Developmental outcome after epilepsy surgery in infancy

Hemispherotomy for isolated infantile spasms following perinatal ischemic stroke

BACKGROUND

Infantile spasms (IS) are a severe epileptic encephalopathy. In patients with early focal ischemia and refractory IS, a preoperative evaluation is required even if IS are the only ictal manifestation.

METHODS

We report three such patients who presented with IS between 5 and 7 months of age without any other focal seizure types. Imaging exhibited a perinatal middle cerebral artery (MCA) stroke.

RESULTS

All patients had hemiparesis and experienced psychomotor regression after the onset of IS. Scalp video-electroencephalogram (EEG) monitoring for presurgical assessment showed interictal and ictal EEG characteristics between the pathological and the healthy hemisphere and surgery was proposed despite the lack of any focal seizures. The three patients underwent hemispherotomy at a mean age of 27 months and became seizure-free without medication (follow-up 49-144 months). The two patients who underwent early hemispherotomy acquired normal verbal intelligence, whereas the third, operated on at 38 months of age, remained with severe mental retardation.

CONCLUSION

Early hemispherotomy in drug-resistant epilepsy related to a perinatal MCA may cure the seizures even if the patient has IS as sole type and prevent mental retardation in some children.

Vagus nerve stimulation therapy for treatment-resistant epilepsy: a 15-year experience at a single institution

OBJECTIVE

Treatment-resistant epilepsy (TRE) occurs in 20-30% of patients. The goal of this study is to assess the efficacy and safety of vagus nerve stimulation (VNS) in this group of patients, including adult and pediatric populations and several off-label indications.

METHODS

This is a retrospective review of 59 consecutive patients in whom 60 VNS devices were implanted at a single institution during a 15-year period. Patients were evaluated in the Multidisciplinary Epilepsy Committee and complete presurgical workup was performed. The series included indications not approved by the FDA, such as children under 12 years of age, pregnancy and right-sided VNS. Performing the procedure on an out-patient basis was recently adopted, minimizing hospital length of stay.

RESULTS

There were 42 adults and 17 children (14 under 12 years of age) and the mean age at implantation was 26 years. Duration of VNS therapy ranged from 6 months to 9 years. For the entire cohort, the mean percentage seizure reduction was 31.37%. Twenty patients (34.48%) were considered responders (seizure reduction ≥50%); 7 patients (12.06%) had seizure reduction of ≥75% and 2 patients had seizure control of ≥90% (3.4%). The patient in whom right-sided VNS was implanted achieved the same reduction in seizure burden and the patient who became pregnant could reduce antiepileptic drugs dosage, without complications. Side-effects were mild and there were no permanent nerve injuries. One patient died in the follow-up due to psychiatric disorders previously known.

CONCLUSIONS

VNS is a safe and effective palliative treatment for TRE patients. There are an increasing number of indications and further randomized trials would potentially expand the number of patients who may benefit from it. A multidisciplinary team is crucial for a complete preoperative evaluation and selection of the optimal candidates for the treatment.

Surgery for epilepsy

BACKGROUND

Focal epilepsies are caused by a malfunction of nerve cells localised in one part of one cerebral hemisphere. In studies, estimates of the number of individuals with focal epilepsy who do not become seizure-free despite optimal drug therapy vary according to the age of the participants and which focal epilepsies are included, but have been reported as at least 20% and in some studies up to 70%. If the epileptogenic zone can be located surgical resection offers the chance of a cure with a corresponding increase in quality of life.

OBJECTIVES

The primary objective is to assess the overall outcome of epilepsy surgery according to evidence from randomised controlled trials.The secondary objectives are to assess the overall outcome of epilepsy surgery according to non-randomised evidence and to identify the factors that correlate to remission of seizures postoperatively.

SEARCH METHODS

We searched the Cochrane Epilepsy Group Specialised Register (June 2013), the Cochrane Central Register of Controlled Trials (CENTRAL 2013, Issue 6), MEDLINE (Ovid) (2001 to 4 July 2013), ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) for relevant trials up to 4 July 2013.

SELECTION CRITERIA

Eligible studies were randomised controlled trials (RCTs), cohort studies or case series, with either a prospective and/or retrospective design, including at least 30 participants, a well-defined population (age, sex, seizure type/frequency, duration of epilepsy, aetiology, magnetic resonance imaging (MRI) diagnosis, surgical findings), an MRI performed in at least 90% of cases and an expected duration of follow-up of at least one year, and reporting an outcome relating to postoperative seizure control.

DATA COLLECTION AND ANALYSIS

Three groups of two review authors independently screened all references for eligibility, assessed study quality and risk of bias, and extracted data. Outcomes were proportion of participants achieving a good outcome according to the presence or absence of each prognostic factor of interest. We intended to combine data with risk ratios (RR) and 95% confidence intervals.

MAIN RESULTS

We identified 177 studies (16,253 participants) investigating the outcome of surgery for epilepsy. Four studies were RCTs (including one that randomised participants to surgery or medical treatment). The risk of bias in the RCTs was unclear or high, limiting our confidence in the evidence that addressed the primary review objective. Most of the remaining 173 non-randomised studies had a retrospective design; they were of variable size, were conducted in a range of countries, recruited a wide demographic range of participants, used a wide range of surgical techniques and used different scales used to measure outcomes. We performed quality assessment using the Effective Public Health Practice Project (EPHPP) tool and determined that most studies provided moderate or weak evidence. For 29 studies reporting multivariate analyses we used the Quality in Prognostic Studies (QUIPS) tool and determined that very few studies were at low risk of bias across the domains.In terms of freedom from seizures, one RCT found surgery to be superior to medical treatment, two RCTs found no statistically significant difference between anterior temporal lobectomy (ATL) with or without corpus callosotomy or between 2.5 cm or 3.5 cm ATL resection, and one RCT found total hippocampectomy to be superior to partial hippocampectomy. We judged the evidence from the four RCTs to be of moderate to very low quality due to the lack of information reported about the randomised trial design and the restricted study populations.Of the 16,253 participants included in this review, 10,518 (65%) achieved a good outcome from surgery; this ranged across studies from 13.5% to 92.5%. Overall, we found the quality of data in relation to the recording of adverse events to be very poor.In total, 118 studies examined between one and eight prognostic factors in univariate analysis. We found the following prognostic factors to be associated with a better post-surgical seizure outcome: an abnormal pre-operative MRI, no use of intracranial monitoring, complete surgical resection, presence of mesial temporal sclerosis, concordance of pre-operative MRI and electroencephalography (EEG), history of febrile seizures, absence of focal cortical dysplasia/malformation of cortical development, presence of tumour, right-sided resection and presence of unilateral interictal spikes. We found no evidence that history of head injury, presence of encephalomalacia, presence of vascular malformation or presence of postoperative discharges were prognostic factors of outcome. We observed variability between studies for many of our analyses, likely due to the small study sizes with unbalanced group sizes, variation in the definition of seizure outcome, definition of the prognostic factor and the influence of the site of surgery, all of which we observed to be related to postoperative seizure outcome. Twenty-nine studies reported multivariable models of prognostic factors and the direction of association of factors with outcome was generally the same as found in the univariate analyses. However, due to the different multivariable analysis approaches and selective reporting of results, meaningful comparison of multivariate analysis with univariate meta-analysis is difficult.

AUTHORS' CONCLUSIONS

The study design issues and limited information presented in the included studies mean that our results provide limited evidence to aid patient selection for surgery and prediction of likely surgical outcome. Future research should be of high quality, have a prospective design, be appropriately powered and focus on specific issues related to diagnostic tools, the site-specific surgical approach and other issues such as the extent of resection. Prognostic factors related to the outcome of surgery should be investigated via multivariable statistical regression modelling, where variables are selected for modelling according to clinical relevance and all numerical results of the prognostic models are fully reported. Protocols should include pre- and postoperative measures of speech and language function, cognition and social functioning along with a mental state assessment. Journal editors should not accept papers where adverse events from a medical intervention are not recorded. Improvements in the development of cancer care over the past three to four decades have been achieved by answering well-defined questions through the conduct of focused RCTs in a step-wise fashion. The same approach to surgery for epilepsy is required.

