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INVITED REVIEW
Year : 2008  |  Volume : 3  |  Issue : 1  |  Page : 97-106
 

Focal cortical resections for the treatment of extratemporal epilepsies in children


Department of Neurology, R. Madhavan Nayar Center for Comprehensive Epilepsy Care, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India

Correspondence Address:
Kurupath Radhakrishnan
Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum - 695 011, Kerala
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/1817-1745.40597

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   Abstract 

Children with lesion-related extratemporal epilepsies with suboptimal seizure control should be identified early and referred for presurgical evaluation before irreversible deterioration in cognitive or psychosocial functions ensues due to long-standing disabling seizures and chronic antiepileptic drug-related side effects. The success of epilepsy surgery depends upon the accurate preoperative localization of the epileptogenic zone and its complete resection. Children with medically refractory lesional epilepsies belong to different categories depending upon the degree of complexity involved in the presurgical evaluation to define their epileptogenic zone. While some patients, such as those with tumoral epilepsy syndrome, can be selected for surgery by simple noninvasive presurgical evaluation strategy, others with malformations of cortical development and those with multiple lesions often require complex and invasive means to define their epileptogenic zone. Recent advances in structural and functional imaging have obviated the need of invasive monitoring in the majority. These advances along with improvement in surgical techniques have made resective surgery safer and more effective. Prospective comprehensive follow-up studies are needed to evaluate the long-term seizure, cognitive, psychosocial, educational and occupational outcomes of surgically treated children with extratemporal epilepsies.


Keywords: Children, epilepsy, epilepsy surgery, extratemporal, focal resections


How to cite this article:
Ramesha KN, Radhakrishnan K. Focal cortical resections for the treatment of extratemporal epilepsies in children. J Pediatr Neurosci 2008;3:97-106

How to cite this URL:
Ramesha KN, Radhakrishnan K. Focal cortical resections for the treatment of extratemporal epilepsies in children. J Pediatr Neurosci [serial online] 2008 [cited 2019 Dec 9];3:97-106. Available from: http://www.pediatricneurosciences.com/text.asp?2008/3/1/97/40597



   Introduction Top


Although majority of the children with epilepsy have a good prognosis, nearly one-fourth of them either do not respond to treatment with antiepileptic drugs or develop significant side effects to antiepileptic drugs, precluding their continued use. [1] Medically refractory seizures are associated with profound deleterious consequences on the cognitive and psychosocial developments of the child. A better understanding of the natural history of pediatric epilepsy syndromes, advent of modern neuroimaging and electroencephalographic (EEG) techniques and safer neurosurgical practices have enabled more and more children with difficult to control seizures to be selected for surgical treatment today much earlier than the years past. [2]

Epilepsy surgeries in children can be divided into palliative (corpus callosotomy, [3] multiple subpial transaction, [4] and vagus nerve stimulation [5] ) and curative (hemispherectomy/hemispherotomy [6] and focal resections) procedures [Table - 1].

Resective surgeries involve either focal cortical, lobar or multilobar resections. While the most common resectve epilepsy surgery performed in adults involve the temporal lobe, [7] extratemporal resections are more frequent than temporal lobe resections in children. [8],[9] For example, out of the 753 epilepsy surgeries undertaken at the R. Madhavan Nayar Center for Comprehensive Epilepsy Care, Trivandrum, between March 1995 and June 2006, 630 (83%) involved the temporal lobe and only 69 (9%) involved the extratemporal regions. However, 35 (51%) patients who had extratemporal resections were younger than 18 years. Mesial temporal sclerosis forms the prototype of the lesion associated with adult refractory focal epilepsies, [10] while focal malformations of cortical development dominates the pediatric substrate. [8],[9]

In this chapter, we intend to elaborate on the pathophysiology and pathological substrates associated with refractory pediatric epilepsies, presurgical evaluation strategies and selection of ideal candidates for resective surgery, surgical procedures and postsurgical outcome of children with refractory seizures due to focal lesions involving the frontal, parietal and occipital lobes. The surgical treatment of epilepsy syndromes associated with hypothalamic hamartoma is briefly discussed.


