INTERVIEW
It concerns less than 200,000 patients in France and represents the second most frequent neurodegenerative disease behind Alzheimer’s disease. Parkinson’s disease affects nearly 8,000 new patients each year, according to figures from Inserm (National Institute for Health and Medical Research). Currently incurable disease, there are however treatments to reduce symptoms such as tremors or pain. Professor Philippe Damier, neurologist at Nantes University Hospital and vice-president of the scientific committee of the France Parkinson association takes stock of Europe 1.
A first treatment to relieve symptoms
“The heart of the disease is a small population of cells”, first summarizes the professor. “Approximately 500,000 cells have the particular property of making a molecule: dopamine. This dopamine is important for carrying out everyday learned gestures: speaking, eating, walking, etc.”. Thus, for patients, these cells age faster and no longer produce enough dopamine for the brain, hence the various symptoms of the disease: tremors, pain, gestural difficulties. This disease develops on average around the age of 70, but 20% of patients trigger this disorder before 65, explains Philippe Damier.
Current treatments are “symptomatic”, that is, they act on the symptoms but not on the disease as such. They thus consist in providing the patient’s brain with the missing dopamine. There are two categories of drug treatments, which can be administered daily as patches or tablets: Levodopa or L-Dopa, or dopamine agonists, “which enter the brain, attach to and mimic dopamine receptors. the effect, “says the professor.
But the patient can be bothered by various side effects: drowsiness, confusion and hallucination in older patients, nausea or even compulsive behavior in some cases. Nevertheless, the response is effective in the context of the disease. “At the start of the disease, if the patient only has Parkinson’s and is not too old, all the symptoms will disappear,” he emphasizes. “It will last an average of 8 to 10 years.”
Change the method of drug admission
“After a few years, the response to treatment is less constant during the day”, explains Philippe Damier, who mentions “fluctuations”. At this time, for the patient, the question arises of a second-line treatment, which refers to the treatment administered after the first-line treatment (or initial treatment), when the latter does not or no longer work.
To prevent these fluctuations, the different drugs can thus be administered in a different form, using a pump, “which will administer the treatment subcutaneously and very continuously”, explains the professor. Injector pens can also be used.
Surgery in some cases
Patients can also benefit, under certain conditions, from a brain surgery operation called “deep brain neurostimulation”. This French discovery, also known as deep brain stimulation (SCP), by Professor Alim-Louis Benabid and Professor Pierre Pollak in the years 1980-1990, involves implanting electrodes in the brain during a surgical operation, connected by a subcutaneous cable and a battery placed under the skin, like a pacemaker.
“This stimulator will cause a continuous electric shock in a very specific nucleus, and this will regulate the dysfunctions of this nucleus caused by the lack of dopamine”, adds Philippe Damier. Stimulation of the electrodes makes it possible to regulate certain dysfunctions.
About 5 to 10% of patients can benefit from this heavy treatment and must first meet criteria: the motor signs are not too developed, it is Parkinson’s disease and not a parkinsonian symptom or even the patient is less than 70 years old.
Ongoing research
In addition to existing treatments, medical research is still working to discover new therapies. The France Parkinson association, whose mission is in particular inform patients about the disease, its treatments and its side effects, also finances part of it to the tune of one million euros per year.
“One of the best hopes today relates to immunotherapies, in a way a vaccine”, explains the professor. “In the disease there is an abnormally accumulating protein called alpha-synuclein. Patients are injected with monoclonal antibodies to try to remove these abnormally aggregated proteins in their brains.” To put it simply, this protein, in some forms, plays a role in the onset of Parkinson’s disease. Immunotherapy consists of helping the development of antibodies or inoculating the patient with artificial antibodies that will recognize alpha-synuclein, attach to it and promote its elimination.
This protocol is still in phase 2 of research, that is to say the early phase of therapeutic trial in humans. “We have some encouraging signals”, confides Professor Philippe Damier. “Within 3 to 5 years, we could hope to have this treatment which would make it possible to slow down the progression of the disease and prevent certain complications that today we do not know how to treat.”
–
