L-DOPA is a precursor capable of crossing the blood-brain barrier, the cellular barrier responsible for protecting the brain.
Dopaminergic agonists, i.e. molecules with the same effect as dopamine. They can also be delivered subcutaneously (apomorphine pump), providing a more regular and continuous treatment that balances the patient better. In this case, it is a treatment for forms that have progressed for a longer period of time (“second-line treatment”).
These treatments for Parkinson’s improve patients’ quality of life and delay the motor progression of the disease. However, depending on the patient, they can have more or less intense and frequent side-effects.
Drug treatments for Parkinson’s disease: side effects
These side-effects may include nausea, vomiting, a drop in blood pressure, drowsiness, hallucinations or abnormal perception of reality, compulsive use of the drugs, all of which should prompt you to consult your GP.
The best known of these side effects are impulse control disorders, observed in 20% of patients taking dopaminergic agonists. These disorders can take the form of addiction to games, shopping, eating disorders, hypersexuality or risky behaviour, for example.
Some of these disorders can be reversed by reducing the dose of treatment, but may require the patient to stop taking the drug altogether.
At the Paris Brain Institute
A study coordinated by Professor Jean-Christophe CORVOL, director of the clinical investigation centre and team leader at the Institut du Cerveau, involved a cohort of 400 patients recruited from all over France through the French Parkinson’s disease clinical research network (NS-PARK/FCRIN). The patients were monitored for 5 years in order to assess their symptoms, readapt treatments and identify the appearance of behavioural problems. This study shows that the onset of behavioural problems increases with the duration of Parkinson’s disease. At baseline, 20% of patients had behavioural problems, compared with 33% after 5 years. Among patients with no disorders at the start of the study, almost 50% developed them during the 5 years of follow-up.
These observations indicate that regular monitoring of patients undergoing Parkinson’s therapy is essential. With this in mind, the AD SCIENTIAM start-up incubated at the Institut du Cerveau is making it possible to study fluctuations in the symptoms of the disease on a daily basis in patients’ homes in real life. This device is currently being tested on the NS-PARK cohort, with the aim of facilitating the implementation of appropriate therapies by neurologists.
Treatment of the various disorders associated with Parkinson’s disease
Late gait disorders can be treated with Deep Brain Stimulation (DBS). In this therapy, an electrode is implanted in the target brain region, most often in the subthalamic nucleus or medial pallidum. This implantation is very often carried out under local anaesthetic in order to adjust the location of the electrode for optimum symptom reduction. The implanted electrode acts in the same way as a pacemaker, delivering regular high-frequency electrical impulses. Stimulation of the thalamus, for example, reduces resting tremor in 80% of cases.
Stimulation of the medial pallidum reduces abnormal involuntary movements in an average of 60% of patients. Stimulation of the subthalamic nucleus results in a 60% reduction in the motor symptoms characteristic of Parkinson’s syndrome.
At the Paris Brain Institute
The team led by Dr Carine KARACHI and Brian LAU at the Institut du Cerveau is studying the anatomy of the subcortical region with the ultimate aim of developing new therapies and applications for deep brain stimulation.
Le laboratoire commun Brain e-NOVATION à l’Institut du Cerveau a développé un jeu thérapeutique “Toap Run” visant à améliorer les troubles de l’équilibre et de la marche des patients atteints de la maladie de Parkinson. Dans ce jeu interactif, le patient doit réaliser des mouvements qui concernent l’ensemble du corps et la motricité axiale en particulier, avec des mouvements latéraux, des mouvements du tronc afin de récolter un maximum de pièces en évitant les obstacles.