Frontal Disconnection for Treating Mild Malformation of Cortical Development with Oligodendroglial Hyperplasia in Epilepsy (MOGHE) in the Frontal Lobe

Summary

Here, we present a protocol to describe the epilepsy outcome and complications of 8 patients with mild malformation of cortical development with oligodendroglial hyperplasia in epilepsy (MOGHE) in the frontal lobe after frontal disconnection. The procedure is characterized by its simplicity, user-friendliness, and fewer postoperative complications.

Abstract

Malformation of cortical development is an important cause of drug-resistant epilepsy in young children. Mild malformation of cortical development with oligodendroglial hyperplasia in epilepsy (MOGHE) has been added to the last focal cortical dysplasia (FCD) classification and commonly involves the frontal lobe. The semiology at the onset of epilepsy is dominated by non-lateralizing infantile spasm; the boundaries of the malformation are usually difficult to determine by magnetic resonance imaging (MRI) and positron emission tomography (PET), and electroencephalography (EEG) findings are often widespread. Therefore, the traditional concept and strategy of preoperative evaluation to determine the extent of the epileptogenic zone by comprehensive anatomo-electro-clinical methods are difficult to implement.

Frontal disconnection is an effective surgical method for the treatment of epilepsy, but there are few related reports. A total of 8 children with histo-pathologically confirmed MOGHE were retrospectively studied. MOGHE was located in the frontal lobe in all patients, and frontal disconnection was performed. The periinsular approach was used in the disconnective procedures, divided into several surgical steps: the partial inferior frontal gyrus resection, the frontobasal and intrafrontal disconnection, and the anterior corpus callosotomy.

One patient presented with a short-term postoperative speech disorder, while another patient exhibited transient postoperative limb weakness. No long-term postoperative complications were observed. At 2 years after surgery, 75% of patients were seizure-free, with cognitive improvement in half of them. This finding suggested that frontal disconnection is an effective and safe surgical procedure for the treatment of MOGHE instead of extensive resection in the frontal lobe.

Introduction

Malformation of cortical development (MCD) is an important cause of drug-resistant epilepsy and developmental delay in young children. There are many types of MCD, among which FCD is the most common type¹. According to the latest updated FCD classification in 2022, MOGHE is described and classified as a predominantly white matter lesion in contrast to juxta-cortical localized FCD² that was primarily described as proliferative oligodendroglial hyperplasia with epilepsy (POGHE) in 2013³ and first proposed in 2017⁴. MOGHE is defined by an increase....

Protocol

The study was approved by the IRB of Peking University First Hospital, and written informed consent was obtained from all participants.

NOTE: All children with intractable epilepsy who underwent frontal disconnection at the Pediatric Epilepsy Center of Peking University First Hospital from January 1, 2017, to March 1, 2022, were included and analyzed. Those who met the clinical and radiological criteria of MOGHE and whose MRI suggested that the epileptogenic lesion was confined to the frontal .......

Discussion

MOGHE is a new white matter entity predominantly at the GM/WM boundaries but shows no cortical layer disorganization as is typical for FCDs². The untypical semiology and extensive EEG make it very difficult to determine the location of the epileptogenic zone using traditional methods of anatomo-electro-clinical evaluation, which creates difficulties in surgical decision-making. Previous studies reported that patients with MOGHE achieved good outcomes after wide resection⁶

Materials

Name	Company	Catalog Number	Comments
Absorbable cranial bone lock	Braun Inc.	FF016
Drainage	Branden Inc.	Fr12
High-speed drill	Stryker	5400-050-000
Microscope	Leica Inc.	M525F40
NIHON KOHDAN EEG system	NIHON KOHDAN Inc.	EEG-1200C	EEG
Philips PET-CT system	Philips Inc.	Gemini GXL	PET-CT
Sinovation Stereotactic system	Sinovation Inc.	SR1	3D construction