Epilepsy surgery for pediatric epilepsy: optimal timing of surgical intervention

Pediatric epilepsy has a wide variety of etiology and severity. A recent epidemiological study suggested that surgery might be indicated in as many as 5% of the pediatric epilepsy population. Now, we know that effective epilepsy surgery can result in seizure freedom and improvement of psychomotor development. Seizure control is the most effective way to improve patients neurologically and psychologically. In this review, we look over the recent evidence related to pediatric epilepsy surgery, and try to establish the optimal surgical timing for patients with intractable epilepsy. Appropriate surgical timing depends on the etiology and natural history of the epilepsy to be treated. The most common etiology of pediatric intractable epilepsy patients is malformation of cortical development (MCD) and early surgery is recommended for them. Patients operated on earlier than 12 months of age tended to improve their psychomotor development compared to those operated on later. Recent progress in neuroimaging and electrophysiological studies provide the possibility of very early diagnosis and comprehensive surgical management even at an age before 12 months. Epilepsy surgery is the only solution for patients with MCD or other congenital diseases associated with intractable epilepsy, therefore physicians should aim at an early and precise diagnosis and predicting the future damage, consider a surgical solution within an optimal timing.

"A journey around the world": Parent narratives of the journey to pediatric resective epilepsy surgery and beyond

OBJECTIVE

Although shorter time to pediatric resective epilepsy surgery is strongly associated with greater disease severity, other nonclinical diagnostic and sociodemographic factors also play a role. We aimed to examine parent-reported barriers to timely receipt of pediatric epilepsy surgery.

METHODS

We conducted 37 interviews of parents of children who previously had resective epilepsy surgery at University of California Los Angeles (UCLA; 2006-2011). Interviews were audio-recorded, transcribed, and systematically coded using thematic analysis by two independent coders, and subsequently checked for agreement. Clinical data, including "time to surgery" (age of epilepsy onset to surgery) were abstracted from medical records.

RESULTS

The mean time to surgery was 5.3 years (standard deviation [SD] 3.8); surgery types included 32% hemispherectomy, 43% lobar/focal, and 24% multilobar. At surgery, parents were on average 38.4 years (SD 6.6) and children were on average 8.2 years (SD 4.7). The more arduous and longer aspect of the journey to surgery was perceived by parents to be experienced prior to presurgical referral. The time from second antiepileptic drug failure to presurgical referral was ≥ 1 year in 64% of children. Thematic analysis revealed four themes (with subthemes) along the journey to surgery and beyond: (1) recognition--"something is wrong" (unfamiliarity with epilepsy, identification of medical emergency); (2) searching and finding--"a circuitous journey" (information seeking, finding the right doctors, multiple medications, insurance obstacles, parental stress); (3) surgery is a viable option--"the right spot" (surgery as last resort, surgery as best option, hoping for candidacy); and (4) life now--"we took the steps we needed to" (a new life, giving back).

SIGNIFICANCE

Multipronged interventions targeting parent-, provider-, and system-based barriers should focus on the critical presurgical referral period; such interventions are needed to remediate delays and improve access to subspecialty care for children with medically refractory epilepsy and potentially eligible for surgery.

Alternate scoring of the Bayley-III improves prediction of performance on Griffiths Mental Development Scales before school entry in preschoolers with developmental concerns

BACKGROUND

The Bayley-III is widely used as an assessment tool in young children; however, its standard composite scores appear to under-estimate delay, severe and profound delay cannot be identified, and the lack of an overall score makes it difficult to compare results with later assessments.

AIMS

To explore the use of Bayley-III quotient subtest and average scores, compared with composite subtest and average scores for both clinical and research purposes, comparing their ability to predict performance on the Griffiths Mental Development Scales (Griffiths) before school entry.

METHOD

One hundred preschoolers referred for a diagnosis were assessed on the Bayley-III before 3.5 years. They were reassessed before school entry on the Griffiths. Composite and quotient scores were calculated and their ability to predict outcome compared across the score range.

RESULTS

Averaging the three subscale quotient scores (Bayley-AQS) gave a similar mean score for this sample (61.1, SD 16.2) as for the Griffiths general quotient (Griffiths-GQ) (61.1, SD 19.6). The average composite scores (Bayley-ACS) had a significantly higher mean (74.2, SD 12.1). Correlations between the average scores on the Bayley-III and the Griffiths-GQ (0.8) were at least as strong as any of the individual subscale scores. Kappa coefficients showed that Bayley-AQS was superior to Bayley-ACS for predicting moderate and severe delay. Average change in scores was -0.1 for Bayley-AQS, and -13.2 for Bayley-ACS. Improvement in category of delay was seen in 28% of children using Bayley-AQS, and deterioration in 22%. In contrast, 5% improvement was seen using Bayley-ACS, and 65% deterioration.

CONCLUSIONS

The three directly assessed subscales of the Bayley-III can be averaged to give an overall score. Bayley-AQS are a better measure of development in young children with delay than Bayley-ACS, and most children maintain their developmental classification using this method of scoring when re-assessed before school entry.

Epilepsy surgery for glioneuronal tumors in childhood: avoid loss of time

BACKGROUND

In contrast to the abundance of seizure outcome reports in epilepsy surgery for glioneuronal tumors in childhood and adolescence, there is a dearth of information regarding cognitive outcomes.

OBJECTIVE

To investigate the seizure and cognitive outcome of children and adolescents that underwent resective surgery for glioneuronal tumor-associated refractory epilepsy and determine their predictive factors.

METHODS

We retrospectively analyzed the presurgical findings, resection types, and outcomes over 1.3 to 12.3 years (mean, 7.3) of 29 consecutive patients, who underwent resection in 2000 to 2011. The mean age at epilepsy onset was 7.9 years (range, 0-15.4), the mean age at surgery was 11.7 years (range, 2.6-17.3), and the mean epilepsy duration to surgery was 3.8 years (range, 0.3-15.3). Etiology comprised 13 dysembryoplastic neuroepithelial tumors and 16 gangliogliomas, with additional focal cortical dysplasia in 5 cases.

RESULTS

Eighty-six percent of children were seizure free 12 months after surgery; at final follow-up, 76% remained seizure free and 62% had discontinued antiepileptic drugs. Gross total resection was related to significantly higher rates of seizure freedom. Higher presurgical cognitive functioning (full-scale IQ, verbal IQ) was related to shorter epilepsy duration to surgery independent of age at epilepsy onset, thus determining postsurgical functioning. Improvements in verbal IQ, performance IQ, and visual memory as well as a trend toward improvement in full-scale IQ were established after surgery. Despite individual losses in full-scale IQ, verbal or visual memory, no deterioration was noted in any cognitive variable on a group level.

CONCLUSION

Completeness of resection predisposes to favorable outcomes regarding seizure alleviation. Whereas cognitive functioning deteriorates with time in glioneuronal tumor-related refractory epilepsy, surgery is linked to improvement rather than to deterioration on a group level.

Increasing utilization of pediatric epilepsy surgery in the United States between 1997 and 2009

OBJECTIVE

To examine national trends of pediatric epilepsy surgery usage in the United States between 1997 and 2009.

METHODS

We performed a serial cross-sectional study of pediatric epilepsy surgery using triennial data from the Kids' Inpatient Database from 1997 to 2009. The rates of epilepsy surgery for lobectomies, partial lobectomies, and hemispherectomies in each study year were calculated based on the number of prevalent epilepsy cases in the corresponding year. The age-race-sex adjusted rates of surgeries were also estimated. Mann-Kendall trend test was used to test for changes in the rates of surgeries over time. Multivariable regression analysis was also performed to estimate the effect of time, age, race, and sex on the annual incidence of epilepsy surgery.

RESULTS

The rates of pediatric epilepsy surgery increased significantly from 0.85 epilepsy surgeries per 1,000 children with epilepsy in 1997 to 1.44 epilepsy surgeries per 1,000 children with epilepsy in 2009. An increment in the rates of epilepsy surgeries was noted across all age groups, in boys and girls, all races, and all payer types. The rate of increase was lowest in blacks and in children with public insurance. The overall number of surgical cases for each study year was lower than 35% of children who were expected to have surgery, based on the estimates from the Connecticut Study of Epilepsy.

SIGNIFICANCE

In contrast to adults, pediatric epilepsy surgery numbers have increased significantly in the past decade. However, epilepsy surgery remains an underutilized treatment for children with epilepsy. In addition, black children and those with public insurance continue to face disparities in the receipt of epilepsy surgery.

