The Association of methylprednisolone dosing to cessation of myotonia in a patient with myotonic dystrophy type 1.

We report the case of a patient suffering from duplicity of myotonic dystrophy type 1 and ulcerative colitis whose treatment for ulcerative colitis included repeated administrations of descending doses of methylprednisolone and in whom we found an association between methylprednisolone dosing and cessation of myotonia. Myotonia severity was expressed as relaxation time after voluntary contraction and as a patient-reported outcome using the Czech version of the Myotonia Behavior Scale. The patient was being treated for a flare of ulcerative colitis, starting with 32 mg of methylprednisolone and reducing the dose by 4 mg a week. The symptoms of myotonia began to wear off three weeks after starting methylprednisolone and had totally disappeared by four weeks after starting methylprednisolone. The first symptoms of myotonia returned about a month after the last dose of methylprednisolone and reached a peak of severity more than two months after the final dose.