Personalising deep brain stimulation treatment for Parkinson's disease
Parkinson's disease is the second most common neurodegenerative disease after Alzheimer's. Its main symptoms are: shaking, rigidity, slowness of movement and difficulty maintaining an upright posture. More than one million people suffer from the effects of this disease in Europe today, and this is forecast to double by 2030. Economically, the impact is significant: Parkinson's costs Europe an estimated € 14 billion a year.
IMPACT is an innovative European Union (EU)-funded research project which aims to improve the quality of life of Parkinson’s disease patients. Its goal is to develop new brain-mapping and brain-stimulation techniques, so they can bring an unprecedented degree of “customisation” to the way each individual patient is treated.
Although there is currently no cure for Parkinson’s disease, its symptoms are treatable. These treatments, however, have serious limitations. Drugs can be used, but they diminish in effectiveness over time and are expensive. Deep Brain Stimulation (DBS) offers a solution when drugs fail. Often described as a “pacemaker for the brain”, DBS works by inserting a probe with tiny electrodes into the brain to deliver mild electric stimuli to restore or improve brain function. But this method is also far from ideal. Still in its infancy, DBS causes significant side-effects in as many as 30% of patients. These side-effects are caused when areas of the brain next to the target area are stimulated unintentionally, and can include speech difficulties, mood swings and blurred vision.
Led by Sapiens Steering Brain Stimulation B.V., a specialised medical device company based in Eindhoven in The Netherlands, the IMPACT project team brings together eight industrial and academic research partners from five European countries. The project team aims to develop a system of imaging and mapping each patient’s brain, to enable personalised optimisation (“tuning”) of DBS therapy in a reliable and efficient manner. In combination with a novel high-resolution DBS probe, the use of dozens of electrodes manufactured with micro-fabrication technology means that the electrical stimulation can be “shaped” precisely to the target area in the brain to deliver the right therapy.
Given that this target area can be just a few millimetres in diameter, and be positioned 10cm down in the brain, the degree of targeting required is highly precise and difficult to achieve. With previous DBS systems, all that was possible after the probe had been inserted was a limited degree of movement up or down, but nothing more precise. If side-effects occurred, adjustment took the form of reducing the power applied to the probe. But while this reduced the area that received the stimulus, it also decreased the beneficial effect on the desired target area.
In the words of Hubert Martens, the Director of Clinical Science and Applications at Sapiens, and one of the company’s co-founders: “Because the stimulation field can be precisely steered, it can be shaped to exactly match the target area. This is something radically new. We expect this will avoid the side-effects of DBS, but without compromising the effectiveness of the treatment,” he explains.
“By using high-quality imaging and high-resolution brain recordings to create a functional map of the brain”, adds Dr Martens, “it is also possible, for the first time, to gather and collate information from the brains of different patients, to overlay them on each other, and use this collective experience to help fine-tune and improve the use of the new Sapiens probe,” he says.
It is expected that the new “personalised” DBS system will also be beneficial for other conditions for which DBS is known to be effective. These include epilepsy, dystonia and Obsessive Compulsive Disorder.