Conceptualizing lennox-gastaut syndrome as a secondary network epilepsy

Lennox–Gastaut Syndrome (LGS) is a category of severe, disabling epilepsy, characterized by frequent, treatment-resistant seizures, and cognitive impairment. Electroencephalography (EEG) shows characteristic generalized epileptic activity that is similar in those with lesional, genetic, or unknown causes, suggesting a common underlying mechanism. The condition typically begins in young children, leaving many severely disabled with recurring seizures throughout their adult life. Scalp EEG of the tonic seizures of LGS is characterized by a diffuse high-voltage slow transient evolving into generalized low-voltage fast activity, likely reflecting sustained fast neuronal firing over a wide cortical area. The typical interictal discharges (runs of slow spike-and-wave and bursts of generalized paroxysmal fast activity) also have a “generalized” electrical field, suggesting widespread cortical involvement. Recent brain mapping studies have begun to reveal which cortical and subcortical regions are active during these “generalized” discharges. In this critical review, we examine findings from neuroimaging studies of LGS and place these in the context of the electrical and clinical features of the syndrome. We suggest that LGS can be conceptualized as “secondary network epilepsy,” where the epileptic activity is expressed through large-scale brain networks, particularly the attention and default-mode networks. Cortical lesions, when present, appear to chronically interact with these networks to produce network instability rather than triggering each individual epileptic discharge. LGS can be considered as “secondary” network epilepsy because the epileptic manifestations of the disorder reflect the networks being driven, rather than the specific initiating process. In this review, we begin with a summation of the clinical manifestations of LGS and what this has revealed about the underlying etiology of the condition. We then undertake a systematic review of the functional neuroimaging literature in LGS, which leads us to conclude that LGS can best be conceptualized as “secondary network epilepsy.”

Infantile spasms syndrome, West syndrome and related phenotypes: what we know in 2013

The current spectrum of disorders associated to clinical spasms with onset in infancy is wider than previously thought; accordingly, its terminology has changed. Nowadays, the term Infantile spasms syndrome (ISs) defines an epileptic syndrome occurring in children younger than 1 year (rarely older than 2 years), with clinical (epileptic: i.e., associated to an epileptiform EEG) spasms usually occurring in clusters whose most characteristic EEG finding is hypsarrhythmia [the spasms are often associated with developmental arrest or regression]. The term West syndrome (WS) refers to a form (a subset) of ISs, characterised by the combination of clustered spasms and hypsarrhythmia on an EEG and delayed brain development or regression [currently, it is no longer required that delayed development occur before the onset of spasms]. Less usually, spasms may occur singly rather than in clusters [infantile spasms single-spasm variant (ISSV)], hypsarrhythmia can be (incidentally) recorded without any evidence of clinical spasms [hypsarrhythmia without infantile spasms (HWIS)] or typical clinical spasms may manifest in absence of hypsarrhythmia [infantile spasms without hypsarrhythmia (ISW)]. There is a growing evidence that ISs and related phenotypes may result, besides from acquired events, from disturbances in key genetic pathways of brain development: specifically, in the gene regulatory network of GABAergic forebrain dorsal-ventral development, and abnormalities in molecules expressed at the synapse. Children with these genetic associations also have phenotypes beyond epilepsy, including dysmorphic features, autism, movement disorders and systemic malformations. The prognosis depends on: (a) the cause, which gives origin to the attacks (the complex malformation forms being more severe); (b) the EEG pattern(s); (c) the appearance of seizures prior to the spasms; and (d) the rapid response to treatment. Currently, the first-line treatment includes the adrenocorticotropic hormone ACTH and vigabatrin. In the near future the gold standard could be the development of new therapies that target specific pathways of pathogenesis. In this article we review the past and growing number of clinical, genetic, molecular and therapeutic discoveries on this expanding topic.

Epilepsy surgery in children: why, when and how?

Epilepsy surgery is safe and effective treatment in children who fail to respond to antiepileptic medications. After failure of two appropriate antiepileptic medications, chances that the child will become seizure free with more or different medications is <5%, and she should be diagnosed with "refractory epilepsy". A consideration for surgical candidacy should be given to all children who fulfill the definition of refractory epilepsy. In appropriately selected children, epilepsy surgery offers a high chance of seizure freedom without incurring any new post-operative neurological deficits. No age is bar to epilepsy surgery. Even infants can safely have epilepsy surgery if they are surgical candidates. For most children, who are surgical candidates, a good history and physical examination, video EEG evaluation, and a high quality brain MRI are sufficient to make surgical decision. These tools are increasingly available all over the world. Better education of families, Pediatricians, Pediatric Neurologists and community care-givers is necessary to salvage children early from mortality and morbidity of untreated, sometimes life long, epilepsy.

Developmental outcome after surgery in focal cortical dysplasia patients with early-onset epilepsy

The purpose of this study was to investigate the developmental outcome after surgery for early-onset epilepsy in patients with focal cortical dysplasia (FCD). Among 108 patients with histopathologically confirmed FCD operated between 1985 and 2008, we selected 17 patients with epilepsy onset up to 3 years of age. Development was evaluated by the developmental quotient or intelligence quotient (DQ-IQ) and mental age was measured by the Mother-Child Counseling baby test or the Tanaka-Binet scale of intelligence. Postsurgical development outcome was evaluated by the changes in DQ-IQ and mental age as well as rate of increase in mental age (RIMA) after surgery. RIMA was calculated as the increase in mental age per chronological year (months/year; normal average rate: 12 months/year). Age at epilepsy onset of 17 patients ranged from 15 days to 36 months (mean±SD, 11.0±10.0 months). Age at surgery ranged from 18 to 145 months (75.1±32.4 months). Evaluation just before surgery showed that 13 of 17 (76.4%) patients had DQ-IQ below 70. Ten patients (58.8%) were seizure-free throughout the postsurgical follow-up period. After surgery, DQ-IQ was maintained within 10 points of the presurgical level in 13 patients (76.4%), and increased by more than 10 points in one patient (5.9%). After surgery, RIMA in patients with Engel's class I (7.5±3.8) was higher than patients with Engel's class II-IV (2.6±3.4) (unpaired t-test with Welch's correction, t=2.99, df=15, p=0.0092). RIMA was particularly low in two patients with spasm. In four patients with presurgical DQ-IQ<70, seizure-free after surgery and without spasm, DQ-IQ did not increase but RIMA improved from 3.6±2.8 before surgery to 6.9±2.5 months/year after surgery. RIMA became better from 2 years after surgery. In four patients with presurgical DQ-IQ≥70 and no spasm, two showed the same or higher RIMA than normal average after surgery. In 58.8% of FCD patients with early onset epilepsy, epilepsy surgery effectively controlled seizures, and in 82.3% of patients, epilepsy surgery preserved or improved development. Residual seizures after surgery and lower DQ-IQ before surgery might be potential risk factors for poor development after surgery. In patients of Engel's class I with lower presurgical DQ-IQ, catch-up increase in mental age was observed after two years following surgery.

Neurodevelopmental outcomes in infants and children with single-suture craniosynostosis: a systematic review

Children with single-suture craniosynostosis (SSC) are increasingly considered to be at high risk of adverse neurodevelopmental outcomes. This systematic review aimed to synthesise and critically appraise the existing literature on the neurodevelopmental features of SSC, with particular attention to methodological quality. A total of 33 articles based on 27 cohorts met inclusion criteria. In the context of variable methodological design and quality, most neurodevelopmental studies indicated that children with SSC are at increased risk for difficulties in cognitive, language, and motor domains during infancy (both pre- and post-surgery) and childhood. Limited information exists on factors influencing outcome.

The challenges and innovations for therapy in children with epilepsy

Major advances have been made in the diagnosis, evaluation and management of children with epilepsy over the past 15 years. There has been a marked increase in genetic diagnoses of a number of key childhood-onset epilepsy syndromes, such as Dravet syndrome, which has been linked to mutations in the SCN1A gene. The reorganization and reclassification of epilepsies, devised by the International League Against Epilepsy, has stimulated specialists to reassess their diagnostic practices; however, many studies have not addressed the global issues in treating children with epilepsy-specifically, the challenges of diagnosis through to optimal, and appropriate, therapeutic management. Also, Class I evidence-based data that are needed as a foundation for the development of treatment guidelines worldwide are lacking. Epilepsy is common, and the impact of this disease crosses age ranges and should be managed at all levels of care from community to quaternary care. In this Review, existing data and new therapeutic management approaches are discussed with the aim of highlighting the incidence of standard practices that may not be based on clinical evidence.

The epileptic encephalopathies

The term epileptic encephalopathy refers to the condition where epileptic activity, clinical or subclinical, is thought to be responsible for any disturbance of cognition, behavior, or motor control. Although currently described as a concept that may occur in any of the epilepsies, children with the severe early onset epilepsies are thought to be more at risk than others. These epilepsies have been termed the "epileptic encephalopathies." The degree to which epileptic activity is responsible for neurodevelopmental compromise may be variable in each individual case, and the degree to which this may be reversible unclear. Data from the laboratory and the clinic may provide greater insight into the degree to which epileptic activity may contribute in individual syndromes, although much is yet to be learnt. The aim in epilepsy management remains one of seizure control; in some specific circumstances this may include subclinical epileptic activity. However, avoidance of treatment that may lead to deterioration of seizure control may be equally important.

