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.

Clinical Utility of Transcranial Magnetic Stimulation (TMS) in the Presurgical Evaluation of Motor, Speech, and Language Functions in Young Children With Refractory Epilepsy or Brain Tumor: Preliminary Evidence.

Accurate presurgical mapping of motor, speech, and language cortices, while crucial for neurosurgical planning and minimizing post-operative functional deficits, is challenging in young children with neurological disease. In such children, both invasive (cortical stimulation mapping) and non-invasive functional mapping imaging methods (MEG, fMRI) have limited success, often leading to delayed surgery or adverse post-surgical outcomes. We therefore examined the clinical utility of transcranial magnetic stimulation (TMS) in young children who require functional mapping. In a retrospective chart review of TMS studies performed on children with refractory epilepsy or a brain tumor, at our institution, we identified 47 mapping sessions in 36 children 3 years of age or younger, in whom upper and lower extremity motor mapping was attempted; and 13 children 5-6 years old in whom language mapping, using a naming paradigm, was attempted. The primary hand motor cortex was identified in at least one hemisphere in 33 of 36 patients, and in both hemispheres in 27 children. In 17 children, primary leg motor cortex was also successfully identified. The language cortices in temporal regions were successfully mapped in 11 of 13 patients, and in six of them language cortices in frontal regions were also mapped, with most children (n = 5) showing right hemisphere dominance for expressive language. Ten children had a seizure that was consistent with their clinical semiology during or immediately following TMS, none of which required intervention or impeded completion of mapping. Using TMS, both normal motor, speech, and language developmental patterns and apparent disease induced reorganization were demonstrated in this young cohort. The successful localization of motor, speech, and language cortices in young children improved the understanding of the risk-benefit ratio prior to surgery and facilitated surgical planning aimed at preserving motor, speech, and language functions. Post-operatively, motor function was preserved or improved in nine out of 11 children who underwent surgery, as was language function in all seven children who had surgery for lesions near eloquent cortices. We provide feasibility data that TMS is a safe, reliable, and effective tool to map eloquent cortices in young children.

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.

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.

Congenital Ocular Neuromyotonia with Partial Third Nerve Palsy.

PURPOSE: We report the first case of congenital ocular neuromyotonia (ONM) and the results of strabismus surgery for this patient's co-existing cranial nerve (CN) III palsy. PATIENTS AND METHOD: The patient presented at 18 months with strabismus that had reportedly been present since the time of birth. On exam, she had persistent exotropia (RXT) and hypertropia (RHT) with episodes of esotropia in the right eye that could be evoked by sustained left gaze. A diagnosis of ONM with partial CN III palsy was made. T1-weighted, T2-weighted, and fluid-attenuated inversion recovery magnetic resonance imaging failed to reveal intracranial pathology. RESULTS: Gaze induced intermittent esotropia resolved with carbamazepine. Surgery was performed to improve the patient's RXT and RHT. Post-operatively, the patient's RXT had improved from 12 to 15 prism diopters (∆) at near and 20∆ at a distance to 10∆ RXT at near with no horizontal deviation at distance. Her deviation has remained stable for 13 years, as has her neurological exam and good state of health. CONCLUSION: This case demonstrates that ONM may present congenitally and adds to the body of knowledge regarding surgical outcomes on concurrent CN palsies in these patients.

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.

SmartWatch by SmartMonitor: Assessment of Seizure Detection Efficacy for Various Seizure Types in Children, a Large Prospective Single-Center Study.

