mark compares it to a thermostat. "If you set it to 20 degrees and the temperature drops, the heating will turn on. If the temperature is above 20 degrees, the heating will turn off. DBS works similarly: if too many brain signals are detected, the amount of electric current is adjusted," he explains. " Measuring brain signals has been possible for a while already, but the technology to automatically adjust the electric current accordingly is just coming to market. Maastricht is one of three hospitals in the Netherlands to start doing this."
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Parkinson's disease
DBS can relieve certain symptoms. "If a patient with Parkinson's is trembling, you can increase the electric current in that brain area, and the trembling will almost immediately stop," Mark says. "With this disease, we are also looking at more basic questions. This is important because more and more people are being diagnosed with Parkinson's. One of the biggest risk factors is age. Furthermore, the chance of complications after surgery increases with age. The ageing process probably also affects brain function, which in turn influences whether DBS treatment is effective. We hope to unravel this further in the future so we can better predict who will benefit from surgery. In the past, it was said that people over 75 should not be operated on. However, I believe it is important to also consider older individuals, especially due to the current ageing population."
Tinnitus
Research is being conducted to explore whether DBS can be used for tinnitus. "In people with tinnitus, fewer sound signals reach the brain via the auditory nerve, due to hearing damage," Mark explains. "The brain's auditory system then becomes overactive and starts generating a sound itself. We try to dampen this overactivity in the brain by placing the electrode in the auditory circuit. The unique aspect of DBS is that you can take measurements deep inside the brain. This allows us to try to better understand tinnitus and specific systems in the human brain. With this, we may be able to treat patients with alternative, less invasive methods in the future."
Looking back
On November 26 2024, it had been 25 years since the first DBS operation took place in Maastricht. "On that exact day, we took a moment to reflect on this, with all the patients we have operated on," Mark says. "We looked back at how such an operation went 25 years ago and the steps that have been taken since. The patient who was the first to be operated on back then was also present. This shows that as a hospital in the Netherlands, but also worldwide, we are at the forefront of research, not only for new indications but also for improvements that benefit the patient."
Photos: Appie Derks
Text: Joëlle van Wissen
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