Taking the street drug Ecstasy could lead to a potentially fatal weakening and rupture of the spinal cord artery, doctors warn. Posterior spinal artery aneurysms -- a blood-filled swelling of the spinal cord artery, caused by a weakening and distension of the vessel wall -- are rare, with only 12 cases reported to date. But all of them caused spinal bleeding which affected the function of the spinal cord. Doctors discovered one of these aneurysms in a previously healthy teenager who had taken Ecstasy or MDMA.