Guanglin Fu, Fan Ye, Shanshan Lu, Xingwang Sun, Peng Zhou
We identified a rare epileptogenic origin. Neuroimaging revealed a right-sided choroidal fissure cyst corresponding to the epileptogenic zone. Combined SEEG and intraoperative ECoG, used for the first time, confirmed an epileptogenic focus adjacent to the cyst, with seizures originating from the hippocampal head and body. The available histopathological specimens showed no definite evidence of hippocampal sclerosis or ILAE-classifiable focal cortical dysplasia (FCD). These findings suggest that, in certain cases, choroidal fissure cysts may act as independent epileptogenic triggers, with implications for epilepsy diagnosis and management.
BACKGROUND: Choroidal fissure cysts (CFCs) are relatively rare, and their exact prevalence in the general population remains unclear. These cysts are most often detected incidentally during neuroimaging performed for unrelated reasons. Whether CFCs are associated with specific clinical symptoms and their potential clinical significance remain controversial.
CASE DESCRIPTION: A 35-year-old woman developed epileptic seizures at age 15 after a high fever. Her seizures remained poorly controlled despite multiple antiseizure drugs. Neuroimaging revealed a choroidal fissure cyst in the right hippocampal region. Stereoelectroencephalography (SEEG) confirmed epileptogenic foci adjacent to the cyst, and SEEG-guided radiofrequency thermocoagulation (RF-TC) was performed initially. She remained seizure-free after RF-TC until definitive surgery, when anterior temporal lobectomy was performed. Available tissue specimens showed no definite histopathological evidence of ILAE-classifiable focal cortical dysplasia or hippocampal sclerosis. At the 12-month postoperative follow-up, she remained seizure-free; outpatient video-electroencephalography showed no significant abnormalities, and emotional status and cognitive function had markedly improved from the preoperative baseline. Postoperatively, she continued lacosamide 150 mg twice daily and lamotrigine 100 mg twice daily. The outcome was Engel Class IA and ILAE Class 1.
CONCLUSION: We identified a rare epileptogenic origin. Neuroimaging revealed a right-sided choroidal fissure cyst corresponding to the epileptogenic zone. Combined SEEG and intraoperative ECoG, used for the first time, confirmed an epileptogenic focus adjacent to the cyst, with seizures originating from the hippocampal head and body. The available histopathological specimens showed no definite evidence of hippocampal sclerosis or ILAE-classifiable focal cortical dysplasia (FCD). These findings suggest that, in certain cases, choroidal fissure cysts may act as independent epileptogenic triggers, with implications for epilepsy diagnosis and management.