   Pathophysiology of Medically Refractory Focal Epilepsies Top


Certain factors are well-known predictors of resistance to antiepileptic drug treatment in children such as the onset of seizures in infancy, organic brain damage (mental retardation and neurological signs), seizure type(s) (tonic, atonic and myoclonic seizures), multiple seizure types, high initial seizure frequency, long duration of uncontrolled seizures, failure of past antiepileptic drug treatments and an abnormal EEG. [11] The underlying pathophysiologic mechanisms of lesion-related epilepsies are multifactorial. While focal malformations of cortical development [12],[13] and hypothalamic hamartomas [14] are intrinsically epileptogenic, in brain tumors and focal gliotic lesions, it is often the alterations in the perilesional cerebral cortex that incites epileptogenesis. The comparison of perilesional cortex from patients with and without seizures have demonstrated significant differences in the number and organization of the synapses with an increase in the excitatory synapses [15] and a decrease in the inhibitory synapses. [16] In addition, the multidrug resistance (MDR) protein-1 and the MDR-associated proteins may play a role in contributing to pharmacoresistance. [17],[18] Occasionally, long-standing lesions adjacent to or outside the temporal lobe can result in hippocampal sclerosis. In these patients with dual pathology, either the extratemporal primary lesion or the secondary hippocampal sclerosis or both may initiate epileptic seizures. [19],[20]

Glioneural tumors like ganglioglioma and dysembryoplastic neuroepileplial tumor (DNET) are frequently associated with dysplasia in the adjacent cortex. In a recent study, in 20 out of 24 (83%) surgically treated cases of DNET, associated cortical dysplasia was found on pathological examination. [21] Similarly, the complete removal of the surrounding hemosiderin-stained brain tissue along with cavernous malformations was shown to result in a better seizure outcome in comparison to the removal of the lesion alone. [22]


   Pathological Substrates Top


The common pathological substrates encountered in pediatric extratemporal focal epilepsy syndromes are listed in [Table - 2].

Malformations of cortical development

Malformations of cortical development constitute the commonest pathological substrate detected in surgically treated children with pharmacoresistent focal epilepsies. [8],[9] The pathologic hallmark of the malformations of cortical development is the presence of columnar and laminar disorganization intermixed with various cellular abnormalities that include dysmorphic neurons, giant neurons and balloon cells. [23] The elaborate classification scheme of Barkovich et al. [24] is centered on three processes of cerebral development: neuronal proliferation and eventual apoptosis of selected cells; neuronal migration; and cortical organization. In relation to resective surgery, the following malformations of cortical development are relevant: focal cortical dysplasia or more appropriately focal malformations of cortical development, periventricular heterotopia, polymicrogyria and schizencephaly. [25],[26] In addition, the malformations of cortical development associated with DNET and tuberous sclerosis significantly contribute to the pathogenesis of refractory focal epilepsies associated with these disorders. [21],[27]

Focal malformations of cortical development

The following magnetic resonance imaging (MRI) features suggest the focal malformations of cortical development: local cortical thickening, blurring of grey-white matter interphase and increased signal in the underlying white matter [23],[25],[28] [Figure - 1]. Distinction from tuberous sclerosis associated lesions may not be possible. [29] The focal malformations of cortical development are important substrates for focal motor status epilepticus or epilepsia partialis continua. [25]

Periventricular heterotopia

This is a form of focal malformations of cortical development in which neurons generated in the periventricular region have failed to migrate, resulting in nodules abutting the ventricular ependymal lining. The pathophysiological basis of epilepsy in periventricular nodular heterotopia may be related to their intrinsic epileptogenicity and connection to other nodules and the cortex. [30]

Polymicrogyria and schizencephaly

In addition to the refractory seizures, patients with polymicrogyria may present with developmental delay, learning disabilities or congenital hemiparesis. [25] Schizencephaly is currently grouped with polymicrogyria, which is defined by the presence of transcortical cleft, open or closed, lined by grey matter and often with microgyria along the cleft borders. [24]

Hemimegalencephaly and hemi-hemimegalencephaly

Hemimegalencephaly is a malformation of cortical development arising from an abnormal proliferation of anomalous neuronal and glial cells leading on to the hypertrophy of the whole affected cerebral hemisphere. Severe drug resistant epilepsy is a dominant clinical picture of hemimegalencephaly. [6],[31] Posterior quadrantic dysplasia (hemi-hemimegalencephaly) involves the occipital, parietal and posterior temporal lobes [32] [Figure - 2].

