Developmental outcomes in children receiving resection surgery for medically intractable infantile spasms

Treatment of epileptic encephalopathies

Epileptic encephalopathy is defined as a condition where the epileptic activity itself may contribute to the severe neurological and cognitive impairment seen, over and above that which would be expected from the underlying pathology alone. The epilepsy syndromes at high risk of this are a disparate group of conditions characterized by epileptic seizures that are difficult to treat and developmental delay. In this review, we discuss the ongoing debate regarding the significance of inter-ictal discharges and the impact of the seizures themselves on the cognitive delay or regression that is a common feature of these syndromes. The syndromes also differ in many ways and we provide a summary of the key features of the early-onset epileptic encephalopathies including Ohtahara and West syndromes in addition to later childhood-onset syndromes such as Lennox Gastaut and Doose syndromes. An understanding of the various severe epilepsy syndromes is vital to understanding the rationale for treatment. For example, the resolution of hypsarrhythmia in West syndrome is associated with an improvement in cognitive outcome and drives treatment choice, but the same cannot be applied to frequent inter-ictal discharges in Lennox Gastaut syndrome. We discuss the evidence base for treatment where it is available and describe current practice where it is not. For example, in West syndrome there is some evidence for preference of hormonal treatments over vigabatrin, although the choice and duration of hormonal treatment remains unclear. We describe the use of conventional and newer anti-epileptic medications in the various syndromes and discuss which medications should be avoided. Older possibly forgotten treatments such as sulthiame and potassium bromide also have a role in the severe epilepsies of childhood. We discuss hormonal treatment with particular focus on the treatment of West syndrome, continuous spike wave in slow wave sleep (CSWS)/electrical status epilepticus in slow wave sleep (ESES) and Landau Kleffner syndrome. The role of the ketogenic diet has in recent years come to the fore of the management of these severe epilepsies and we describe successful use in myoclonic astatic epilepsy, Lennox Gastaut syndrome and Dravet syndrome. It is important that resective epilepsy surgery is not ignored in the management of these children, particularly those with hemi-pathology who may present with ESES and respond well to hemispheric disconnection. Adjunctive and symptomatic surgical treatments such as vagal nerve stimulation and corpus callosotomy may improve seizure burden. Finally, it is vital that the identification and treatment of developmental, behavioural and psychiatric co-morbidities are not neglected and that a rational, holistic approach is taken to the management of epileptic encephalopathies.

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.

Long-term developmental outcome in patients with West syndrome after epilepsy surgery

It has been hypothesized that early seizure control may prevent children with intractable epileptic spasms (ES) from developmental regression and may contribute to better developmental outcome. The effectiveness of surgery for ES has been reported. We investigated long-term post-operative outcomes of seizure control and development in patients with symptomatic West syndrome (S-WS) who underwent epilepsy surgery. Six children who underwent surgical intervention for intractable ES were retrospectively investigated. Cortical malformations were observed on pre-operative MRI in all patients, with hemispheric or multilobar involvement in four children and focal lesions in two. Following surgery, we measured motor function, developmental age (DA), language skills, and sociopsychological function for up to 7years (mean, 4.9years). Post-operative seizure outcome was Engel Class I (n=4) or III (n=2). Motor function and DA was increased following surgery in six and five patients, respectively. Two patients started to speak in sentences following focal resection. Autistic features were noted in four of the five examined patients post-operatively. None of the patients showed developmental regression following surgery. Epilepsy surgery for S-WS with ES may result in good seizure control and improvement in motor development. Improvement in cognitive function was modest in this small cohort of children and autistic features were noted post-operatively in a substantial proportion of the children. While seizure control can be obtained by epilepsy surgery, early intervention for sociopsychological comorbidities may be warranted in children with S-WS.

Surgical outcomes for intractable epilepsy in children with epileptic spasms

Epileptic spasms, or seizures marked by flexor, extensor, or flexor-extensor spasms, are not always responsive to medical management. The purpose of our study was to evaluate the outcome of epilepsy surgery in children with medically intractable epileptic spasms. We identified 11 children with epileptic spasms who underwent lesionectomy (36%), lobectomy (27%), multi-lobectomy (9%), hemispherectomy (18%), or corpus callosotomy (9%). At the time of surgery, 6 children had developed other concurrent seizure type(s), including simple partial (9%), complex partial (27%), partial undifferentiated (9%), primary generalized tonic clonic (9%), tonic (9%), atonic (27%), and myoclonic (9%) seizures. Six children (55%) were seizure free at last follow-up from initial surgery. Predictors of favorable outcome included lack of focal slowing and the presence of less than 2 interictal epileptiform abnormalities on postoperative electroencephalogram (P = .035 and .035, respectively). Favorable outcome was significantly associated with parent/caregiver report of improved postoperative developmental outcomes (P = .026).

