A quadrigeminal cistern arachnoid cyst is an extremely rare cause of trigeminal neuralgia in adulthood. This report presents the fourth case in the literature of trigeminal neuralgia caused by a giant quadrigeminal cistern arachnoid cyst. A 52-year-old woman presented with a 3-month history of cerebellar ataxia and vertigo. She had a 2-year history of trigeminal neuralgia that was unresponsive to medical therapy. Neuroimaging studies revealed a cystic lesion in the quadrigeminal cistern associated with hydrocephalic enlargement. Using an infratentorial supracerebellar approach, neuroendoscope-assisted decompression and fenestration of the cyst were performed. Postoperatively, the patient was pain-free and able to walk unaided without symptoms of ataxia.
Keywords: Arachnoid cyst, ataxia, hydrocephalus, quadrigeminal cistern, trigeminal neuralgia.