Outcome of surgery in 40 children with temporal-lobe epilepsy

A prospective cohort study estimating total pre-surgical healthcare costs before and two-year total societal costs after resective brain surgery, and quality of life of patients with drug-resistant epilepsy undergoing surgery

BACKGROUND

In contrast to clinical effectiveness of resective epilepsy surgery (RES) for patients with drug-resistant epilepsy, societal costs of RES is still unclear. The aim of this study was to report on total societal costs up until two years after surgery and analyse the trend of post-surgical costs over time. Secondary objectives included assessing quality of life (QoL) changes and identifying determinants of post-surgical costs.

METHODS

Data were derived from the patients' entire medical history based on hospital files and accompanied by validated questionnaires before and 3-, 6-, 12-, and 24-months post-surgery to additionally include medical consumption outside of the hospital, productivity losses and gains, and QoL. To explore the trend of post-surgical costs over time and identify determinants of post-surgical costs, linear mixed effects and linear regression models were performed.

RESULTS

The study included 44 patients. Mean complete costs from diagnostics and treatment strategies in the period before referral for pre-surgical evaluation up until two years after RES were €121,856 (Interquartile range = €76,058-€137,027). Post-surgical costs significantly decreased 12 months (mean 3-month difference = €-6,675, p = 0.000) and 24 months (mean 3-month difference = €-7,690, p = 0.000) after surgery compared to 3 months before surgery. Higher post-surgical costs were associated with a clinically relevant increase in disease-specific QoL after RES (p = 0.000), previous ketogenic diet (p = 0.005), RES in the left hemisphere (p = 0.014), previous RES (p = 0.007), and higher diagnostics and treatment strategies costs before referral for pre-surgical evaluation (p = 0.021). For disease-specific and generic QoL, 20 (45%) patients reached a clinically relevant QoL increase two years after surgery compared to before RES.

CONCLUSION

In conclusion, RES leads to significant reduction in costs 2 years post-surgery. History of RES and ketogenic diet, clinically relevant disease-specific QoL increase, surgery in the left hemisphere, and higher costs of diagnostics and treatment strategies before referral for pre-surgical evaluation were significant determinants for higher post-surgical costs after RES.

Surgery for Intractable Epilepsy in Pediatrics, a Systematic Review of Outcomes other than Seizure Freedom

To perform a systematic review evaluating reported outcomes for epilepsy surgery in pediatric patients with pharmacoresistant epilepsy beyond seizure control, including impact on quality of life, behavioral, neurocognitive outcomes as well as complications, and death. We reviewed articles from both EMBASE and MEDLINE/PubMed articles that met formal criteria (patients ≤18 years, those with intractable epilepsy, at least 5 patients in the case series, published in peer-reviewed journal). Each reviewer independently reviewed the articles and those with discrepancies were discussed and consensus was reached. Out of a total of 536 abstracts obtained from EMBASE and MEDLINE/PubMed searches combined with additional cross-referencing, a total of 98 manuscripts ultimately met all inclusion criteria. The manuscripts were divided into 3 outcomes categories: Quality of Life (16), Cognitive Outcomes (60), and Deficits and Complications (50). Several papers fell into more than 1 category. These were separated by surgical types and evaluated. We found that overall reporting in all domains was variable and inconsistent amongst the different studies. This systematic review highlights the lack of completeness in reporting outcomes and complications involving pediatric epilepsy surgery and discordant results. This underscores the importance of multicenter systematic prospective data collection in pediatric patients who undergo pediatric epilepsy surgery.

Neuroimaging in pediatric temporal lobe epilepsy: Does neuroimaging accurately predict pathology and surgical outcome?

Temporal lobe epilepsy (TLE) in children is considered different from that in adults. As such, characterizing the structural lesions present in pediatric patients with TLE and their association with long-term seizure control is important. Here, we aimed to assess the concordance between preoperative imaging and postoperative histopathological diagnoses and their associations with seizure outcomes in pediatric patients with TLE undergoing temporal lobe surgery. We retrospectively reviewed the charts of pediatric patients with TLE who underwent surgical treatment between 1988 and 2020 as a part of the Comprehensive Epilepsy Program at the University of Alberta. Demographic, age at seizure onset, age at surgery, preoperative electroencephalography (EEG), long-term video EEG, imaging (magnetic resonance imaging [MRI] and computed tomography), neuropathology, and long-term seizure outcome data were acquired and analyzed. One hundred and seventeen patients underwent surgery for refractory TLE; the preoperative MRI diagnosis was concordant with the histopathological diagnosis in 76 % of cases. Tumors were identified with high accuracy (91 %). Mesial temporal sclerosis (MTS) was strongly associated with an excellent outcome after surgery (94 %). Patients with normal imaging results or non-specific pathologies were more likely to experience poor seizure outcomes after surgery (50 %). The radiological identification of lesions was associated with good long-term seizure outcomes, whereas normal MRI results were associated with significantly poorer long-term seizure outcomes. An accurate preoperative MRI is essential to epilepsy surgery since it impacts all stages of management; these results will thereafter help inform practitioners' efforts to predict seizure outcome.

The Putative Role of mTOR Inhibitors in Non-tuberous Sclerosis Complex-Related Epilepsy

Epilepsy affects ~5 out of every 10,000 children per year. Up to one-third of these children have medically refractory epilepsy, with limited to no options for improved seizure control. mTOR, a ubiquitous 289 kDa serine/threonine kinase in the phosphatidylinositol 3-kinase (PI3K)-related kinases (PIKK) family, is dysregulated in a number of human diseases, including tuberous sclerosis complex (TSC) and epilepsy. In cell models of epilepsy and TSC, rapamycin, an mTOR inhibitor, has been shown to decrease seizure frequency and duration, and positively affect cell growth and morphology. Rapamycin has also been shown to prevent or improve epilepsy and prolong survival in animal models of TSC. To date, clinical studies looking at the effects of mTOR inhibitors on the reduction of seizures have mainly focused on patients with TSC. Everolimus (Novartis Pharmaceuticals), a chemically modified rapamycin derivative, has been shown to reduce seizure frequency with reasonable safety and tolerability. Mutations in mTOR or the mTOR pathway have been found in hemimegalencephaly (HME) and focal cortical dysplasias (FCDs), both of which are highly correlated with medically refractory epilepsy. Given the evidence to date, a logical next step is to investigate the role of mTOR inhibitors in the treatment of children with medically refractory non-TSC epilepsy, particularly those children who have also failed resective surgery.

