[Multiple sclerosis as an adverse effect of anti-tumor necrosis factor agents: an infrequent but important complication of infliximab in Crohn's disease].

Anti-tumor necrosis factor alpha (TNF-α) agents have been a great advantage in the treatment of inflammatory bowel disease. The safety profile of these agents is well-known and they can be considered safe when properly used. In clinical practice, the most important adverse events are infections. Other adverse effects are also possible but are much less frequent. However, because of the widespread use of these drugs, these uncommon adverse effects may also occur in clinical practice. We report one of these infrequent adverse events, multiple sclerosis, which is rare but important because of its severity. When neurological symptoms appear during treatment with anti-TNF-α, multiple sclerosis must be ruled out. The diagnosis and therapeutic management of this entity, led by a neurologist with our collaboration, required permanent cessation of anti-TNF-α therapy. Azathioprine, interferon, and even natalizumab, may be used as alternatives in patients who require therapy.