The pyramidal pathway is frequently affected early on in multiple sclerosis (MS) and impaired motor performance is a major cause of disability. Pyramidal tract function can be assessed using transcranial magnetic stimulation (TMS). TMS supports the diagnosis of MS, detecting corticospinal tract involvement and monitoring its course with or without treatment. It has been never investigated whether any relationship exists between the TMS outcome measure and minimally invasive treatment of multiple severe extracranial stenosis, affecting the principal ce rebrospinal venous segments in MS patients. We report the clinical and transcranial magnetic stimulation follow-up of a patient during a relapse in relapsing-remitting MS. She underwent percutaneous balloon angioplasty of the associated chronic cerebrospinal venous insufficiency (CCSVI), due to membranous obstruction of the proximal azygous vein, with severe stenosis of the left internal jugular vein. Treatment of the associated CCSVI made a parallel improvement in both clinical and neurophysiological parameters, allowing us to avoid high dose steroid therapy. The relationship between the clinical and neurophysiological course on the one hand, and haemodynamic correction of the associated CCSVI on the other, calls for further exploration on a wider number of patients. The impact of CCSVI on the different neuro-physiological parameters has not been fully estimated, but the intriguing case here reported suggests that it may be greater than previously assumed. The demonstration of a modification of the cerebrovenous function with both clinical manifestation and via TMS suggests that the hampered cerebral venous return may contribute to the clinical course of MS.