Functional correlates of response inhibition in impulse control disorders in Parkinson’s disease

• Published in: NeuroImage clinical 2021-01, Vol.32, p.102822-102822, Article 102822
• Main Authors: Esteban-Peñalba, Teresa, Paz-Alonso, Pedro M., Navalpotro-Gómez, Irene, Rodríguez-Oroz, María C.
• Format: Article
• Language: English
• Subjects: Attention; Brain - diagnostic imaging; Disruptive, Impulse Control, and Conduct Disorders - diagnostic imaging; Disruptive, Impulse Control, and Conduct Disorders - etiology; Humans; Impulse control disorders; Inhibitory control; Magnetic Resonance Imaging; Parkinson Disease - diagnostic imaging; Parkinson’s disease; Quality of Life; Regular
• ISSN: 2213-1582; 2213-1582
• DOI: 10.1016/j.nicl.2021.102822

•PD patients with ICD behave like controls in proactive and reactive inhibition.•PD patients with ICD recruit different mechanisms depending on the inhibition type.•Proactive inhibition is executed hyperactivating the stopping network bilaterally.•Restrained inhibition is accomplished with the coactivation of attentional areas.•In restrained inhibition, connectivity between right STN and precuneus is reduced. Impulse control disorder is a prevalent side-effect of Parkinson’s disease (PD) medication, with a strong negative impact on the quality of life of those affected. Although impulsivity has classically been associated with response inhibition deficits, previous evidence from PD patients with impulse control disorder (ICD) has not revealed behavioral dysfunction in response inhibition. In this study, 18 PD patients with ICD, 17 PD patients without this complication, and 15 healthy controls performed a version of the conditional Stop Signal Task during functional magnetic resonance imaging. Whole-brain contrasts, regions of interest, and functional connectivity analyses were conducted. Our aim was to investigate the neural underpinnings of two aspects of response inhibition: proactive inhibition, inhibition that has been prepared beforehand, and restrained inhibition, inhibition of an invalid inhibitory tendency. We observed that, in respect to the other two groups, PD patients with ICD exhibited hyperactivation of the stopping network bilaterally while performing proactive inhibition. When engaged in restrained inhibition, they showed hyperactivation of the left inferior frontal gyrus, an area linked to action monitoring. Restrained inhibition also resulted in changes to the functional co-activation between inhibitory regions and left inferior parietal cortex and right supramarginal gyrus. Our findings indicate that PD patients with ICD completed the inhibition task correctly, showing altered engagement of inhibitory and attentional areas. During proactive inhibition they showed bilateral hyperactivation of two inhibitory regions, while during restrained inhibition they showed additional involvement of attentional areas responsible for alerting and orienting.