Tuberous sclerosis complex

Disordered neurogenesis and neuronal migration in tuberous sclerosis result in varying neurological phenotypes including seizures, mental retardation, learning disabilities and autism. The seizures may be focal or multifocal in origin and are often resistant to antiepileptic drugs. [27] Electrophysiologic evidences have indicated that the neurons within cortical tubers are intrinsically epileptogenic. [27] The surgical management of epilepsy is challenging in patients with tuberous sclerosis complex because the epileptogenic tubers are often multiple, bilateral, extratemporal and overlapping with eloquent cortex. [33],[34]

Tumoral epilepsies

Ganglioglioma is the commonest cause of tumor-related refractory epilepsies and account for nearly half of the tumoral substrates in majority of the series. [35],[36],[37] In the Sree Chitra series of 23 patients with surgically treated ganglioglioma, the median age at surgery was 20 years and the median duration of epilepsy prior to surgery was 9 years, illustrating the delayed referral of patients for surgical treatment [38] [Figure - 3]. The DNET accounts for 10-20% of chronic tumoral epilepsy syndromes. [36],[39] The frequent association of DNET with cortical dysplasia is being increasingly recognized. [21],[40] In a group of 39 patients with DNET, the age at onset of seizures ranged from 1 to 19 years (mean: 9 years) and the duration of epilepsy prior to surgery averaged 9 years (range: 2-18 years). [39] Pilocytic astrocytoma, low-grade gliomas, pleomorphic xanthoastroctoma and oligodendroglioma comprise other tumoral substrates associated with chronic epilepsies. [36],[41],[42]

Vascular malformations

Seizures occur in about one-third of patients with arteriovenous malformations and the response to antiepileptic drug therapy is variable. [43] Among those with medically refractory focal seizures, nearly three-fourth of the patients benefit either from lesion resection [43],[44] or from radiosurgery. [45] Recurrent microhemorrahages and the resultant hemosiderin deposition may contribute to the epileptogenic potential of cavernomas. [22]

Focal encephalomalacia

Encephalomalacia related to perinatal insults, head injuries or previous surgical procedures accounted for as much as 17% of all the focal structural lesions in a recent large MRI series of patients with refractory focal epilepsies. [46] Patients with encephalomalacia benefit from the resection of the lesion and the adjacent electrophysiologically abnormal brain tissues. [47] Accompanying porencephalic cyst may necessitate the modification of the surgical procedure. [48]

Focal gliotic lesions related to perinatal insults, particulary bilateral occipital gliosis due to neonatal hypoglycemia, form a significant proportion of patients who undergo extratemporal epilepsy surgeries in developing countries [Figure - 4]. The distribution of 35 children with extratemporal resective surgeries at the R. Madhavan Nayar Center for Comprehensive Epilepsy Care, Trivandrum according to pathology of the lesions is provided in [Figure - 5]. While 15 (43%) of them had focal gliotic lesions, 8 (23%) and 9 (26%) had malformations of cortical development and benign neoplasms, respectively. Thirteen of the lesions involved the occipital lobes; 12, frontal lobes; and 6, parietal lobes. In four patients, the lesions involved more than one lobe.

Multilobar and widespread hemispheric lesions

Patients with major lesions involving one hemisphere such as Rasmussen's encephalitis,  Sturge- Weber syndrome More Details More Details, hemimegalencephaly and hemiconvulsion-hemiplegia-epilepsy (HHE) syndrome are potential candidates for hemispherectomy or multilobar resections. [6],[49] Although in some patients, the progression of Rasmussen's encephalitis may be arrested by immunotherapy with corticosteroids, intravenous immunoglobulin or plasma exchange, a majority would require hemispherectomy to control their severely disabling epilepsia partialis continua and secondary generalized seizures. [50],[51] An occasional patient presenting in the residual stage of the disease with epilepsia partials continua of a restricted distribution may benefit from focal cortical resection. [52]

Hypothalamic hamartomas

In addition to gelastic seizures, hypothalamic hamartoma can manifest with partial seizures of the temporal or frontal semiology and with a catastrophic pediatric epileptic encephalopathy with polymorphic seizures, intellectual deterioration and marked behavioral disturbances. [53],[54] The seizures in individuals with hypothalamic hamartoma are often refractory to antiepileptic drugs; however, most cases are reversed by surgical excision, radiofrequency thermocoagulation or by gamma-knife surgery. [55],[56]

