Epilepsy surgery in early infancy: A retrospective, multicenter study

Although epilepsy surgery is the only curative therapeutic approach for lesional drug-resistant epilepsy (DRE), there is reluctance to operate on infants due to a fear of complications. A recent meta-analysis showed that epilepsy surgery in the first 6 months of life can achieve seizure control in about two thirds of children. However, robust data on surgical complications and postoperative cognitive development are lacking. We performed a retrospective multicenter study of infants who underwent epilepsy surgery in the first 6 months of life. 15 infants underwent epilepsy surgery at a median age of 134 days (IQR: 58) at four centers. The most common cause was malformation of cortical development, and 13 patients underwent a hemispherotomy. Two thirds required intraoperative red blood transfusions. Severe intraoperative complications occurred in two patients including death in one infant due to cardiovascular insufficiency. At a median follow-up of 1.5 years (IQR: 1.8), 57% of patients were seizure-free. Three patients where reoperated at a later age, resulting in 79% seizure freedom. Anti-seizure medication could be reduced in two thirds, and all patients improved in their development. Our findings suggest that early epilepsy surgery can result in good seizure control and developmental improvement. However, given the perioperative risks, it should be performed only in specialized centers.

Cognitive and Behavioral Development of 9-Year-Old Children After Maternal Cancer During Pregnancy: A Prospective Multicenter Cohort Study

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.This multicenter cohort study reports on the long-term effects of prenatal exposure to maternal cancer and its treatment on cognitive and behavioral outcomes in 9-year-old children. In total, 151 children (mean age, 9.3 years; range, 7.8-10.6 years) were assessed using a neurocognitive test battery and parent-report behavioral questionnaires. During pregnancy, 109 children (72.2%) were exposed to chemotherapy (only or in combination with other treatment modalities), 18 (11.9%) to surgery only, 16 (10.6%) to radiotherapy, one to trastuzumab, and 16 (10.6%) were not exposed to oncologic treatment. Mean cognitive and behavioral outcomes were within normal ranges. Gestational age at birth showed a positive association with Full Scale Intelligence Quotient (FSIQ), with the average FSIQ score increasing by 1.6 points for each week increase in gestational age (95% CI, 0.7 to 2.5; P < .001). No difference in FSIQ was found between treatment types (F[4,140] = 0.45, P = .776). In children prenatally exposed to chemotherapy, no associations were found between FSIQ and chemotherapeutic agent, exposure level, or timing during pregnancy. These results indicate a reassuring follow-up during the critical maturational period of late childhood, when complex functions develop and rely on the integrity of early brain development. However, associations were observed with preterm birth, maternal death, and maternal education.

Epilepsy and Cognitive Impairment in Childhood and Adolescence: A Mini-Review

Managing epilepsy in people with an intellectual disability remains a therapeutic challenge and must take into account additional issues such as diagnostic difficulties and frequent drug resistance. Advances in genomic technologies improved our understanding of epilepsy and raised the possibility to develop patients-tailored treatments acting on the key molecular mechanisms involved in the development of the disease. In addition to conventional antiseizure medications (ASMs), ketogenic diet, hormone therapy and epilepsy surgery play an important role, especially in cases of drugresistance. This review aims to provide a comprehensive overview of the mainfactors influencing cognition in children and adolescents with epilepsy and the main therapeutic options available for the epilepsies associated with intellectual disability.

Development and Validation of Prediction Models for Developmental and Intellectual Outcome Following Pediatric Epilepsy Surgery

BACKGROUND AND OBJECTIVES

To (1) identify predictors of postoperative intelligence and developmental quotients (IQ/DQ) and (2) develop and validate clinically applicable IQ/DQ prediction models.

METHODS

We retrospectively analyzed neuropsychological outcomes and their possible determinants for children treated in Bethel and Utrecht since 1990. We performed separate analyses for patients with IQ and those with only DQ available. We developed prediction models based on presurgical determinants to predict dichotomized levels of performance (IQ≥85, IQ≥70, DQ≥50).