Memory dysfunctions

Since the seminal work on the patient HM, who in his adulthood presented an acquired amnesic syndrome following the resection of the bilateral temporal lobe, other research has described several cases of isolated memory dysfunction in children. This chapter presents developmental and long-lasting memory disorders emerging from an organic or neurologic cause at birth or in infancy. More notably, we focus on developmental amnesic syndrome caused by neonatal bihippocampal damage and memory dysfunction caused by medial temporal developmental epilepsy. We describe these two pediatric populations and present the consequences of hippocampal/medial temporal lobe damage in the development of memory systems. We review episodic memory deficits in children with developmental amnesia and temporal lobe epilepsy and highlight their impact on new learning, personal memories, and independent life. Finally, we provide a brief overview of some of the insights and debates emerging from classic work and recent advances in the context of episodic memory dysfunction displayed by children with hippocampal/medial temporal lobe amnesia and propose new perspectives in child neuropsychology of memory, suggesting new avenues for more ecologic memory assessment and rehabilitation.

Surgical Management of Pediatric Epilepsy: Decision-Making and Outcomes

First-line treatment for epilepsy is antiepileptic drug and requires an interdisciplinary approach and enduring commitment and adherence from the patient and family for successful outcome. Despite adherence to antiepileptic drugs, refractory epilepsy occurs in approximately 30% of children with epilepsy, and surgical treatment is an important intervention to consider. Surgical management of pediatric epilepsy is highly effective in selected patients with refractory epilepsy; however, an evidence-based protocol, including best methods of presurgical imaging assessments, and neurodevelopmental and/or behavioral health assessments, is not currently available for clinicians. Surgical treatment of epilepsy can be critical to avoid negative outcomes in functional, cognitive, and behavioral health status. Furthermore, it is often the only method to achieve seizure freedom in refractory epilepsy. Although a large literature base can be found for adults with refractory epilepsy undergoing surgical treatment, less is known about how surgical management affects outcomes in children with epilepsy. The purpose of the review was fourfold: (1) to evaluate the available literature regarding presurgical assessment and postsurgical outcomes in children with medically refractory epilepsy, (2) to identify gaps in our knowledge of surgical treatment and its outcomes in children with epilepsy, (3) to pose questions for further research, and (4) to advocate for a more unified presurgical evaluation protocol including earlier referral for surgical candidacy of pediatric patients with refractory epilepsy. Despite its effectiveness, epilepsy surgery remains an underutilized but evidence-based approach that could lead to positive short- and long-term outcomes for children with refractory epilepsy.

Alexander Falconer Sr Seamen's missionary in New Zealand, son Alexander Falconer medical superintendent for mentally ill, grandson Murray Falconer neurosurgeon

Alexander Falconer Sr (1843-1915) came from Scotland to New Zealand. A practical Christian, he set up places of relaxation for miners, sailors and soldiers; he became the Seamen's Missionary. Son, Dr Alexander Falconer (1874-1955) trained at Otago University Medical School. As medical superintendent for the mentally ill, he urged the early introduction of psychotherapy. His son, Murray Falconer (1910-1977) was the first Nuffield Dominions Clinical Fellow, training in neurosurgery in Oxford. He was the first director of the Guy's-Maudsley Neurosurgical Unit in London and was internationally known for the surgical management of temporal lobe epilepsy in adults and children.

Pediatric epilepsy surgery: could age be a predictor of outcomes?

OBJECTIVE Like adults, many children suffering from intractable seizures benefit from surgical therapy. Although various reports indicate that early intervention may avoid severe developmental consequences often associated with intractable epilepsy, surgery is still considered a last option for many children. In this retrospective study, the authors aimed to determine whether pediatric epilepsy surgery, in particular during the first years of life, relates to measurable benefits. METHODS Data from 78 patients (age range 5 months to 17 years) who underwent epilepsy surgery at the Geneva and Lausanne University Hospitals between 1997 and 2012 were reviewed retrospectively. Patients were dichotomized into 2 groups: infants (≤ 3 years of age, n = 19), and children/adolescents (4-17 years of age, n = 59). Compared with children/adolescents, infants more often had a diagnosis of dysplasia (37% vs 10%, respectively; p < 0.05, chi-square test). RESULTS The overall seizure-free rate was 76.9%, with 89.5% in infants and 72.9% in the children/adolescents group. Infants were 2.76 times as likely to achieve seizure-free status as children/adolescents. Postoperative antiepileptic medication was reduced in 67.9% of patients. Only 11.4% of the patients were taking more than 2 antiepileptic drugs after surgery, compared with 43% before surgery (p < 0.0001). The overall complication rate was 15.1% (6.4% transient hemiparesis), and no major complications or deaths occurred. CONCLUSIONS The data show a high seizure-free rate in children ≤ 3 years of age, despite a higher occurrence of dysplastic, potentially ill-defined lesions. Pediatric patients undergoing epilepsy surgery can expect a significant reduction in their need for medication. Given the excellent results in the infant group, prospective studies are warranted to determine whether age ≤ 3 years is a predictor for excellent surgical outcome.

Costs and Clinical Outcomes of Epilepsy Surgery in Children With Drug-Resistant Epilepsy

PURPOSE

Approximately 20% of children with epilepsy are drug-resistant, incurring considerable costs. Epilepsy surgery has been shown to be an effective intervention in this population. This study provides an initial look at the costs associated with surgical management of children with drug-resistant epilepsy as compared with medical management alone.

PROCEDURES

In a retrospective cohort study of children with drug-resistant epilepsy referred for possible surgical intervention, we compared direct costs of those treated surgically versus those offered surgery but managed medically instead. We also assessed the difference in seizure frequency between the two groups.

FINDINGS

There were 94 total patients, 78 (83%) in the surgical group and 16 (17%) in the medical group. The median (25th-75th percentile) cost of the epilepsy surgery hospitalization was $118,400 ($101,900-$143,800). Total median annual follow-up costs, not including the cost of surgical hospitalization, were not significantly different between the two groups at 1- or 2-year follow-up. However, the surgical patients who were seizure-free at 1-year follow-up, and those that remained seizure-free at 2-year follow-up, had significantly lower costs compared with the medical group ($8000 versus $16,200, P = 0.04 and $4300 versus $7600, P = 0.05, respectively). The surgical group had significantly fewer seizures compared with the medical group at 1-year follow-up.

