title: Impaired Functional Connectivity Unmasked by Simple Repetitive Motor Task in Early Relapsing-Remitting Multiple Sclerosis.
abstract: BACKGROUND
  Resting brain activity can be modulated by motor tasks to adapt to function. In multiple sclerosis (MS) patients, altered resting-state functional connectivity (RS-FC) has been reported and associated with impaired function and disability; little is known on how RS-FC is modulated by a simple repetitive motor task.
  
  
  OBJECTIVE
  To assess changes in RS-FC in early relapsing-remitting MS (RRMS) patients associated with repetitive thumb flexions (RTFs).
  
  
  METHODS
  A total of 20 right-handed patients with early RRMS and 14 healthy controls underwent a resting functional magnetic resonance imaging (fMRI) scan, before and after 25 minutes of alternate 30-s blocks of right RTF and rest. Dual-regression analysis of resting fMRI data followed the independent component analysis. Individual spatial maps of coherence between brain areas for 2 networks of interest, sensorimotor and cerebellar, were compared at the group level and correlated with measures of both clinical impairment and brain damage.
  
  
  RESULTS
  Significant RTF-induced differences in RS-FC were observed between groups in the cerebellar network because of increased RS-FC in patients but not in controls. In the sensorimotor network, the RS-FC after RTF increased in both groups, with no significant between-group differences. The sensorimotor and the cerebellar RS-FC were intercorrelated only in patients and only after the RTF. The sensorimotor RS-FC increase in patients correlated with structural MRI alterations.
  
  
  CONCLUSIONS
  Our study unmasked RS-FC changes of motor-related networks occurring after a simple repetitive motor task in early RRMS patients only. Evaluation of altered RSN dynamics might prove useful for anticipating neuroplasticity and for MRI-informed neurorehabilitation.
authors.affiliation: Sapienza University, Rome, Italy IRCCS Santa Lucia Foundation, Rome, Italy petsas@gmail.com.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Petsas
authors.affiliation: IRCCS Santa Lucia Foundation, Rome, Italy Cardiff University, Cardiff, UK.
authors.forename: Valentina
authors.initials: V
authors.lastname: Tomassini
authors.affiliation: University of Oxford, Oxford, UK.
authors.forename: Nicola
authors.initials: N
authors.lastname: Filippini
authors.affiliation: Sapienza University, Rome, Italy IRCCS Santa Lucia Foundation, Rome, Italy.
authors.forename: Emilia
authors.initials: E
authors.lastname: Sbardella
authors.affiliation: Sapienza University, Rome, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Tona
authors.affiliation: Sapienza University, Rome, Italy.
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Piattella
authors.affiliation: Sapienza University, Rome, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Pozzilli
authors.affiliation: Cardiff University Brain Research Imaging Centre, Cardiff, UK.
authors.forename: Richard G
authors.initials: RG
authors.lastname: Wise
authors.affiliation: Sapienza University, Rome, Italy IRCCS Neuromed, Pozzilli (IS), Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Pantano
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D001931:Brain Mapping; D056324:Diffusion Tensor Imaging; D005260:Female; D066128:Gray Matter / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000473:pathology / Q000503:physiopathology*; D009434:Neural Pathways / Q000473:pathology / Q000503:physiopathology; D012044:Regression Analysis; D012146:Rest
keywords: fmri; functional connectivity; motor task; multiple sclerosis; resting state