Pediatric epileptology

Challenges facing children with epilepsy are understanding the neurobiology of pharmacoresistance of epileptic encephalopathies and the development of effective surgical treatment options for those with "non-lesional" epilepsy. Although, understanding the genetics of childhood epilepsy has advanced, an effective treatment intervention has not occurred. Recently, understanding the neurobiology of hamartin and tuberin in the development of epilepsy and cognitive impairment associated with tuberous sclerosis complex allowed the development of sirolimus and everolimus to be used in human clinical trials. In spite of these breakthroughs a large number of children are likely to be outside the scope of interventional therapies. For such patients the burden of seizures is onerous and psycho-social consequences debilitating. Surgical resective options are often limited by the lack of a well defined epileptic lesion. Co-registered synthesis of advanced functional, structural and electrographic seizure onset allows identification of a focus in patients thought to have "non-lesional" epilepsy. Developments of a Pipeline for prospective data sharing are likely to increase understanding and validation of the epileptogenic zone and offer the hope of seizure freedom. Two outstanding young investigators provide a review of their exciting research and its implications in pediatric epilepsy.

Resting-state activity in development and maintenance of normal brain function

One of the most intriguing recent discoveries concerning brain function is that intrinsic neuronal activity manifests as spontaneous fluctuations of the blood oxygen level-dependent (BOLD) functional MRI signal. These BOLD fluctuations exhibit temporal synchrony within widely distributed brain regions known as resting-state networks. Resting-state networks are present in the waking state, during sleep, and under general anesthesia, suggesting that spontaneous neuronal activity plays a fundamental role in brain function. Despite its ubiquitous presence, the physiological role of correlated, spontaneous neuronal activity remains poorly understood. One hypothesis is that this activity is critical for the development of synaptic connections and maintenance of synaptic homeostasis. We had a unique opportunity to test this hypothesis in a 5-y-old boy with severe epileptic encephalopathy. The child developed marked neurologic dysfunction in association with a seizure disorder, resulting in a 1-y period of behavioral regression and progressive loss of developmental milestones. His EEG showed a markedly abnormal pattern of high-amplitude, disorganized slow activity with frequent generalized and multifocal epileptiform discharges. Resting-state functional connectivity MRI showed reduced BOLD fluctuations and a pervasive lack of normal connectivity. The child underwent successful corpus callosotomy surgery for treatment of drop seizures. Postoperatively, the patient's behavior returned to baseline, and he resumed development of new skills. The waking EEG revealed a normal background, and functional connectivity MRI demonstrated restoration of functional connectivity architecture. These results provide evidence that intrinsic, coherent neuronal signaling may be essential to the development and maintenance of the brain's functional organization.

Surgical treatment for localization-related infantile spasms: excellent long-term outcomes

OBJECTIVE

Focal epileptogenic lesions can manifest as infantile spasms, a catastrophic type of epilepsy. Although early surgery for catastrophic epilepsies has shown positive effects, little is known regarding long-term outcomes. The present study examined long-term outcomes in patients with localization-related infantile spasms treated surgically.

METHODS

Data from localization-related infantile spasm cases treated surgically between 1998 and 2002 at the Asan Medical Center were retrospectively reviewed. Presurgical evaluation, surgery, postoperative seizure frequency and developmental outcome data were analyzed.

RESULTS

Five patients met the inclusion criteria, and had etiologies of tuberous sclerosis, fetal infection, encephalomalacia, malformation of cortical development and low-grade astrocytoma, respectively. The mean seizure onset age was 5.4 months (range, 3 days to 11 months), and the mean age at surgery was 19 months (range, 9-29 months). Two patients underwent a functional hemispherectomy, and the remaining three underwent lesionectomy or temporal lobectomy. The follow-up duration was 6-9 years. We found that following surgery, 4 of the 5 patients were seizure-free at the final follow-up. The 2 patients with low grade astrocytoma and cortical dysplasia, respectively showed relatively good developmental outcomes.

CONCLUSION

Surgery may be an excellent option for treating selected patients with infantile spasms due to unilateral or focal congenital or early-acquired cortical lesions. However, developmental outcomes appear to be strongly linked to etiology and the pre-operative developmental level.

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.

