Epilepsy Surgery in Children

Resective epilepsy surgery in pediatric patients with normal MRI: outcomes, challenges, and cost-effectiveness in low-resource settings

BACKGROUND

Pediatric patients with drug-resistant epilepsy and normal preoperative MRIs present significant challenges in surgical planning. Advanced diagnostic techniques, including PET, SPECT, and intraoperative ECOG, are used to localize seizure foci, but their high cost and limited availability pose challenges, especially in low-resource settings. This study aims to evaluate the outcomes of resective epilepsy surgery in these cases and assess the role of advanced imaging in a middle-income country.

METHODS

This retrospective cohort study included 12 pediatric patients (mean age 10.21 years) with normal preoperative 3 T MRI who underwent resective epilepsy surgery or functional hemispherectomy between 2007 and 2021 at two centers in Medellín, Colombia. Demographic, clinical, and surgical data were collected, including the use of advanced imaging techniques (PET, SPECT) and intraoperative ECOG. Seizure outcomes were assessed using the Engel Epilepsy Surgery Outcome Scale.

RESULTS

Of the 12 patients, 10 underwent extratemporal resections, and 2 underwent temporal lobe surgery. Seven patients had advanced imaging, and 5 were evaluated with intraoperative ECOG. At 2-year follow-up, 83.3% of patients who underwent resective surgery achieved favorable outcomes (Engel Classes I and II). Temporal lobe resections had a higher rate of seizure freedom (50%) compared to extratemporal resections (30%), although the difference was not statistically significant (p = 0.47). Reoperations due to seizure recurrence were required in 30% of extratemporal resections (p = 0.02). Complications were minimal, with three superficial wound infections. Histopathology revealed cortical dysplasia in 33.3% of cases.

CONCLUSION

Epilepsy surgery in pediatric patients with normal MRIs can yield favorable outcomes, especially with temporal lobe resections. Advanced imaging improves localization but remains costly, highlighting the need for cost-effective surgical strategies in resource-limited settings.

A multidisciplinary approach to posterior quadrant disconnective epilepsy surgery in pediatric patients

PURPOSE

Extensive lesions of the posterior quadrant are a relevant cause of pediatric drug-resistant epilepsy. Early surgery is the best treatment in these cases, but conventional multilobar resections carry a significant risk in pediatric patients. Despite temporo-parieto-occipital (TPO) disconnection being the preferable technique due to the preservation of motor function, studies reporting long-term longitudinal outcomes are still limited. This study aims to analyze seizures and developmental outcomes after TPO disconnection.

METHODS

A prospective analysis was carried out on 12 children who underwent TPO disconnection.

RESULTS

TPO disconnection was performed in 12 pediatric patients aged between 14 months and 18 years (median 6.29 years). The average age of seizure onset was 0.97 ± 1.22 years. Causes of TPO included perinatal ischemia in 4 patients and malformation of cortical development (MCD) in 8 patients. The presenting seizure types were focal motor impaired awareness seizures in 7 children and generalized in 5. The affected hemisphere was the right in 9 patients and the left in 3. In half of the patients, the temporal approach was performed through T1, and in the other 50%, it was performed through T2. After neuropsychological examination, 2 children improved, 7 remained stable, 2 patients presented stagnation and 1 declined. Regarding postoperative complications, nonresorptive hydrocephalus and an asymptomatic caudate nucleus infarct were observed. After a median follow-up of 2 years, 9 patients were in Engel's Class I seizure outcome.

CONCLUSION

TPO disconnection is a safe and effective motor-sparing epilepsy surgery for children with refractory seizures located in the posterior quadrant that prevents further cognitive deterioration.

Predictors of surgical outcomes in patients with drug-resistant temporal lobe epilepsy

Aim. To identify predictors of surgical outcomes in patients with drug-resistant temporal lobe epilepsy in a multivariate model.

Materials and methods. Aretrospective study included 69 patients with drug-resistant temporal lobe epilepsy who underwent microsurgical anterior temporal lobectomy. The study included 31 (45%) men and 38 (55%) women. The median age was 28 (21; 36). Surgical treatment outcomes were assessed at 6, 12, 36, and 60 months after surgical intervention according to the Engel Epilepsy Surgery Outcome Scale. Logistic regression equations were calculated, a ROC curve was constructed, and odds ratio (OR) with 95% confidence interval (CI), sensitivity, specificity, area under the ROC curve (AUC) were calculated.

Results. In all assessed time periods, 88.3–93.0% of patients had outcomes consistent with Engel classes I and II. The distribution of patients by outcome classes did not change statistically significantly over the entire follow-up period. There were the following predictors of high efficacy of surgical treatment at 6 months after surgery: relatively shorter duration of active disease course (OR 0.719, 95%, CI: 0.437–0.966, p < 0.05), absence of status epilepticus (OR 0.048, 95% CI: 0.002–0.472, p < 0.05), absence of subdominant foci of irritative activity (OR 0.123, 95% CI: 0.012–0.845, p < 0.01), presence of mesial temporal sclerosis (OR 1008, 95% CI: 21.59–1310851, p < 0.01), a relatively longer resection margin on the temporal lobe (OR 637.32, 95% CI: 5.43–1960062, p < 0.05), lateralization of epileptogenic zone in subdominant hemisphere (OR 0.103, 95% CI 0.004–0.937, p = 0.0532). AUC was 0.957 (0.917–0.997), p < 0.0001; sensitivity 87.5%, and specificity 82.8%.

