Microvascular decompression for superior oblique myokymia: case report.

BACKGROUND: Superior oblique myokymia (SOM) is a rare disorder in which the patient suffers episodic uniocular torsional eye movement associated with diplopia and oscillopsia . Although the pathophysiology has been narrowed down to erratic discharge of the trochlear nerve, yet the exact etiology remains unclear; a handful of cases have been described in association with an identifiable space occupying lesions or dural AV fistulae. Neurovascular compression theory has been postulated in the early 1980s and to our knowledge, very few reports exist in the literature accrediting this hypothesis in the pathogenesis of superior oblique myokymia. CASE REPORT: We report a case of successful resolution of severe medication refractory SOM following microvascular decompression of the trochlear nerve. The clinical response has been sustained for a follow-up period of 18 months to date. CONCLUSION: Microvascular decompression may be considered as a definitive and least destructive surgical option for the treatment of medication refractory superior oblique myokymia.

Superior Oblique Myokymia: A Case Report of Surgical Treatment, Review of the Literature, and Consideration of Surgical Approach.

BACKGROUND: Superior oblique myokymia (SOM) is a rare disorder characterized by episodic microtremor of the eyeball. in patients with SOM, intermittent contraction of the superior oblique muscle causes irregular and rotatory eye movement, causing oscillopsia and diplopia. Microvascular decompression (MVD) of the trochlear nerve is potentially a definitive treatment method for SOM; however, owing to its rarity, this disorder is not well-known to neurosurgeons, and thus the optimal surgical approach has not yet been determined. CASE DESCRIPTION: A 77-year-old woman with left SOM had experienced oscillopsia for 2 years. MVD was performed via a left lateral superior cerebellar approach with the patient in the park-bench position. Her symptom resolved immediately after the surgery. CONCLUSIONS: We believe that MVD via a left lateral superior cerebellar approach can be safely performed to SOM in elderly patients like our patient. Therefore, MVD should be considered as the definitive treatment method for more patients with SOM.