Interictal spikes in developing rats cause long-standing cognitive deficits

Frequent interictal spikes are a common finding in the electroencephalograms of children with epileptic encephalopathies. While it is well recognized that interictal spikes are a biological marker of seizures and can lead to transitory cognitive impairment, whether interictal spikes can result in long-standing adverse effects on learning and memory in children is not known. Here we investigated the consequences of interictal spikes in rat pups without seizures on long-term learning and memory. Rat pups were given a low dose of flurothyl for 4h for 10 days during continuous electroencephalographic monitoring. Rats developed interictal spikes without seizures while age-matched controls under similar testing conditions had few interictal spikes. When rats were tested as adults, there was impairment in reference memory in the probe test of the Morris water maze, reference memory impairment in the four-trial radial-arm water maze and impaired long-term potentiation. Early-life interictal spikes resulted in impaired new cell formation and decreased cell counts in the hippocampus but did not cause an increase in apoptosis. This study, for the first time demonstrates that interictal spikes in rat pups without seizures can result in long-standing spatial cognitive impairment. Our findings suggest that suppressing IIS may be as important as treating seizures during brain development.

Infantile spasms: little seizures, BIG consequences

Infantile spasms is one of the "catastrophic childhood epilepsies" because of the difficulty in controlling seizures and the association with mental retardation. However, early recognition, a careful diagnostic evaluation, and proper treatment may allow some children to attain seizure control and to achieve a normal, or at least much improved, level of development. Thus, there is the opportunity to have an important impact in the lives of these unfortunate children and their families.

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.

Epilepsy surgery outcomes: quality of life and seizure control

A consecutive, retrospective analysis of seizure control and quality of life was performed among 83 pediatric patients undergoing epilepsy surgery at Children's Hospital of Wisconsin. Seizure outcomes were generally favorable, with 68.7% class I outcomes; class II, 12%; and class III, 19.3%. Seizure freedom was highest among temporal lobectomies (84.2%) and hemispherectomies (76.2%). Outcomes among hemispherectomies were substantially superior to those of multilobar resections. Cortical dysplasia was associated with lower seizure freedom, at 57.5%. Among age groups, seizure-free outcomes in infants were lowest, at 50%. The lower infant seizure-free rate was likely attributable to frequency of multilobar resections and type of pathology (cortical dysplasia). Quality-of-life measures generally paralleled seizure outcomes. These results indicate that epilepsy surgery in children with intractable epilepsy can result in significant improvements in seizure control, quality of life, and development. Anticipated type of surgery, presumed location of epileptogenic site, absence of a defined lesion on magnetic resonance imaging scan of the brain, and patient's age should not prevent surgical evaluations of children with intractable epilepsy.

Longer duration of epilepsy and earlier age at epilepsy onset correlate with impaired cognitive development in infancy

We assessed the impact of age at onset of epilepsy and duration and frequency of seizures on cognitive development in children less than 3 years old. Retrospective analysis was conducted on clinical data and neuropsychological testing of 33 infants with epilepsy. Developmental quotients were calculated and were correlated with age at epilepsy onset, duration of epilepsy, seizure frequency, brain pathology, and types of seizures (with/without spasms) as potential predictors. Infants with longer duration and earlier onset of epilepsy performed worse on developmental neuropsychological testing. Regression analyses showed that age at epilepsy onset and percentage of life with epilepsy were both strongly associated (regression model P<0.0001) with developmental quotient. There was no correlation with seizure frequency. Infants with spasms had worse developmental quotients than infants without spasms (P<0.001). These results suggest that duration of epilepsy and age at onset may be the best developmental predictors during the first years of life in patients with epilepsy. Early aggressive intervention should be considered.

Hemispherotomy and other disconnective techniques

The surgical treatment of intractable epilepsy has evolved as new technical innovations have been made. Hemispherotomy techniques have been developed to replace hemispherectomy in order to reduce the complication rates while maintaining good seizure control. Disconnective procedures are based on the interruption of the epileptic network rather than the removal of the epileptogenic zone. They can be applied to hemispheric pathologies, leading to hemispherotomy, but they can also be applied to posterior quadrant epilepsies, or hypothalamic hamartomas. In this paper, the authors review the literature, present an overview of the historical background, and discuss the different techniques along with their outcomes and complications.

Psychopathology, psychosocial functioning, and IQ before and after epilepsy surgery in children with drug-resistant epilepsy

This is a prospective study of a consecutive series of children undergoing epilepsy surgery. The main aims were to evaluate the heterogeneity with respect to psychopathology and IQ, and to use a global assessment scale (Children's Global Assessment Scale [CGAS]) to evaluate psychosocial functioning. Clinical neuropsychiatric and neuropsychological assessments were made at baseline and at the 2-year follow-up in 24 patients, and changes were analyzed at an individual level. Psychiatric disorders (mainly attention deficit hyperactivity disorder and/or autism spectrum disorders) were found in 17 of 24 at some point. All except one child with psychiatric diagnoses before surgery still had at least one diagnosis at follow-up. Intellectual ability remained stable in the majority of cases, both in individuals with and in individuals without mental retardation. The CGAS illustrated the consequences of the extensive comorbidity in this cohort. The behavioral problems had been undiagnosed despite parental concern in many cases, indicating an unrecognized need for services for children with drug-resistant epilepsy.