CONCLUSIONS

Although epilepsy surgery is expensive and the overall costs of surgical and medical management are similar in the first 2 years, patients who achieved seizure freedom after surgery had lower costs compared with those treated medically.

Temporal lobe epilepsy in infants and children

Clinical expression of temporal lobe seizures is different with a more diverse and more extensive etiology in infants and children than it is in adults. It is dominated by cortical dysplasia, low-grade tumors and perinatal damage. Hippocampal sclerosis, although less frequent, exists in children usually as a dual pathology associated with ipsilateral neocortical lesions. The clinical semiology of temporal seizures is more varied, and sometimes misleading. Motor features including tonic, clonic or myoclonic behaviors, and infantile spasms predominate in infants. Classical complex partial seizures with behavioral arrest and automatisms, as well as lateralizing signs are rare and occur mostly with onset after the age of two years. Interestingly, aura, emotional, and autonomic signs seem to be independent on the brain maturation process. Moreover, the neuropsychological profile varies according to age of onset and duration, lateralization of the focus and etiology. Quality of care benefits from individual cognitive assessment for memory and emotional processes.

Temporal lobe epilepsy in children: executive and mnestic impairments

The current definition of epilepsy emphasizes the importance of cognitive impairment for a complete understanding of the disorder. Cognitive deficits have distinct functional manifestations that differentially impact the daily life experiences of children and adolescents with epilepsy and are a particular concern as they frequently impair academic performance. In particular, memory impairment and executive dysfunction are common disabilities in adults with temporal lobe epilepsy but are less easily recognized and studied in the pediatric population. This review focuses on the consequences of early-onset temporal lobe epilepsy for the development of memory and executive function and discusses current theories to explain these deficits.

The significance of insular hypometabolism in temporal lobe epilepsy in children

BACKGROUND AND PURPOSE

Temporal lobe epilepsy is one of the most common forms of medically refractory epileptic syndromes. In a small percentage, temporal lobectomy fails to control the seizures in patients with epilepsy of clear temporal origin, and in some of these patients, seizures originating from the insular cortex is believed to be the cause behind the surgical failures. We retrospectively analyzed the [(18)F]FDG-positron emission tomography (PET) results of patients who received temporal lobe surgery for presence of insular hypometabolism, and compared the surgical outcome to verify whether insular hypometablism was related with difference in post-operative results.

METHODS

13 patients were enrolled, and clinical variables, post-operative pathology, magnetic resonance imaging and PET results were analyzed for possible differences between the patients with or without insular hypometabolism.

RESULTS

7 patients showed insular hypometabolism, while 6 patients were clear of insular lesion on PET exam. 8 patients received anterior temporal lobectomy with amygdalohippocampectomy (AH), 2 patients received radical temporal lobectomy with AH, and 3 patients received insular cortisectomy. Post-operative results were favorable in 8 patients and unfavorable in 5, with unfavorable outcomes in all recipients of insular cortisectomy. Presence of insular hypometabolism did not have any significant relationship with the post-surgical outcome (p=0.266), but its trend showed a tendency towards favorable outcome if insular hypometabolism was not present.

CONCLUSIONS

Presence of insular hypometabolism in [(18)F]FDG-PET analysis was not significantly correlated with the post-operative outcome, and recipients of insular cortisectomy among our patients with insular hypometabolism resulted in poor surgical outcome. However, the outcome trend showed a tendency towards better surgical outcome with absence of hypometabolic lesion in the ipsilateral insular cortex. Further studies employing a larger patient group is needed.

Depth electrodes in pediatric epilepsy surgery

BACKGROUND

The surgical removal of the epileptogenic zone in medically intractable seizures depends on accurate localization to minimize the neurological sequelae and prevent future seizures. To date, few studies have demonstrated the use of depth electrodes in a pediatric epilepsy population. Here, we report our study of pediatric epilepsy patients at our epilepsy center who were successfully operated for medically intractable seizures following the use of intracranial depth electrodes. In addition, we detail three individuals with distinct clinical scenarios in which depth electrodes were helpful and describe our technical approach to implantation and surgery.

METHODS

We retrospectively reviewed 18 pediatric epilepsy patients requiring depth electrode studies who presented at the University of Alberta Comprehensive Epilepsy Program between 1999 and 2010 with medically intractable epilepsy. Patients underwent cortical resection following depth electrode placement according to the Comprehensive Epilepsy Program surgical protocols after failure of surface electroencephalogram and magnetic resonance imaging to localize ictal onset zone.

RESULT

The ictal onset zone was successfully identified in all 18 patients. Treatment of all surgical patients resulted in successful seizure freedom (Engel class I) without neurological complications.

CONCLUSION

Intracranial depth electrode use is safe and able to provide sufficient information for the identification of the epileptogenic zone in pediatric epilepsy patients previously not considered for epilepsy surgery.

Predicting and preventing psychopathology following temporal lobe epilepsy surgery

Less than 3% of temporal lobe epilepsy (TLE) surgical outcome studies have investigated the psychiatric sequelae and morbidity associated with surgery. This is disproportionate to the extent of the problem. Variable prevalence rates have been reported for post-surgical depression, anxiety, and interictal psychosis. Until recently, very few studies distinguished de novo postoperative presentations from pre-existing conditions, making it difficult to accurately assess the impact of TLE surgery on psychiatric morbidity. Predictors of de novo postoperative presentations have proved elusive. This current review summarizes the findings from a systematic literature review of the psychiatric morbidity associated with TLE surgery including newly published follow-up data from our own series of 280 surgical patients. A framework for future research, possible pathophysiological mechanisms, and translational models are also discussed.

Cognitive disorders in pediatric epilepsy

Childhood epilepsy may cause cognitive disorders and the intellectual quotient is indeed not normally distributed in epileptic children, a fair proportion of whom show an IQ in the deficient range. Some epileptic syndromes happen during vulnerability periods of brain maturation and interfere with the development of specific cognitive functions. This is the case for the Landau-Kleffner syndrome, which generally appears during speech development and affects language. Similarly, West syndrome - or infantile spasms - is an epileptogenic encephalopathy appearing during the first years of life and induces a major delay in social and oculo-motor development. Specific impairments can also be identified in partial childhood epilepsies in relation with seizure focus localization. For instance, left temporal and frontal epilepsies are frequently associated with verbal impairments. Moreover, episodic memory disorders have been described in children suffering from temporal lobe epilepsy whereas executive deficits (planning, self-control, problem solving) have been reported in frontal lobe epilepsy. In most cases, including its mildest forms, childhood epilepsy induces attention deficits, which may affect academic achievement. These observations militate in favor of individual neuropsychological assessments as well as early interventions in order to provide the child with an optimal individualized treatment program.

