Fall risk is associated with amplified functional connectivity of the central executive network in patients with Parkinson's disease.

Abstract

Falls are debilitating problems that markedly impact the health-related quality of life of many patients with Parkinson's disease (PD). Numerous studies point to the role of executive function and attention in falls; however, the brain mechanisms underlying these relationships are less clear. Here, we aim to evaluate the brain mechanisms underlying the role of executive function in falls. Patients with PD who were fallers (n = 27) or non-fallers (n = 53) and 27 healthy older adults were examined in a cross-sectional study. Gray matter volumes of the caudate head and posterior putamen were evaluated, as these striatal regions play a role in the executive and the sensorimotor cortico-striatal networks, respectively. The functional connectivity of the central executive network and of the sensorimotor network was measured using intrinsic brain connectivity during resting state functional magnetic resonance imaging. Compared to non-fallers and healthy controls, fallers had lower gray matter volume in the caudate head, but not in the posterior putamen, and increased connectivity between posterior partial regions of the central executive network, with no difference within the sensorimotor network. Mediation analysis demonstrated that the relationships between caudate head gray matter volume and fall history and risk were mediated by increased connectivity within the central executive network, apparently via attentional changes. The above findings provide additional converging evidence for the involvement of executive-related brain changes in falls in PD and support the important role of attention and executive function in fall risk.