Cervical Motion Alterations and Brain Functional Connectivity in Cervical Dystonia
Elisabetta Sarasso1, Daniele Emedoli2, Andrea Gardoni3, Lucia Zenere3, Elisa Canu3, Silvia Basaia3, Alberto Doretti5, Nicola Ticozzi6, Sandro Iannaccone2, Stefano Amadio4, Ubaldo Del Carro4, Massimo Filippi7, Federica Agosta8
1Neuroimaging Research Unit, Division of Neuroscience; Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal Child Health, IRCCS San Raffaele Scientific Institute; and University of Genoa, 2Department of Rehabilitation and Functional Recovery, 3Neuroimaging Research Unit, Division of Neuroscience, 4Neurophysiology Service, IRCCS San Raffaele Scientific Institute, 5Department of Neurology, RCCS Istituto Auxologico Italiano, 6Department of Neurology; and Department of Pathophysiology and Transplantation, "Dino Ferrari" Center, RCCS Istituto Auxologico Italiano; and Università degli Studi di Milano, 7Neuroimaging Research Unit, Division of Neuroscience; Neurology Unit; Neurorehabilitation Unit; and Neurophysiology Service, 8Neuroimaging Research Unit, Division of Neuroscience; and Neurology Unit, IRCCS San Raffaele Scientific Institute; and Vita-Salute San Raffaele University
Objective:
To assess kinematic and resting-state functional connectivity (FC) characteristics in CD patients relative to healthy controls.
Background:
Evaluating the neural correlates of sensorimotor control deficits in cervical dystonia (CD) is fundamental to plan the best treatment.
Design/Methods:
Seventeen CD patients and 14 age-/sex-matched healthy controls were recruited. Electromagnetic sensors were used to evaluate dystonic pattern, mean/maximal cervical movement amplitude and joint position error with eyes open and closed, and movement quality during target reaching. Resting-state functional MRI (RS-fMRI) was acquired to compare the FC of brain sensorimotor regions between patients and controls. In patients, correlations between motion analysis and FC data were assessed.
Results:
CD patients relative to controls showed reduced mean and maximal range of motion (RoM) in rotation both towards and against dystonia pattern and reduced total RoM in rotation both with eyes open and closed. They had less severe dystonia pattern with eyes open vs eyes closed. CD patients showed an altered movement quality and sensorimotor control during target reaching and a higher joint position error. Compared to controls, CD patients showed reduced FC between supplementary motor area (SMA), occipital and cerebellar areas, which correlated with lower cervical RoM in rotation both with eyes open and closed and with worse movement quality during target reaching.
Conclusions:
FC alterations between SMA and occipital and cerebellar areas may represent the neural basis of cervical sensorimotor control deficits in CD patients. Electromagnetic sensors and RS-fMRI might be promising tools to monitor CD and assess the efficacy of rehabilitative interventions.