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.

Neurosurgical management of frontal lobe epilepsy in children

OBJECT

Pediatric frontal lobe epilepsy (FLE) remains a challenging condition for neurosurgeons and epileptologists to manage. Postoperative seizure outcomes remain far inferior to those observed in temporal lobe epilepsies, possibly due to inherent difficulties in delineating and subsequently completely resecting responsible epileptogenic regions. In this study, the authors review their institutional experience with the surgical management of FLE and attempt to find predictors that may help to improve seizure outcome in this population.

METHODS

All surgically treated cases of intractable FLE from 1990 to 2008 were reviewed. Demographic information, preoperative and intraoperative imaging and electrophysiological investigations, and follow-up seizure outcome were assessed. Inferential statistics were performed to look for potential predictors of seizure outcome.

RESULTS

Forty patients (20 male, 20 female) underwent surgical management of FLE during the study period. Patients were an average of 5.6 years old at the time of FLE onset and 11.7 years at the time of surgery; patients were followed for a mean of 40.25 months. Most patients displayed typical FLE semiology. Twenty-eight patients had discrete lesions identified on MRI. Eight patients underwent 2 operations. Cortical dysplasia was the most common pathological diagnosis. Engel Class I outcome was obtained in 25 patients (62.5%), while Engel Class II outcome was observed in 5 patients (12.5%). No statistically significant predictors of outcome were found.

CONCLUSIONS

Control of FLE remains a challenging problem. Favorable seizure outcome, obtained in 62% of patients in this series, is still not as easily obtained in FLE as it is in temporal lobe epilepsy. While no statistically significant predictors of seizure outcome were revealed in this study, patients with FLE continue to require extensive workup and investigation to arrive at a logical and comprehensive neurosurgical treatment plan. Future studies with improved neuroimaging and advanced invasive monitoring strategies may well help define factors for success in this form of epilepsy that is difficult to control.

Association of magnetic resonance imaging identification of mesial temporal sclerosis with pathological diagnosis and surgical outcomes in children following epilepsy surgery

OBJECT

Mesial temporal sclerosis (MTS) is widely recognized as a significant underlying cause of temporal lobe epilepsy. Magnetic resonance imaging is routinely used in the preoperative evaluation of children with epilepsy. The purpose of this study was to evaluate the prevalence, reliability, and prognostic value of MRI identification of MTS and MRI findings indicative of MTS in a series of patients who underwent resection of the medial temporal lobe for medically refractory epilepsy.

METHODS

The authors reviewed the medical records and preoperative MRI reports of 25 patients who had undergone medial temporal resections (anterior temporal lobectomy or functional hemispherotomy) for medically intractable epilepsy. The preoperative MRI studies were presented for blinded review by 2 neuroradiologists who independently evaluated the radiographs for selected MTS features and provided a final interpretation. To quantify interrater agreement and accuracy, the findings of the 2 blinded neuroradiologists, the nonblinded clinical preoperative radiology report, and the final pathology interpretation were compared.

RESULTS

The preoperative MRI studies revealed MTS in 6 patients (24%), and histopathological analysis verified MTS in 8 (32%) of 25 specimens. Six MRI features of MTS were specifically evaluated: 1) increased hippocampal signal intensity, 2) reduced hippocampal size, 3) atrophy of the ipsilateral hippocampal collateral white matter, 4) enlarged ipsilateral temporal horn, 5) reduced gray-white matter demarcation in the temporal lobe, and 6) decreased temporal lobe size. The most prevalent feature of MTS identified on MRI was a reduced hippocampal size, found in 11 of the MRI studies (44%). Analysis revealed moderate interrater agreement for MRI identification of MTS between the 2 blinded neuroradiologists and the nonblinded preoperative report (Cohen κ 0.40-0.59). Interrater agreement was highly variable for different MTS features indicative of MTS, ranging from poor to near perfect. Agreement was highest for increased hippocampal signal and decreased temporal lobe size and was consistently poor for reduced gray-white matter demarcation. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and proportion perfect agreement were highest for increased hippocampal signal and reduced hippocampal size. An MRI finding of MTS was not predictive of seizure outcome in this small series.

CONCLUSIONS

Mesial temporal sclerosis identification on brain MRI in children evaluated for medial temporal resections has a PPV of 55%-67% and an NPV of 79%-87%. Increased hippocampal signal and reduced hippocampal size were associated with high predictive values, while gray-white differentiation and an enlarged temporal horn were not predictive of MTS. Seizure outcome following medial temporal resections was not associated with MRI findings of MTS or MRI abnormalities indicative of MTS in this small sample size.

Improved outcomes in pediatric epilepsy surgery: the UCLA experience, 1986-2008

OBJECTIVE

Epilepsy neurosurgery is a treatment option for children with refractory epilepsy. Our aim was to determine if outcomes improved over time.

METHODS

Pediatric epilepsy surgery patients operated in the first 11 years (1986-1997; pre-1997) were compared with the second 11 years (1998-2008; post-1997) for differences in presurgical and postsurgical variables.

RESULTS

Despite similarities in seizure frequency, age at seizure onset, and age at surgery, the post-1997 series had more lobar/focal and fewer multilobar resections, and more patients with tuberous sclerosis complex and fewer cases of nonspecific gliosis compared with the pre-1997 group. Fewer cases had intracranial EEG studies in the post-1997 (0.8%) compared with the pre-1997 group (9%). Compared with the pre-1997 group, the post-1997 series had more seizure-free patients at 0.5 (83%, +16%), 1 (81%, +18%), 2 (77%, +19%), and 5 (74%, +29%) years, and more seizure-free patients were on medications at 0.5 (97%, +6%), 1 (88%, +9%), and 2 (76%, +29%), but not 5 (64%, +8%) years after surgery. There were fewer complications and reoperations in the post-1997 series compared with the pre-1997 group. Logistic regression identified post-1997 series and less aggressive medication withdrawal as the main predictors of becoming seizure-free 2 years after surgery.

CONCLUSIONS

Improved technology and surgical procedures along with changes in clinical practice were likely factors linked with enhanced and sustained seizure-free outcomes in the post-1997 series. These findings support the general concept that clearer identification of lesions and complete resection are linked with better outcomes in pediatric epilepsy surgery patients.

