Elsevier

World Neurosurgery

Volume 140, August 2020, Pages e161-e168
World Neurosurgery

Original Article
Application of Robot-Assisted Frameless Stereoelectroencephalography Based on Multimodal Image Guidance in Pediatric Refractory Epilepsy: Experience of a Pediatric Center in a Developing Country

https://doi.org/10.1016/j.wneu.2020.04.218Get rights and content

Objective

To introduce the application of robot-assisted frameless stereoelectroencephalography (SEEG) based on multimodal image fusion technology in pediatric refractory epilepsy in a pediatric center from a developing country.

Methods

We retrospectively evaluated pediatric patients with drug-resistant epilepsy who underwent SEEG monitoring at the Children's Hospital of Fudan University from July 2014 to August 2017. Application of multimodal image fusion technology in SEEG was described in detail. Seizure outcomes were assessed according to the International League Against Epilepsy classification.

Results

A total of 208 patients were initially eligible and underwent a rigorous phase I evaluation. SEEG explorations were performed in 20 patients who entered phase II assessment (11 male and 9 female patients) with a median age of 7.99 ± 4.07 years. In total, 181 electrodes were implanted (9 per implantation), among which 16 implantations were unilateral (6 left and 10 right) and 4 were bilateral. The mean operating time was 3 hours and no obvious hemorrhage occurred. Electrode displacement and pneumocephalus were observed in 1 and 2 patients, respectively. Thirteen and 7 patients underwent tailored resection and radiofrequency thermocoagulation, respectively. Among resection cases, focal cortical dysplasia was the predominant pathologic type. The overall seizure outcome after a mean follow-up of 2.65 years was International League Against Epilepsy class 1 in 13, class 2 in 2, class 3 in 3, class 4 in 1, and class 5 in 1 patient, respectively.

Conclusions

The combination of multimodal image fusion and frameless robot-assisted SEEG is demonstrated to be safe and effective on children with refractory epilepsy in developing countries.

Introduction

Stereotactic implantation of intracerebral electrodes for chronic electroencephalography (EEG) recording of seizures, or stereoelectroencephalography (SEEG), was developed in late 1950s at Saint Anne Hospital in Paris, France, for the presurgical evaluation of patients with drug-resistant focal epilepsy.1 SEEG explorations are indicated whenever the noninvasive tests fail to adequately localize the epileptogenic zone (EZ).2 With the development of multimodal imaging technology, SEEG has become more valuable in the preoperative evaluation and surgical treatment of patients with refractory epilepsy, which has achieved satisfactory outcomes.3 However, refractory epilepsy in children remains a challenge. Due to complex anatomy of the brain, single-mode approaches such as computed tomography (CT) and magnetic resonance imaging (MRI) scans can only provide 2-dimensional images that cannot sufficiently meet clinical needs. With multimodal image fusion technology, registration fusion, and 3-dimensional (3D) reconstruction of CT, MRI and positron emission tomography (PET) data can be used for efficient visual display of the lesions and adjacent structures. The combination of SEEG and multimodal images has demonstrated potential benefits in epileptic foci detection.4 Most of the experience of SEEG used to come from sophisticated epileptic centers in Europe, although some epileptic centers outside Europe have also taken steps recently to develop SEEG monitoring technology. Few reports from developing countries are available so far, however. As a pediatric medical center in the largest developing country that has frequently carried out this technology in recent years, we have developed a relatively simple SEEG protocol with the combination of multimodal images that has led to satisfactory results. In this retrospective analysis, we assessed the role of this simple and practical approach utilizing multimodal imaging and robot-assisted SEEG in the treatment of refractory epilepsy in children, especially MRI-negative patients.

Section snippets

Methods

A total of 208 children with refractory epilepsy admitted to Children's Hospital of Fudan University from July 2014 to August 2017 were enrolled in this retrospective study. All patients underwent a rigorous presurgical evaluation according to a standardized flowchart (Figure 1): (1) Patients initially underwent phase I evaluation including detailed medical history, neurologic examinations, scalp EEG, long-term video EEG monitoring, MRI scan (3-mm thickness), and neuropsychological testing. (2)

General Characteristics

Stereotactic intracranial electrode implantation guided by multimodal image was successfully conducted (Figure 2). Baseline characteristics and outcomes of children undergoing robot-assisted SEEG is summarized in Table 1. Twenty children underwent robot-assisted SEEG electrode implantation at Children's Hospital of Fudan University, performed by a single surgeon. The mean age at implantation was 7.99 ± 4.07 years, with a range between 1.5 and 15 years. Three (range: 2–4) kinds of antiepileptic

Discussion

SEEG has been demonstrated to be able to identify cortical regions suspected of being involved in seizure onset and early propagation of the ictal discharge and delineate the border of the EZ to facilitate surgical planning among minimum cortical resection, disconnection, or thermocoagulation.2,7, 8, 9 The semiology of pediatric epilepsy is not as typical as adults, and the aura often cannot be accurately described by affected children. Furthermore, the abnormal discharge on EEG is easy to

Conclusions

In this study, multimodal imaging-guided SEEG technique on electrode implantations is demonstrated to be safe and effective. It is important to understand, however, that the success of a SEEG electrode implantation for EZ localization hinges on reasonable anatomo-electro-clinical assessment and hypothesis prior to implantation.17,19 A multidisciplinary team consisting of neurologists, radiologists, and neurosurgeons who are experienced in SEEG methodology is essential to establishing a

CRediT authorship contribution statement

Rui Zhao: Conceptualization, Writing - original draft, Visualization, Methodology. Ping Xue: Validation, Formal analysis, Writing - review & editing. Yuanfeng Zhou: Software, Validation. Haowei Yang: Resources, Data curation. Shuizhen Zhou: Investigation. Yi Wang: Validation. Hao Li: Conceptualization, Supervision.

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Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Rui Zhao and Ping Xue contributed equally to this work.

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