The neural correlates of falls: Alterations in large-scale resting-state networks in elderly fallers

Introduction: Falls are associated with numerous risk factors, such as motor and cognitive impairments. However, the neural correlates of falls are poorly understood. Objectives: Here, we aimed to assess patterns of structural, and resting-state functional connectivity (FC) alterations related to falls in a group of older adults with a history of falls compared to non-fallers. Methods: Fourteen elderly fallers (mean age = 78.1 +/- 1.5 yrs, > 2 falls previous six months), and 20 healthy controls (mean age = 69.6 +/- 1.3 yrs) were examined. All participants underwent a 3T MRI scan obtaining 3D T1-weighted images, and eyes-open resting-state (rs)-fMRI. Voxel-based morphometry was conducted to detect grey matter differences between the groups. Independent component analysis was conducted based on rs-fMRI and number of attention-and-motor related functional networks was identified and compared between groups using an independent-sample T-test. Results: No differences were observed in grey matter between the groups after correcting for age and gender (p > 0.01, FWEc). Compared with non-fallers, the fallers had lower FC in cerebellar, frontal and parietal cortical nodes within the sensorimotor network (SMN), lateral motor network (M1), Cerebellar network (CBL), frontalstriatal network (FSN), executive control network (ECN), and dorsal attention network (DAN). Moreover, fallers had increased FC in the basal ganglia network (BGN), Left paracentral in M1 and SMN, and right hippocampus in DAN (p< 0.01, FWEc). Conclusions: Among fallers, reduced connectivity was observed in areas that relate to integration of information, while increased connectivity was found in areas associated with motor and sensory information processing. Together, these results provide evidence to the complex multidimensionality of the neural underpinnings of falls. Furthermore, these findings may help emphasize the importance of interventions that target both motor and cognitive aspects.