Journal article
Cerebellar and premotor activity during a non-fatiguing grip task reflects motor fatigue in relapsing-remitting multiple sclerosis
Fatigue is a common and highly disabling symptom of multiple sclerosis. Patients experience an effort-independent general subjective feeling of fatigue as well as excessive fatigability when engaging in physical or mental activity. Previous research using functional magnetic resonance imaging (fMRI) has revealed heterogeneous findings, but some evidence implicates the motor system.
To identify brain correlates of fatigue, 44 mildly impaired patients with relapsing-remitting multiple sclerosis and 25 age-and gender-matched healthy controls underwent functional magnetic resonance imaging at 3 Tesla, while they performed alternating blocks of rest and a non-fatiguing precision grip task.
We investigated neural correlates of fatigue using the motor subscore of Fatigue Scale for Motor and Cognitive Functions (FSMCMOTOR) using the bilateral motor cerebellum, putamen, and dorsal premotor cortex as regions of interest. Patients and healthy controls performed the grip force task equally well without being fatigued.
In patients, task-related activity in lobule VI of right motor cerebellum changed in proportion with individual FSMCMOTOR scores. In right dorsal premotor cortex, linear increases in activity across consecutive task blocks scaled with individual FSMCMOTOR scores in healthy controls, but not in patients.
In premotor and dorsomedial prefrontal areas, patients were impaired at upscaling task-related activity the more they were affected by motor fatigue. The results support the notion that increased sensorimotor processing in the cerebellum contributes to the experience of motor fatigue and fatigability in multiple sclerosis.
Additionally, downscaling of motivational input or sensorimotor processing in prefrontal and premotor areas may constitute an additional pathophysiological factor.
Language: | English |
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Publisher: | Public Library of Science |
Year: | 2018 |
Pages: | e0201162 |
ISSN: | 19326203 , 15537358 and 1553734x |
Types: | Journal article |
DOI: | 10.1371/journal.pone.0201162 |
ORCIDs: | Madsen, Kristoffer Hougaard and 0000-0002-8006-8595 |
Adult Brain Brain Mapping Brain/pathology Case-Control Studies Cerebellum Cerebellum/diagnostic imaging Cognition Female Hand Strength Hand Strength/physiology Humans Image Processing, Computer-Assisted Magnetic Resonance Imaging Male Medicine Middle Aged Motor Cortex Motor Cortex/diagnostic imaging Motor Skills Multiple Sclerosis, Relapsing-Remitting Multiple Sclerosis, Relapsing-Remitting/pathology Muscle Fatigue Prefrontal Cortex Prefrontal Cortex/diagnostic imaging Psychomotor Performance Psychomotor Performance/physiology Q R Science Surveys and Questionnaires Young Adult