A 58-year-old man from Cumbria has had electrodes implanted his brain in order to treat his compulsive gambling.
Raymond Mandale (right), who suffers from Parkinson’s, claims that his gambling habit was caused by a prescribed drug he had been taking to alleviate the symptoms of his condition, and is now seeking compensation from the manufacturers of the drug.
Mandale’s case is not unprecedented. In the past few months, several Parkinson’s patients who began gambling compulsively after taking the dopamine agonist Mirapex have brought lawsuits against the pharmaceuticals companies involved.
Dopamine agonists are associated with various other compulsive behaviours too: it is estimated that up to 14% of Parkinson’s patients who take them experience binge eating, hypersexuality or compulsive shopping or gambling as side effects.
Parkinsonian patients are increasingly being treated with deep brain stimulation (DBS), the experimental technique that was used to treat Mandale, and they, too, often begin to behave compulsively following surgery.
This occurs because Parkinson’s involves degeneration of dopamine-producing cells in a part of the brain stem called the substantia nigra. These cells normally form connections with neurons in a nearby area called the subthalamic nucleus (STN), which is now known to play an important role in decision making.
Thus, although chronic stimulation of the STN is effective in treating Parkinson’s, perturbation of the cellular activity in this part of the brain can affect the decision making process, leading to compulsive behaviour. Likewise, so too can dopamine agonists, by their actions on receptors in the STN.