Current trends in the treatment of infantile spasms

Infantile spasms are an epilepsy syndrome with distinctive features, including age onset during infancy, characteristic epileptic spasms, and specific electroencephalographic patterns (interictal hypsarrhythmia and ictal voltage suppression). Adrenocorticotropic hormone (ACTH) was first employed to treat infantile spasms in 1958, and since then it has been tried in prospective and retrospective studies for infantile spasms. Oral corticosteroids were also used in a few studies for infantile spasms. Variable success in cessation of infantile spasms and normalization of electroencephalograms was demonstrated. However, frequent significant adverse effects are associated with ACTH and oral corticosteroids. Vigabatrin has been used since the 1990s, and shown to be successful in resolution of infantile spasms, especially for infantile spasms associated with tuberous sclerosis. It is associated with visual field constriction, which is often asymptomatic and requires perimetric visual field study to identify. When ACTH, oral corticosteroids, and vigabatrin fail to induce cessation of infantile spasms, other alternative treatments include valproic acid, nitrazepam, pyridoxine, topiramate, zonisamide, lamotrigine, levetiracetam, felbamate, ganaxolone, liposteroid, thyrotropin-releasing hormone, intravenous immunoglobulin and a ketogenic diet. Rarely, infantile spasms in association with biotinidase deficiency, phenylketonuria, and pyridoxine-dependent seizures are successfully treated with biotin, a low phenylalanine diet, and pyridoxine, respectively. For medically intractable infantile spasms, some properly selected patients may have complete cessation of infantile spasms with appropriate surgical treatments.

Outcomes of epilepsy surgery in adults and children

Surgery is widely accepted as an effective therapy for selected individuals with medically refractory epilepsy. Numerous studies in the past 20 years have reported seizure freedom for at least 1 year in 53-84% of patients after anteromesial temporal lobe resections for mesial temporal lobe sclerosis, in 66-100% of patients with dual pathology, in 36-76% of patients with localised neocortical epilepsy, and in 43-79% of patients after hemispherectomies. Reported rates for non-resective surgery have been less impressive in terms of seizure freedom; however, the benefit is more apparent when reported in terms of significant seizure reductions. In this Review, we consider the outcomes of surgery in adults and children with epilepsy and review studies of neurological and cognitive sequelae, psychiatric and behavioural outcomes, and overall health-related quality of life.

Changing the paradigm of 1-stage total callosotomy for the treatment of pediatric generalized epilepsy

OBJECT

The authors propose that anterior callosotomy -- thought to have some advantages over total callosotomy -- is not superior to total callosotomy for prevention of seizure propagation or other complications.

METHODS

The study comprised 34 patients in whom generalized epilepsy syndrome or frontal lobe seizures with a secondary generalization were diagnosed. Preoperatively, all patients suffered from disabling drop attacks or intense head-drop seizures, and some patients also experienced other types of seizures. The male/female ratio was 22:12, and patients ranged in age between 1 to 19 years (mean 8.7 years). The follow-up period ranged from 1.08 to 5.0 years (mean 2.58 years). Seizure outcome, parental assessment of daily function, and parental satisfaction with the outcome was assessed postoperatively.

RESULTS

After undergoing 1-stage total callosotomy, drop attacks disappeared completely in 25 patients during the follow-up period, and in 6 patients the frequency of drop attacks decreased to < 10% of baseline. With regard to other types of seizures, seizures resolved completely in 12 patients, and in another 18 seizure frequency decreased. Two patients experienced a transient disconnection syndrome for 2 and 4 weeks. One patient experienced ataxic hemiparesis for 3 weeks before it completely abated. The overall daily function of the patients improved, and all parents were satisfied with the surgical outcome.

CONCLUSIONS

For pediatric generalized epilepsy syndrome, 1-stage total callosotomy will be the first choice in treatment for controlling generalized seizures.

Epilepsy surgery in children: outcomes and complications

OBJECT

Ideal epilepsy surgery would eliminate seizures without causing any functional deficits. The aim of the present study was to assess seizure outcomes and complications after epilepsy surgery in children with intractable epilepsy.