Murray Alexander Falconer and the Guy's-Maudsley Hospital seizure surgery program

The 1949 appointment of Murray Falconer to the neurosurgical post of Guy's Hospital, London, resulted in the creation of an extremely productive seizure surgery program, in the early days of this discipline. In association with the Institute of Psychiatry at the Maudsley Hospital, his program produced in-depth research on the neuropsychiatry, the neuropathology and the psychosocial follow-up of temporal lobe epilepsy treated by surgical ablation. These results constitute a very significant landmark in the history of the early days of the neurosurgical attack on refractory epilepsy.

Surgery for medically intractable temporal lobe epilepsy during early life

PURPOSE

Temporal lobe epilepsy (TLE) in early life is often a catastrophic disorder with pharmacoresistant seizures and secondary neurological deterioration. there is little data available regarding epilepsy surgery performed in infants and young children and no prior study has focused on tle.

METHODS

We analyzed the results of temporal resection for epilepsy as the primary indication in children less than age 5 years who had at least 2 years of follow-up.

RESULTS

20 children (14 males) were identified with a mean age at surgery of 26 months and a mean age at seizure onset of 12 months. Clinical presentation was diverse. Typical psychomotor seizures (n = 4; mean age at surgery 37 months) were followed by prominent motor changes (n = 7; 30 months) and were occasionally isolated (n = 3; 23 months). Epileptic spasms were noted in six patients and were frequently associated with lateralizing features. The interictal EEG was lateralizing in 15 patients and the ictal EEG was lateralizing in 18 patients. Brain MRI provided localizing value in 16 patients, ictal SPECT was concordant in 4/8 cases. Invasive EEG was employed in six cases. At mean follow-up of 5.5 years, 65% of the children were seizure-free and 15% had >90% seizure reduction. Morbidity included infection and hydrocephalus in one case and stroke-related hemiparesis in two cases. Cortical dysplasia was identified in eight children, tumors in eight including two DNET, two ganglioglioma, and four malignant tumors. Hippocampal sclerosis was present in four cases, always as dual pathology.

CONCLUSION

TLE presents in early life with varied and severe manifestations. Excisional procedures in this age group are associated with favorable seizure reduction similar to older children and in adults.

The Impact of Cerebral Source Area and Synchrony on Recording Scalp Electroencephalography Ictal Patterns

PURPOSE

To determine the cerebral electroencephalography (EEG) substrates of scalp EEG seizure patterns, such as source area and synchrony, and in so doing assess the limitations of scalp seizure recording in the localization of seizure onset zones in patients with temporal lobe epilepsy.

METHODS

We recorded simultaneously 26 channels of scalp EEG with subtemporal supplementary electrodes and 46-98 channels of intracranial EEG in presurgical candidates with temporal lobe epilepsy. We correlated intracranial EEG source area and synchrony at seizure onset with the corresponding scalp EEG. Eighty-six simultaneous intracranial- and scalp-recorded seizures from 23 patients were evaluated.

RESULTS

Thirty-four intracranial ictal discharges (40%) from 9 patients (39%) had sufficient cortical source area (namely > 10 cm(2)) and synchrony at seizure onset to produce a simultaneous or nearly simultaneous focal scalp EEG ictal pattern. Forty-one intracranial ictal discharges (48%) from 10 patients (43%) gradually achieved the necessary source area and synchrony over several seconds to generate a scalp EEG ictal pattern. These scalp rhythms were lateralized, but not localizable as to seizure origin. Eleven intracranial ictal discharges (13%) from 4 patients (17%) recruited the necessary source area, but lacked sufficient synchrony to result in a clearly localized or lateralized scalp ictal pattern.

CONCLUSIONS

Sufficient source area and synchrony are mandatory cerebral EEG requirements for generating scalp-recordable ictal EEG patterns. The dynamic interaction of cortical source area and synchrony at the onset and during a seizure is a primary reason for heterogeneous scalp ictal EEG patterns.

Apnea caused by mesial temporal lobe mass lesions in infants: report of 3 cases

Apnea as an isolated manifestation of seizures is well described in neonates but is only occasionally observed in infants. This article reports 3 infants presenting with apneic events as the main manifestation of seizure, documented by video electroencephalogram, all with mesial temporal lobe lesions. The 3 infants, after normal pregnancy and delivery at term, showed the first apnea at the age of 4 to 10 months. Although the interictal electroencephalogram result was often normal, ictal video electroencephalogram in all infants showed focal rhythmic discharges with or without generalization. Magnetic resonance imaging showed an inferior mesial temporal lobe mass lesion in all infants. All patients underwent lesion removal, and they are seizure free with normal psychomotor development.

Psychiatric outcome of surgery for temporal lobe epilepsy and presurgical considerations

In recent years, surgery has become a treatment option for some patients with intractable epilepsy, particularly those with temporal lobe epilepsy. Psychiatric disturbances may complicate the postsurgical outcome in some patients and de novo psychiatric symptoms have been reported. In many but not all epilepsy surgical centres, a psychiatric assessment is included as part of the presurgical evaluation of potential candidates for surgery. This review indicates that affective disorders, namely, depression and anxiety, and psychosis are the most frequently reported postsurgical psychiatric disturbances. Whilst there are no absolute psychiatric contraindications to surgery, certain pre-existing psychiatric conditions may need careful consideration as there may be a risk of postsurgical psychiatric complications. Routine pre- and postsurgical psychiatric evaluations in patients undergoing epilepsy surgery are recommended. Clinicians involved in the care of surgical candidates should be aware of the possible psychiatric complications following surgery and ensure that the psychiatric risks are discussed with the patient and family.

Memory functions following surgery for temporal lobe epilepsy in children

Surgical treatment appears to improve the cognitive prognosis in children undergoing surgery for temporal lobe epilepsy (TLE). The beneficial effects of surgery on memory functions, particularly on material-specific memory, are more difficult to assess because of potentially interacting factors such as age range, intellectual level, left-handedness, type of surgery and seizure outcome. This study investigated memory functions in 20 right-handed children who had left or right-temporal lobe surgery - including hippocampectomy - and became seizure-free. The neuropsychological evaluation included tests measuring verbally and visually mediated episodic memory, everyday memory as well as attention/working memory and language/semantic memory. We also assessed the relationships between age of seizure onset, general cognitive ability and memory functions. Children with TLE showed poor memory efficiency before surgery that tended to improve about 1 year after surgery. We found a material-specific memory effect, especially after surgery-9 (out of 12) children with left TLE had worse verbal memory results while 5 (out of 8) with right TLE had worse visual memory results. Post-operatively, most children had poor everyday memory performance on the Rivermead Behavioural Memory Test. No significant relationship was observed between episodic memory scores and age of epilepsy onset but children with early onset remained with lower Performance IQ values, Rey's figure copy scores and naming performances after surgery. Surgery significantly improved all the attention/working memory scores, some verbal episodic memory tasks and naming test performances. A different pattern of episodic and semantic memory limitations related to left or right TLE was observed.