RESULTS

IQ/DQ data before and two years after surgery were available for 492 patients (IQ n=365, DQ n=127). At a cutoff-level ±10 points, the chance of improvement was considerably higher than the chance of deterioration (IQ 37.3% vs. 6.6% and DQ 31.5% vs. 15.0%, respectively). Presurgical IQ/DQ was the strongest predictor of postoperative cognition (IQ r=0.85, p<.001, DQ: r=0.57, p<.001).Two IQ models were developed in the Bethel cohort (n=258) and externally validated in the Utrecht cohort (n=102). For DQ, we developed the model in the Bethel cohort and used 10-fold cross-validation. Models allowed good prediction at all three cutoff-levels (correct classification for IQ≥85=86%, IQ≥70=91%, DQ≥50=76%). External validation of the IQ models showed high accuracy (IQ≥85: 0.82, CI 0.75-0.91, IQ≥70: 0.84, CI 0.77-0.92) and excellent discrimination (ROC curves IQ≥85: AUC 0.90, CI 0.84-0.96; IQ≥70: AUC 0.92, CI 0.87-0.97).

DISCUSSION

After epilepsy surgery in children, the risk of cognitive deterioration is very low. Presurgical development has a strong impact on the postoperative trajectory. The presented models can improve presurgical counseling of patients and parents by reliably predicting cognitive outcomes.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that for children undergoing epilepsy surgery presurgical IQ/DQ was the strongest predictor of postoperative cognition.

Does etiology really matter for epilepsy surgery outcome?

Multiple factors influence the outcomes of epilepsy surgery. Prognostic indicators varying from clinical characteristics, imaging findings, ictal, and interictal electrophysiological activity have been linked to surgical outcomes. In this review, we focus on the relatively under‐studied role of the underlying epilepsy histopathology in driving post‐surgical outcomes, specifically focusing on the broad categories of seizure outcomes and cognitive outcomes. For each of these two outcomes of interest, we answer two questions: 1)‐ does etiology matter? and 2)‐ how could it matter? The goal is to review the existing literature on the relationship between etiology and surgical outcomes to provide the best possible judgment as to whether a causal relationship exists between histopathology and the ultimate surgical outcome as an initial step. Then, we delve into the possible mechanisms via which such relationships can be explained. We conclude with a call to action to the epilepsy surgery and histopathology research community to push the mechanistic understanding of the pathology‐outcome interaction and identify actionable knowledge and biomarkers that could inform patient care in a timely fashion.

In this review, we focus on the relatively under‐studied role of the underlying epilepsy histopathology in driving post‐surgical outcomes, specifically focusing on the broad categories of seizure outcomes and cognitive outcomes. For each of these two outcomes of interest, we answer two questions: (1) does etiology matter? and (2) how could it matter? We then delve into the mechanisms of these answers.

Freedom From Seizures Might Be Key to Continuing Occupation After Epilepsy Surgery

Introduction: We hypothesized that epilepsy surgery for adult patients with temporal lobe epilepsy (TLE) who obtained freedom from seizures could provide opportunities for these patients to continue their occupation, and investigated continuity of occupation to test this postulation.

Methods: Data were obtained from patients who had undergone resective surgery for medically intractable TLE between October 2009 and April 2019 in our hospital. Inclusion criteria were as follows: (1) ≥16 years old at surgery; (2) post-operative follow-up ≥12 months; (3) seizure-free period ≥12 months. As a primary outcome, we evaluated employment status before and after surgery, classified into three categories as follows: Level 0, no job; Level 1, students or homemakers (financially supported by a family member); and Level 2, working. Neuropsychological status was also evaluated as a secondary outcome.

Results: Fifty-one (87.9%) of the 58 enrolled TLE patients who obtained freedom from seizures after surgery continued working as before or obtained a new job (employment status: Level 2). A significant difference in employment status was identified between before and after surgery (p = 0.007; Wilcoxon signed-rank test). Twenty-eight patients (48.3%) were evaluated for neuropsychological status both before and after surgery. Significant differences in Wechsler Adult Intelligence Scale-III scores were identified between before and after surgery (p < 0.05 each; paired t-test).

Conclusion: Seizure freedom could be a factor that facilitates job continuity, although additional data are needed to confirm that possibility. Further investigation of job continuity after epilepsy surgery warrants an international, multicenter study.