INTRODUCTION: Patients with epilepsy and their caregivers are constantly burdened with the possibility of a seizure and its consequences, such as accidents, injuries, and sudden unexplained death in epilepsy. It is the unpredictable nature of seizures that often affects both patients with seizures and their caregivers, limits independence, and hinders quality of life. There are several types of motion detectors on the market, each with varying degrees of sensitivity. MATERIAL AND METHODS: We prospectively tested the SmartWatch, a wrist-worn monitor, on children, adolescents, and young adults with various types of seizures in an epilepsy monitoring unit. Confirmation of seizure type and if there was rhythmic upper extremity jerking associated with the seizure was determined by review of the video electroencephalograph. This was compared with the standard detection system of the watch. RESULTS: This study analyzed a total of 191 seizures in 41 patients aged 5-41 years. Fifty-one of the seizures were generalized tonic-clonic. Forty-seven of the seizures had a rhythmic arm movement component. The SmartWatch detected 30 seizures (16%) of the total, 16 (31%) of the generalized tonic-clonic seizures, and 16 (34%) seizures associated with rhythmic arm movements. DISCUSSION: Overall, only a minority of generalized tonic-clonic seizures or seizures with rhythmic movements were detected, highlighting the need for an effective seizure detection device.

Clinical Applications of Transcranial Magnetic Stimulation in Pediatric Neurology.

Noninvasive brain stimulation is now an accepted technique that is used as a diagnostic aid and in the treatment of neuropsychiatric disorders in adults, and is being increasingly used in children. In this review, we will discuss the basic principles and safety of one noninvasive brain stimulation method, transcranial magnetic stimulation. Improvements in the spatial accuracy of transcranial magnetic stimulation are described in the context of image-guided transcranial magnetic stimulation. The article describes and provides examples of the current clinical applications of transcranial magnetic stimulation in children as an aid in the diagnosis and treatment of neuropsychiatric disorders and discusses future potential applications. Transcranial magnetic stimulation is a noninvasive tool that is safe for use in children and adolescents for functional mapping and treatment, and for many children it aids in the preoperative evaluation and the risk-benefit decision making.

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.

Cerebellar seizures.

Epilepsy, especially with refractory seizures, is thought to arise only from cortical lesions or substrate. The authors report on 2 patients with refractory epilepsy and cerebellar lesions. Depth electrodes were placed within the cerebellar lesions in both patients, and intracranial electroencephalographic recordings showed seizure origin from the cerebellar lesions. One patient eventually attained seizure control with antiepileptic drugs. The other case involved a child with generalized myoclonic epilepsy associated with a pilocytic astrocytoma of the cerebellum. This patient obtained seizure control following gross-total resection of the tumor.

Prospective Study of the Emfit Movement Monitor.

Sudden unexplained death in epilepsy (SUDEP) is associated with generalized tonic-clonic seizures and occurs most often when patients are in bed. There are several seizure detection monitors on the market, but little data are available on the sensitivity and specificity of these devices. We recently tested 2 models of seizure detection alarms with disappointing results. Here we tested the Emfit movement monitor on children with various seizure types who also had standard video electroencephalography (EEG), cardiopulmonary, and nursing monitoring. Video EEG records were reviewed to detect any seizures. In 45 patients, 78 seizures were recorded by video EEG. The Emfit movement monitor captured 23 seizure events (30%) in total, and 15 of the 28 (54%) that occurred during sleep. Most importantly, the alarm was activated with 11 of the 13 (85%) generalized tonic-clonic seizures that occurred in sleeping children. The Emfit movement monitor performed very well in comparison to previously tested devices.

Prospective Study of 2 Bed Alarms for Detection of Nocturnal Seizures.

For parents of children with epilepsy, seizures occurring in sleep are a major concern. Risk factors for sudden unexplained death in epilepsy patients include being in bed and generalized tonic-clonic seizures. A device for detecting nocturnal seizure activity would be valuable. Children with various seizure types undergoing evaluation had standard video electroencephalography (EEG), cardiopulmonary and nursing monitoring, and 1 of 2 models (ST-2 and MP5) of a Medpage bed alarm. The video EEG record was reviewed to detect any seizures missed by the bed alarms or caregivers. The ability of the bed alarms to detect motor seizures in general and specific seizure types was tested. In 15 patients, 69 seizures were recorded by video EEG. The ST-2 did not detect any nocturnal seizures. The MP5 alarm detected 1 of 15 in sleeping patients: a generalized tonic-clonic seizure. The Medpage seizure alarms do not appear to adequately detect nocturnal seizures.

