Relating brain damage to brain plasticity in patients with multiple sclerosis.
BACKGROUND
Failure of adaptive plasticity with increasing pathology is suggested to contribute to progression of disability in multiple sclerosis (MS). However, functional impairments can be reduced with practice, suggesting that brain plasticity is preserved even in patients with substantial damage.


OBJECTIVE
. Here, functional magnetic resonance imaging (fMRI) was used to probe systems-level mechanisms of brain plasticity associated with improvements in visuomotor performance in MS patients and related to measures of microstructural damage.


METHODS
23 MS patients and 12 healthy controls underwent brain fMRI during the first practice session of a visuomotor task (short-term practice) and after 2 weeks of daily practice with the same task (longer-term practice). Participants also underwent a structural brain MRI scan.


RESULTS
Patients performed more poorly than controls at baseline. Nonetheless, with practice, patients showed performance improvements similar to controls and independent of the extent of MRI measures of brain pathology. Different relationships between performance improvements and activations were found between groups: greater short-term improvements were associated with lower activation in the sensorimotor, posterior cingulate, and parahippocampal cortices for patients, whereas greater long-term improvements correlated with smaller activation reductions in the visual cortex of controls.


CONCLUSIONS
Brain plasticity for visuomotor practice is preserved in MS patients despite a high burden of cerebral pathology. Cognitive systems different from those acting in controls contribute to this plasticity in patients. These findings challenge the notion that increasing pathology is accompanied by an outright failure of adaptive plasticity, supporting a neuroscientific rationale for recovery-oriented strategies even in chronically disabled patients.
Oxford Centre for Functional MRI of the Brain (FMRIB), University of Oxford, Oxford, UK. tomassiniv@cardiff.ac.uk
Valentina
V
Tomassini
Heidi
H
Johansen-Berg
Saad
S
Jbabdi
Richard G
RG
Wise
Carlo
C
Pozzilli
Jacqueline
J
Palace
Paul M
PM
Matthews
D000328:Adult; D016880:Anisotropy; D001921:Brain / Q000098:blood supply / Q000473:pathology* / Q000503:physiopathology*; D001931:Brain Mapping; D004185:Disability Evaluation; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009048:Motor Skills; D009103:Multiple Sclerosis / Q000473:pathology / Q000503:physiopathology / Q000534:rehabilitation; D009473:Neuronal Plasticity / Q000502:physiology*; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D011214:Practice, Psychological; D011597:Psychomotor Performance / Q000502:physiology*; D013223:Statistics as Topic
D010100:Oxygen