Utility of Epilepsy Surgery in Survivors of Childhood Cancer.

Resection of an epileptogenic focus improves seizure control in patients with drug-resistant epilepsy. There is little data available on usefulness of epilepsy surgery in childhood cancer survivors with drug-resistant epilepsy. To learn about seizure outcome after epilepsy surgery in childhood cancer survivors, we retrospectively reviewed charts of 42 children who were referred to an epilepsy center for surgical evaluation. Sixteen children (38%) were offered epilepsy surgery and 10 consented. Seizure outcome was classified based on International League Against Epilepsy outcome scale. All 10 children were having multiple seizures a month on therapeutic doses of three antiepilepsy drugs (AEDs). At a median follow-up of 5.6 years after epilepsy surgery, three children had class 1 outcome (no seizures), four had class 3 outcome (1-3 seizure days/year), and three had class 4 outcome (≥ 50% reduction in seizure frequency). One child was off AEDs, seven were on a single AED, and two were on three AEDs at their last follow-up. Epilepsy surgery had low morbidity and improved seizure control in childhood cancer survivors with drug-resistant epilepsy. Childhood cancer survivors with drug-resistant epilepsy should be referred to an epilepsy center for a higher level of care.

Diffusion tensor imaging to evaluate commissural disconnection after corpus callosotomy.

INTRODUCTION: Corpus callosum transection can prevent propagation of epileptic discharges. If seizures persist after surgery, assessment of the efficacy of the transection requires knowledge that the commissural fibers have been disrupted. We evaluated whether diffusion tensor imaging (DTI) and diffusion tensor fiber tracking can assess the degree of callosal transection and determine which white matter pathways remain intact. METHODS: This HIPAA-compliant retrospective study was performed after Institutional Review Board approval. Patients who underwent corpus callosotomy with postoperative magnetic resonance imaging (MRI) that included DTI were identified. Axial DTI was performed with either 15 or 25 noncollinear directions of encoding. MRI and DTI were reviewed by two board-certified neuroradiologists to evaluate commissural disconnection. RESULTS: One hundred eleven patients underwent corpus callosotomy with postoperative MRI, of which 32 had postoperative DTI. Of these 32, there were 16 males and 16 females, with a mean age of 12.2 ± 6.3 years (range 0.24 to 32.8 years, median 12.3). Eighteen patients had undergone complete callosal transection and 14 patients had partial callosal transection. Seventeen of 18 patients undergoing complete callosal transection had structural and diffusion tensor fiber tracking (DT-FT) evidence of complete transection. The forceps major was intact in all patients undergoing partial transection. At least some commissural fibers originating from the precuneus, postcentral gyrus, and posterior cingulate were intact in all six partial transections which spared the callosal isthmus. CONCLUSION: DTI and DT-FT aid in the postoperative characterization in patients with callosal transection for seizure control. This can confirm whether the intended fibers have been disconnected, helping in the planning for possible further surgical intervention versus other therapies.

Publications in Pediatric Epilepsy: Using Bibliometrics to Determine Readings in the Field.

Bibliometrics and citation analysis are popular forms of analyzing medical literature based on article impact as determined by the number of citations an article has received from other publications. Many bibliometric studies published within the past 10 years have assembled lists of highly cited papers, top 100 papers, or citation classics of specialties, subspecialties, and specific morbidities. For pediatric epilepsy, there is only 1 study that bibliometrically examines articles in this subspecialty. Although bibliometrics generally examines trends in the literature, we used bibliometrics as a methodology for determining a core set of pediatric epilepsy articles with the highest impact (ie, citation count) that could be used as an introductory reading list for residents, fellows, and early career epileptologists. Therefore, we searched Web of Science to identify the 100 top-cited pediatric epilepsy articles and develop 10 topic areas into which we sorted each article. These recommended articles could be used as essential readings for pediatric epilepsy.

Intractable Generalized Epilepsy and Autosomal Dominant Hypocalcemia: A Case Report.

Calcium-sensing receptor gain-of-function mutations are known to cause autosomal dominant hypocalcemia and independently an epilepsy syndrome. We report the unique case of a child with both intractable generalized epilepsy and a chronic abnormality in calcium homeostasis due to a calcium-sensing receptor gene mutation. She is a 16-year-old female who began having staring events around 3 years of age. After her first generalized convulsion at age 5 years, investigations revealed hypocalcemia, hypercalciuria, and central nervous system calcifications. Her electroencephalogram demonstrated generalized epileptiform discharges, a hyperventilation-induced electroclinical seizure, and a photoconvulsive response. She has since been diagnosed with intellectual impairment, behavior disorder, and intractable childhood-onset seizures, the latter of which include eyelid myoclonia with absences. We conclude that calcium-sensing receptor gain-of-function mutations may precipitate an intractable generalized epilepsy syndrome with a comorbid endocrinopathy and that further investigations should be pursued in children with seizures presumed to be provoked by hypocalcemia.

Benign rolandic epilepsy -- perhaps not so benign: use of magnetic source imaging as a predictor of outcome.

