The natural history and results of treatment of superior oblique myokymia.

Abstract

To investigate the clinical presentations and long-term course of patients with superior oblique myokymia (SOM). The medical records of all 16 patients with the diagnosis of SOM seen in the Neuro-Ophthalmology Unit of The Wilmer Ophthalmological Institute, The Johns Hopkins Hospital, Baltimore, Md, between 1976 and 1993 were reviewed. Follow-up information was obtained for 14 (88%) of the 16 patients. Of the 16 patients with SOM, nine (56%) were male and seven (44%) were female. The age of onset of symptoms ranged from 22 to 50 years (mean age, 34 years). All patients were otherwise healthy with no history of neurologic illness. Seven (44%) of the 16 patients complained of paroxysms of uniocular "shimmering," "fluttering," or oscillopsia lasting seconds, three (19%) complained of vertical and torsional diplopia, and six (38%) had both types of symptoms. Five (31%) of the 16 patients underwent neuroimaging studies within 1 year of onset of symptoms. All imaging study results were normal. Follow-up information was obtained for 14 patients (88%). The time from onset of symptoms to our most recent contact was 3 to 29 years. Of the seven patients who received no treatment, five (71%) continue to have symptoms to date. Three patients received medical treatment only; one of the three has experienced lasting benefit with carbamazepine. Four patients underwent superior oblique tenectomy combined with inferior oblique myectomy after not responding to medical treatment. All four patients experienced resolution of all ocular symptoms after surgery. Because SOM is a much more chronic disease than formerly realized and because of the poor long-term effects and potential side effects of the medications used, medical treatment of SOM is not the optimum way to manage the disease. Extraocular muscle surgery is the treatment of choice when symptoms of SOM are intolerable to the patient.