METHODS

Data obtained in 134 children (75 boys and 59 girls) age 17 years or younger who underwent epilepsy surgery at Seoul National University Children's Hospital between 1993 and 2005 were retrospectively reviewed. Epilepsy surgery included temporal resection (59 cases), extratemporal resection (56 cases), functional hemispherectomy (7 cases), callosotomy (9 cases), multiple subpial transection (1 case), and disconnection of a hamartoma (2 cases). The mean follow-up duration was 62.3 months (range 12-168 months).

RESULTS

The overall seizure-free rate was 69% (93 of 134 cases). The seizure-free rate was significantly higher in children who underwent temporal resection than in those in whom extratemporal resection was performed (88 vs 55%, p < 0.05). The most frequent causes of treatment failure were related to the absence of structural abnormality demonstrated on magnetic resonance imaging, development-associated disease, widespread disease documented by postoperative electroencephalography, and limited resection due to the presence of functional cortex. There were no postoperative deaths. Visual field defects were the most common complication after temporal resection (22% [13 of 59 cases]), whereas hemiparesis (mostly transient) was the most common morbidity after extratemporal resection (18% [10 of 56 cases]).

CONCLUSIONS

Epilepsy surgery is an effective and safe therapeutic modality in childhood. In children with extratemporal epilepsy, more careful interpretation of clinical and investigative data is needed to achieve favorable seizure outcome.

Early hemispherectomy in catastrophic epilepsy

The authors report their experience about a neuro-cognitive and epileptic long-term follow-up of children with catastrophic epilepsy treated with hemispherectomy in the first 5 years of life. Nineteen children with resistant epilepsy that significantly interfered with their neuro-cognitive development underwent hemispherectomy within 5 years of life (mean: 2 years, 3 months; range: 5 months to 5 years). All patients were assessed before surgery and after, at least at the end of the follow-up (mean: 6 years and 6 months; range: 2-11 years and 2 months) with a full clinical examination including motor ability and functional status evaluation as well as behaviour observation, neuroimaging and an ictal/interictal prolonged scalp video-EEG. A seizure-free outcome was obtained in 73.7% of patients. Gross motility generally improved and cognitive competence did not worsen, with an evident progress in two cases. Consistently with previous reports, evolution was worse in cortical dysplasia than in progressive or acquired vascular cerebropathies. The excellent epileptic outcome and the lack of developmental deterioration in comparison with other more aged series seem to suggest a possible better evolution in earlier surgery treatment. To confirm this suggestion, however, further experience with larger series is needed.

Developmental outcome after epilepsy surgery in infancy

OBJECTIVES

Our goals were to determine the effect of epilepsy surgery in infants (<3 years of age) on development and describe factors associated with postoperative developmental outcome.

METHODS

We identified 50 infants among 251 consecutive pediatric patients (<18 years old) undergoing epilepsy surgery. Charts were reviewed for clinical data and neurodevelopmental testing with the Bayley Scales of Infant Development. A developmental quotient was calculated to compare scores of children at different ages.

RESULTS

Complete data were available on 24 of 50 infants. Surgeries included 14 hemispherectomies and 10 focal resections. Seventeen patients became seizure free; 5 patients had >90% seizure reduction, 1 had >50% seizure reduction, and 1 had no change. The developmental quotient indicated modest postoperative improvement of mental age. The preoperative and postoperative development quotients correlated well. Younger infants had a higher increase in developmental quotient after surgery. Patients with epileptic spasms were younger and had a lower developmental quotient at presentation, but increase in developmental quotient was higher in this subgroup.

CONCLUSIONS

After surgery, seizure frequency and developmental quotient improved. Developmental status before surgery predicted developmental function after surgery. Patients who were operated on at younger age and with epileptic spasms showed the largest increase in developmental quotient after surgery.

Surgical treatment of two patients with infantile spasms in early infancy

Early surgery for catastrophic epilepsy may prevent developmental deterioration and minimize functional deficit resulting from the surgical procedure. We report two patients who had infantile spasms and underwent surgery for epilepsy in early infancy (younger than 6 months old). Magnetic resonance imaging showed cortical dysplasia in both patients. One patient underwent lesionectomy in the right perirolandic area at 49 weeks conceptional age (CA) and the other infant underwent left temporo-occipital disconnection at 45 weeks CA. Both showed Engel classification I and catch-up developmental progress. However, with the second patient, we were concerned about the high volume transfusion relative to her body weight during the extensive disconnection because of the patient's small blood volume. We discuss the benefits and potential risks of surgical treatment for intractable epilepsy in early infancy.

Cognitive assessment in epilepsy surgery of children

INTRODUCTION

Although the neurocognitive assessment in children as in the adults is an important step before and after surgery, in the literature, the data about pre- and postoperative neurocognitive evaluations in children are very few.

