Safety and Efficacy of Brivaracetam in Pediatric Refractory Epilepsy: A Single-Center Clinical Experience.

Brivaracetam is a new antiepileptic drug with limited data in children. The objective of this study was to assess the efficacy/tolerability of brivaracetam. This is a retrospective chart review of children/adolescents with refractory epilepsy treated with brivaracetam from 2016 to 2018. The primary outcome was seizure reduction (decrease in seizure frequency >50%). Twenty-three patients were identified. Mean age at initiation was 12.5 years. Fourteen were females. Epilepsy was focal in 11, generalized in 6, and mixed in 3. Average dose was 3.9 mg/kg/d. The mean duration of treatment was 8.2 months. Eight had greater than 50% decrease in seizure frequency, of which 7 had focal epilepsy, and 1 had Lennox-Gastaut/mixed epilepsy. Two had drowsiness and 3 behavioral complaints. One experienced tingling and dizziness. Our retrospective review suggests that brivaracetam is an effective therapy for refractory focal epilepsy in children older than 4 years of age.

A case of 5,10-methenyltetrahydrofolate synthetase deficiency due to biallelic null mutations with novel findings of elevated neopterin and macrocytic anemia.

We describe a case of 5,10-methenyltetrahydrofolate synthetase (MTHFS) deficiency characterized by microcephaly, global developmental delay, epilepsy, and cerebral hypomyelination. Whole exome sequencing (WES) demonstrated homozygosity for the R74X mutation in the MTHFS gene. The patient had the unexpected finding of elevated cerebrospinal fluid (CSF) neopterin. The novel finding of macrocytic anemia in this patient may provide a clue to the diagnosis of this rare neurometabolic disorder.

Paroxysmal Dyskinesias.

Paroxysmal dyskinesias (PD) are hyperkinetic movement disorders where patients usually retain consciousness. Paroxysmal dyskinesias can be kinesigenic (PKD), nonkinesigenic (PNKD), and exercise induced (PED). These are usually differentiated from each other based on their phenotypic and genotypic characteristics. Genetic causes of PD are continuing to be discovered. Genes found to be involved in the pathogenesis of PD include MR-1, PRRT2, SLC2A1, and KCNMA1. The differential diagnosis is broad as PDs can mimic psychogenic events, seizure, or other movement disorders. This review also includes secondary causes of PDs, which can range from infections, metabolic, structural malformations to malignancies. Treatment is usually based on the correct identification of type of PD. PKD responds well to antiepileptic medications, whereas PNKD and PED respond to avoidance of triggers and exercise, respectively. In this article, we review the classification, clinical features, genetics, differential diagnosis, and management of PD.

Cost-Effectiveness of Evaluation of Children With Epilepsy in the Emergency Department: Need for Investment in Patient Education.

We aimed to study cost-effectiveness of seizure evaluation of children with epilepsy in the emergency department (ED). We reviewed epilepsy patients seen at our ED for 1 year. Age, laboratory and neuroimaging results, treatment, disposition, and usefulness of the visit (need for hospitalization, clinical improvement) were analyzed. We identified 330 patients, aged 23 days-21 years, 190 (57.5%) had blood tests, 45 (13.6%) urinalysis, 2 (0.6%) cerebrospinal fluid testing, and 44 neuroimaging studies (13.3%). Tests' positive yield were 41%, 11%, 0%, and 4.5%, respectively. One-third of patients (n = 122) were treated with antiepileptic drugs. Other treatments were administered to 44 (13.3%). One hundred eighteen patients (35.7%) were admitted to our hospital, 208 (63%) discharged to home. Two hundred eight visits were useful (63%). One-third of visits did not provide useful patient care. Their visits were expensive and not very cost-effective. Investment in patient education could decrease unnecessary ED visits.

Efficacy and Tolerability of Lacosamide in the Treatment of Children With Refractory Generalized Epilepsy.

Lacosamide is FDA-approved in patients 17 years or older with partial-onset epilepsy. We evaluated the efficacy and tolerability of lacosamide in children with refractory generalized epilepsy. We retrospectively reviewed records of 21 children with refractory generalized epilepsy treated with lacosamide in our institution from 2009-2013 divided into 2 subgroups- I, Lennox-Gastaut Syndrome, and II, other generalized epilepsies. Efficacy was defined as seizure freedom or ≥50% seizure reduction. Descriptive data analysis including seizure freedom was compared using c(2) analysis. There were eleven females and ten males with a mean age, of 11.9 years. Five patients became seizure free, nine had ≥50% seizure reduction, and seven had no response. Group I: seven had ≥50% improvement, one did not respond. Group II: five became seizure free, two had ≥50% improvement, five had no response. Lacosamide is effective and well tolerated in children with refractory generalized epilepsy particularly patients with Lennox-Gastaut Syndrome.