Temporal lobe surgery for intractable epilepsy in children: an analysis of outcomes in 126 children

OBJECTIVE

Temporal lobectomy is a well-established neurosurgical procedure for temporal lobe epilepsy. In this study, we conducted a retrospective review of children with drug-resistant temporal lobe epilepsy to evaluate seizure outcome after temporal lobe surgery.

METHODS

We reviewed the medical records of 126 children who had surgery for temporal lobe epilepsy at The Hospital for Sick Children between 1983 and 2003. The records were examined for preoperative and intraoperative factors that could predict patient outcome after surgery.

RESULTS

The mean age at seizure onset was 5.9 years. The mean seizure duration before surgery was 5.6 years. All patients had preoperative computed tomographic scans, magnetic resonance imaging scans, or both. The mean age at the time of surgery was 13.5 years. Sixty-two patients underwent left temporal resections and 64 patients underwent right temporal resections. The histopathology of the temporal resections revealed low-grade brain tumors in 65 children (52%) and cavernous malformations in four children. Ganglioglioma and astrocytoma were the most common tumors encountered. Mesial temporal sclerosis was found in 16 patients (13%), astrogliosis in 15 patients (12%), and cortical dysplasia in eight patients (7%). Postoperative follow-up of at least 2 years was available for 106 patients and ranged up to 13.0 years. Seventy-four percent of patients had an Engel Class I or II outcome. Patients with temporal lobe lesions had better outcomes compared with those without lesions (P < 0.05). Patients without a history of secondary generalization of seizures also had a better outcome when compared with those with secondary generalization. Complications in the form of contralateral homonymous hemianopsia, dysphasia, and infection were found in 5% of patients. Twelve patients had a second temporal lobe procedure for intractable recurrent seizures. After a second procedure, seven patients returned to a seizure-free state.

CONCLUSION

Temporal lobe resections for epilepsy in children are effective and safe procedures, with a favorable impact on seizure control. Repeat temporal resections for recurrent seizures may also be effective in restoring a seizure-free outcome to children.

Efficacy of intraoperative electrocorticography for assessing seizure outcomes in intractable epilepsy patients with temporal-lobe-mass lesions

PURPOSE

The findings of previous studies have been controversial regarding the optimal surgical procedures required for effective seizure control. In particular, there are varying views as to whether or not lesionectomy of a temporal-lobe-mass lesion is a satisfactory process or whether removal of additional seizure foci is necessary. In this study, we evaluated the efficacy of additional removal of electrically positive foci using intraoperative electrocorticography on mass lesions related to temporal lobe epilepsy.

METHODS

Thirty-five medically intractable epilepsy patients with temporal-lobe benign mass lesions, who had been surgically treated, were assessed. The relationship between resection of the epilepsy focus using intraoperative electrocorticography and seizure outcome was analyzed. In addition, the sites of residual spikes after lesion removal were evaluated.

RESULTS

In this study, the benign mass lesions consisted of 21 gangliogliomas, 8 cavernous angiomas and 6 dysembryoplastic neuroepithelial tumors. The number of 3-year postoperative seizure-free incidences for the group that underwent lesionectomy plus additional spike-positive site resection equated to 90.9%. In contrast, in the group that underwent a lesionectomy only, 76.9% were seizure-free for 3-years postoperatively. After complete removal of mass lesions, 86.4% of the residual spikes were detected over the hippocampus.

CONCLUSION

Even after the complete removal of temporal-lobe-mass lesions, a high frequency of residual spikes was obtained from the hippocampus. Effective surgical seizure control was achieved by carrying out additional procedures on the affected hippocampus. To detect seizure foci surrounding the lesion, especially over the hippocampus, intraoperative electrocorticogram monitoring was shown to be an effective technique.

Childhood mesial temporal sclerosis

The prevalence and clinical characteristics of mesial temporal sclerosis have not been well studied in children. All brain magnetic resonance imaging (MRI) reports of children less than 14 years of age were reviewed from two tertiary institutions. A 52-month period from one institution and a 37-month period from the other were reviewed. All reports of definite or possible mesial temporal sclerosis were noted. These patients' MRIs were then reviewed to confirm the MRI diagnostic criteria of mesial temporal sclerosis. The charts of the patients who satisfied these criteria were reviewed in detail. Three thousand one hundred brain MRI reports were reviewed. Twenty-six reports of mesial temporal sclerosis were found. Twenty-four of the 26 films satisfied the criteria of mesial temporal sclerosis by MRI after the films were reviewed. The prevalence among all pediatric brain MRI studies was 0.77%. All patients had presented with seizures, that is, there were no "incidental" findings of mesial temporal sclerosis. Four patients had a history of febrile seizures. Mesial temporal sclerosis is an uncommon finding in children, but when it occurs, it is always associated with epilepsy. Asymptomatic mesial temporal sclerosis or mesial temporal sclerosis not associated with a seizure disorder did not occur in our series. Febrile seizures can occur in association with mesial temporal sclerosis presenting in childhood.

Resective epilepsy surgery in childhood: the Dutch experience 1992-2002

PURPOSE

We present the outcome of resective epilepsy surgery in 69 pediatric patients who participated in the Dutch Collaborative Epilepsy Surgery Program (DCESP) between 1992 and 2002 with special emphasis on long-term follow-up.

METHODS

Sixty-nine children (aged 3 months to 17 years) operated on before 2003 were included in this study (34 temporal resections (49%), 17 extra-temporal resections (24%) and 19 hemispherectomies (27%)). Engel classification was used to assess seizure outcome annually. Cognitive outcome was assessed if possible. Two telephone surveys were carried out with an interval of 2(1/2) years to obtain data on seizure frequency, use of AEDs and on aspects op psychosocial development. Kaplan-Meier survival curves were constructed to assess recurrence of seizures after initial postsurgical seizure freedom, based on both telephone surveys.