OBJECTIVE

The purpose of this paper is to consider some peculiar aspects of the neurocognitive assessment during development, and report literature data about neuropsychological outcome of epileptic children treated with focal resection and hemispherectomy.

RESULTS AND DISCUSSION

The second section concerns our personal experience about a cohort of 45 children with refractory epilepsy operated on before 7 years. The results suggest that early surgical treatment is generally effective for seizure control and behavior improvement in children with refractory epilepsy. Concerning cognitive outcome, we found that the neurocognitive level was unchanged in the majority of the patients.

CONCLUSION

We underline the importance of multicentric studies with standardized neuropsychological assessments in large series of young children.

Role of interictal epileptiform abnormalities in cognitive impairment

The epileptic encephalopathies are conditions in which neurological deterioration is attributable entirely or partly to epileptic activity and is due to very frequent or severe seizures or severely abnormal electroencephalograms (EEGs), or both. Evidence for the concept that seizures or the abnormal EEGs are responsible for the cognitive deterioration is the observation that patients can improve dramatically when therapy eliminates or reduces seizure frequency and improves or normalizes the EEG. For example, children with the syndrome of continuous spike-wave of sleep (CSWS) have electrical status epilepticus during sleep (ESES) and cognitive regression. Although seizures often occur in the disorder, there are indications that the EEG abnormalities are responsible for the cognitive regression. Interictal spikes, which correspond to a large intracellular depolarization with evoked action potentials, in many ways mimic a "miniseizure." Interictal spikes can result in transitory cognitive impairment with the type of deficit dependent on where in the cortex the spike arises. We suggest that interictal spikes, particularly if frequent and widespread, can impair cognitive abilities, through interference with waking learning and memory, and memory consolidation during sleep.

Total callosotomy for a case of lissencephaly presenting with West syndrome and generalized seizures

CASE REPORT

An 11-month-old girl had an onset of oculogyric crisis at 2 months and she presented with epileptic spasms and generalized tonic seizures with series formation at 3 months. Her seizures were medically intractable and her development had gradually regressed after that. MRI showed severe lissencephaly in bilateral hemispheres. Interictal EEG showed hypsarrhythmia periodically and sporadic spike waves in the right hemisphere. The generalized tonic seizures began with bi-frontal polyspikes on EEG. Our diagnosis was lissencephaly presenting with West syndrome and generalized tonic seizures. A total callosotomy was performed at 11 months.

OUTCOME

Postoperative frequency of seizures decreased prominently and developmental progression was resumed.

CONCLUSIONS

This case showed that the corpus callosum may play an important role in some types of symptomatic West syndrome. Corpus callosotomy for treating symptomatic West syndrome should be considered as an option after careful selection and consideration of the timing of surgery.

The United Kingdom Infantile Spasms Study (UKISS) comparing hormone treatment with vigabatrin on developmental and epilepsy outcomes to age 14 months: a multicentre randomised trial

BACKGROUND

Infantile spasms is a severe infantile seizure disorder that is difficult to treat and has a high morbidity. Absence of spasms on days 13 and 14 after randomisation is more common in infants allocated hormone treatments than in those allocated vigabatrin. We sought to assess whether early control of spasms is associated with improved developmental or epilepsy outcomes.

METHODS

Infants enrolled in the United Kingdom Infantile Spasms Study (UKISS) were randomly assigned hormone treatment (n=55) or vigabatrin (n=52) and were followed up until clinical assessment at 12-14 months of age. We assessed neurodevelopment with the Vineland adaptive behaviour scales (VABS) at 14 months of age on an intention to treat basis.

FINDINGS

Of 107 infants enrolled, five died and 101 survivors reached both follow-up assessments. Absence of spasms at final clinical assessment (hormone 41/55 [75%] vs vigabatrin 39/51 [76%]) was similar in each treatment group (difference 1.9%, 95% CI -18.3% to 14.4%; chi(2)=0.05; p=0.82). Mean VABS score did not differ significantly (hormone 78.6 [SD 16.8] vs vigabatrin 77.5 [SD 12.7]; difference 1.0, 95% CI -4.9 to 7.0; t(99)=0.35, p=0.73). In infants with no identified underlying aetiology, the mean VABS score was higher in those allocated hormone treatment than in those allocated vigabatrin (88.2 [17.3] vs 78.9 [14.3]; difference 9.3, 95% CI 1.2 to 17.3; t(95)=2.28, p=0.025).

INTERPRETATION

Hormone treatment controls spasms better than does vigabatrin initially, but not at 12-14 months of age. Better initial control of spasms by hormone treatment in those with no identified underlying aetiology may lead to improved developmental outcome.