Diagnostic delays in children with early onset epilepsy: impact, reasons, and opportunities to improve care

PURPOSE

Delayed diagnosis of early onset epilepsy is a potentially important and avoidable complication in epilepsy care. We examined the frequency of diagnostic delays in young children with newly presenting epilepsy, their developmental impact, and reasons for delays.

METHODS

Children who developed epilepsy before their third birthday were identified in a prospective community-based cohort. An interval ≥1 month from second seizure to diagnosis was considered a delay. Testing of development at baseline and for up to 3 years after and of intelligence quotient (IQ) 8-9 years later was performed. Detailed parental baseline interview accounts and medical records were reviewed to identify potential reasons for delays. Factors associated with delays included the parent, child, pediatrician, neurologist, and scheduling.

RESULTS

Diagnostic delays occurred in 70 (41%) of 172 children. Delays occurred less often if children had received medical attention for the first seizure (p < 0.0001), previously had neonatal or febrile seizures (p = 0.02), had only convulsions before diagnosis (p = 0.005), or had a college-educated parent (p = 0.01). A ≥1 month diagnostic delay was associated with an average 7.4 point drop (p = 0.02) in the Vineland Scales of Adaptive Behavior motor score. The effect was present at diagnosis, persisted for at least 3 years, and was also apparent in IQ scores 8-9 years later, which were lower in association with a diagnostic delay by 8.4 points (p = 0.06) for processing speed up to 14.5 points (p = 0.004) for full scale IQ, after adjustment for parental education and other epilepsy-related clinical factors. Factors associated with delayed diagnosis included parents not recognizing events as seizures (N = 47), pediatricians missing or deferring diagnosis (N = 15), neurologists deferring diagnosis (N = 7), and scheduling problems (N = 11).

SIGNIFICANCE

Diagnostic delays occur in many young children with epilepsy. They are associated with substantial decrements in development and IQ later in childhood. Several factors influence diagnostic delays and may represent opportunities for intervention and improved care.

Epilepsy surgery in children with drug-resistant epilepsy, a long-term follow-up

OBJECTIVES

In this follow-up study, we wanted to present the long-term outcome (5-21 years) in terms of seizure freedom, seizure reduction, and the cognitive development in the first 47 children who underwent epilepsy surgery at the University Hospital in Lund from 1991 to 2007.

MATERIALS AND METHODS

All children who underwent epilepsy surgery in the southern region of Sweden were assessed for cognitive function before surgery and at follow-up. A review of medical documents for demographic data and seizure-related characteristics was made by retrospectively examining the clinical records.

RESULTS

Forty-seven children with a median age at surgery of 8 years (range 0.5-18.7 years) were included. Twenty-three children achieved seizure freedom, six demonstrated >75% improvement in seizure frequency, and none of the children experienced an increase in seizure frequency. Twenty-one children required a reoperation to achieve satisfactory seizure outcomes. Cognitive functional level was preserved, and the majority of patients, 34 (76%), followed their expected cognitive trajectory. The patients who became seizure free significantly improved their cognitive processing speed, even after long-term follow-up.

CONCLUSIONS

Epilepsy surgery in children offers suitable candidates a good chance of significantly improved outcome and low rates of complications. Several children, however, required a reoperation to achieve satisfactory seizure outcomes. Cognitive level was preserved, and the majority of patients followed their expected cognitive trajectory. Cognitive improvements in processing speed appear to occur in parallel with seizure control and were even more pronounced in subjects with no anti-epilepsy drugs. These improvements persisted even after long-term follow-up.

Long-term developmental outcome after early hemispherotomy for hemimegalencephaly in infants with epileptic encephalopathy

This study aimed to identify the effect of early hemispherotomy on development in a consecutive series of 12 infants with hemimegalencephaly (HME) demonstrating epileptic encephalopathy. Mean age at onset was 20.4 days (range, 1-140), mean age at surgery was 4.3 months (range, 2-9), and mean follow-up time was 78.8 months (range, 36-121). Eleven patients had a history of early infantile epileptic encephalopathy. Vertical parasagittal hemispherotomy was performed without mortality or severe morbidities. At follow-up, seizure freedom was obtained in 8 patients (66.7%), who showed significantly higher postoperative developmental quotient (DQ) (mean, 31.3; range, 7-61) than those with seizures (mean, 5.5; range, 3-8) (p=0.02). Within the seizure-free group, postoperative DQ correlated with preoperative seizure duration (r=-0.811, p=0.01). Our results showed that shorter seizure duration during early infancy could provide better postoperative DQ in infants with HME and epileptic encephalopathy.

Seizure and cognitive outcomes of epilepsy surgery in infancy and early childhood

AIMS

To investigate seizure and developmental outcomes following epilepsy surgery in very young children and determine their predictive factors.

METHODS

We retrospectively reviewed the clinical data, surgical variables, and outcomes of 30 children under 3 years of age that underwent resection for refractory focal epilepsy in our institution in 2001-2011.

RESULTS

Seizure onset was in the first year of life in 27 (90%) cases and mean age at surgery was 20 months (range 5-33.6). Pathology consisted of cortical malformations in 24 (80%) cases, glioneuronal tumour and infarction with or without cortical dysplasia in three (10%) cases each. Morbidity was comparable with older paediatric cohorts. At 1-11.6 year follow-up (mean 4.1) 21 of 30 (70%) children achieved seizure freedom (Engel I), six (20%) demonstrated worthwhile improvement (Engel II/III) and three (10%) did not benefit from surgery (Engel IV). Intralobar lesionectomy more often resulted in seizure freedom than multilobar or hemispheric surgery. The abundance of non-regional interictal and ictal EEG findings did not preclude seizure freedom. Presurgical developmental impairment was established in 25 of 28 (89%) children; its severity correlated with longer epilepsy duration and determined postoperative developmental outcome. Developmental progress was established in 26 out of 28 (93%) children following surgery, showing stabilized trajectories rather than catch-up.

CONCLUSIONS

Resective surgery in very young children is safe and effective in terms of seizure control and developmental progress. Our findings underline the importance of early intervention in order to timely stop seizures and their deleterious effects on the developing brain.

Surgical management of cortical dysplasia in infancy and early childhood

PURPOSE

To describe operative procedures, seizure control and complications of surgery for cortical dysplasia (CD) causing intractable epilepsy in infancy and early childhood.

METHODS

Fifty-six consecutive children (less than 6years old) underwent resective epilepsy surgery for CD from December 2000 to August 2011. Age at surgery ranged from 2 to 69months (mean 23months) and the follow-up was from 1 to 11years (mean 4years 4months).

RESULTS

Half of the children underwent surgery during infancy at an age less than 10months, and the majority (80%) of these infants needed extensive surgical procedures, such as hemispherotomy and multi-lobar disconnection. Seizure free (ILAE class 1) outcome was obtained in 66% of the cases (class 1a; 55%): 85% with focal resection (n=13), 50% with lobar resection (n=18), 71% with multilobar disconnection (n=7) and 67% with hemispherotomy (n=18). Peri-ventricular and insular structures were resected in 23% of focal and 61% of lobar resections. Repeated surgery was performed in 9 children and 5 (56%) became seizure free. Histological subtypes included hemimegalencephaly (16 patients), polymicrogyria (5 patients), and FCD type I (6 patients), type IIA (19 patients), type IIB (10 patients). Polymicrogyria had the worst seizure outcome compared to other pathologies. Surgical complications included 1 post-operative hydrocephalus, 1 chronic subdural hematoma, 2 intracranial cysts, and 1 case of meningitis. No mortality or severe morbidities occurred.

CONCLUSIONS

Early surgical intervention in children with CD and intractable seizures in infancy and early childhood can yield favorable seizure outcome without mortality or severe morbidities although younger children often need extensive surgical procedures.

