The clinical classification and treatment of middle cranial fossa arachnoid cysts in children.

OBJECTIVE: The optimal management for middle fossa arachnoid cysts (MFAC) remains controversial, but cystocistern fenestration is effective. MFACs are divided into non-communicating arachnoid cysts (NCIAC) and communicating arachnoid cysts (CIAC). This retrospective observational study evaluated the role of phase-contrast cine magnetic resonance imaging (PC-MRI) in the diagnosis and postoperative evaluation of MFACs and assessed surgical outcomes.

METHODS: Twenty-eight children with MFAC that were diagnosed by conventional neuroradiology were enrolled. PC-MRI was performed preoperatively. The clinical manifestations, cyst volumes and PC-MRI data were analyzed, and the flow of cerebrospinal fluid (CSF) at the fistula was qualitatively evaluated.

RESULTS: No communication with the adjacent subarachnoid space was found on preoperative PC-MRI in 20 patients, and they were diagnosed with NCIAC. A statistically significant decrease in cyst volume was observed in all 20 patients postoperatively. Symptoms resolved or improved in the 14 patients who were symptomatic preoperatively, and a positive CSF flow was found in all 20 patients postoperatively. PC-MRI diagnosed eight patients with CIAC, and the cyst sizes did not increase during follow-up.

CONCLUSIONS: Cystocistern fenestration is an effective treatment for children with lateral fissure IAC. PC-MRI can be used to determine the IAC type and to evaluate the effectiveness of cystocistern fenestration.