Impulse Control Disorders (ICD) and Parkinson Disease (PD) Sotirios A. Parashos, MD, PhD Minneapolis Clinic of Neurology and Struthers Parkinson’s Center

Disclaimer This presentation contains discussion of use of medications for indications not approved by the FDA

What are ICDs? Disorders characterized by impulsivity Impulsivity is a tendency to engage in behaviors that offer a small temporary gain despite the fact that they lead to a much greater long term loss People with ICD are repeatedly unable to resist these behaviors In Psychiatry ICDs are classified with Obsessive Compulsive Disorders They are often associated with substance use disorders

What are the symptoms? Pathological gambling Hypersexuality Hoarding Compulsive or binge eating Compulsive shopping Punding Dopamine dysregulation syndrome (DDS) Excessive hobbying Drug addiction

What are ICBs and how are they different from ICDs? Impulsive behaviors may not necessarily be classified as a “disorder” Psychiatrists consider certain behaviors as a disorder, only if the behavior impairs the person’s normal functioning The term “impulse control and compulsive behaviors” has also been used in the PD literature, as some of these behaviors may be relatively “benign”

Why in PD? Dopamine is the “feel good” chemical in our brain (a function of the D-3 type dopamine receptors in the limbic system – the “emotional brain”) PD affects a person’s “executive functions”, one of which is inhibition control; the subthalamic nucleus, a cluster of cells in the brain inactivated by DBS plays a role in inhibition control. Depressive traits, common in PD, are a well known risk factor for ICDs The combination of decreased inhibition control, a “negative” affect, and a “feel good about it” effect from dopamine-like drugs used to treat PD can result in impulse control disorders Similar behaviors are often seen in cocaine addiction – cocaine exerts some of its actions through dopamine in the brain

What brings on ICDs in people with PD? Drugs: Dopamine agonists (pramipexole, ropinirole, rotigotine, piribedil, cabergoline): ICDs have been reported with these medications in people without PD who take them for RLS, or pituitary hormonal disorders L-dopa Selegiline Amantadine Deep Brain Stimulation Surgery (DBS)

How often do they happen? Part 1 Multiple studies in PD have reported a frequency of ICDs and ICBs of up to 14% In one series of 159 persons with PD undergoing DBS: 28 qualified for a diagnosis of ICD or DDS 17 developed the problem after the surgery (Moum et al. PLoS One. 2012;7(1)) In a study of 140 people with restless legs syndrome (RLS) 10 had ICDs – suggesting that drug treatment is an important, independent factor 8/10 were taking a dopamine agonist 2/10 were taking l-dopa (Voon et al. BMC Neurol. 2011 Sep 28;11:117 )

How often do they happen? Part 2 In PD the following frequencies have been reported: Pathological gambling: 3.4 – 8 % Hypersexuality: 2 – 3.5 % Punding: 1.4 – 4.2 % DDS: 3.4 – 4.1 % Compulsive shopping: 3.4 – 5.7 % Binge eating: 4.3 %

What can be done about ICDs? Step 1 Prevention first! An informed patient/care-partner Assessment of risk factors (personality traits, depression, support system) before prescribing dopamine agonists If ICB is not problematic, a frank discussion with carepartner and doctor may be all that’s needed

What can be done about ICDs? Step 2a Reduce the dose of the suspected drug Sometimes that is sufficient – if not, then Discontinue the suspected drug Switch to a different drug If the drug is absolutely necessary, then add a medication to help control the ICD SSRI and SNRI antidepressants Atypical antipsychotics (like quetiapine) Anticonvulsants (like carbamazepine) Opioid antagonists (like naloxone) Amantadine (?!)

What can be done about ICDs? Step 2b Assess the psychological factors that may be contributing and consider counseling Cognitive behavioral therapy Family/carepartner/provider interventions Limit access to credit cards, bank accounts etc. for pathological gambling and shopping Minimize junk food, snacks etc. in the home and work environment for overeating Special medications affecting sexual function may work for hypersexuality Strict control of prescriptions, alerting the pharmacist and allowing only one doctor to prescribe l-dopa for DDS