Contributions
Abstract: P1133
Type: Poster Sessions
Abstract Category: Pathology and pathogenesis of MS - MRI and PET
Introduction: Impairment of gait and balance occurs since the early stages in patients with multiple sclerosis (PwMS) and deficits of the position sense (PS) at the lower limbs could play a key role. However, while in healthy subjects (HS), the right fronto-parietal cortex activity has been significantly associated with PS control, studies examining the neural correlates of PS in PwMS are still lacking.
Aims: To investigate the neural correlates of PS at the lower limbs in PwMS at the early stage of the disease, by means of foot position matching tasks and balance assessment.
Materials and methods: Patients with relapsing-remitting MS, low disability and short disease duration and HS were prospectively recruited. All subjects underwent bilateral and unilateral matching tasks and motor tasks consisting in foot dorsi-flexion movements, during functional MRI (fMRI). The constant error (CE) was calculated per each task. Standing balance was assessed in PwMS using a Nintendo Wii balance board, obtaining 2 parameters related to PS: the root mean square and mean velocity in antero-posterior direction (RMS-AP and MV-AP, respectively). fMRI data were processed with FSL. Behavioral and imaging data of PwMS and HS groups were compared adding age and gender as covariates. The effect of the behavioral metrics on brain activation was also assessed.
Results: 25 PwMS (18 females; aged 32.1±6.9 years; disease duration 37.9±24.3 months; median EDSS 1.0, range 0-3.5) and 25 HS (16 females; aged 30.7±4.5 years) were recruited. In PwMS, brain activity related to PS was localized at the level of the bilateral premotor and parietal cortex. PwMS showed higher CE during bilateral, but not unilateral, matching task, compared to HS (p=.024). During unilateral matching task PwMS additionally recruited the left parietal cortex but not the cingulate gyrus, compared to HS, and the CE inversely correlated with brain activity at the level of the right parietal cortex. Finally, RMS-AP and MV-AP correlated with cerebellar and parietal cortex activity in PwMS.
Conclusions: PS at the lower limbs is impaired in PwMS, since the early stage of the disease. Both the recruitment of additional brain areas and the correlation between behavioral performance and brain activity suggest a functional reorganization underlying PS control in PwMS, with fronto-parietal areas playing a dominant role. These findings could represent a new milestone in the choice of the most appropriate rehabilitative strategy
Disclosure: G. Bommarito, R. Iandolo, L. Falcitano, N. Piaggio have nothing to disclose. G.L. Mancardi has received honoraria for lecturing, travel expenses for attending meetings, and financial support for research from Bayer Schering, Biogen Idec, Genzyme, Merck Serono, Novartis, Sanofi-Aventis, and Teva Pharmaceuticals. M. Casadio was supported by by Marie Curie Integration Grant. M. Inglese has received has received research grants from NIH, NMSS, DOD and Teva Neuroscience.
Abstract: P1133
Type: Poster Sessions
Abstract Category: Pathology and pathogenesis of MS - MRI and PET
Introduction: Impairment of gait and balance occurs since the early stages in patients with multiple sclerosis (PwMS) and deficits of the position sense (PS) at the lower limbs could play a key role. However, while in healthy subjects (HS), the right fronto-parietal cortex activity has been significantly associated with PS control, studies examining the neural correlates of PS in PwMS are still lacking.
Aims: To investigate the neural correlates of PS at the lower limbs in PwMS at the early stage of the disease, by means of foot position matching tasks and balance assessment.
Materials and methods: Patients with relapsing-remitting MS, low disability and short disease duration and HS were prospectively recruited. All subjects underwent bilateral and unilateral matching tasks and motor tasks consisting in foot dorsi-flexion movements, during functional MRI (fMRI). The constant error (CE) was calculated per each task. Standing balance was assessed in PwMS using a Nintendo Wii balance board, obtaining 2 parameters related to PS: the root mean square and mean velocity in antero-posterior direction (RMS-AP and MV-AP, respectively). fMRI data were processed with FSL. Behavioral and imaging data of PwMS and HS groups were compared adding age and gender as covariates. The effect of the behavioral metrics on brain activation was also assessed.
Results: 25 PwMS (18 females; aged 32.1±6.9 years; disease duration 37.9±24.3 months; median EDSS 1.0, range 0-3.5) and 25 HS (16 females; aged 30.7±4.5 years) were recruited. In PwMS, brain activity related to PS was localized at the level of the bilateral premotor and parietal cortex. PwMS showed higher CE during bilateral, but not unilateral, matching task, compared to HS (p=.024). During unilateral matching task PwMS additionally recruited the left parietal cortex but not the cingulate gyrus, compared to HS, and the CE inversely correlated with brain activity at the level of the right parietal cortex. Finally, RMS-AP and MV-AP correlated with cerebellar and parietal cortex activity in PwMS.
Conclusions: PS at the lower limbs is impaired in PwMS, since the early stage of the disease. Both the recruitment of additional brain areas and the correlation between behavioral performance and brain activity suggest a functional reorganization underlying PS control in PwMS, with fronto-parietal areas playing a dominant role. These findings could represent a new milestone in the choice of the most appropriate rehabilitative strategy
Disclosure: G. Bommarito, R. Iandolo, L. Falcitano, N. Piaggio have nothing to disclose. G.L. Mancardi has received honoraria for lecturing, travel expenses for attending meetings, and financial support for research from Bayer Schering, Biogen Idec, Genzyme, Merck Serono, Novartis, Sanofi-Aventis, and Teva Pharmaceuticals. M. Casadio was supported by by Marie Curie Integration Grant. M. Inglese has received has received research grants from NIH, NMSS, DOD and Teva Neuroscience.