Precise epileptogenic zone location with stereotactic electroencephalography navigated by ROSA in patients with focal cortical dyplasia in children

Objective: To evaluate the application of robotized stereo-tactic assistant (ROSA) navigated intracranial electrode implantation in precise epileptogenic zone localization. To evaluate the location capability on epileptogenic foci (EF) of stereotactic electroencephalography (SEEG) in patients with intractable symptomatic epilepsy (PISE) in children caused by focal cortical dysplasia.

Method: The data of 15 patients with drug-resistant epilepsy in Capital Medical University Sanbo Brain Hospital from March 2012 to September 2014 who underwent ROSA navigated intracranial electrode implantation, and after resection operation confirmed by pathology with foca cortical dysplasia. We retrospectively analyzed the clinical data of PISE under 14 receiving resective surgery after epileptogenic foci located by SEEG, including age at surgery, age of onset, course of epilepsy, type of seizures, medication, video electroencephalography (vEEG) and MRI pattern, surgery data, pathology and seizure remission after surgery.

Results: 5 PISE were included in our analysis, 10 male and 5 female, with ages at surgery of 4 years to 14 years, ages of onset of 20 days to 11 years, and epilepsy course of 2 years to 22 years, all medically intractable. Two patients showed a normal MRI finding, 4 with obvious MRI findings, 9 with obscure finding, and all with a discordant vEEG pattern. SEEG located EF on frontal lobe in 5 PISE, temporal in 2, central in 1, insular in 1, multiple foci in 5, and multiple lobes in 1. All foci located by SEEG were resected with surgery, and all patients were acquire effective followed-up, from 8 to 36 months. In the 15 patient's follow-up, 10 achieved Engel class I, 3 class II, 1 class III, and 1 class IV. All patients with postoperative pathology were all focal cortical dysplasia, 2 patients FCDIA, 3 patients FCDIB, 6 patients FCDIIA, 4 patients FCDIIB.

Conclusion: For intractable epilepsy in children, focal cortical dysplasia is the most common pathogeny, when noninvasive assessment could not find the epileptogenic foci, SEEG is an effective pre surgical assessment method for PISE with discordant findings of other preoperative examination, especially the ROSA navigated sterotactic electrode implantation. Which was a microinvasive, short time, less-complication, safe-guaranteed and precise technique.