Cognitive outcome after epilepsy surgery in children

The ultimate goal of epilepsy surgery in young children is to stop seizures, interrupt the downhill course of the epileptic encephalopathy, and improve developmental capacities. Postoperative outcome after childhood epilepsy surgery should therefore not only be expressed in terms of seizure freedom, cognitive outcome is an equally important outcome measure. Insight in the mutually dependent variables that can determine pre and postoperative cognitive developmental abilities will improve prediction of outcome and presurgical counseling of parents. The purpose of this review is to discuss the literature regarding cognitive outcome and the predictors of postoperative cognitive functioning after epilepsy surgery in children, particularly those with "catastrophic" epilepsy. There are only few studies in which the relation between possible determinants and cognitive outcome or change was statistically tested in a multivariable manner. Duration of epilepsy, presurgical Developmental Quotient (DQ) or Intelligence Quotient (IQ), and postoperative seizure freedom were the only factors reported in different studies to be independently related to eventual cognitive outcome after epilepsy surgery. Underlying etiology, gender, age at surgery, presurgical DQ/IQ, postoperative seizure freedom, cessation of antiepileptic medication, and follow-up interval have all been described in different surgical cohorts to be independently related to a postoperative change of IQ or DQ scores. To appreciate how each of the pre-epileptic, presurgical, and postoperative variables may independently influence eventual cognitive outcome and postoperative cognitive improvement, we need multicenter studies with large homogenous surgical populations, using standardized tests and multivariable analyses.

Prognostic factors of infantile spasms: role of treatment options including a ketogenic diet

OBJECTIVES

The aim of this study was to provide additional evidences on prognostic factors for infantile spasms and the possible role of a ketogenic diet.

METHODS

A retrospective analysis was performed for patients with infantile spasms who had been followed up for more than 6months between January 2000 and July 2012 at Samsung Medical Center (Seoul, Republic of Korea). We analyzed the association between possible prognostic factors and seizure/developmental outcomes.

RESULTS

Sixty-nine patients were included in this study and their mean follow-up duration was 52.5 (9-147) months. In the patients who had been followed up for more than 2years, 53.6% (n=30/57) remained seizure-free at the last visit. Sixty patients (86.9%) showed developmental delay at last follow-up. Forty-two patients (60.9%) became spasm-free with one or two antiepileptic drugs, one patient with epilepsy surgery for a tumor, and seven patients with a ketogenic diet after the failure of two or more antiepileptic drugs. The etiology and age of seizure onset were the significant prognostic factors.

CONCLUSIONS

In this study, about 60% of the patients became spasm-free with vigabatrin and topiramate. Ketogenic diet increased the rate by 10% in the remaining antiepileptic drug resistant patients. However, 86.9% of the patients showed developmental delay, mostly a severe degree. Early diagnosis and prompt application of treatment options such as antiepileptic drugs, a ketogenic diet or epilepsy surgery can improve outcomes in patients with infantile spasms.

Towards early diagnosis and treatment to save children from catastrophic epilepsy -- focus on epilepsy surgery

OBJECTIVE

To analyze and to discuss whether by paying attention to the many recent advancements in the field of pediatric epilepsy surgery catastrophic childhood epilepsies caused by definitive or suspected structural lesions can be prevented more often these days in comparison to the past.

METHODS

Based on data from the literature and supplemented by the authors own experience, risks for children suffering from structural focal epilepsies that the epilepsy becomes catastrophic and ways how such evolutions can possibly be prevented are discussed for the different lesion-types separately - in the order of their frequency as they are seen at pediatric epilepsy surgery centers. Special emphasis is put on data regarding attempts to prevent permanent severe mental retardations.

RESULTS

There are common factors predisposing to catastrophic courses in all structural focal epilepsies, such as early onset and a longer duration of epilepsy (with respect to cognitive outcome not with respect to seizure outcome), but there are also differences. Moreover the better perspectives now in comparison to the past for children with conditions like MRI-negative focal epilepsies, subtle focal cortical dysplasias, epilepsies post hypoxic-ischemic events, tuberous sclerosis etc. are not well recognized yet. While there is agreement that "early" (and successful) surgery is essential in many instances to prevent permanent mental retardations there is insufficient data regarding the issue that "early surgery "might not be early enough under certain circumstances and there is also only little data regarding variables which would allow to keep calm when a child is presenting with early onset difficult to control seizures. One of the biggest changes seen over the last decade is the fact that children with very severe epilepsies, who have unilateral lesions, but "generalized" seizures and/or "generalized" EEGs, are not excluded anymore from considerations for epilepsy surgery. Even children with bilateral lesions can be surgical candidates.

CONCLUSION

The gradually widening spectrum of indications for epilepsy surgery in children is resulting in an increasing number of preventions of catastrophic epilepsies. Insufficient data regarding timing of surgery in order to prevent permanent mental retardations are calling for prospective multi-center studies.

Pediatric epilepsy surgery: long-term 5-year seizure remission and medication use

BACKGROUND

It is unclear whether long-term seizure outcomes in children are similar to those in adult epilepsy surgery patients.

OBJECTIVE

To determine 5-year outcomes and antiepilepsy drug (AED) use in pediatric epilepsy surgery patients from a single institution.

METHODS

The cohort consisted of children younger than 18 years of age whose 5-year outcome data would have been available by 2010. Comparisons were made between patients with and without 5-year data (n = 338), patients with 5-year data for seizure outcome (n = 257), and seizure-free patients on and off AEDs (n = 137).

RESULTS

Five-year data were available from 76% of patients. More seizure-free patients with focal resections for hippocampal sclerosis and tumors lacked 5-year data compared with other cases. Of those with 5-year data, 53% were continuously seizure free, 18% had late seizure recurrence, 3% became seizure free after initial failure, and 25% were never seizure free. Patients were more likely to be continuously seizure free if their surgery was performed during the period 2001 to 2005 (68%) compared with surgery performed from 1996 to 2000 (61%), 1991 to 1995 (36%), and 1986 to 1990 (46%). More patients had 1 or fewer seizures per month in the late seizure recurrence (47%) compared with the not seizure-free group (20%). Four late deaths occurred in the not seizure-free group compared with 1 in the seizure-free group. Of patients who were continuously seizure free, 55% were not taking AEDs, and more cortical dysplasia patients (74%) had stopped taking AEDs compared with hemimegalencephaly patients (18%).

CONCLUSION

In children, 5-year outcomes improved over 20 years of clinical experience. Our results are similar to those of adult epilepsy surgery patients despite mostly extratemporal and hemispheric operations for diverse developmental etiologies.

Time to Pediatric Epilepsy Surgery Is Longer and Developmental Outcomes Lower for Government Compared With Private Insurance

BACKGROUND:

It is unclear if socioeconomic factors like type of insurance influence time to referral and developmental outcomes for pediatric patients undergoing epilepsy surgery.

OBJECTIVE:

This study determined whether private compared with state government insurance was associated with shorter intervals of seizure onset to surgery and better developmental quotients for pediatric patients undergoing epilepsy surgery.

METHODS:

A consecutive cohort (n = 420) of pediatric patients undergoing epilepsy surgery were retrospectively categorized into those with Medicaid (California Children's Services; n = 91) or private (Preferred Provider Organization, Health Maintenance Organization, Indemnity; n = 329) insurance. Intervals from seizure onset to referral and surgery and Vineland developmental assessments were compared by insurance type with the use of log-rank tests.

RESULTS:

Compared with private insurance, children with Medicaid had longer intervals from seizure onset to referral for evaluation (log-rank test, P = .034), and from seizure onset to surgery (P = .017). In a subset (25%) that had Vineland assessments, children with Medicaid compared with private insurance had lower Vineland scores presurgery (P = .042) and postsurgery (P = .003). Type of insurance was not associated with seizure severity, types of operations, etiology, postsurgical seizure-free outcomes, and complication rate.

CONCLUSION:

Compared with Medicaid, children with private insurance had shorter intervals from seizure onset to referral and to epilepsy surgery, and this was associated with lower Vineland scores before surgery. These findings may reflect delayed access for uninsured children who eventually obtained state insurance. Reasons for the delay and whether longer intervals before epilepsy surgery affect long-term cognitive and developmental outcomes warrant further prospective investigations.

Time to pediatric epilepsy surgery is related to disease severity and nonclinical factors

OBJECTIVE

To identify clinical and nonclinical factors associated with time from epilepsy onset to surgical evaluation and treatment among a cohort of children having epilepsy surgery.

METHODS

Data were abstracted from records of 430 children (younger than 18 years) who had epilepsy neurosurgery at the University of California, Los Angeles from 1986 to 2010. Multivariable Cox proportional hazards models were used to analyze unique associations of clinical severity, pre-referral brain MRI, and sociodemographic characteristics with time to surgery.

RESULTS

Shorter time to surgery was associated with active (hazard ratio [HR] 5.67, 95% confidence interval [CI] 3.74-8.70) and successfully treated infantile spasms (HR 2.20, 95% CI 1.63-2.96); daily or more seizures (HR 2.09, 95% CI 1.58-2.76); MRI before referral regardless of imaging findings (HR 1.95, 95% CI 1.47-2.58); private insurance (HR 1.54, 95% CI 1.14-2.09); and Hispanic ethnicity (HR 1.38, 95% CI 1.01-1.87). There were race/ethnicity by insurance interactions (log-rank p = 0.049) with shortest time to surgery for Hispanic children with private insurance.