Conclusion. Independent predictors of the efficacy of microsurgical anterior temporal lobectomy in patients with drug-resistant temporal lobe epilepsy are the following: shorter duration of active disease course, absence of status epilepticus in the history, absence of subdominant foci, presence of mesial temporal sclerosis, a relatively longer resection margin on the temporal lobe, and lateralization of the epileptogenic zone in the temporal lobe of the subdominant hemisphere.

Repeat surgery for pediatric epilepsy: a systematic review and meta-analysis of resection and disconnection approaches

OBJECTIVE

Resection and disconnection surgeries for epilepsy in the pediatric demographic (patients ≤ 18 years of age) are two separate, definitive intervention options in medically refractory cases. Questions remain regarding the role of surgery when seizures persist after an initial incomplete surgery. The aim of this study was to review the contemporary literature and summarize the metadata on the outcomes of repeat surgery in this specific demographic.

METHODS

Searches of seven electronic databases from inception to July 2022 were conducted using PRISMA guidelines. Articles were screened using prespecified criteria. Metadata from the articles were abstracted and pooled by random-effects meta-analysis of proportions.

RESULTS

Eleven studies describing 12 cohorts satisfied all criteria, reporting outcomes of 170 pediatric patients with epilepsy who underwent repeat resection or disconnection surgery. Of these patients, 55% were male, and across all studies, median ages at initial and repeat surgeries were 7.2 and 9.4 years, respectively. The median follow-up duration after repeat surgery was 47.7 months. The most commonly reported etiology for epilepsy was cortical dysplasia. Overall, the estimated incidence of complete seizure freedom (Engel class I) following repeat surgery was 48% (95% CI 40%-56%, p value for heterogeneity = 0.93), and the estimated incidence of postoperative complications following repeat surgery was 25% (95% CI 12%-39%, p = 0.04). There were six cohorts each that described outcomes for repeat resection and repeat disconnection surgeries. There was no statistical difference between these two subgroups with respect to estimated incidence of complete seizure freedom (p value for interaction = 0.92), but postoperative complications were statistically more common following repeat resection (p ≤ 0.01).

CONCLUSIONS

For both resection and disconnection surgeries, repeat epilepsy surgery in children is likely to confer complete seizure freedom in approximately half of the patients who experience unsuccessful initial incomplete epilepsy surgery. More data are needed to elucidate the impact on efficacy based on surgical approach selection. Judicious discussion and planning between the patient, family, and a multidisciplinary team of epilepsy specialists is recommended to optimize expectations and outcomes in this setting.

Abnormal electroencephalogram (EEG) after drug withdrawal is a risk factor for epilepsy recurrence in children: a systematic review and meta-analysis

BACKGROUND

The relationship between abnormal electroencephalogram (EEG) and epilepsy recurrence after antiepileptic drug (AED) withdrawal has been controversial. We aimed to explore the relationship between abnormal EEG after AED withdrawal and the risk of epilepsy recurrence in children.

METHODS

Literature retrieval was performed using the PubMed, EMBASE, Medline, CENTRAL, and China National Knowledge Infrastructure (CNKI) databases. Included literatures were subjects of pediatric epilepsy patients who discontinued medication. The recurrence rate of epilepsy in patients with normal and abnormal EEG after AED withdrawal was observed. The Newcastle-Ottawa scale (NOS) was used to evaluate the quality of literatures. The Chi-square test was used to test heterogeneity. If heterogeneity between the articles existed, a random-effects model was used; otherwise, fixed-effects models were used. Subgroup analysis was used to explore the causes of heterogeneity. The odds ratio (OR) and 95% confidence interval (CI) were calculated using the Mantel-Haenszel statistical method. OR was not adjusted for other factors.

RESULTS

A total of 843 articles were retrieved. Nine studies were included, with a total of 1,663 patients, including 1,299 patients with normal EEG and 364 patients with abnormal EEG. Compared with the normal EEG patients, the OR of recurrence rate after AEDs withdrawal was 3.02 (P=0.0003), with heterogeneity (P<0.0001). The funnel plot indicated that there was no publication bias among the studies. The not partial seizure group analysis showed OR =1.70 (P=0.003) and no heterogeneity (P=0.70) in patients with abnormal EEG compared to those with normal EEG. In the partial seizures subgroup, the OR of the recurrence rate after AED withdrawal was 8.08 (P<0.00001) compared with the normal EEG patients, and there was no heterogeneity (P=0.29). The funnel chart shows that the partial seizures type subgroup analysis revealed positive results, while the not partial seizure group analysis reported negative results, indicating publication bias.

CONCLUSIONS

The risk of epilepsy recurrence is higher in children with abnormal EEG after AED withdrawal, regardless of seizure type. For pediatric epilepsy patients with abnormal EEG after AED withdrawal, a more cautious discontinuation regimen, closer follow-up and monitoring are required.