Parkinson's disease: Brain pacemaker keeps impulsive behavior in check
Parkinson's disease is an incurable, chronic, progressive disease of the central nervous system. However, there are treatment options that make life with Parkinson's more tolerable. Among other things, patients can benefit from a brain pacemaker.
Second most common neurodegenerative disease in Germany
According to the German Society for Neurology (DGN), Parkinson's disease is one of the most common diseases of the central nervous system. According to estimates, over 400,000 people are affected in Germany. Parkinson's is the second most common neurodegenerative disease after Alzheimer's. The nerve disease is still incurable to this day, but there are therapy options that make life more tolerable for those affected. Deep brain stimulation (THS) not only alleviates movement disorders but also stabilizes mood, as researchers have now found, in advanced Parkinson's disease.
Deep brain stimulation improves the state of mind
As the DGN and the Deutsche Parkinson Gesellschaft (DPG) report in a joint press release, the additional evaluation of a German-French study (EARLYSTIM) published in the specialist magazine "Lancet Neurology" refutes the fear that the operative procedure contributes to emotional fluctuations and disturbances in the impulse control Parkinson's patients could worsen.
“On the contrary: The evaluation of the EARLYSTIM study shows that fluctuations under stimulation treatment actually decrease. The THS improves the condition significantly and to an extent that cannot be achieved with medication alone, ”says Professor Dr. Günter Deuschl from the DGN.
"The study provides good arguments for recommending THS for selected patients with neuropsychiatric fluctuations or impulse control disorders," commented Professor Rüdiger Hilker-Roggendorf, chief physician of the Clinic for Neurology at the Klinikum Vest (Recklinghausen) and member of the board of the DPG.
150,000 patients successfully treated
Parkinson's disease is a chronically progressive disease in which, among other things, cells in the so-called black substance (substantia nigra) die in the brain. These cells produce the messenger substance dopamine, which e.g. is important for controlling motor skills.
If dopamine is absent, the typical motor symptoms appear, such as slowing down the speed of movement, small steps, speech disorders, tremors and stiffness in the arms and legs.
Deep brain stimulation (THS) - sometimes referred to as a "brain pacemaker" - can help if the movement disorders can no longer be adequately controlled by medication.
In an operation, microelectrodes are then implanted in the brain, which inhibit certain brain regions with weak current surges. More than 150,000 patients have already been successfully treated with this method worldwide.
Impulse control disorders are common
However, some experts feared that the procedure could increase the risk of uninhibited behaviors such as gambling addiction and shopping spree or uninhibited sexuality.
Without an in-depth investigation, it was impossible to distinguish whether the cause of these so-called hyperdopaminergic disorders was the disease itself or the electrical stimulation.
However, a study with 251 Italian Parkinson's patients who already suffered from motor complications from drug therapy (dyskinesia) had recently shown that impulse control disorders are common:
The proportion of those affected with impulse control disorder was 55 percent, in 36 percent of the cases this was classified as clinically significant.
"The present sub-analysis of the EARLYSTIM study shows with high scientific evidence that disorders of behavior and mood regulation can improve if the patient receives THS early and the dosage of drug treatment can then be reduced," says Professor Hilker-Roggendorf .
Quality of life improved
The first results of the study, funded by the German and French ministries of health and the brain pacemaker manufacturer, were published five years ago.
At that time, the researchers led by co-study director Professor Deuschl had made quality of life the central objective of the study.
Parkinson's patients who were additionally treated with deep brain stimulation had a higher quality of life than those who only received medication.
Less mood swings, better impulse control
The follow-up evaluation now shows that under a THS the emotional fluctuations of the patients are also improved. In patients who were only given medication, the neuropsychiatric fluctuations remained unchanged.
Under an additional THS, the corresponding value on the Ardouin Scale (Ardouin Scale of Behavior in Parkinson's Disease) decreased by 0.65 points.
The difference was also very large for hyperdopaminergic behavior disorders (impulse control disorders, hypomania, volatility): with THS, the value decreased by 1.26 points - compared to an increase of 1.12 points if the patients only received medication.
On the other hand, no difference was found in so-called hypodopaminergic behavior disorders such as apathy and depression, regardless of whether the patients were only given medication or additionally the THS.
"The study answers important questions about the therapy of Parkinson's patients who suffer from an unstable disease with mood swings and behavioral disorders," says Professor Hilker-Roggendorf.
“Impulse control disorders caused by medication can improve under THS, apathy and depression do not increase under THS. With suitable patients, the THS can be used with good efficacy and sufficient safety even in the middle stage of the disease. ”(Ad)