CONCLUSIONS

Shorter intervals to surgical treatment were associated with greater epilepsy severity and insurance type, consistent with existing literature. However, associations of shorter times to treatment with having a brain MRI before referral and Hispanic ethnicity were unexpected and warrant further investigation. More knowledgeable referring providers and parents with greater help-seeking capability may explain obtaining an MRI before referral. Shorter intervals to surgery among Hispanic children may relate to the same factors yielding an increased volume of Hispanic children receiving surgery at the University of California, Los Angeles since 2000.

Pediatric epilepsy surgery

Whereas there is no specific neurosurgical technique in pediatric epilepsy, the frequency of each type of surgery is very different from epilepsy surgery applied in adults, and reflects the underlying etiologies, which are much more diverse in children, with malformations of cortical development and tumors as the prevailing etiologies. Extensive resective or disconnective procedures for extratemporal epilepsy are more frequently performed in infants and younger children, whereas temporo-mesial resection is by far the most common surgical treatment for adults with epilepsy. More recently, less invasive techniques in children with an extensive epileptogenic zone, such as multilobar disconnection, hemispherotomy and other functional hemispherectomy variants, have been introduced in order to reduce duration of surgery, perioperative morbidity and length of hospital stay. Likewise, minimally invasive techniques are utilized, such as the endoscopic disconnection of hypothalamic hamartomas for gelastic epilepsy. This development has been encouraged with the introduction of image-guided navigation systems for the preoperative planning and during surgery. Historically, epilepsy surgery for children has been established much later than for adults. Apart from the particular aspects in perioperative management of younger infants, surgery-related morbidity as well as seizure outcome is in general similar to those in adults, depending rather on each type of surgery.

Behavioural and cognitive effects during vagus nerve stimulation in children with intractable epilepsy - a randomized controlled trial

BACKGROUND/AIMS

In addition to effects on seizure frequency in intractable epilepsy, multiple studies report benefits of vagus nerve stimulation (VNS) on behavioural outcomes and quality of life. The present study aims to investigate the effects of VNS on cognition, mood in general, depression, epilepsy-related restrictions and psychosocial adjustment in children with intractable epilepsy, as well as the relation between these effects and seizure reduction.

METHODS

We conducted a randomized, active-controlled, double-blinded, add-on study in 41 children (age 4-18) with medically refractory epilepsy. We performed cognitive and behavioural testing at baseline (12 weeks), at the end of the blinded phase (20 weeks) in children receiving either high-output or low-output (active control) stimulation, and at the end of the open label phase (19 weeks) with all children receiving high-output stimulation. Seizure frequency was recorded using seizure diaries.

RESULTS

VNS did not have a negative effect on cognition nor on psychosocial adjustment. At the end of the follow-up phase we noted an improvement of mood in general and the depression subscale for the entire group, unrelated to a reduction of seizure frequency. At the end of the blinded phase a ≥50% reduction of seizure frequency occurred in 16% of the high-stimulation group and 21% of the low-stimulation group. At the end of the open-label follow-up phase, 26% of the children experienced a seizure frequency reduction of 50% or more (responders).

CONCLUSIONS

VNS has additional beneficial effects in children with intractable epilepsy. As opposed to anti-epileptic drugs, there are no negative effects on cognition. Moreover, we observed an improvement of mood in general and depressed feelings in particular, irrespective of a reduction in seizure frequency. These beneficial effects should be taken into account when deciding whether to initiate or continue VNS treatment in these children.

Cognitive outcome of surgery

Epilepsy surgery is now widely accepted as an effective therapeutic option for carefully selected children with medically refractory epilepsy. The surgical procedure may cause cognitive deficits or exacerbate existing impairments, but it may also improve cognitive abilities by the restoration of functions located in adjacent or contralateral areas that had been secondarily affected by the epilepsy or the underlying pathology. Compared to adults, better cognitive outcome has been reported in children, a finding probably due to the developing state of the brain, which possesses considerable structural and functional plasticity. More extensive and effective surgery such as hemispherectomy is more commonly used in the pediatric population, and this must also influence surgical outcome. However, studies related to cognitive outcome of epilepsy surgery in children are limited, and controversial results are often reported. In this chapter, we provide a current overview of the literature on cognitive outcomes in children who undergo different types of epilepsy surgery, including focal resections as well as corpus callosotomy and hemispherectomy. Early surgical intervention appears to be a rational option for the treatment of childhood epilepsy since many cognitive deficits are linked to the epileptic process and may disappear when seizures are controlled.

Long-term outcome of resective epilepsy surgery in Norwegian children

AIM

The aim of this study was to evaluate the long-term results of resective surgery on children with difficult-to-treat epilepsy in Norway.

METHODS

In the period 1995-2004, 64 surgical procedures (54 resections and 10 functional hemispherotomies) were performed in 54 children. The children's medical records were retrospectively reviewed at a minimum of 2 years after surgery. We sent a questionnaire regarding their epilepsy (seizures, usage of antiepileptic drugs) and general functioning (social situation, motor, language, cognition, behavioural or emotional problems, any remedial action) to the children/parents after a mean follow-up period of 7 years.

RESULTS

55.5% of the children were seizure-free. The success rate varied according to the type of surgery. Best results were found after functional hemispherotomies and temporal lobe resections, as nine of 10 (90%) and 10 of 19 (53%) of these patients, respectively, became seizure-free. In addition to a better seizure control, 71% of the children/parents reported of a better cognitive and psychosocial functioning.

CONCLUSION

The results of epilepsy surgery in this paediatric cohort are very edifying, and it is our impression that this treatment option is underused in Norway.

Age at onset of epilepsy, pharmacoresistance, and cognitive outcomes: a prospective cohort study

OBJECTIVES

Increasing evidence suggests that uncontrolled seizures have deleterious effects on cognition and behavior, particularly in the developing brain.

METHODS

In a community-based cohort, 198 children, aged <8 years with new-onset epilepsy were followed prospectively and reassessed with the Wechsler Intelligence Scales for Children, Third Edition (WISC-III) 8-9 years later. Linear regression analyses with interactions between age at onset (age) and pharmacoresistance (PR) were used to test whether earlier onset conveyed greater vulnerability to the effects of uncontrolled seizures. Full-scale IQ (FSIQ) and the 4 subdomain scores were examined. Adjustment for adaptive behavior scores in a subset was performed. A dichotomous indicator for IQ <80 or ≥80 was used to permit inclusion of children who were not tested, particularly those who were untestable.

RESULTS

FSIQ was not correlated with age. PR was associated with an 11.4 point lower FSIQ (p = 0.002) and similar decrements in each WISC-III domain. There were substantial age-PR interactions for FSIQ (p = 0.003) and 3 domain scores, indicating a lessening impact of PR with increasing age. The dichotomous IQ indicator was strongly correlated with age at onset in the pharmacoresistant group (p < 0.0001) and not in the non-pharmacoresistant group (p = 0.61). Adjustment for adaptive behavior measured near onset did not alter the conclusions.

CONCLUSIONS

Uncontrolled seizures impair cognitive function with effects being most severe in infancy and lessening with increasing age at onset. These findings further emphasize the need for early aggressive treatment and seizure control in infants and young children.

Epilepsy surgery of the temporal lobe in pediatric population: a retrospective analysis

BACKGROUND

There is still some reluctance to refer pediatric patients for epilepsy surgery, despite evidence of success in retrospective series.

OBJECTIVE

To describe surgical experience and long-term outcome in pediatric temporal lobe epilepsy (TLE) at a single institution.

METHODS

Retrospective review of pediatric (<18-years-old) TLE patients who underwent surgery between November 1996 and December 2006 at Cleveland Clinic Epilepsy Center. Cox proportional hazard modeling was used to assess outcome predictors.