A Patient With Atypical Multiple Sulfatase Deficiency.

BACKGROUND: Multiple sulfatase deficiency is an autosomal recessive lysosomal storage disorder characterized by the absence of several sulfatases and resulting from mutations in the gene encoding the human C (alpha)-formylglycine-generating enzyme. There have been a variety of biochemical and clinical presentations reported in this disorder. PATIENT DESCRIPTION: We present a 4-year-old girl with clinical findings of microcephaly, spondylolisthesis and neurological regression without ichthyosis, coarse facies, and organomegaly. RESULTS: The child's magnetic resonance imaging demonstrated confluent white matter abnormalities involving the periventricular and deep cerebral white matter with the U-fibers relatively spared. Biochemical testing showing low arylsulfatase A levels were initially thought to be consistent with a diagnosis of metachromatic leukodystrophy. The diagnosis of multiple sulfatase deficiency was pursued when genetic testing for metachromatic leukodystrophy was negative. CONCLUSION: This child illustrates the clinical heterogeneity of multiple sulfatase deficiency and that this disorder can occur without the classic clinical features.

A novel 2q37 microdeletion containing human neural progenitors genes including STK25 results in severe developmental delay, epilepsy, and microcephaly.

2q37 microdeletion syndrome is a rare syndrome characterized by neurodevelopmental delay, bone, cardiovascular, and neurological alterations. This syndrome is typically associated with loss of genetic material of approximately 100 genes in the 2q37 band. However, the genes associated with neurodevelopmental phenotype in this syndrome are still unknown. We identified a deleted region of 496 kb by whole genome array CGH in a patient who fulfilled criteria for 2q37 microdeletion syndrome with developmental delay, microcephaly, hypoplasia of the corpus callosum, hand wringing, toe walking, and seizures. The deleted segment contains genes that are highly expressed in the developing human cortical plate and the subventricular zone (SVZ) in vivo and human neural progenitors in vitro, including SEPT2, THAP4, ATG4B, PPP1R7, and STK25. Network analysis revealed that STK25 was the most interacting gene associated with neural development in this deletion. Our report narrows the likely causative genomic region for microcephaly and neurodevelopmental delay in 2q37 microdeletion syndrome to a small genomic region enriched with neural progenitor genes that may represent an important locus for the development of the human cortex and corpus callosum.

EEG Duration: The Long and the Short of It.

Current American Clinical Neurophysiology Society guidelines require a minimum of 20 minutes of artifact-free EEG recording; however, the optimum duration for routine EEGs is not established. Our hypothesis was that an EEG recording of 40 minutes' duration would yield more information than a 20-minute EEG in capturing epileptiform abnormalities and in obtaining sleep. We retrospectively studied 150 consecutive EEGs of 40 minutes' duration performed at St Christopher's Hospital for Children. Although the majority (89%) of interictal EEG abnormalities can be identified within the first 20 minutes of a routine EEG, extending the time of a routine EEG increases the yield significantly by identifying an additional 11% of abnormal studies (P = .0001), precluding the need for further long-term monitoring in these patients. Forty-three percent of interictal epileptiform abnormalities were found during sleep. We recommend that routine EEGs be performed for 40 minutes, whenever possible, to improve yield in a cost-effective manner.

Focal epilepsies: immunologic and inflammatory mechanisms.

There is increasing evidence documenting activation of inflammatory processes in focal epilepsies. This review article summarizes current data regarding immune mediated inflammatory processes in patients with symptomatic partial epilepsies such as mesial temporal sclerosis, focal cortical dysplasia, and Rasmussen's encephalitis. We have also reviewed several neuronal surface antibody-associated syndromes, which have been recently described with focal seizures as an important part of clinical presentation, such as antibody-associated limbic encephalitis and N-methyl-D-aspartic acid receptor antibody syndrome. An autoimmune mechanism may be one pathogenic factor in some symptomatic epilepsies acting as a triggering event in the process leading to the development of epilepsy.

Ataxia, ophthalmoplegia, and impairment of consciousness in a 19-month-old American boy.

