The FDA issued a warning to health care professionals and their patients on recently about injuries and death associated with a multiple sclerosis (MS) treatment called “liberation therapy” by some.

“Liberation therapy,” an experimental procedure, is meant to treat chronic cerebrospinal venous insufficiency (CCSVI), a narrowing of veins in the neck and chest, which may be a cause of MS or may contribute to the disease’s progression. The recent FDA news release, however, said “studies exploring a link between MS and CCSVI are inconclusive, and the criteria used to diagnose CCSVI have not been adequately established.” The procedure uses balloon angioplasty devices or stents to widen the narrowed veins in the chest and neck. But the procedure can lead to a myriad of health problems, according to the FDA.

“The FDA has learned of death, stroke, detachment and migration of the stents, damage to the treated vein, blood clots, cranial nerve damage and abdominal bleeding associated with the experimental procedure. Balloon angioplasty devices and stents have not been approved by the FDA for use in treating CCSVI.”

The cause of MS remains unknown, though its damaging effects are well understood. The disease damages the ability of nerve cells in the brain and spinal cord to communicate with each other, and can lead to a host of problems, such as loss of sensitivity, loss of balance, speech issues, cognitive impairment and depression, to name a few. MS gradually deteriorates neurological function.