Indication and timing of surgery

The natural history studies on persons with newly diagnosed epilepsy have shown that most of the patients who are destined to achieve satisfactory seizure control will do so within few months of the onset of epilepsy. [57],[58] Continuing frequent seizures during infancy, childhood, adolescence and early adult life can produce devastating cognitive, psychosocial, familial, educational and occupational sequel. [59],[60],[61] As the immature brain is more plastic than the mature brain, the functional recovery is often greater after surgery in children than in adults. For example, an insult to the language area in the dominant hemisphere before 6 years of age would not result in significant language problems in later life because the dominant language field would subsequently shift to the other hemisphere. [60],[61] The available data suggest that the developmental outcome is significantly better with the early cessation of seizures, thereby making a compelling argument in favor of considering early surgical intervention. [62] Because of these reasons, more emphasis is recently being placed on the early referral for epilepsy surgery.

The indications for epilepsy surgeries are better defined in adults than in children. [60],[61] In adults, an arbitrary period of two years of failed supervised antiepileptic drug therapy is considered to define refractoriness. [57],[58] However, because of the high seizure burden associated with a majority of the difficult-to-control pediatric epilepsy syndromes, refractoriness to antiepileptic drug therapy in children can be diagnosed within few weeks or months of the onset of seizures. [62]

In patients with normal MRI and marked interictal epileptiform abnormalities in the EEG, a remittable localization-related childhood epilepsy syndrome should be considered. Furthermore, benign and refractory localization-related epilepsy syndromes can occasionally coexist. [63],[64] The exclusion of a diffuse progressive brain disorder is a prerequisite before the consideration for the resective epilepsy surgery. Children with marked mental retardation are generally excluded from consideration for focal resective surgery, unless a reduction in the seizure burden can be anticipated to significantly influence the quality of life. [65]

Selection of ideal surgical candidates

Patients with medically refractory focal extratemporal epilepsies belong to different categories, depending upon the degree of complexity involved in presurgical evaluation and the postoperative seizure outcomes [Table - 3]. The objective of the presurgical investigations is the localization of the epileptogenic focus by good electroclinical and radiological concordance. Noninvasive evaluation utilizing history, MRI, scalp video-EEG and neuropsychological findings can identify a majority of patients with circumscribed, potentially epileptogenic lesions. Children with large epileptogenic lesions that involve primarily one hemisphere and those with diffuse epileptic encephalopathies and multifocal disease can be selected for functional hemispherectomy or hemispherotomy [6],[31] and corpus callosotomy, [3] respectively, based on noninvasive data. Patients with malformations in the cortical development and those with normal MRI will require extensive, sometimes repetitive, studies with positron emission tomography, single photon emission tomography and intracranial electrode placement, which enormously escalate the cost of presurgical evaluation. [66],[67] Even with these expensive evaluations, in this group of patients, the postoperative outcome is often not favorable. [66],[67]

The current experience suggest that the complete resection of the epileptogenic area is the major determinant for a satisfactory surgical result. [8],[9] A focal abnormality on high resolution (1.5 T) MRI along with concordant interictal and ictal EEG localization markedly increases the chances of successful surgical outcome. [68] The spatial resolution of MRI can be increased by use of phased array surface coil and with higher magnetic fields (3T). [69] Newly developed MRI techniques such as double inversion recovery, magnetization transfer imaging, fast FLAIR T2 and diffusion tensor imaging analyzed with voxel-based approaches can identify focal lesions in patients with normal conventional MRI. [70] Certain post-processing MRI methods such as 3D and curvilinear reformatting, texture analysis and quantification of grey and white matter by voxel-based morphometry can assist in identifying the subtle areas of cortical thickness and focal cortical dysplasias. [70],[71]

The changes in the ratio of deoxy- and oxyhemoglobin that occur in specific regions of brain in response to motor, sensory or cognitive tasks allow the recognition of areas that are activated during these tasks by functional MRI (fMRI). [72] The fMRI has two important uses in the management of epilepsy: to identify eloquent areas in relation to an epileptic lesion being considered for resection in order to minimize post-operative neurological deficit and to detect fMRI activity in relation to interictal epileptic spikes on EEG that may be helpful in the localization of seizure focus. [73]

