Refractory trigeminal neuralgia due to compression from a fusiform superior cerebellar artery aneurysm: A single case report

Abstract

Introduction: Trigeminal neuralgia (TGN) is a debilitating pain disorder most commonly due to compression of the trigeminal nerve (CN V) by the superior cerebellar artery (SCA). Less commonly, other arteries or veins may compress CN V, and rarely, vascular malformations may be the culprit. SCA aneurysm are uncommon, especially when arising beyond the SCA-basilar bifurcation. Here we report a case of a distal SCA aneurysm resulting in refractory TGN. Brief Case Description: A 78-year-old female presented with frequent attacks of severe, lancinating right V2 and V3 distribution face pain since 2008. She had responded only transiently to carbamazepine and other neuropathic agents. She underwent stereotactic neurosurgery in 2008 and 2011 with only temporary relief. Subsequent glycerol rhizolyses in 2018 and 2019 did not provide lasting relief. Finally, in January 2021, she underwent microvascular decompression (MVD) during which a small, fusiform (or “blister”) distal SCA aneurysm was found to be compressing CN V directly at the dorsal root entry zone. This lesion was obliterated intraoperatively, and CN V was wrapped. At the time of this publication, she has continued to be pain-free following surgery. Conclusion: TGN is a debilitating pain disorder and is most often caused by the SCA or a pontomesencephalic vein. Distal SCA (SCA-2) aneurysms are extremely uncommon, but large SCA-2 aneurysms have been reported to cause TGN, albeit in only 2 instances. Here, we present the first reported case of refractory TGN due to a small, “blister” SCA-2 aneurysm immediately adjacent to the trigeminal DREZ.

Keywords

• Trigeminal neuralgia
• Superior cerebellar artery aneurysm
• Microvascular decompression
• Case report