Epilepsy in Association with Giant Skull Base Tumors: A Retrospective Case Series of Giant Skull Base Tumors in the Anterior and Middle Fossa.

Abstract

Objective This study aims to investigate the association between giant anterior and middle fossa skull base tumors and epilepsy, and implications for clinical management. Methods A retrospective analysis was conducted on a cohort of patients diagnosed with anterior skull base tumors between 2016 and 2023. Radiologic data was used to identify tumors with major diameter larger than 5cm involving skull base with intracranial involvement. Relevant demographic information, tumor characteristics, seizure type, seizure frequency, and treatment outcomes were analyzed. Results Among the 236 patients diagnosed and operated with skull base tumors by senior author, 7.63 percent (n=18) had giant skull base tumors of anterior and middle fossa, and 2.96 percent (n=7) presented with concurrent epilepsy. Overall, in giant anterior and middle fossa skull base tumors, epilepsy was present in 38% of cases. The average age at operation was 47.56 ±16.96, with 44.4% of cases male and 55.6% of the cases female. The majority of these cases exhibited focal epilepsy (71 %), characterized by seizures originating from the proximity of the tumor location suggesting a potential correlation between tumor location and seizure generation. Of the remaining, 29% were generalized seizures. Tumors of the anterior fossa included 11 meningiomas, 3 pituitary adenomas, 1 chondrosarcoma, 1 hemangioperycitoma, 1 schwannoma, and 1 adenoid cyst carcinoma, half of which (n=9) were of low grade. Conclusion Our findings provide evidence of low frequency of epilepsy in skull base tumors in general, although a significant association among giant anterior and middle fossa skull base tumor and epilepsy.