The invasive surgical investigations with intracranial electrode placement are indicated when the limits of a planned resection have to be defined precisely or when the focus is located nearby a functionally eloquent region (sensorimotor and language regions). [66],[67]

The complications of invasive subdural monitoring, such as cerebrospinal fluid leak, cerebral edema, intracranial hematoma and various infections like meningitis, osteomyelitis and superficial wound infections, are rare in experienced pediatric epilepsy surgery centres. [66],[74]

The success of epilepsy surgery program in a developing country setup depends upon the ability of the team to select, through a patient management conference, ideal surgical candidates whose epileptogenic zone can be unequivocally established using locally available technology and expertise without compromising on the safety of the patients. [75] Knowing when not to operate because of the need for further studies is as important as knowing the selection of patients, who may benefit from surgery with the limited facilities available; this requires considerable experience and a team approach.


   Surgical Strategies Top


Lesionectomy

The resection of the lesion and the surrounding epileptogenic cortex may be carried out by conventional neurosurgical approach or by stereotactic extirpation of the lesion (stereotactic lesionectomy). [76] The advantage of conventional neurosurgical procedure is wider exposure facilitating better resection of the epileptogenic zone under electrocorticographic guidance and therefore better anticipated postoperative seizure outcomes.

Extended lesionectomy

Lesions such as malformations of cortical development and DNET, where the epileptogenic zone is likely to extend well beyond the MRI visualized lesion, needs wider resection guided by electrocorticography (ECoG), if not limited by the eloquent cortical areas. [21],[77] The seizure outcome has been shown to be better after the resection of vascular malformations when the hemosiderin-stained brain tissue is included within the resection rather than without it. [22] The best outcome in focal malformations of cortical development is achieved when the resection of both the MRI-identified lesion and the cortical areas that display continuous rhythmic spiking (ictal-like patterns) can be performed. [78]

Lesionectomy with multiple subpial transections

The neuroanatomic rationale of multiple subpial transections is that vertical incisions in the cortex interrupt transverse synaptic connections, thereby preventing seizure propagation while preserving the vertical column subserving the neuronal function. [79] Multiple subpial transections is a surgical technique mainly used when epileptiform activity emanates from eloquent or functional cortical areas. [80] In patients, where the resection of the epileptogenic zone is limited because of encroachment to eloquent cortex, lesionectomy plus multiple subpial transection has been shown to provide better seizure control with less neurological morbidity. [4],[81]

Dual pathology

High resolution MRI can detect extrahippocampal lesion plus hippocampal atrophy in approximately 10% of patients referred for refractory focal epilepsies. [19],[82] Some structural substrates such as malformations of cortical development and porencephalic cysts are more likely to be associated with hippocampal atrophy, independent of the distance of the lesion from the hippocampal formation. [19] In an analysis of 41 surgical interventions in patients with dual pathology, lesionectomy plus mesial temporal resection resulted in complete freedom from seizures in 73% patients, while only 20% who had mesial temporal resection alone and 12.5% who had lesionectomy alone were seizure-free. [82] Therefore, whenever possible, in patients with dual pathology, the removal of both the lesion and atrophic hippocampus should be considered as the best surgical option.

Role of electrocorticography

The role of ECoG in tailoring resection in tumoral focal epilepsies is uncertain. Some studies have found better seizure outcome in patients who underwent resection of the neoplasm under electrocorticographic guidance, [77],[83],[84] while others have achieved the same results without assistance of ECoG. [37],[85] In particular, in patients with DNET, because of the frequent association with malformations of cortical development, extended resection guided by ECoG may achieve better postoperative seizure control. [21]

Hypothalamic hamartoma

In 2001, Rosenfeld and colleagues [86] described the use of transcallosal, anterior forniceal approach for the microsurgical resection of hypothalamic hamartoma in patients with refractory epilepsy with good results. Alternate surgical approaches such as lateral pterional and midline frontal through the lamina terminalis and endoscopic treatment through the foramen of Monro, radiofrequency ablation and gamma knife surgery are currently available to treat hypothalamic hamartoma. [53],[56] The specific approach should be tailored according to the surgical anatomy of the lesion and the experience of the surgeon. While small lesions may be amenable to gamma knife, larger lesions will require surgical excision or disconnection.

