Sex differences in the structural rich-club connectivity in patients with Alzheimer's disease.

Background And Objectives: Alzheimer's disease (AD) is more prevalent in women than in men; however, there is a discrepancy in research on sex differences in AD. The human brain is a large-scale network with hub regions forming a central core, the rich-club, which is vital to cognitive functions. However, it is unknown whether alterations in the rich-clubs in AD differ between men and women.

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.