Disrupted salience network dynamics in Parkinson's disease patients with impulse control disorders

Dynamic functional network analysis may add relevant information about the temporal nature of the neurocognitive alterations in PD patients with impulse control disorders (PD-ICD). Our aim was to investigate changes in dynamic functional network connectivity (dFNC) in PD-ICD patients, and topological properties of such networks. Resting state fMRI was performed on 16 PD PD-ICD patients, 20 PD patients without ICD and 17 healthy controls, whose demographic, clinical and behavioral scores were assessed. We conducted a group spatial independent component analysis, sliding window and graph-theory analyses. PD-ICD patients, in contrast to PD-noICD and HC subjects, were engaged across time in a brain configuration pattern characterized by a lack of between-network connections at the expense of strong within-network connections (State III) in temporal, frontoinsular and cingulate cortices, all key nodes of the salience network. Moreover, this increased maintenance of State III in PD-ICD patients was positively correlated with the severity of impulsivity and novelty seeking as measured by specific scales. While in State III, these patients also exhibited increased local efficiency in all the aforementioned areas. Our findings show for the first time that PD-ICD patients have a dynamic functional engagement of local connectivity involving the limbic circuit, leading to the inefficient modulation in emotional processing and reward-related decision-making. These results provide new insights into the pathophysiology of ICD in PD patients and indicate that the dFC study of fMRI could be a useful biomarker to identify patients at risk to develop ICD. •Is the first work showing dFC alterations and graph properties in PD-ICD patients.•PD-ICD patients were engaged in a brain configuration pattern with strong connections in frontotemporal and cingulate areas.•This increased permanence was directly correlated with the severity ofimpulsivity and novelty-seeking in PD-ICD patients.•PD-ICD patients exhibited increased local efficiency in all these aforementioned areas, all key nodes in the salience network.•dFC analysis could be used to identify PD patients at risk of developing ICD when treated with dopaminergic drugs.