Complications

Because of the availability of comprehensive preoperative evaluation data and microneurosurgical techniques, the complication rate of resective surgery is very low. The aggravation of preoperative deficits and addition of postoperative deficits can be minimized by the precise demarcation of the eloquent areas preoperatively by fMRI and pre- or intraoperatively by cortical stimulation and mapping. Postoperative hematomas, infections or hydrocephalus occur in less than 5% of patients. [8],[9]

Postoperative outcome

Although the outcome extratemporal resective epilepsy surgeries is generally considered to be far inferior to that of temporal resections in the past, many recent series report similar results, because of improved presurgical evaluation and surgical strategies. Among the 35 pediatric epilepsy patients who underwent extratemporal focal resections at the R. Madhavan Nayar Center for Comprehensive Epilepsy Care, Trivandrum, 15 of those with a postoperative follow-up for more than 1 year are totally seizure-free and an additional 8 patients had more than 90% reduction in their seizure frequency (Engel Class I and II outcomes of 68%).

Tumoral substrates

In a recent analysis of 207 patients with tumor-associated chronic epilepsies, during a median follow-up of 8 years, 82% of patients were seizure-free. [36] While patients with ganglioglioma and low-grade gliomas have an excellent seizure-free outcome, because of its frequent association with peritumoral malformations of cortical development, DNET carries a less favorable outcome. [21] All attempts should be made to define the extent of the epileptogenic activity pre- and intraoperatively and if necessary and feasible to undertake a rather radical resection of the epileptogenic zone to achieve better seizure control in DNET-associated refractory epilepsy.

Malformations of cortical development

The postoperative seizure outcome of patients with malformations of cortical development has improved in recent years because of better definition of the lesion due to advances in structural and functional imaging, careful selection of ideal surgical candidates and more radical resection of the lesions guided by ECoG and functional mapping. [87] A significant proportion of patients with malformations of cortical development still require invasive EEG monitoring to localize the ictal onset zone. In a recent series of 41 patients (22 adults and 19 children) with MRI-defined malformations of cortical development, after a minimum follow-up of 1 year, 63.4% of patients were seizure-free. [88] In another study involving 53 patients with histopathologically confirmed malformations of cortical development (24 temporal and 29 extratemporal), after a mean follow-up of 50 months, 38 (72%) patients were seizure-free. [89] The patients who required multilobar resection had the poorest outcome.

Vascular malformations

Approximately three-fourth of the patients with refractory seizures who underwent resection of arteriovenous malformations had significant reduction in seizures. [43],[44] Noto et al. [90] recently compared the outcome of 15 patients with cavernous angiomas who were continued on medical treatment without surgery to 16 who were treated surgically. During the mean follow-up period of 5.3 years, the seizure-free outcome was significantly higher in the surgical group than the medical group (80% vs 19%). The resection of hemosiderin-stained adjacent brain tissue may improve seizure control. [22]

Hypothalamic hamartoma

The previous dismal outlook for children with severe seizures and encephalopathy with hypothalamic hamartoma has now dramatically changed. Following transcallosal removal, over three-fourth of patients become essentially free of all seizures. [55],[91],[92] Gelastic seizures respond immediately, while other seizure types may take few weeks or months to abate. In children with epileptic encephalopathy, cognitive decline stops and marked improvement in the behavior has been reported. [53]

Tuberous sclerosis

Most of the studies that have evaluated the postsurgical outcome of patients with tuberous sclerosis have concluded that good seizure outcome correlated with focal seizures and concordant imaging and EEG findings. [27],[93] In a recent analysis of 25 consecutive children (13 had invasive monitoring), at when followed-up for 6 months or more, 84% were practically seizure-free. [94] There is a concern that the nonresected tubers could become epileptogenic, and this could result in seizure recurrence during follow-up. However, in a recent study, only a one-fourth of patients who achieved an initial excellent outcome had the recurrence of seizures when followed for five years or more. [33]

Developmental outcomes

Refractory seizures occurring in infancy and early childhood is a catastrophic disorder often leading to profound neurological deterioration. Early surgical intervention leads to, although not guaranteed, enhanced neurological development. [95] Long-term follow-up assessment of cognition, behavior, mood, psychosocial adjustment and quality of life in children who have undergone resective surgery during the first 3 years of life are not available.

 
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    Figures

  [Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4], [Figure - 5]
 
 
    Tables

  [Table - 1], [Table - 2], [Table - 3]


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