FUNCTIONAL MRI AND GAIT ANALYSIS CHARACTERISTICS IN PATIENTS WITH ISOLATED REM SLEEP BEHAVIOR DISORDER

Introduction

Clinical, gait analysis, and MRI features might predict the conversion from idiopathic REM sleep behavioral disorder (iRBD) to clinically manifested alpha-synucleinopathies [1, 2]. The aims of this study were to assess gait analysis, neurological, neuropsychological and resting-state functional MRI (RS-fMRI) functional connectivity (FC) characteristics in iRBD patients and to study the correlations between clinical features and RS-fMRI alterations.

Methods

Ten patients with a polysomnography-confirmed iRBD underwent clinical, cognitive, and RS-fMRI evaluations. Ten age/sex-matched healthy controls underwent neuropsychological evaluation and RS-fMRI. Gait analysis was performed using a stereophotogrammetric system to assess asymmetry of spatio-temporal gait parameters during a four-meter walking test with and without a cognitive dual-task.

Results

IRBD patients showed mild asymmetry of spatio-temporal gait parameters, particularly during dual-task gait. IRBD patients showed an increased FC in the right executive control, sensorimotor and dorsal default mode networks compared to healthy controls. Basal ganglia and cerebellar networks showed reduced FC. Correlation analyses showed that an increased asymmetry in the lower limb swing time during gait correlated with an increased FC in the right executive control network, whereas an increased asymmetry of lower limb stride length during dual-task gait correlated with an increased FC in the sensorimotor network.

Discussion and Conclusion

This study suggested that RS-fMRI and gait analysis characteristics could be promising biomarkers for early alpha-synucleinopathy detection and prediction. The collection of longitudinal data in a larger sample will allow the assessment of conversion from iRBD to parkinsonian syndromes and to test a multifactorial prediction model combining fMRI, gait analysis, clinical and neuropsychological data.

Funding: Italian Ministry of Health [grant number # RF-2018-12366746]

REFERENCES

[ 1 ] Ferini-Strambi L, et al. REM sleep Behaviour Disorder. Parkinsonism and Related Disorders. 2016. Doi: 10.1016/j.parkreldis.2015.09.002

[ 2 ] Galbiati A, et al. The risk of neurodegeneration in REM sleep behavior disorder: A systematic review and meta-analysis of longitudinal studies. Sleep Medicine Reviews. 2019. Doi: 10.1016/j.smrv.2018.09.008