Unusual Cause of Trigeminal Neuralgia: Arachnoid Cyst of Petrous Apex

Abstract

Arachnoid cyst of petrous apex is an uncommon cyst lesion that herniates from the posterolateral portion of the Meckel's cave into the petrous apex. It can be unilateral or bilateral, usually observed in female population. Its etiopathogenesis is still uncertain and many theories were reported in the literature. The characteristic imaging appearance, topography and benign behavior of the lesion allow to differentiate arachnoid cyst from other cyst-like lesions of petrous apex and prevent abusive surgery or unnecessary investigations. The purpose of this study is to illustrate through this observation the role of sectional imaging in the diagnosis of symptomatic arachnoid cyst of petrous apex.