Influence of epilepsy surgery on developmental outcomes in children

Epilepsy surgery is the most effective treatment option for children with refractory focal lesional epilepsy, with seizure-freedom rates exceeding 70% two years after surgery. Although numbers of procedures in children are increasing over time, epilepsy surgery remains underutilized. Particularly in young children with developmental delay, arrest, or even regression, surgery can improve cognitive outcome. Many factors determine eventual developmental abilities, of which epilepsy duration is the most important modifiable predictor. Earlier surgery is not only associated with higher seizure-freedom rates, it also improves postoperative developmental outcomes. Every child with focal lesional epilepsy should therefore be referred early, to evaluate the possibilities of epilepsy surgery.

Cognitive performance in distinct groups of children undergoing epilepsy surgery-a single-centre experience

Background

We aimed first to describe trends in cognitive performance over time in a large patient cohort (n = 203) from a single tertiary centre for paediatric epilepsy surgery over the period of 16 years divided in two (developing—pre-2011 vs. established—post-2011). Secondly, we tried to identify subgroups of epilepsy surgery candidates with distinctive epilepsy-related characteristics that associate with their pre- and post-surgical cognitive performance. Thirdly, we analysed variables affecting pre-surgical and post-surgical IQ/DQ and their change (post- vs. pre-surgical).

Methods

We analysed IQ/DQ data obtained using standardized neuropsychological tests before epilepsy surgery and one year post-surgically, along with details of patient’s epilepsy, epilepsy surgery and outcomes in terms of freedom from seizures. Using regression analysis, we described the trend in post-operative IQ/DQ. Cognitive outcomes and the associated epilepsy- and epilepsy surgery-related variables were compared between periods before and after 2011. Using multivariate analysis we analysed the effect of individual variables on pre- and post-operative IQ/DQ and its change.

Results

Epilepsy surgery tends to improve post-surgical IQ/DQ, most significantly in patients with lower pre-surgical IQ/DQ, and post-surgical IQ/DQ strongly correlates with pre-surgical IQ/DQ (Rho = 0.888, p < 0.001). We found no significant difference in pre-, post-surgical IQ/DQ and IQ/DQ change between the periods of pre-2011 and post-2011 (p = 0.7, p = 0.469, p = 0.796, respectively). Patients with temporal or extratemporal epilepsy differed in their pre-surgical IQ/DQ (p = 0.001) and in IQ/DQ change (p = 0.002) from those with hemispheric epilepsy, with no significant difference in post-surgical IQ/DQ (p = 0.888). Groups of patients with different underlying histopathology showed significantly different pre- and post-surgical IQ/DQ (p < 0.001 and p < 0.001 respectively) but not IQ/DQ change (p = 0.345).Variables associated with severe epilepsy showed effect on cognitive performance in multivariate model.

Discussion

Post-surgical IQ/DQ strongly correlates with pre-surgical IQ/DQ and greatest IQ/DQ gain occurs in patients with lower pre-surgical IQ/DQ scores. Cognitive performance was not affected by changes in paediatric epilepsy surgery practice. Pre- and post-operative cognitive performances, as well as patients’ potential for cognitive recovery, are highly dependent on the underlying aetiology and epileptic syndrome.

Cognitive functioning after epilepsy surgery in children with mild malformation of cortical development and focal cortical dysplasia

Mild malformation of cortical development (mMCD) and focal cortical dysplasia (FCD) subtypes combined are by far the most common histological diagnoses in children who undergo surgery as treatment for refractory epilepsy. In patients with refractory epilepsy, a substantial burden of disease is due to cognitive impairment. We studied intelligence quotient (IQ) or developmental quotient (DQ) values and their change after epilepsy surgery in a consecutive series of 42 children (median age at surgery: 4.5, range: 0-17.0 years) with refractory epilepsy due to mMCD/FCD. Cognitive impairment, defined as IQ/DQ below 70, was present in 51% prior to surgery. Cognitive impairment was associated with earlier onset of epilepsy, longer epilepsy duration, and FCD type I histology. Clinically relevant improvement of ≥10 IQ/DQ points was found in 24% of children and was related to the presence of presurgical epileptic encephalopathy (EE). At time of postsurgical cognitive testing, 59% of children were completely seizure-free (Engel 1A). We found no association between cognitive outcome and seizure or medication status at two years of follow-up. Epilepsy surgery in children with mMCD or FCD not only is likely to result in complete and continuous seizure freedom, but also improves cognitive function in many.

