A longitudinal fMRI study on motor activity in patients with multiple sclerosis

Abstract

Using functional MRI (fMRI), patients with multiple sclerosis showed a greater extent of motor activation than controls. Although functional changes are often interpreted as adaptive and as a contributing factor in limiting the clinical deficit, no longitudinal studies have yet been performed for multiple sclerosis. Sixteen patients with multiple sclerosis, two patients with possible multiple sclerosis and nine age-matched controls underwent two fMRI studies with a time interval of 15-26 months. The motor task consisted of a self-paced sequential finger opposition movement with the right hand. Patients with multiple sclerosis exhibited greater bilateral activation than controls in both fMRI studies. At follow-up, patients showed a reduction in functional activity in the ipsilateral sensorimotor cortex and in the contralateral cerebellum. No significant differences between the two fMRI studies were observed in controls. Activation changes in ipsilateral motor areas correlated inversely with age, extent and progression of T1 lesion load, and occurrence of a new relapse. This study may help the understanding of the evolution of brain plastic changes in multiple sclerosis indicating that, in younger patients with a less structural brain damage and benign clinical course, the brain reorganizes its functional activity towards a more lateralized pattern of brain activation. The tendency towards a normalization of brain functional activity is hampered in older patients and in those developing relapses or new irreversible brain damage.

Effect of corpus callosum damage on ipsilateral motor activation in patients with multiple sclerosis: A functional and anatomical study

“…On the other hand, the fact that the T1-LL of the whole brain correlated with iM1-increased activation suggests that it is also an expression of cortical reorganization (i.e., recruitment of ipsilateral motor output), serving maintenance of normal motor behavior despite diffuse brain damage that presumably also affects other parts of the motor network-an idea reported by our group and others [Pantano et al, 2002b[Pantano et al, , 2005Reddy et al, 2000b]. Central conduction time in our patients was increased above normal, suggesting that the motor system was indeed affected by the disease.…”

Molecular alterations in the cerebellum of the plasma membrane calcium ATPase 2 (PMCA2)-null mouse indicate abnormalities in Purkinje neurons

“…Our findings raise the possibility that perturbations in the expression of mGluR1 and its downstream effectors as well as abnormal increases in NFH in Purkinje neurons might be a cause of cerebellar dysfunction in the PMCA2-null mouse. It is worth noting that cerebellar pathology occurs in several neurological diseases including ataxia and multiple sclerosis (Black et al, 2000;Muller et al, 2000;Hickman et al, 2001;Downey et al, 2002;Saab et al, 2004;Li et al, 2004;Pantano et al, 2005). Therefore, our findings might have relevance to these conditions, a possibility that requires further investigations.…”

Impaired Object Manipulation in Mildly Involved Individuals with Multiple Sclerosis

“…We believe that a part of explanation could be found in adaptation within the CNS. For example, recent brain imaging studies conducted on mildly involved MS patients have suggested normal neurological functioning due to cortical reorganization (Lee et al, 2000;Pantano et al, 2005;Reddy, Narayanan, Arnoutelis et al, 2000;. In addition, no performance deficits in reaction time motor tasks was observed between mildly affected MS patients (with a mean EDSS score of 1.4) indicating an adaptive mechanism in the cortex (Cerasa et al, 2006).…”