Lateral Supracerebellar Infratentorial Approach for Superior Oblique Myokymia: A Case Series

Abstract

BACKGROUND: Few reports have shown that superior oblique myokymia (SOM) may result from vascular compression of the trochlear nerve and may be curable using microvascular decompression (MVD). OBJECTIVE: To report the clinical characteristics and surgical treatment of 2 cases of SOM and provide a review of the related literature. METHODS: Two patients with SOM were treated using MVD with the lateral supracerebellar infratentorial approach. The patients underwent diagnostic magnetic resonance imaging and three-dimensional fusion imaging preoperatively. A lateral suboccipital craniotomy was performed in the park-bench position. The trochlear nerve and branches of the superior cerebellar artery were confirmed after opening the cerebellomesencephalic fissure over the tentorial surface of the cerebellum. The vessel, which compressed the root exit zone of the trochlear nerve, was transposed far from the nerve and attached to the surface of the midbrain using Teflon felt and fibrin glue. RESULTS: The first case showed compression on both the ventral and rostral sides of the trochlear nerve root exit zone, and the second showed compression only on the ventral side. Large bridging veins on the tentorial surface of the cerebellum complicated the approach in the second case. Postoperatively, both patients had immediate and complete resolution of symptoms without recurrence at the 24-mo and 17-mo follow-ups, respectively. Five previous reports described the complete resolution of SOM after MVD. CONCLUSION: A presentation of an intermittent fluttering ocular sensation should prompt magnetic resonance imaging for ipsilateral trochlear nerve compression. The lateral supracerebellar infratentorial approach allows safe and efficacious MVD for SOM.

Microvascular Decompression for Concurrent Trigeminal Neuralgia and Hemi-Laryngopharyngeal Spasm: A Case Report

“…4 There is no literature on 3D fusion imaging for HeLPS to date; however, it can aid in supporting a surgical approach and ultimately improving procedural safety. 9…”

“…The patient underwent 3.0-T MRI with true fast imaging with steady-state precession (FISP) and T2 sampling perfection with application-optimized contrast using different flip angle evolution (SPACE). 9 3D fusion imaging was performed preoperatively. 9…”

“…He had no new deficits postoperatively, especially no vagal nerve dysfunction. The medication was tapered off, and he was discharged on the seventh postoperative day (standard recovery period for trigeminal neuralgia in Japan 9 ) because he was satisfied with the treatment. The facial pain and throat contractions did not recur, and no neurological deficit was observed at the 18-month follow-up.…”

“…9 3D fusion imaging was performed preoperatively. 9 He was referred to our hospital because of exacerbated TN symptoms. 3D fusion imaging demonstrated compression of the trigeminal nerve by the superior cerebellar artery and petrosal vein.…”