The purpose of this study was to evaluate children with benign rolandic epilepsy, a childhood epilepsy characterized by centrotemporal/rolandic spike-wave discharges with infrequent partial seizures that may secondarily generalize. Recently, some investigators have questioned whether benign rolandic epilepsy is indeed "benign" or whether long-term cognitive outcome may be adversely affected. We initiated an ongoing study to identify children with benign rolandic epilepsy. The children were evaluated in the Texas Comprehensive Epilepsy Program using outpatient or continuous video-electroencephalographic monitoring, brain magnetic resonance imaging, magnetoencephalography, and neuropsychological testing. Neuropsychological testing revealed fine motor dysfunction, visuomotor integration deficits, dyscalculia, and/or expressive language deficits in all of the 9 patients evaluated, reaffirming that benign rolandic epilepsy is not necessarily a benign disorder. Our study shows a high concordance of motor and cognitive deficits in benign rolandic epilepsy, as others have previously suggested. Furthermore, magnetic source imaging shows a higher resolution of dipole localization compared with conventional electroencephalography, which may ultimately improve prediction of deficits. This reaffirms that magnetoencephalography is a valuable diagnostic tool in the evaluation of children with benign rolandic epilepsy.

Pediatric extratemporal epilepsy presenting with a complex auditory aura.

INTRODUCTION: Ear plugging (placing fingers in or covering the ears) is a clinical seizure semiology that has been described as a response to an unformed, auditory hallucination localized to the superior temporal neocortex. The localizing value of ear plugging in more complex auditory hallucinations may have more involved circuitry. We report on one child, whose aura was a more complex auditory phenomenon, consisting of a door opening and closing, getting louder as the ictus persisted. METHODS: This child presented, at four years of age, with brief episodes of ear plugging followed by an acute emotional change that persisted until surgical resection of a left mesial frontal lesion at 11 years of age. Scalp video-EEG, magnetic resource imaging, magnetoencephalography, and invasive video-EEG monitoring were carried out. RESULTS: The scalp EEG changes always started after clinical onset. These were not localizing, and encompassed a wide field over the bi-frontal head regions, the left side predominant over the right. Intracranial video-EEG monitoring with subdural electrodes over both frontal and temporal regions localized the seizure-onset to the left mesial frontal lesion. The patient has remained seizure-free since the resection on June 28, 2006, approximately one and a half years ago. CONCLUSION: Ear plugging in response to simple auditory auras localize to the superior temporal gyrus. If the patient has more complex, formed auditory auras, not only may the secondary auditory areas in the temporal lobe be involved, but one has to entertain the possibility of ictal-onset from the frontal cortex.

Vagus Nerve Stimulation in Intractable Epilepsy Associated With SCN1A Gene Abnormalities.

Mutations in the SCN1A gene cause a spectrum of epilepsy syndromes. There are 2 syndromes that are on the severe end of this spectrum. The classic severe form, Dravet syndrome, is an epileptic encephalopathy of childhood, causing cognitive decline as well as intractable seizures. Severe Myoclonic Epilepsy of Infancy-Borderline (SMEIB) is a term used to include cases with similar severities as those with Dravet syndrome, but lacking a single feature of classic severe myoclonic epilepsy of infancy. Vagus nerve stimulation is a nonpharmacologic treatment for intractable epilepsy. A retrospective review was conducted of patients with deleterious SCN1A mutations who had vagus nerve stimulation placement for treatment of their intractable epilepsy. These children had onset of their epilepsy between 3 and 29 months of age. Seizure control was assessed 6 months after implantation. Twenty patients are included in the study, with 12 implanted at our institution. Nine of the 12 patients implanted at our institution, who had confirmed pre- and post-implantation seizure assessments, showed improvement in seizure control, which was defined as >50% reduction in generalized tonic-clonic seizures, and 4 of those 12 reported improvement in cognitive or speech development. Seven of the 8 patients not implanted at our institution reported subjective benefit, with 4 relating "marked improvement" or seizure freedom. Vagus nerve stimulation appears to impart a benefit to children with deleterious SCN1A gene abnormalities associated with intractable epilepsy.

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.

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.

The ketogenic diet: adolescents can do it, too.

PURPOSE: To determine both the efficacy of and compliance with the ketogenic diet in the adolescent population. METHODS: A retrospective study of 45 patients, aged 12-19 years, consecutively enrolled in a ketogenic diet program from 1994 to 2002, was performed. Thirty-seven patients were from The Johns Hopkins Medical Institutions; eight were from The University of Texas at Houston. Charts were reviewed, and patients were contacted by telephone. RESULTS: Six months after diet initiation, 28 (62%) of 45 remained on the ketogenic diet, with six (21%) of 28 having 50-90% seizure reduction, and eight (29%) of 28 having >90%. At 12 months, 20 (44%) of 45 remained on the diet, with seven (35%) of 20 having 50-90% seizure reduction and six (30%) of 20 achieving >90% efficacy. Only 22% discontinued the diet for perceived restrictiveness. The mean diet duration was 1.2 years. Patients with multiple seizure types did best, whereas gender, prior seizure frequency, diet ratio, and age did not influence outcome. Patients dependent on parents for daily care were more likely to remain on the diet at 6 months, but had less efficacy. Weight loss (60%) and menstrual dysfunction (45% of female subjects) were the most commonly reported side effects. CONCLUSIONS: The ketogenic diet is as well tolerated and efficacious for adolescents with epilepsy as for the general childhood population.