RESULTS

Seventy percent scored Engel 1, 18% Engel 2, 6% Engel 3 and 6% Engel 4 at the time of the first telephone survey (2(1/2) years later: 77% Engel 1, 8% Engel 2, 12% Engel 3 and 3% Engel 4). Temporal resections were associated with the best seizure outcome (Engel 1 74% and 82%). AEDs could be withdrawn successfully in 53% of patients at time of the last follow-up. No negative impact on cognition was found. The first long-term follow-up (mean 4.5 years after surgery) measurement showed recurrence of seizures after initial seizure freedom in 17%. At time of the second long-term follow-up measurement (mean 7.5 years after surgery) this percentage had increased to 21%.

CONCLUSIONS

Our results support previous reports that surgery for intractable epilepsy in pediatric patients can be safely performed with satisfactory long-term results. Best results are attained in temporal resections.

Posterior resection for childhood epilepsy

We reviewed our experience with posterior resection for intractable childhood epilepsy. Fifteen patients, seven males and eight females, were studied. Age of surgery was 18 months to 16 years. Nine patients had a parietal resection and six patients had an occipital resection. Surgical outcome was variable. Nine patients had an excellent outcome (Engel Class I or II), two patients had a poor outcome (Engel Class III), and four patients had a very poor outcome (Engel Class IV). Pathology at surgery included focal cortical dysplasias (4), brain tumors (4), tubers of tuberous sclerosis (2), cerebrovascular accidents (2), porencephalic cysts (1), and normal pathology (2). Complications included visual field loss in the occipital lobe patients (4/6). Posterior resection can be successful for children with intractable epilepsy originating in the parietal and occipital lobes. Invasive monitoring is necessary in some patients to establish the extent of the epileptic zone before surgery. A good surgical outcome is dependent on the presence of a circumscribed lesion on MRI and ability to surgically remove all the pathology. Visual abnormalities are an expected complication of surgery in the occipital lobe, but may improve over time.

Neuropsychological outcome following focal cortical removal for intractable epilepsy in children

In children, surgery for epilepsy has been recognized as a viable treatment option since publication of S. Davidson and M.A. Falconer's outcome study in 1975 [Lancet North Am Ed 5:1260-3], which demonstrated that medical outcome of children who underwent anterior temporal lobectomy paralleled that of adults. Pediatric surgical programs and the literature on medical outcome have grown considerably since that time, with surgery being offered to children with temporal but also extratemporal epilepsy foci. Comparatively little work has been conducted in the area of neuropsychological outcome. This article outlines differences in adult and pediatric outcome studies, reviews the literature on the intellectual and memory outcome in children, and discusses shortcomings of the pediatric outcome research conducted to date.

Abnormal behavior in children with temporal lobe epilepsy and ganglioglioma

Temporal lobe epilepsy in childhood is characterized by great clinical, electroencephalographic, and etiological diversity. The prognosis after temporal lobe epilepsy surgery in childhood is usually good, with most patients achieving complete seizure control. However, in some children behavior deteriorates postoperatively. We report two girls (2 and 6 years of age) with refractory seizures due to temporal lobe ganglioglioma. They exhibited aggression and hyperactivity since the beginning of their epilepsy. In both patients, behavioral disturbances worsened postoperatively, despite complete seizure control. Patients and parents should be advised about possible behavioral disturbances after epilepsy surgery, especially in the presence of a temporal lobe developmental tumor, even when seizure control is achieved postoperatively.

Analysis of different types of resection for pediatric patients with temporal lobe epilepsy

OBJECTIVE

Resection strategies for the treatment of temporal lobe epilepsy (TLE) are a matter of discussion. Few data on the significance of resection type are available for pediatric patients with TLE.

METHODS

Data for a series of 89 children who were surgically treated for TLE were analyzed. A first cohort of patients were mainly surgically treated with anterior temporal lobectomies. For a second cohort, resections were preoperatively "tailored" to the lesion and presumed epileptogenic area.

RESULTS

The follow-up period was 46 months (range, 14-118 mo). Seventy-seven patients (87%) attained satisfactory seizure control (82% Engel Class I and 5% Class II). For 12 patients (13%), seizure control was unsatisfactory (8% Class III and 5% Class IV). Anterior temporal lobectomies resulted in 94% satisfactory seizure control (33 patients), whereas the success rates were only 74% (20 patients) for amygdalohippocampectomy (AH) (P = 0.023) and 77% (13 patients) for lesionectomy plus hippocampectomy (not significant). All patients who underwent purely lateral temporal lesionectomies became seizure-free (14 patients). Logistic regression revealed the factors of AH (P = 0.021) and left-side surgery (P = 0.017) as significant predictors of unsatisfactory seizure control. Satisfactory seizure control was not dependent on the histopathological diagnoses. There was a low rate of verbal memory deterioration after left-side operations. Neuropsychological deterioration was rare after right temporal resections. Attentional and contralateral functions improved after surgery.

CONCLUSION

Surgery for the treatment of juvenile TLE is successful and safe, but the resection type may influence outcomes. Results after AHs were disappointing, probably because of difficulties in precise localization of the epileptogenic focus among children. Neuropsychological results demonstrated minimal rates of deterioration and significant improvements in contralateral functions. Surgical treatment of juvenile TLE should be encouraged, but the use of especially left AH should possibly be restricted.

Clinical, electroencephalographic, and behavioral features of temporal lobe epilepsy in childhood

This study describes the clinical, electroencephalographic, and behavioral features of 36 children with temporal lobe epilepsy. Patients were divided into two groups: group A, with 6 patients (< 6 years), and group B, with 30 patients (6-18 years). Statistical analysis was performed considering the significance level of .05. Regarding the clinical features of the focal seizures, motor components were more frequently seen in children younger than 6 years of age (P < .01), whereas automatisms were more frequently seen in patients older than 6 years of age (P < .05). Associated myoclonic seizures were more frequent in the younger age group (P < .01). Behavioral disorders such as hyperactivity and aggressiveness and speech delay were more common in the younger age group (P < .05). Temporal lobe epilepsy in children younger than 6 years of age is more frequently associated with motor components, myoclonic seizures, behavioral disorders, and speech delay. Conversely, temporal lobe epilepsy in older patients has frequent automatisms.

Cognitive, Psychosocial, and Family Function One Year after Pediatric Epilepsy Surgery

PURPOSE

Assumptions regarding the benefits of seizure control after pediatric epilepsy surgery for cognitive, psychosocial, and family function were explored in a prospective study of 51 children with intractable epilepsy.