Passive language mapping with magnetoencephalography in pediatric patients with epilepsy.

OBJECT: Functional mapping is important for determining surgical candidacy and also in epilepsy surgery planning. However, in young children and uncooperative patients, language mapping has been particularly challenging despite the advances in performing noninvasive functional studies. In this study the authors review a series of children with epilepsy who underwent language mapping with magnetoencephalography (MEG) while sedated or sleeping, to determine receptive language localization for presurgical evaluation. METHODS: The authors undertook a retrospective review of patients who underwent MEG between December 2007 and July 2009, and identified 15 individuals who underwent passive language testing as part of their presurgical evaluation because they were unable to participate in traditional language testing, such as Wada or functional MRI. Factors necessitating passive language testing included age and neurocognitive development. RESULTS: Three of the 15 patients were deemed candidates for epilepsy surgery based on the results from standard preoperative testing, including video electroencephalography, MRI, and passive receptive language testing using MEG technology. The MEG studies were used successfully to localize language in all 3 patients, creating opportunities for seizure freedom through surgery that would not otherwise have been available. All 3 patients then underwent resective epilepsy surgery without experiencing postoperative language deficits. CONCLUSIONS: This case series is the first to look at language mapping during sleep (passive language mapping) in which MEG was used and is the first to evaluate passive language testing in a patient population with intracranial pathological entities. This case series demonstrates that MEG can provide an alternative method for receptive language localization in patients with barriers to more traditional language testing, and in these 3 cases surgery was performed safely based on the results.

Mesial temporal sclerosis in a cohort of children with SCN1A gene mutation.

Mesial temporal sclerosis is uncommon in childhood but has been associated with febrile status epilepticus. SCN1A gene mutations are linked to multiple epilepsy syndromes with patients frequently presenting with prolonged febrile seizures. After observing mesial temporal sclerosis in a child with SCN1A gene mutation, we retrospectively reviewed magnetic resonance imaging (MRI) findings in all patients with SCN1A gene mutation identified between 2005 and 2010. We identified 20 patients with SCN1A mutations. Six patients had evidence of definite mesial temporal sclerosis with 2 patients having bilateral abnormalities. Another 4 patients were defined as having possible mesial temporal sclerosis. This patient group revealed that 50% had findings consistent with definite or possible mesial temporal sclerosis and many did not have a history of prolonged febrile seizures. We conclude that mesial temporal sclerosis is a common finding in children with SCN1A mutations. Many of these children will have Dravet syndrome but not all.

Rapid infusion of a loading dose of intravenous levetiracetam with minimal dilution: a safety study.

Intravenous antiepileptic drugs are required in patients needing urgent treatment or unable to take oral medication. The safety of intravenous levetiracetam has been established in prospective studies of adult epilepsy and healthy participants. The authors performed a prospective, single-center study to evaluate the safety of a rapid loading dose of intravenous levetiracetam. Patients were divided into 3 equal dosing groups (N = 15 each): 20, 40, and 60 mg/kg (corresponding to maximum doses of 1, 2, and 3 g). Electrocardiogram and safety assessment were performed during the infusion. Ages were 4 to 32 years. Postinfusion serum levetiracetam concentrations were 14 to 189 microg/mL. There were no significant changes in blood pressure, no local infusion site reactions, and no electrocardiogram abnormalities. The authors concluded that high serum levels of parenteral levetiracetam can be achieved rapidly and safely, in a small infusion volume. This finding has important implications for the treatment of status epilepticus.

A case that is not for the faint of heart.

A 5-year-old was admitted after an episode of loss of consciousness and an episode of convulsive activity. Information that aids in differentiating seizures and syncope is discussed.

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.

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.

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.