Ifosfamide associated myoclonus-encephalopathy syndrome.

The aim of this study was to investigate the presence of movement disorders associated with ifosfamide toxicity. One of the most common adverse events of ifosfamide treatment is central nervous system toxicity. However, little is known about the occurrence of movement disorders associated with ifosfamide toxicity. We performed a retrospective computer search of the electronic medical records database of the Mayo Clinic, Rochester, MN from 1 January 1997-30 June 2010, using a series of search terms to identify all patients that had been treated with ifosfamide for systemic cancer. Among 400 patients that have ever used ifosfamide, we selected those patients that had any neurological complication in their medical records after the use of ifosfamide. Fifty-two had a neurological complication after ifosfamide administration. The most common neurological complication was encephalopathy that was present in 11 cases (21%). The presence of a movement disorder time locked to the administration of ifosfamide was reported in seven cases (13%). Generalized myoclonus was most common, occurring in four patients while postural tremor was documented in the other three. All patients with myoclonus had asterixis. Four of the patients also had encephalopathy. In six patients the movement disorders resolved within 48 h, spontaneously, after the discontinuation of ifosfamide, while in one case resolved in 24 h after the treatment with methylene blue. Our study demonstrates that although encephalopathy is the most common adverse neurological event associated with ifosfamide toxicity, movement disorders, including generalized myoclonus, asterixis, and postural tremors may also occur. Treatment with methylene blue may be further considered as useful to ameliorate the movement disorders.