METHODS

Thirty children who underwent surgery were studied before and 1 year after surgery, and a comparison group of 21 children with medically refractory seizures was examined at comparable times.

RESULTS

One year after surgery, 57% of the surgical group was seizure free. Seizure status after surgery did not predict change over time in any of the areas measured. Cognitive and psychosocial status did not change over time in either group, and the strongest predictor of individual change in psychosocial status in the surgical group was baseline level of function. Within the surgical group, a trend toward an increase in independence promotion was noted in the family, but the children's satisfaction with the family declined.

CONCLUSIONS

These findings challenge the assumption that elimination of seizures will result in improved cognitive, psychosocial, and family functioning, at least within the first year after surgery.

Extratemporal resection for childhood epilepsy

There have been relatively few studies reporting the safety, efficacy, and outcome in children undergoing extratemporal resection for epilepsy. We reviewed the pediatric cases of extratemporal resection for intractable epilepsy performed by the Comprehensive Epilepsy Program at the University of Alberta Hospitals between 1988-1998. Thirty-five patients were studied, 14 male and 21 female. The age at operation ranged from 6 months to 16 years. The operations included frontal excisions (12), parietal (8), occipital (4), hemispherectomies or multilobar resections (10), and one removal of a hypothalamic hamartoma. The pathology at surgery included patients with focal cortical dysplasia (8), brain tumors (6), neurocutaneous syndrome (7), Rasmussen's encephalitis (2), porencephalic cysts (4), hypothalamic hamartoma (1), and nonspecific gliosis (6). Twenty-four of 35 patients (68.5%) had an Engel Class I outcome after surgery and an additional six patients (11%) had a significant decrease in seizure frequency (Engel Class III). Complications were observed in two patients (5%) and there were no deaths. Extratemporal resection is a safe and effective treatment for children with intractable epilepsy. Overall, 68% of patients were seizure-free after surgery, although outcome may be dependent on site and pathology. A wide range of developmental pathology was observed including focal cortical dysplasia, brain tumors, and lesions with neurocutaneous syndromes. Many families reported improvement in behavior and psychosocial function after surgery.

Magnetic resonance imaging detection of mesial temporal sclerosis in children

The objective of this study was to investigate the prevalence and clinical characteristics of mesial temporal sclerosis as diagnosed by brain magnetic resonance imaging in children. A total of 390 consecutive brain magnetic resonance imaging studies in children were reviewed for evidence of mesial temporal sclerosis. Subsequently, the magnetic resonance imaging scans and charts of patients with mesial temporal sclerosis were reviewed and their clinical details were evaluated. The magnetic resonance imaging studies had been performed for multiple indications, including seizures, headache, and developmental problems. In children, the prevalence of mesial temporal sclerosis among all brain magnetic resonance imaging studies was 3.1% (12 of 390 studies) and 12.1% (12 of 99 studies) among all brain magnetic resonance imaging studies performed for seizures. These children all presented with a history of seizure disorder, often had other medical problems, and histopathology (when available) nearly always (5 of 6 patients) confirmed their magnetic resonance imaging diagnosis of mesial temporal sclerosis. The prevalence of mesial temporal sclerosis is low among all pediatric patients who had magnetic resonance imaging brain studies. All our mesial temporal sclerosis patients had clinical seizures; i.e., it was never an "incidental finding". Children with mesial temporal sclerosis often had comorbid conditions, and the diagnosis of mesial temporal sclerosis made by magnetic resonance imaging was accurate when compared with the available histopathology.

Practice parameter: temporal lobe and localized neocortical resections for epilepsy

PURPOSE

To examine evidence for effectiveness of anteromesial temporal lobe and localized neocortical resections for disabling complex partial seizures.

METHODS

Systemic review and analysis of the literature since 1990.

RESULTS

One intention-to-treat Class I randomized controlled trial of surgery for mesial temporal lobe epilepsy found that 58% of patients randomized to be evaluated for surgical therapy (64% of those who received surgery) were free of disabling seizures and 10 to 15% were unimproved at the end of 1 year, compared with 8% free of disabling seizures in the group randomized to continued medical therapy. There was a significant improvement in quantitative quality-of-life scores and a trend toward better social function at the end of 1 year for patients in the surgical group, no surgical mortality, and infrequent morbidity. Twenty-four Class IV series of temporal lobe resections yielded essentially identical results. There are similar Class IV results for localized neocortical resections; no Class I or II studies are available.

CONCLUSIONS

A single Class I study and 24 Class IV studies indicate that the benefits of anteromesial temporal lobe resection for disabling complex partial seizures is greater than continued treatment with antiepileptic drugs, and the risks are at least comparable. For patients who are compromised by such seizures, referral to an epilepsy surgery center should be strongly considered. Further studies are needed to determine if neocortical seizures benefit from surgery, and whether early surgical intervention should be the treatment of choice for certain surgically remediable epileptic syndromes.

Therapeutics in pediatric epilepsy, Part 2: Epilepsy surgery and vagus nerve stimulation

When antiepileptic drugs fail to relieve seizures adequately in children and adolescents, more invasive therapies such as epilepsy surgery and an implanted device to stimulate the vagus nerve should be considered. Temporal lobectomy is an effective treatment of complex partial and secondarily generalized tonic-clonic seizures arising in the mesial structures or lateral temporal neocortex. Excellent outcomes (seizure free or rare, nondisabling seizures) are achieved in at least 70% of children. The most common adverse effect is a superior quadrant field cut that is usually asymptomatic. Transient and more long-lasting language difficulties have been reported when the surgery involves the dominant temporal lobe. The excellent outcome rate for extratemporal surgery ranges from approximately 20% to 80%, with better results seen in patients with an identifiable lesion. Potential morbidity is related to the region of resected neocortex. Corpus callosotomy is an excellent procedure for palliation but is not a cure for seizures that cause falls, with substantial improvement seen in more than 80% of patients. Potential adverse effects include more intense focal seizures and dysphasia, depending on the developmental level of the individual. Hemispherectomy provides seizure relief in 60% to 80% of patients with hemispherical pathologies such as Sturge-Weber or Rasmussen syndromes. Operative mortality has been reported in the range of 0% to 6%; other morbidities include infection and hydrocephalus. Stimulation of the vagus nerve has reduced partial seizures by 50% or more in approximately one third of patients. No adverse cognitive or systemic effects are associated with use of the implanted vagus nerve stimulator.