RESULTS

One hundred thirty pediatric patients met study criteria. Mean time between seizure onset and surgery was 6.3 years. Invasive evaluation was used in 32 patients (24.5%). Hippocampal sclerosis was present in 70 patients (53.8%), either alone or associated in dual pathology. The complication rate was 7%. The seizure-freedom rates at 1, 2, 5, and 12 years were 76%, 72%, 54%, and 41%, respectively (Kaplan-Meier). With the use of the Engel outcome classification, 98 (75.3%) patients were class I, 11 (8.5%) class II, 9 (7%) class III, and 12 (9.2%) were class IV at last follow-up. Only 4 (3.1%) patients underwent reoperations. Antiepileptic drugs (AEDs) were discontinued in 36 patients (28.3%) in a mean period of 18 months (SD ± 17 months; range, 6-102 months). Although left-sided resection, lower number of preoperative AED trials (≤ 4), and tumor pathology correlated with favorable seizure outcomes, extensive surgical resection remained the only significant outcome predictor after multivariate analysis (P = .007; HR = 0.13 [95% confidence interval 0.007-0.64]).

CONCLUSION

Careful selection of surgical candidates by multidisciplinary evaluations is required. Long-term seizure control is achieved successfully with acceptable low complication rates.

Surgical treatment of patients with Lennox-Gastaut syndrome phenotype

Lennox-Gastaut syndrome (LGS) is a devastating and refractory generalized epilepsy affecting children and adolescents. In this study we report the results of resective surgery in 18 patients with LGS phenotype who underwent single-lobe/lesionectomy or multilobe resection plus multiple subpial transection and/or callosotomy. After surgery, seven patients became completely seizure-free (Engel Class I) and five almost seizure-free (Engel Class II). Additional four had significant seizure control (Engel Class III), and two had no change in seizure frequency (Engel Class IV). Of the 4 patients without any lesion on brain MRI, 2 ended with Engel Class II, 1 with III and the other with IV in Engels' classification. Mean intelligence quotient (IQ) increased from 56.1 ± 8.1 (mean ± SD) before operation to 67.4 ± 8.2 (mean ± SD) after operation, a significant improvement (P = 0.001). Results also indicated that the younger the patient at surgery, or the shorter the interval between onset of seizure and resective operation, the better the intellectual outcome. Our data suggest that resective epilepsy surgery can be successful in patients with LGS phenotype as long as the EEG shows dominance of discharges in one hemisphere and corresponding ipsilateral imaging findings, even with contralateral ictal discharges.

Outcomes of epileptic spasms in patients aged less than 3 years: single-center United States experience

Retrospective review was performed of children aged <3 years with epileptic spasms at our center from 2004-2010. Short-term (<6 months) and long-term (≥6 months) outcomes were assessed. We included 173 children (104 boys; median age of onset, 6.8 months) with epileptic spasms of known (62%) and unknown (38%) etiology. Treatments included adrenocorticotropic hormone (n = 103), vigabatrin (n = 82), phenobarbital (n = 34), and other agents (n = 121). Short-term treatment with adrenocorticotropic hormone and vigabatrin provided better epileptic spasm control in groups with known and unknown etiology than other agents. At follow-up (6-27 months), 54% of children manifested seizures, and 83% manifested developmental delay. Known etiology was a predictor of poor developmental outcome (P = 0.006), whereas bilateral/diffuse brain lesions predicted both poor development and seizures (P = 0.001 and 0.005, respectively). Initial presentations of epileptic spasms with hypotonia or developmental delay most strongly predicted both seizures and neurodevelopmental outcomes (P < 0.001). In a child presenting with epileptic spasms with developmental delay or hypotonia, no specific treatment may offer superior benefit.

Stereoelectroencephalography in the presurgical evaluation of focal epilepsy in infancy and early childhood

OBJECT

The authors report on the use of stereoelectroencephalography (stereo-EEG) in the presurgical electroclinical evaluation of infants and very young children with focal drug-resistant epilepsy.

METHODS

Fifteen patients (9 girls and 6 boys, mean age 34.1 ± 7.3 months, range 21-45 months), potentially candidates to receive surgical treatment for their focal drug-resistant epilepsy, were evaluated using stereo-EEG recording for a detailed definition of the epileptogenic zone. Stereoelectroencephalography was indicated because neuroradiological (brain MRI) and video-EEG data failed to adequately localize the epileptogenic zone. Stereotactic placement of multicontact intracerebral electrodes was preceded by the acquisition of all pertinent anatomical information from structural and functional MRI and from brain angiography, enabling the accurate targeting of desired structures through avascular trajectories. Stereoelectroencephalography monitoring attempted to record habitual seizures; electrical stimulations were performed to induce seizures and for the functional mapping of eloquent areas. Stereoelectroencephalography-guided microsurgery, when indicated, pointed to removal of the epileptogenic zone and seizure control.

RESULTS

Brain MRI revealed an anatomical lesion in 13 patients (lobar in 2 cases, multilobar or hemispheric in 11 cases) and was unremarkable in 2 patients. One patient underwent 2 stereo-EEG studies. The arrangement of the intracerebral electrodes was unilateral in all but 1 case. One patient died the day following electrode placement due to massive brain edema and profound hyponatremia of undetermined cause. In 8 cases intracerebral electrical stimulations allowed mapping of functionally critical areas; in 3 other cases that received purposeful placement of electrodes in presumably eloquent areas, no functional response was obtained. Of the 14 patients who completed stereo-EEG monitoring, 1 was excluded from surgery for multifocality of seizures and 13 underwent operations. Postoperatively, 2 patients exhibited an anticipated, permanent motor deficit, 3 experienced a transient motor deficit, and 2 experienced transient worsening of a preexisting motor deficit. Three patients developed a permanent homonymous hemianopia after posterior resections. Histological analysis revealed cortical malformations in 10 cases. Of the 10 patients with a postoperative follow-up of at least 12 months, 6 (60%) were seizure-free (Engel Class Ia), 2 (20%) experienced a significant reduction of seizures (Engel Class II), and 2 (20%) were unchanged (Engel Class IV).

CONCLUSIONS

The present study indicates that stereo-EEG plays a prominent role in the presurgical evaluation of focal epilepsies also in the first years of life and that it may offer a surgical option in particularly complex cases that would have scarcely benefitted from further medical treatment. Results of stereo-EEG-guided resective surgery were excellent, with 80% of patients exhibiting a substantial improvement in seizures. In consideration of the potentially life-threatening risks of major intracranial surgery in this specific age group, the authors recommend reserving stereo-EEG evaluations for infants with realistic chances of benefiting from surgery.

Paediatric intractable epilepsy syndromes: changing concepts in diagnosis and management

Epilepsy surgery for drug-resistant childhood epilepsy is not new. However, brain imaging, surgical and anaesthetic techniques have improved to the extent that they are now as much safer and realistic option than they were in the past. Further, the range of surgical candidates is wide, and previous concepts about likely surgical candidates are now challenged as children with previously thought widespread or apparent multifocal disease are evaluated. Outcomes for seizure freedom range from 40 to 80 % depending on the underlying aetiology and the extent of resection. However, the aims of surgery may include seizure reduction in some and improvement in neurodevelopment and behaviour in others, which are less -predictable. Epilepsy surgery in children is no longer a last resort. Children thought to be likely candidates should be evaluated early in their natural history to optimise outcomes in the long term.

Hemispherectomy for the control of intractable epilepsy in childhood: comparison of 2 surgical techniques in a single institution

BACKGROUND

Hemispherectomy is an established neurosurgical procedure for catastrophic epilepsy in childhood. However, the technique used to achieve an optimum outcome remains to be determined.

OBJECTIVE

We examined the influence of hemidecortication (HD) vs peri-insular hemispherotomy (PIH) on patient outcome.

METHODS

The medical records of 41 children undergoing hemispherectomy were reviewed for patient demographics, clinical criteria, and surgical outcomes.

RESULTS

HD and PIH were performed in 21 and 20 children, respectively. The mean age at surgery for HD was 54 months and 61 months for PIH. The median durations of surgery for HD and PIH were 5 hours and 7 hours, respectively (P < .001). For HD, 6 patients required a second surgery and 3 required a third. One PIH patient required a second procedure. Postoperative shunting was required in 5 HD patients, but only 1 PIH patient. All patients had increased hemiparesis after surgery. The overall mean follow-up time was 72 months. Engel class I or II outcomes after initial surgery were better after PIH (85%) compared with HD (48%) (P < .02). After subsequent surgeries for seizure control, 4 HD patients and 1 PIH patient improved to Engel class I or II.

CONCLUSION

Hemispherectomy is an effective surgical procedure for childhood intractable catastrophic epilepsy. In patients with diffuse hemispheric disorder, PIH tends to have fewer major complications, more favorable seizure outcomes, and a decreased need for subsequent surgical procedures, including shunting for hydrocephalus, compared with HD.

