Decisional impairment (IOWA gambling task) in Parkinson’s disease patients with active and remitted pathological gambling behavior

Among the non-motor features of Parkinson Disease (PD), impulsive-compulsive behaviours such as Pathological Gambling (PG) have been described in the last decade. These abnormal behaviours occur in about 14%-25% of the patients and their relation with Dopamine Replacement Therapy (DRT) and cognitive features of PD is still debated. Stable remission from PG has been described in about 40% of the PD PG patients but few studies explored this topic. We studied the decisional process in non demented PD patients with PG, patients who remitted from PG and those who never gambled (CNTR) using the IOWA Gambling Task (IGT). We also evaluated electrophysiological activity (EEG) during the performance. We included in the study non-demented patients with PD treated with stable DRT. We enrolled 14 patients with PG, 10 patients who developed PG in the course of the disease but that were in stable remission (ex-PG) and 18 patients who never gambled. Gambling behaviour was evaluated by clinical interview and QUIP rating scale for the assessment of impulsive compulsive behavior in PD; we also asked to caregivers about patient’s gambling attitude. A short cognitive and behavioural assessment was conducted in order to generally evaluate cognitive status. Decision making abilities were evaluated using the IGT and electrophysiological correlates were recorded. The analysis of IGT performances revealed many differences between groups: PG group had worse performances in the IGT total score and did not show any learning effect among blocks. PG showed also a tendency to prefer disadvantageous decks and they more frequently chose the most disadvantageous compared to the other two groups. Interestingly, ex-PG group results were similar but not as good as those of CNTR. However both ex-PG and CNTR showed a good learning trend and had better total scores than PG. Therefore, whereas the performances of PG group were clearly pathological in term of decisional processes, the data on ex-PG are new and interesting since it seems they are more close to PD who never gambled than to active gamblers as if the decisional process could be partially restored.