A 19-month-old, white, Pennsylvanian boy, with an unremarkable medical history, presented to our hospital with a 3-week history of nonbloody, nonbilious emesis up to 5 times a day and nonbloody diarrhea. Ten days before admission, his gait became progressively unsteady, until he finally refused to walk. A day before admission, he found it difficult to move his eyes. The patient was hypoactive. History, physical and neurologic examination, blood and cerebrospinal (CSF) fluid studies, and neuroimaging studies ruled out the most frequent causes of acute ataxia. The etiology of bilateral, complete ophthalmoplegia was also taken into consideration. Magnetic resonance imaging (MRI) findings of bilateral thalami and mammillary bodies provided diagnostic clues. Additional history and specific tests established the final diagnosis and treatment plan. The patient improved to a normal neurologic state. This case provides important practical information about an unusual malnutrition cause of acute ataxia, particularly in young children of developing countries.

Fraternal twins with autism, severe cognitive deficit, and epilepsy: diagnostic role of chromosomal microarray analysis.

A 7-year-old child presented with atypical absence epilepsy. He also had autism and severe cognitive deficit. As part of his diagnostic workup, a chromosomal microarray analysis was performed, which showed novel biallelic deletions in the neurexin 1 gene (NRXN1). His fraternal twin sister, who also had autism and cognitive impairment, was subsequently found to have the same biallelic deletions. Deletions included a 272-282kb loss at band 2p16.3 in one allele and a smaller 135-174-kb loss on the second allele. Neurexin 1 (NRXN1) is a cell adhesion protein, forming a synaptic complex with neuroligin. This signals a pathway that is critical for activity-dependent synaptic transmission. Mutations in this gene have been associated with autism and neurodevelopmental delay. Although there are many reports of heterozygous mutations with variable expressivity, only 3 cases with biallelic NRXN1 mutations have been previously reported, all of which have a more severe phenotype. We report 2 siblings with biallelic deletions, both of which affect the promoter region and exons 1-5 in the α-NRXN1 isoform, which has a role in the Ca(2+)-dependent release of neurotransmitters in the central nervous system. Our cases expand the phenotype of biallelic α NRXN 1 mutations and emphasize the important role of NRXN1 in autism and intellectual disability. Chromosomal microarray analysis should be the clinical standard in all specialties for first-tier genetic testing in autistic spectrum disorders.

Efficacy of lacosamide as adjunctive therapy in children with refractory epilepsy.

Lacosamide is a US Food and Drug Administration (FDA)-approved antiepileptic drug for patients 17 years or older with partial epilepsy. There are sparse data on children. The objective of our study was to evaluate its efficacy/safety in children with refractory epilepsy. Forty children (mean age 14.3 years) were treated with lacosamide at our institution (adjunctive therapy in 36, monotherapy in 4). Fifteen patients had symptomatic focal epilepsy, 2 had cryptogenic focal epilepsy, 20 had symptomatic generalized epilepsy, and 3 had cryptogenic generalized epilepsy. Two had juvenile myoclonic epilepsy and 5 had Lennox-Gastaut syndrome. Forty-two percent had at least >50% reduction in seizure frequency, and 6 became seizure free. Average dose was 7 mg/kg/d and average follow-up was 9.2 months. Responders had a 76.5% mean decrease in seizures. Fifteen children experienced an adverse reaction and 7 discontinued lacosamide (4: Ineffective, I: insurance denial, 1: tremor, 1: behavior). Lacosamide is effective and well-tolerated in children with refractory epilepsy.

Mitochondrial dysfunction in epilepsy.

Epilepsy is the most common neurologic disorder worldwide and is characterized by recurrent unprovoked seizures. The mitochondrial (mt) respiratory chain is the final common pathway for cellular energy production through the process of oxidative phosphorylation. As neurons are terminally differentiated cells that lack significant regenerative capacity and have a high energy demand, they are more vulnerable to mt dysfunction. Therefore, epileptic seizures have been well described in several diseases such as mt encephalomyopathy, lactic acidosis, and stroke-like episodes and myoclonic epilepsy and ragged red fibers, which are caused by gene mutations in mtDNA, among others. Mutations in nuclear DNA regulating mt function are also being described (eg, POLG gene mutation). The role of mitochondria (mt) in acquired epilepsies, which account for about 60% of all epilepsies, is equally important but less well understood. Oxidative stress is one of the possible mechanisms in the pathogenesis of epilepsy resulting from mt dysfunction gradually disrupting the intracellular Ca(2+) homeostasis, which modulates neuronal excitability and synaptic transmission, making neurons more vulnerable to additional stress, and leading to energy failure and neuronal loss in epilepsy. Antiepileptic drugs (AEDs) also affect mt function in several ways. There must be caution when treating epilepsy in patients with known mt disorders as some AEDs are toxic to the mt. This review summarizes our current knowledge of the effect of mt disorders on epilepsy, of epileptic seizures on mt, and of AEDs on mt function and the implications of all these interactions for the management of epilepsy in patients with or without mt disease.

