Impulse Control Disorders in Parkinson’s Disease

A" was diagnosed with Parkinson's disease at 51 years of age, 5 years after seeing a neurologist for a variety of symptoms, ranging from assumed complications of bulging vertebral discs, cervical radiculopathy, headaches, and carpal tunnel syndrome.Ultimately, she was referred to a movement disorders neurologist who assessed her pain, decreased left upper extremity dexterity and arm swing, gait stiffness and weakness, and rigidity, as well as prominent depression and anxiety symptoms, and she received a diagnosis of mild idiopathic Parkinson's disease (stage 1.5 on the Hoehn and Yahr scale).She received a prescription for a dopamine agonist (pergolide) as part of an openlabel monotherapy study for young-onset Parkinson's disease.However, she began to experience gastrointestinal side effects, and, in an effort to delay initiating levodopa therapy, her neurologist prescribed another dopamine agonist, pramipexole, at a dosage of 0.25 mg t.i.d.Pramipexole resulted in improvement in parkinsonism without gastrointestinal upset.After approximately 4-6 months of pramipexole treatment, the patient noticed that sporadic trips to casinos with friends became more frequent, lasted longer than a few hours, and involved spending, on slot machines, more than her allotted $40 per trip.While at the casino, it became increasingly difficult for Ms. A's spouse to persuade her to leave.She would feel euphoric while gambling, and she used her winnings for continued gambling.Given that she was by nature a conscientious and responsible individual with no history of significant gambling, this behavior was out of character.She did have chronic depression and anxiety symptoms that long predated onset of Parkinson's disease and had been managed over the years with various psychotropic medications (including bupropion at the time of impulse control disorder onset) and psychotherapy.She asked her neurologist if pramipexole was linked to personality changes or compulsive behaviors and was informed that it was not a potential side effect.Over the course of the next 2 years, Ms. A's thrice-daily dose of pramipexole was gradually increased to 0.5 mg, then 0.75 mg, and finally 1 mg.During that period, Ms.A gambled away $1 million dollars and gained 40 pounds.