Rossi PJ et al. – The study evaluated the hypothesis that in patients with Parkinson’s disease (PD) diagnosed with impulse control disorder (ICD), neurons in the subthalamic nucleus (STN) and globus pallidus internus (GPi) would be more responsive to reward–related stimuli and less responsive to loss–related stimuli and focused on the evidence implicating the STN and GPi in reward and punishment processing, and alliance of deep brain stimulation (DBS) of these structures with changes in ICD symptoms. These findings helped in providing evidence that STN is involved in impulsive behavior in population with PD.

Methods

• In total, 43 patients with PD (12 with an ICD and 31 without) undergoing DBS electrode placement surgery were included in the cohort study.
• Patients performed a behavioral task in which their action choices were motivated by the potential for either a monetary reward or a monetary loss.
• The activity of individual neurons was recorded during task performance in either STN (n = 100) or the GPi (n = 100).

Results

• Significantly greater proportions of reward–responsive neurons (P<.01) and significantly lower proportions of loss–responsive neurons (P<.05) in the STN (not in the GPi) was due to the presence of an ICD.