Effects of epilepsy surgery on psychiatric and behavioral comorbidities in children and adolescents

When considering surgery in children, it is important to think about the potential effect on psychiatric and behavioral outcome. A growing body of evidence suggests that the type of epilepsy (benign or catastrophic) and the age of the patient affect developmental outcome. In younger children with catastrophic epilepsy, the primary goal of therapy is not only to control seizures, but also to offer the child the opportunity for the best possible development. In older children with partial seizures, the therapeutic goal is to control seizures, which may allow a more normal life and improve behavior. Epilepsy surgery generally appears to have a positive effect on behavior and development in many younger children with catastrophic epilepsy. Psychiatric and behavioral outcomes in older children with complex partial epilepsy are less clear; many patients improve, but there does appear to be a small risk of developing new psychiatric or behavioral disorders postoperatively.

Nonpharmacologic Treatment of the Catastrophic Epilepsies of Childhood

The catastrophic epilepsy syndromes of childhood are initially treated with a pharmacologic intervention in most cases. However, due to the poor response patients often have to pharmacologic interventions, nonpharmacologic treatment options are an important part of a comprehensive treatment plan for this group of children. Additionally, nonpharmacologic therapy may offer a method to minimize associated morbidity and mortality. This article discusses the use of epilepsy surgery, the ketogenic diet, and vagus nerve stimulation in the treatment of patients with infantile spasms, Lennox-Gastaut syndrome, and progressive myoclonic epilepsy. Efficacy of the nonpharmacologic treatment options, as measured by reduction in seizure frequency, as well as by developmental progress or behavioral improvement, varies according to the specific catastrophic epilepsy disorder and the treatment option.

Early epilepsy surgery

Uncontrolled epilepsy is associated with progressive cortical and hippocampal atrophy, substantial cognitive and psychosocial morbidity, and increased mortality. Seizure freedom is required to reverse such morbidity and mortality. Surgery is vastly superior to medical therapy for patients with chronic, refractory temporal lobe seizures, and is now the standard of care for these patients. On the other hand, the concept of early surgery requires further exploration and definition. Although there is no robust, direct evidence to support early epilepsy surgery, case series and cohort studies report an association between earlier surgery and better outcomes. The evidence for earlier epilepsy surgery is reviewed.

Five or More Acute Postoperative Seizures Predict Hospital Course and Long-term Seizure Control after Hemispherectomy

PURPOSE

Acute postoperative seizures (APOSs) are those that occur in the first 7 to 10 days after surgery, and previous studies in temporal lobe epilepsy patients support the notion that APOSs may foretell failure of long-term seizure control. It is unknown whether APOSs also predict seizure outcome or hospital course after hemispherectomy.

METHODS

Hemispherectomy patients (n = 114) were studied retrospectively and subdivided into the following groups: No APOSs, 1 to 5 APOSs, or >5 APOSs. Intensive care unit (ICU) nursing staff or family members reported and described the APOS events. APOS categories were compared with pre- and postsurgery clinical variables abstracted from the medical record.

RESULTS

APOSs occurred in 22.6% of hemispherectomy patients. Compared with the 0 and 1 to 5 APOS groups, patients with >5 APOS showed (a) longer seizure durations before surgery, (b) longer hospitalizations, (c) later oral food intake, (d) more frequent lumbar punctures, (e) worse seizure control at 0.5 and 1 year after surgery, (f) more antiepileptic drug (AED) use at 2 and 5 years after surgery, and (g) higher reoperation rate. No similar differences were found between the 0 and 1 to 5 APOS groups. The day of the APOS, whether the APOS was typical of preoperative seizures, and postsurgery scalp EEG did not predict long-term seizure control. APOS patients in the 1 to 5 and >5 groups had lower pre- and postsurgery Vineland developmental quotients compared with those without an APOS.

CONCLUSIONS

Hemispherectomy patients with >5 APOSs had a more prolonged and complicated hospital course and worse postsurgery seizure control, more AED use, and higher reoperation rate than did patients with 0 or 1 to 5 APOSs. Thus the number of APOSs was a predictor of postsurgery seizure control and can be used to counsel patients and families about prognosis after hemispherectomy.

Developmental outcome with and without successful intervention

A review of the literature on the developmental outcome of medically and surgically treated symptomatic infantile spasms (IS) indicates that poor seizure control, severe mental retardation, and marked behavioral disorders are found at long-term outcome of symptomatic IS. The 2-year outcome findings of the UCLA Pediatric Epilepsy Surgery Research Group in children with symptomatic infantile spasms and in children with early onset intractable symptomatic epilepsy other than IS (non-IS) demonstrate impaired development of cognition, language, and social communication despite improved seizure control. The social communication deficits of these children are similar to those found in autistic children. Finally, the underlying pathology of the resected brain, rather than ongoing seizures and seizure type, plays an important role in development of the remaining brain tissue and the outcome of early onset symptomatic IS and non-IS.

