Intraoperative magnetic resonance imaging during surgical resection for drug resistant epilepsy eliminates the incidence of inadvertent incomplete resection of the epileptogenic zone and early surgical failure.

OBJECTIVE

We present a case series of pediatric subjects with drug resistant epilepsy (DRE) that underwent surgical resection utilizing intraoperative MRI (IOMRI) to confirm resection of the hypothesized epileptogenic zone (EZ). Clinical, radiographic and seizure control outcome measures are presented to support the hypothesis that inclusion of IOMRI enables assessment and confirmation of total resection of the hypothesized EZ and eliminates the incidence of inadvertent incomplete resections.

METHODS

We reviewed records for all pediatric patients (< 21 years) with DRE who underwent surgical resection between Dec 2017 and Aug 2023.

RESULTS

Thirty subjects with a mean follow-up duration of 4.2 ± 0.3 years (range: 1.6-7.3 years) were identified. The most prevalent pathological subtypes were focal cortical dysplasia (33%) followed by gliosis (30%). Phase II evaluation was undertaken in 24 subjects (80%). IOMRI revealed incomplete resection of the intended EZ in 73% (n = 22) of subjects, who then underwent additional resection. Two subjects underwent an incomplete resection due to functional constraints. Seizure improvement (Engel I + II) following surgery was observed in 90% of subjects with 80% (n = 24) subjects with Engel I outcome. An incomplete resection due to functional overlap or widespread network was associated with Engel III outcome in 3 subjects (10%).

CONCLUSIONS

Intraoperative imaging during surgical resection for DRE eliminates the incidence of inadvertent incomplete resections and reduces the risk of early seizure recurrence. Our results over an extended follow-up period, elucidate long-term epilepsy outcomes for DRE surgery with IOMRI assistance, that are associated with a low incidence of repeat resection due to epilepsy recurrence.