Quadrigeminal cistern arachnoid cyst as a probable cause of hemifacial spasm

• DOI: 10.1016/j.radcr.2021.02.061
• Publication Date: 2021-03-28T20:58:35Z
• Authors: Yuki Takaki; Satoshi Tsutsumi; Shinichiro Teramoto; Senshu Nonaka; Hidehiro Okura; Takamoto Suzuki; Hisato Ishii
• Keywords: Hemifacial spasm; Cistern; Cisterna

Arachnoid cysts arising in the quadrigeminal cistern (ACQCs) are uncommon. A 68-year-old woman presented with an unsteady gait, facial spasm, and cerebellar ataxia. Non-contrast head computed tomography showed a cystic mass centered accompanying ventriculomegaly. On MRI, cyst appeared hypointense on T1- hyperintense T2-weighted sequence. There was no restricted diffusion diffusion-weighted imaging. The cerebral aqueduct obstructed prepontine narrowed. left vertebral artery (VA) coursed adjacent to nerve at its origin. patient underwent neuroendoscopic fenestration of posterior wall third ventricle ventral ACQC. Postoperatively, patient's symptoms resolved. MRI considerable reduction ACQC expansion cistern, whereas relationship between VA proximal segment did not change. We assumed that pre-existing close might have been aggravated by anterior displacement brainstem, thus causing spasm.