Dysautonomia is associated with structural and functional alterations in Parkinson disease.

Objective: To investigate whether the presence of autonomic dysfunction is associated with white matter and functional connectivities and the level of cognitive performance in patients with de novo Parkinson disease (PD).

Methods: Seventy-five patients with de novo PD underwent a comprehensive autonomic function test and were classified into 2 groups according to the Composite Autonomic Severity Score (CASS; 30 with moderate to severe autonomic dysfunction [CASS 4-10, PD-AUT+] and 45 without significant autonomic dysfunction [CASS 0-3, PD-AUT-]). Network-based statistics and a graph theoretical analysis were performed to assess the interregional white matter connectivity using diffusion tensor imaging. We also performed analyses of resting-state functional connectivity and compared cognitive performance between the 2 groups.

Results: There were no significant differences in demographic characteristics and vascular risk factors between the PD-AUT+ and PD-AUT- groups. The PD-AUT+ group showed poorer cognitive performance on frontal/executive function than the PD-AUT- group. The PD-AUT+ group exhibited severely disrupted white matter connectivity in both fronto-subcortical and posterior cortical regions, which was well correlated with the severity of autonomic dysfunction assessed by the CASS. In addition, functional connectivity within the executive control network and dorsal attention network negatively correlated with the CASS.

Conclusions: Our results suggest that autonomic dysfunction is associated with disrupted white matter and functional brain connectivity as well as cognitive impairment in de novo patients with PD.