title: Hyperconnectivity of the dorsolateral prefrontal cortex following mental effort in multiple sclerosis patients with cognitive fatigue.
abstract: To investigate the dynamic temporal changes of brain resting-state functional connectivity (RS-FC) following mental effort in multiple sclerosis (MS) patients with cognitive fatigue (CF).
  
  
  
  Twenty-two MS patients, 11 with (F) and 11 without CF, and 12 healthy controls were included. Separate RS-FC scans were acquired on a 3T MR scanner immediately before (t0), immediately after (t1) and 30 minutes after (t2) execution of the paced auditory serial addition test (PASAT), a cognitively demanding task. Subjectively perceived CF after PASAT execution was also assessed. RS-FC changes were investigated by using a data-driven approach (the Intrinsic Connectivity Contrast-power), complemented by a priori defined regions of interest analyses.
  
  
  
  The F-group patients experienced stronger RS-FC at t2 between the left superior frontal gyrus (L-SFG) and occipital, frontal and temporal areas, which increased over time after PASAT execution. In the F-group patients, the L-SFG was hyperconnected at t1 with the left caudate nucleus and hypoconnected at t2 with the left anterior thalamus. These variations were correlated with both subjectively perceived and clinically assessed CF, and-for the left thalamus-with PASAT performance.
  
  
  
  The development of cortico-cortical and cortico-subcortical hyperconnectivity following mental effort is related to CF symptoms in MS patients.
authors: Neuroradiology Department, Neurocenter of Southern Switzerland, Lugano, Switzerland.
authors: Emanuele
authors: E
authors: Pravatà
authors: Neurology Department, Neurocenter of Southern Switzerland, Lugano, Switzerland.
authors: Chiara
authors: C
authors: Zecca
authors: Department of Neuroscience and Imaging, Institute for Advanced Biomedical Technologies, "G. D'Annunzio University" Foundation, Chieti, Italy.
authors: Carlo
authors: C
authors: Sestieri
authors: Department of Neuroscience and Imaging, Institute for Advanced Biomedical Technologies, "G. D'Annunzio University" Foundation, Chieti, Italy.
authors: Massimo
authors: M
authors: Caulo
authors: Neurology Department, Neurocenter of Southern Switzerland, Lugano, Switzerland/Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, Scientific Institute and University Ospedale San Raffaele, Milan, Italy.
authors: Gianna Carla
authors: GC
authors: Riccitelli
authors: Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, Scientific Institute and University Ospedale San Raffaele, Milan, Italy.
authors: Maria Assunta
authors: MA
authors: Rocca
authors: Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, Scientific Institute and University Ospedale San Raffaele, Milan, Italy.
authors: Massimo
authors: M
authors: Filippi
authors: Neuroradiology Department, Neurocenter of Southern Switzerland, Lugano, Switzerland.
authors: Alessandro
authors: A
authors: Cianfoni
authors: Neurology Department, Neurocenter of Southern Switzerland, Lugano, Switzerland Claudio.gobbi@eoc.ch.
authors: Claudio
authors: C
authors: Gobbi
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000503:physiopathology*; D063132:Connectome; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D005222:Mental Fatigue / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D017397:Prefrontal Cortex / Q000000981:diagnostic imaging / Q000503:physiopathology*
keywords: MRI; Multiple sclerosis; fatigue; frontal lobe; functional connectivity