Review ArticlesSurgical treatment of epilepsy in children
Introduction
Several series have shown that intractable seizures may be eliminated or greatly reduced in children, as well as adults, after cortical resection [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12], [13] or hemispherectomy [14], [15], [16], [17]. Small series have also reported gratifying outcomes after epilepsy surgery in infants [18], [19], [20], [21], [22], [23]. Critical features of surgical candidacy include intractable epilepsy interfering with quality of life (QOL) or development, a localized epileptogenic zone, and a low risk of new postoperative neurologic deficits. At first glance, this formula appears clear-cut, but extensive clinical judgment enters into every case. How many and which drugs must fail before the epilepsy is declared intractable? How frequent must the seizures be to warrant surgery? What will be the psychosocial and developmental costs of continued seizures if surgery is not performed? What are the risks of new postoperative deficits if surgery is performed during infancy or early childhood when active brain maturation allows developmental plasticity? These issues complicate the identification of appropriate pediatric candidates for epilepsy surgery.
An added concern is that compared with adult patients, pediatric epilepsy surgery candidates are especially likely to present with poorly localizing electroencephalographic (EEG) features because of their high incidence of extratemporal localization and developmental abnormalities. Maturation factors may also be important, as suggested by age-specific manifestations of focal cortical lesions, such as infantile spasms and hypsarrhythmia [19], [20], [23], [24], [25], [26].
Clearly, the potential risk/benefit ratio for surgery must be carefully weighed for each child on the basis of the results of an extensive preoperative evaluation. Factors weighing into these analyses are addressed here in the context of the experience with pediatric epilepsy surgery at The Cleveland Clinic Foundation (CCF) [13] and other centers.
Section snippets
Temporal lobe resection
Temporal lobe resection is the most common epilepsy surgery performed in adults, usually for hippocampal sclerosis [27]. This epileptogenic lesion can now be reliably identified in vivo with high-resolution magnetic resonance imaging (MRI), including thin cuts through the temporal lobes [28], [29], [30], [31], [32], [33], [34], and further confirmed by glucose hypometabolism in the temporal lobe on positron emission tomography (PET) scan [35]. Patients typically have complex partial seizures
Extratemporal and multilobar resection
Extratemporal or multilobar resections and hemispherectomies comprise a large percentage of pediatric epilepsy surgeries, especially at younger ages. In the CCF series [13], these procedures comprised 50% of the epilepsy surgeries performed by 12 years of age, 68% of those performed by 6 years of age, and 90% of those performed by 2 years of age.
Among focal extratemporal surgeries, frontal resections predominate in children and adults [13], although in infants, temporoparietal-occipital
Case 1
A male presented for preoperative evaluation at 3 months of age. Perinatal course was unremarkable, but seizures began at 6 weeks of age and occurred at a rate of 30-100/day despite multiple trials of antiepileptic medication. Seizures involved sustained, forceful bilateral eye deviation to the right with chewing movements, restless limb movements, and apparent partial preservation of awareness, punctuated by brief epileptic spasms with abrupt extension and stiffening of the arms. Neurologic
Hemispherectomy
Hemispherectomy results in near or complete seizure freedom for 60-85% of patients [16], [17], [27], [67], [68]. The experience [13] at CCF has been similar, with 11 (69%) of 16 patients seizure-free. The procedure may be indicated for patients with extensive unilateral hemispheric damage, hemiparesis without fine finger movements, and intractable seizures arising from multiple or widespread regions of the damaged hemisphere [67]. Candidates typically have intractable epilepsy because of
Epilepsy surgery in infants
Although many of the principles described above apply at all ages, some considerations are specific to infants. The approach to epilepsy surgery in the youngest age groups has undergone significant recent evolution.
The earliest reports of epilepsy surgery in infants included small numbers of patients who had good outcomes after hemispherectomy for Sturge-Weber syndrome [22] or hemimegalencephaly [79], [80], [81]. These syndromes were easily appreciated by physical examination and computed
Weighing the risk/benefit ratio for surgery
Certain difficult questions arise in every case during the evaluation for pediatric epilepsy surgery. No pat answers are available, but one approach is presented here.
How many drugs must fail before surgery should be considered? It appears that the answer differs between patients on the basis of etiology, location of the epileptogenic zone, and severity of the epilepsy. Some children may be appropriate surgical candidates before many drugs have been tried, for example when the cause is a tumor
Conclusions
Epilepsy surgery is a well-established treatment for intractable localization-related epilepsy in adolescents and adults [27], but it is less often considered for children. The usual delay from onset of intractability to surgery remains in the range of 12-15 years at most centers, reflecting a reluctance to consider epilepsy surgery during childhood. Results from pediatric surgical series so far do not justify this reluctance but instead suggest that children should be referred for surgical
Acknowledgements
Case surgery performed by Dr. William Bingaman.
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Extratemporal Procedures and Hemispherectomy for Epilepsy
2018, Principles of Neurological SurgerySurgical outcomes in two different age groups with Focal Cortical Dysplasia type II: Any real difference?
2017, Epilepsy and BehaviorCitation Excerpt :Data are still scarce concerning the comparison between patients harboring Type II FCD operated at young and/or adult age, investigating whether age at surgery is an important factor influencing surgical outcome. Some evidence exhibits no significant difference in the surgical outcome between children and adults, regardless of the onset age [8,23,24], even in a selected FCD Type II population [18]. The aim of our study was to compare presurgical clinical features and surgical outcomes of patients with histopathologically identified FCD II, the first group operated on at less than 6 years, the second sharing the same seizure onset age but with a delayed surgery, carried out after the age of 20 years.
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Long-term EEG in children
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2015, Current Problems in Pediatric and Adolescent Health CareCitation Excerpt :The epilepsy presurgical evaluation is followed by an interdisciplinary patient management conference where candidacy for surgery and surgical intervention is discussed, including the need for invasive monitoring and mapping. In general, seizure freedom after surgery ranges from 60% to 70%.56 Children undergoing temporal lobe resections have better outcomes than extratemporal lobe resections.