Dopamine dysregulation syndrome, otherwise known as hedonistic homeostatic dysregulation in Parkinson's disease, is a disorder characterized by the degeneration of the dopaminergic system. The condition commonly occurs in people with Parkinson's disease who have had long-standing exposure to dopaminergic drugs. These individuals develop an abnormality of the internal impulse control system. This syndrome manifests with addiction to levodopa and behavioral disturbances associated with the impulse control or reward system.
Role of Dopamine in Parkinson's Disease
Parkinson's disease is a degenerative neurological disorder that compromises balance, movement and muscle control. This disease is a member of a larger group of diseases known as motor system disorders. Motor system disorders result in the loss of dopamine-producing cells. Parkinson's disease evolves as certain parts of your brain stem deteriorate. According to the book "Parkinson's Disease: A Complete Guide for Patients and Families," dopamine deficiency is a primary characteristic of Parkinson's. Dopamine is a neurotransmitter that allows your body to respond to stress, and your memory and concentration require dopamine to function properly.
Parkinson's Disease and Dopamine Replacement Therapy
Dopamine replacement therapy aims at improving motor symptoms in Parkinson's patients, but it can cause behavioral disturbances in some. Doctors call this altered behavior "incentive or reward-based repetitive symptom" or "dopamine dysregulation syndrome." Behaviors associated with DDS include hypersexuality, compulsive eating, pathological gambling, compulsive shopping and compulsive drug use. It is not clear whether the symptoms result entirely from the dopamine replacement therapy medications or if the disease itself plays a role.
DDS and the Reward System
Administration of levodopa, or L-dopa, is a primary treatment for Parkinson's. L-dopa is the precursor of dopamine. Dopamine plays a critical role in your reward system. With long-term use of L-dopa, the reward system may become dependent on the drug and require higher quantities. As you increase your L-dopa intake, your dopaminergic receptors start to deteriorate. This leads to impairment of the goal-direction mental functions.
Prevention and Management
According to the book "Comprehensive Nursing Care for Parkinson's Disease," to prevent the onset of DDS, doctors will typically prescribe the minimum effective dopamine doses. The book further states that management of this disorder involves reducing the L-dopa dosage, and many patients respond positively to this measure. Some behavioral symptoms can also improve through psychotherapy and social support.
References
- "Comprehensive Nursing Care for Parkinson's Disease"; Lisette K. Bunting-Perry, et al.; 2007
- "The Non-Motor Symptoms Complex of Parkinson's Disease"; K Ray Chaudhuri, et al.; 2009
- "Ask the Doctor About Parkinson's Disease"; Michael S. Okun, et al.; 2009
- "Parkinson's Disease"; William J. Weiner, et al.; 2006
