Neurology 2002 Mar 26;58(6):866-872
Rocca MA, Matthews PM, Caputo D, Ghezzi A, Falini A, Scotti G, Comi G, Filippi M.
Neuroimaging Research (Drs. Rocca and Filippi) and Clinical Trials (Dr. Comi) Units, Department of Neuroscience, and Department of Neuroradiology (Drs. Falini and Scotti), Scientific Institute and University Ospedale San Raffaele, and Department of Neurology (Dr. Caputo), Scientific Institute "Fondazione Don Gnocchi," Milan, and Multiple Sclerosis Center (Dr. Ghezzi), Ospedale di Gallarate, Gallarate, Italy.
Previous work has suggested that functional reorganization of cortical motor areas might have a role in limiting the motor deficits in patients with MS.
To test whether movement-associated cortical changes in MS might extend beyond the "classic" motor areas and involve sites for multimodal integration.
fMRI was used to assess patterns of brain activations associated with 3 different motor tasks in 30 right-handed patients with primary progressive MS (PPMS) and variable degrees of motor impairment, which were compared with those from 15 right-handed, sex- and age-matched control subjects.
Compared with control subjects, patients with MS showed increased activation of brain regions within both traditional motor planning and execution regions (including the supplementary motor area and the cingulate motor area), the insula (a region implicated in sensory processing), and several multimodal cortical regions in the temporal, parietal, and occipital lobes. In patients, the extent of the fMRI activations was strongly correlated with MR lesion burden (r ranging from 0.70 to 0.86, p < 0.001).
This study shows that movement-associated cortical activation in patients with PPMS is widely distributed and also involves multimodal "nonmotor" cortical networks. It also suggests that adaptive cortical reorganization might be one of the mechanisms limiting the clinical impact of MS in the progressive phases of the disease.