Craniosynostosis following hemispherectomy in a 2.5-month-old boy with intractable epilepsy

The authors report on the case of a 6-week-old boy who presented with infantile spasms. At 2.5 months of age, the patient underwent a right hemispherectomy. Approximately 3 months postoperatively, the patient presented with left coronal craniosynostosis. Subsequent cranial vault remodeling resulted in satisfactory cosmesis. Four years after surgery, the patient remains seizure free without the need for anticonvulsant medications. The authors believe this to be the first reported case of iatrogenic craniosynostosis due to hemispherectomy, and they describe 2 potential mechanisms for its development. This case suggests that, in the surgical treatment of infants with intractable epilepsy, minimization of brain volume loss through disconnection techniques should be considered, among other factors, when determining the best course of action.

Ethical issues in surgical decision making concerning children with medically intractable epilepsy

The widespread inclusion of surgical strategies in the treatment of medically intractable epilepsy is largely justified by the medical and psychosocial burden of the illness. Performing these procedures in pediatric populations is associated with distinct challenges ranging from unique seizure etiologies to issues surrounding brain development and functional plasticity. As the trend toward more aggressive surgical intervention continues, the ethical foundation of current and emerging practices must be increasingly scrutinized. Here, we present the first article discussing ethical issues in the surgical management of medically intractable epilepsies in children. We discuss principles of informed consent, harm reduction, and justice in this vulnerable patient population. We also highlight the unique ethical challenge of surgical decision making concerning developmentally delayed children. The recognition of these issues is essential to providing patient-centered, responsible, and ethical care.

Differentiating developmental outcome between infants with severe disability in research studies: the role of Bayley Developmental Quotients

OBJECTIVES

To investigate whether infants with a score <50 on the Bayley Scales of Infant Development, Second Edition (BSID-II) demonstrated differences in functional ability, and to assess whether the Bayley Developmental Quotients (DQs) indicated such differences.

STUDY DESIGN

Preterm infants (n = 67; 47 boys) with posthemorrhagic ventricular dilatation were evaluated at 25 months past term age using the BSID-II and grading of functional ability. Mental and Motor Bayley DQs were derived and compared with functional ability.

RESULTS

Among the 34 subjects (51%) with a BSID-II score <50, there were clinically significant differences in the ability to walk, sit, eat, speak, and see. In all subjects, there were significant differences in Mental and Motor Bayley DQs based on grade of disability in each domain except hearing.

CONCLUSIONS

Bayley DQ quantified the spread of functional ability in all children, provided a continuous parameter to compare ability in severely delayed children, and should be considered in future therapeutic trials of infants with brain injury.

Vagus nerve stimulation for children with treatment-resistant epilepsy: a consecutive series of 141 cases

OBJECT

The authors undertook this study to analyze the efficacy of vagus nerve stimulation (VNS) in a large consecutive series of children 18 years of age and younger with treatment-resistant epilepsy and compare the safety and efficacy in children under 12 years of age with the outcomes in older children.

METHODS

The authors retrospectively reviewed 141 consecutive cases involving children (75 girls and 66 boys) with treatment-resistant epilepsy in whom primary VNS implantation was performed by the senior author between November 1997 and April 2008 and who had at least 1 year of follow-up since implantation. The patients' mean age at vagus nerve stimulator insertion was 11.1 years (range 1-18 years). Eighty-six children (61.0%) were younger than 12 years at time of VNS insertion (which constitutes off-label usage of this device).

RESULTS

Follow-up was complete for 91.8% of patients and the mean duration of VNS therapy in these patients was 5.2 years (range 25 days-11.4 years). Seizure frequency significantly improved with VNS therapy (mean reduction 58.9%, p < 0.0001) without a significant reduction in antiepileptic medication burden (median number of antiepileptic drugs taken 3, unchanged). Reduction in seizure frequency of at least 50% occurred in 64.8% of patients and 41.4% of patients experienced at least a 75% reduction. Major (3) and minor (6) complications occurred in 9 patients (6.4%) and included 1 deep infection requiring device removal, 1 pneumothorax, 2 superficial infections treated with antibiotics, 1 seroma/hematoma treated with aspiration, persistent cough in 1 patient, severe but transient neck pain in 1 patient, and hoarseness in 2 patients. There was no difference in efficacy or complications between children 12 years of age and older (FDA-approved indication) and those younger than 12 years of age (off-label usage). Linear regression analyses did not identify any demographic and clinical variables that predicted response to VNS.

CONCLUSIONS

Vagus nerve stimulation is a safe and effective treatment for treatment-resistant epilepsy in young adults and children. Over 50% of patients experienced at least 50% reduction in seizure burden. Children younger than 12 years had a response similar to that of older children with no increase in complications. Given the efficacy of this device and the devastating effects of persistent epilepsy during critical developmental epochs, randomized trials are needed to potentially expand the indications for VNS to include younger children.

Electrocorticography and seizure outcomes in children with lesional epilepsy

PURPOSE

The use of electrocorticographically (ECoG)-guided cortical resection in children with lesional epilepsy is controversial. Given the important developmental issues associated with recurrent childhood seizures, sustained seizure control is a key therapeutic goal. We therefore evaluated the effect of the decision to perform lesionectomy or ECoG-guided cortical resection on seizure outcome and surgical morbidity in the pediatric population.

METHODS

We retrospectively analyzed seizure outcomes in 67 patients between the ages of 3 months and 16 years who underwent surgery for lesional epilepsy at British Columbia Children's Hospital. Thirty-four patients underwent ECoG, and 33 patients had lesionectomy without ECoG.

RESULTS

One year post-operatively, 80% of patients who had ECoG-guided cortical resection or lesionectomy were seizure free. However, there was a trend toward improved seizure freedom in patients who had ECoG at most recent follow-up (79% patients with ECoG seizure free, vs. 61% with lesionectomy only; mean follow-up time 5.8 year, P=0.078). There was no increase in neurological morbidity in patients who had ECoG-guided cortical resection, and these patients were less likely to experience repeat epilepsy surgery.

CONCLUSIONS

Overall, using ECoG to guide additional cortical resection may lead to more robust seizure freedom in children with lesional epilepsy without increasing their risk of surgical morbidity.

Epilepsy surgery in a pediatric population: a retrospective study of 129 children from a tertiary care hospital in a developing country along with assessment of quality of life

PURPOSE

To assess the outcome of a pediatric population operated for drug-resistant epilepsy from a large tertiary care center in India.

METHODS

Retrospectively: quality of life (QOL); prospectively: preoperative assessment included interictal EEG, MRI (as per epilepsy protocol), video-EEG. Ictal SPECT (with subtraction) and PET were performed when required. QOL scores were assessed using the HASS or SSQ for seizure severity, Quality of Life in Childhood Epilepsy (QOLCE) for QOL, and Child Behavior Check List (CBCL) for behavior.

RESULTS

142 were operated from January 2000 to June 2011 by the senior author. 118 patients with at least 1 year of follow-up were included in the study. Mean age at surgery was 9.8 ± 4.3 years. In addition, 40 patients underwent QOL assessment prospectively both before and after surgery. Mean duration of epilepsy was 5.3 ± 3.3 years. A class I outcome (Engel's) was seen in 79.5% patients, class II in 8.6%, class III in 10.7%, and class IV in 1 patient. As per surgical procedures, class I outcome in patients who underwent temporal resection, hemispherotomy and extratemporal resection was 76, 87 and 72%, respectively. QOL scores correlated with duration of seizures, epileptic encephalopathy and outcome of surgery, but not with side of surgery, age and sex.

CONCLUSIONS

This study, the largest reported from India, has demonstrated satisfactory results for epilepsy surgery in children.

Surgical treatment of refractory status epilepticus in children: candidate selection and outcome

Surgical treatment emerges as a therapeutic option for refractory status epilepticus (RSE) in children. Surgical approaches for RSE include focal cortical resections, hemispherectomies, multiple subpial transections, and rarely corpus callosotomy and vagal nerve stimulator implantation. Resective surgery has shown immediate- and long-term benefits in cases of definite localization of the epileptogenic focus by elecrographic and imaging data. Evidence of focal electrographic activity may not always be available during prolonged status. Nevertheless, resection may be an option in these cases if extensive, and confined pathology is seen on magnetic resonance imaging. On the contrary, electrographic localization may be complemented by intraoperative electrocorticography during multiple subpial transections in cases of nonlesional pathology. The optimal timing of surgery in eligible patients has been determined by concerns about medical intractability weighed against accumulating risks of RSE and the possible appearance of secondary epileptogenic zones caused by ongoing seizures. Overall, preliminary case series suggest that epilepsy surgery may be an alternative treatment option for selected children with RSE. Additional studies are needed to delineate timing and criteria for intervention as well as prognostic factors.