The primary endpoint will be to further evaluate the safety and feasibility of the treatment with MSC infusions, in MS patients. Additionally, the migration ability of the transplanted cells will be evaluated by tagging MSCs with the superparamagnetic iron oxide particle (Feridex) (an FDA approved cell tracking drug) for detection by MRI. MRI of the brain and spinal cord will be performed at weeks 1, 4, 12 and 24 to detect the migration of the stem cells. Clinically the patients will be followed by monthly evaluations of the MS functional rating scale (EDSS) scale. The MRI, will be also used to evaluate changes in the total volume of lesions in the brain and the degree of atrophy.