Functional imaging studies of Impulse Control Disorders in Parkinson’s disease need a stronger neurocognitive footing

Abstract

HighlightsThe number of neuroimaging studies on PD‐ICDs is small and results are inconsistent.Multiple abnormalities have been observed in the mesocorticolimbic system and beyond……but were not associated with specific neurocognitive processes.Accurate psychological models are needed to track the neurocognitive bases of ICDs.Future studies should use refined behavioral tasks and adapted neuroimaging methods. ABSTRACT Impulse control disorders (ICDs) in Parkinson s disease (PD) are associated with dopaminergic dysfunction and treatment, but have no satisfactory therapeutic solution. While studies assessing the neurofunctional bases of ICDs are important for advancing our understanding and management of ICDs, they remain sparse and inconsistent. Based on a systematic analysis of the neuroimaging literature, the present review pinpoints various abnormalities beyond the mesocorticolimbic circuit that supports reward processing, suggesting possible dysfunction at the sensorimotor, executive and affective levels. We advocate that: 1) Future studies should use more sophisticated psychological models and behavioral designs that take into account the potentially multifaceted aspect of ICDs; this would allow a more accurate assessment of the underlying neurocognitive processes, which are not all dependent on the dopaminergic system. 2) Future neuroimaging studies should rely more strongly on task‐based, event‐related analyses to disentangle the various mechanisms that can be dysfunctional in ICDs. We believe these guidelines constitute a prerequisite towards distinguishing causes, correlates and individual susceptibility factors of PD patients with ICDs.