TORONTO–Like electrical wires, neurons are insulated. But in multiple sclerosis (MS), the insulation (called myelin) is stripped or worn down, slowing conduction along the axons–the wires of the nervous system. MS is widely considered to be an autoimmune disease , in which the myelin is attacked by the body’s own T cells. But Paulo Zamboni, director of the Vascular Diseases Center at the University of Ferrara in Italy, thinks a blockage in the veins that drain blood from the brain is the part of the problem. In his pilot study, published December 2009 in The Journal of Vascular Surgery , MS patients who had such blockages (called chronic cerebrospinal venous insufficiencies) fixed surgically, including Zamboni’s wife, showed a significant improvement.