Effects of lead, mercury, aluminium and manganese co-exposure on the serum BDNF concentration of pre-school children in Taizhou, China

Previous studies have shown that toxic metal exposure can have adverse effects on the nervous system of children, but the toxicology of metal co-exposure on neurodevelopment remains to be clarified. Brain derived neurotrophic factor (BDNF) plays an important role in nervous system development, but the possible effects of metal co-exposure on the serum BDNF concentrations of children remain unknown. A total of 561 children living in Taizhou City, China were recruited to participate in our cross-sectional multicenter survey. We measured their blood Pb, Hg, Al and Mn levels and serum BDNF concentrations as well as determined their associations in the total and within sex subgroups. The geometric means of the blood Pb, Hg, Al and Mn levels in all the participants were 67.18 μg/L, 1.01 μg/L, 52.03 μg/L and 18.26 μg/L, respectively. The serum BDNF concentration in children was 19.45 ng/mL. After adjusting for confounders, the blood Pb levels were significantly negatively associated with the serum BDNF concentrations in all the subjects and boys but not in girls. In addition, a significantly negative interaction between blood Pb and blood Hg and a positive interaction between blood Pb and blood Al on serum BDNF concentrations were also observed in boys but not in girls. Our findings highlight the toxic effects of metal co-exposure on serum BDNF levels in pre-school children and indicate that these effects might differ by gender, which suggest that special attention should be paid to the sex-specific effects of metal exposure.

Preventing cognitive impairment in children with epilepsy

PURPOSE OF REVIEW

Cognitive impairments are common in children with epilepsy. They may already be present before the onset of epilepsy or occur - and even progress - during its course. Many variables contribute to cognitive dysfunction. Those that can be targeted to prevent (further) cognitive impairment will be highlighted in this review.

RECENT FINDINGS

Ideally, but not yet realistically, epileptogenesis is prevented to avert seizures and cognitive impairments in high-risk patients. New and targeted treatments of progressive epileptogenic disorders and precision medicine approaches in genetic epilepsies are increasingly applied. Cognitive outcome benefits from early diagnosis and treatment of epileptic encephalopathy. Ongoing seizures may cause permanent and progressive changes in brain structure and connectivity, suggesting that early seizure control optimizes eventual cognitive functioning. Frequent interictal epileptiform discharges justify treatment in children with cognitive impairments that are otherwise unexplained. Cognitive adverse effects of antiepileptic drugs should be closely monitored and balanced against potential benefits. Finally, early surgical treatment in selected candidates will improve their cognitive outcome.

SUMMARY

Although important determinants of intellectual functioning - including the child's genetic and environmental background and the epileptogenic pathology - may not be modifiable, several variables that contribute to cognitive impairment can be targeted to improve outcome. Early etiological diagnosis, personalized therapies, presurgical evaluation, and strict control of seizures - or in some patients interictal discharges - can prevent (further) cognitive impairments.

Predictors of intellectual functioning after epilepsy surgery in childhood: The role of socioeconomic status

OBJECTIVE

The objective of this study was to evaluate the association between socioeconomic status and intellectual functioning in children with medically refractory epilepsy, before and after resective epilepsy surgery. Family environment is a strong contributor to cognitive development in children and has been recently shown to play a significant role in intellectual outcome after surgery in children with epilepsy.

METHODS

One hundred children who had undergone resective epilepsy surgery and completed preoperative and postoperative assessments of IQ as part of clinical care were included in the study. We evaluated the impact of epilepsy-related variables, income quintile, and residence location on IQ.

RESULTS

Greater improvements in IQ after surgery were associated with an older age at surgery (β=.235, p=.018). Higher IQ scores at follow-up were associated with an older age of seizure onset (β=.371, p<.001), older age at surgery (β=.356, p<.001), unilobar epileptogenic focus (β=.394, p<.001), and mesial temporal sclerosis (β=.338, p=.001) or tumor (β=.457, p<.001) in comparison with malformation of cortical development; age at seizure onset did not remain as a significant predictor in multivariable regression analysis. Income quintile, residence location, seizure control, and antiepileptic medication use were not significant predictors.

CONCLUSIONS

Epilepsy-related variables were the strongest predictors of IQ and postoperative change in IQ. We were unable to identify a significant association between IQ and socioeconomic status. Future research should evaluate the impact of multiple aspects of family environment.