Evaluation of the activity changes in the brain occuring during motor tasks in patients with Multiple Sclerosis by using functional Magnetic Resonance Imaging

Purpose: In this study, we aimed to evaluate the functional adaptive changes in the brain occurring during basic motor tasks by using the method of functional Magnetic Resonance Imaging (fMRI) in two different clinical subgroups of the in multiple sclerosis disease such as Relapsing-Remitting Multiple Sclerosis (RRMS) and Clinical Isolated Syndrome (CIS). We analyzed if such changes vary according to age, disease duration, disability and treatment method and also we studied the differences compared with the control group.Material and method: Our study included 30 cases in total: 8 patients with the diagnosis of CIS, 12 with Relapsing-Remitting MS, 10 healthy subjects at similar age and sex. Each person was performed 3 times in a second the flexion-extension movement with the fingers of their right hand during the dynamic imaging. Statistical parametric mapping (SPM) was carried out on these data obtained by using image analyzing soft ware at work stations connected to the MR device. The mappings of Z-score, standard deviation, correlations, log-p value were obtained. Signal changes occurring during the stimulation periods were obtained by selecting 11 different cortical region "region of interest: ROI" for both cerebral hemispheres.In the statistical changes, we used non-parametric tests (Kruskal-Wallis, Mann-Whitney U-test) to compare the group averages and personal ki-square was used to compare the independent groups. Spearman Correlation Analysis was made to evaluate the relationship between the age, duration of disease, EDSS score and the cortical activity.Results: High activities (z-score > 5) were detected in left precentral gyrus, left postcentral gyrus and left superior frontal gyrus in RRMS groups as well as in the left precentral girus, in left and right postcentral gyri in CIS group; also in left precentral and postcentral gyrus in control group. Z score value measure in right postcentral girus and in left anterior cingulate gyrus of the CIS group has been significantly higher compared to the RRMS group (respectively *p = 0.021 and *p = 0.025). Z score values measured in left thalamus has been significantly lower in RRMS group compared to the one in control group (*p = 0.022). The cortical activity values measured at right postcentral gyrus in CIS group were found to be approximately 2.5 times higher compared to the control group; however this difference was not statistically significant (p > 0.05).In RRMS group, cortical activity which showed strong correlation with the age (respectively r = -0.594, *p = 0.042, r = -0.585, *p = 0.046) has been detected to decrease in right and left postcentral gyrus according to the age increase of the subjects. In CIS group, increase in cortical activity at left middle frontal gyrus showed strong correlation according to the age (r = 0.731, *p = 0.04). In control group, decrease in cortical activity at left talamus has been detected according to the age, which represent a strong correlation with the age increase (r = -0.689, *p = 0.028).In RRMS group, the level of activation at left postcentral gyrus of the patients that have been subject to immune modulator treatment has significantly increased compared to those that have not been subject to such treatment (*p = 0.012). Cortical activation in right posterior cingulate gyrus of the patients, who have undergone immune suppressive treatment is significantly lower compared to the ones that have not received such treatment (*p = 0.032); whereas the activity values at the right posterior cingulate gyrus of the patients who have not been subject to any treatment has found out to be significantly higher compared with those that have been subject to any treatment (*p = 0.013).Conclusion: This study showed that adaptive mechanisms consequently interfere in to the process in order to help the patients with MS to sustain at optimum extends their normal functions against the damages in SSS. Increased activity has been found at ipsilateral postcentral gyrus in CIS group and at ipsilateral precentral gyrus in RRMS group compared to the healthy controls. This data in the CIS group has showed us that adaptation against the damage starts even at the early stages of the disease. Among the areas that received the most activity in the RRMS patients group, includes also the left superior frontal gyrus which does not involve in the basic motor movement. These findings point out that the basic motor tasks are comprehended as new or more complex ones due to the damage which has been accumulated during the later stages of the disease.In RRMS patients, even though we found out significant changes between the type of the treatment and the activity in the right posterior singulate girus, we need more comprehensive and more organized studies which will help us to reach sound results that may be applied practical clinics. The results that may be obtained from such studies will not only help to form the types of the treatments that will be applied in various subtypes of the MS disease but also can contribute to highlight the effects of such treatments on the SSS functions.