Postoperative development of children after hemispherotomy

We studied the postoperative development of 14 children with cortical dysgenesis who underwent modified functional hemispherectomy (hemispherotomy) at the age of 6 years or younger. At follow-up of 24-72 months (median of 47 months), six (43%) were seizure-free, six achieved>90% reduction, one achieved 50-90% reduction, and one achieved 0-50% reduction in seizure frequency. At the preoperative and final postoperative examinations, mean scores of developmental quotient (DQ) were as follows: 25.5 and 31.9 in total DQ, 26.0 and 33.7 in intellectual DQ, and 27.4 and 22.9 in motor DQ. Children scoring >50 points in preoperative intellectual DQ score obtained near-normal intellectual DQ postoperatively, while, those scoring <10 DQ preoperatively remained at a low developmental level. Among children with DQ scores in the range from 10 to 50, two children who obtained seizure-free outcome and were operated upon in the first 3 years of life achieved marked developmental progress. The present study indicated that high preoperative intellectual DQ and cessation of seizures seem to be associated with better postoperative intellectual development. However, long-term observation of postoperative development and an accumulation of more cases will be needed before we can reach a firm conclusion.

A risk-benefit assessment of treatments for infantile spasms

Infantile spasms are a devastating epileptic encephalopathy of the young child. The continuing spasms and hypsarrhythmia have a deleterious effect on brain maturation and further cognitive development. Corticotropin (adrenocorticotropic hormone) or corticosteroids have been the gold standard treatment for the last 40 years, but there is little agreement on the best agent to use, or the dosage and duration of the treatment. Despite this empirical approach, corticotropin or corticosteroids are effective in controlling spasms and normalising electroencephalograms in about 60% of cases. The major concern with this treatment is the occurrence of frequent and severe adverse effects. The introduction of vigabatrin in the 1990s improved the outcome of infantile spasms. Vigabatrin shows an efficacy at least equal to that of corticosteroids, and even higher in specific groups such as those with tuberous sclerosis. The major advantages of vigabatrin are the ability to initiate treatment at the full dosage. rapid efficacy, suitability for outpatient treatment and particularly good tolerability with only minor adverse effects. Recently, however, the safety of vigabatrin has caused concern since a specific visual field loss has been reported in treated adults. The current problem is determining the risk-benefit ratio of vigabatrin and corticosteroids/corticotropin in children with infantile spasms, and to specify the groups where their use could be optimal. Visual field loss is usually asymptomatic and can be detected only by perimetric visual field studies. In children, especially in the young or disabled, it is difficult if not impossible to detect the visual field loss and it is not yet known if children are at higher or lower risk for this adverse effect. Until a clear answer about the occurrence of this adverse effect in children has been established through randomised study, vigabatrin may still be considered first-line therapy in infantile spasms. Children who do not achieve a good response to vigabatrin should be switched to corticotropin/corticosteroid therapy. Despite the efficacy of corticosteroids and vigabatrin, the use of the conventional antiepileptic drugs, the newly developed antiepileptic drugs and some promising results with ketogenic diet, 25 to 30% of patients with infantile spasms continue to have spasms and experience psychomotor regression. These drug-resistant patients could be candidates for surgery.

Temporal Lobe Resections in Children with Epilepsy: Neuropsychiatric Status in Relation to Neuropathology and Seizure Outcome

The purpose of this work was to relate clinical neuropsychiatric findings to histopathological diagnoses and seizure outcome in a retrospective study of 16 children undergoing temporal lobe resections due to medically intractable epilepsy. These children constitute a heterogeneous group in which neuropsychiatric symptoms were common. The results of this study indicate a correlation between malformations of cortical development, less chance of seizure freedom, and neuropsychiatric problems in children with pharmacoresistant temporal lobe epilepsy. It is important to include neuropsychiatric assessments pre- and postoperatively and to inform parents that symptoms of autism spectrum disorders may or may not be improved after epilepsy surgery.

Outcome after surgical treatment

Approximately 50% of patients will become seizure free following surgery for intractable epilepsy caused by malformations of cortical development. Another 20% have only rare seizures. The outcome is dependent on the completeness of the resection as determined by MR imaging and electroencephalography. The surgical procedures performed for malformations of cortical development in infants, children, and adults include lobar and multilobar resections or hemispherectomy.