Brainstem auditory evoked potentials and middle latency auditory evoked potentials in young children.

Measurements of brainstem auditory evoked potentials (BAEP) and middle latency auditory evoked potentials (MLAEP) are readily available neurophysiologic assessments. The generators for BAEP are believed to involve the structures of cochlear nerve, cochlear nucleus, superior olive complex, dorsal and rostral pons, and lateral lemniscus. The generators for MLAEP are assumed to be located in the subcortical area and auditory cortex. BAEP are commonly used in evaluating children with autistic and hearing disorders. However, measurement of MLAEP is rarely performed in young children. To explore the feasibility of this procedure in young children, we retrospectively reviewed our neurophysiology databank and charts for a 3-year period to identify subjects who had both BAEP and MLAEP performed. Subjects with known or identifiable central nervous system abnormalities from the history, neurologic examination and neuroimaging studies were excluded. This cohort of 93 children up to 3 years of age was divided into 10 groups based on the age at testing (upper limits of: 1 week; 1, 2, 4, 6, 8, 10 and 12 months; 2 years; and 3 years of age). Evolution of peak latency, interpeak latency and amplitude of waveforms in BAEP and MLAEP were demonstrated. We concluded that measurement of BAEP and MLAEP is feasible in children, as early as the first few months of life. The combination of both MLAEP and BAEP may increase the diagnostic sensitivity of neurophysiologic assessment of the integrity or functional status of both the peripheral (acoustic nerve) and the central (brainstem, subcortical and cortical) auditory conduction systems in young children with developmental speech and language disorders.

Persistence of hypsarrhythmia in children beyond the age of three years.

Occurrence of hypsarrhythmia after the age of 3 years is rare. The objective of this study is to describe a group of patients who have persistence of hypsarrhythmia after the age of 3 years. The authors retrospectively reviewed the EEGs of 24 patients with hypsarrhythmia. Electroencephalographies (EEGs) were scored using a hypsarrhythmia scale. The clinical data of 7 patients with EEG scores greater than 9 at ages ≥ 3 years were analyzed. The mean age was 5.7 years (range, 3-8.7 years). EEG background amplitudes ranged from 200 to 500 µV in 5 patients and it was greater than 500 µV in the other 2. Six patients had electrodecremental responses. The etiology was developmental in 3 patients, mitochondrial disease in 2, and hypoxic ischemic encephalopathy in 2. Our study suggests that a subgroup of patients with hypsarrhythmia may not transition to a Lennox-Gastaut pattern or normalization after the age of 3 years.

Early-onset childhood absence epilepsy: is it a distinct entity?

Childhood absence epilepsy (CAE) typically starts between four and seven years of age. Onset before three years is rare and has not been previously reported from North America. We retrospectively reviewed the electroencephalography laboratory database and paediatric neurology clinic records (from January 2000 to June 2009) at our institution in order to identify patients with absence seizures beginning before age three. Information was collected for age, gender, neurodevelopment, antiepileptic drugs (AEDs) used, seizure control, follow-up, and side effects. Of 12 patients identified, mean age at onset was 20.5 months (range: 11 months to two years; follow-up: six months to 11 years). Seven of 12 patients had normal neurodevelopment and five had speech delay. Four patients were seizure-free without AEDs, three were seizure-free with a single AED, and five still had seizures with multiple AEDs. Three patients had recurrences after medication withdrawal. Other previously published series have identified better seizure control than that reported here, however, 16% of the 130 patients so far documented are reported to have poorly controlled epilepsy, indicating that early-onset CAE is not a homogeneous condition. The debate as to whether early-onset CAE is a distinct epilepsy syndrome therefore continues. We believe that early-onset CAE may be a distinct epilepsy syndrome, with some features that overlap with those of typical CAE, as well as unique distinguishing features. Large prospective multicentric studies would be necessary to definitely resolve this matter.

Significance of interictal occipital epileptiform discharges in children.

OBJECTIVE: Interictal occipital epileptiform abnormalities have not been well characterized. The objective of this pilot study was to assess their significance in children. METHODS: A search was performed on the EEG database for the keywords "occipital", "spike", "sharp wave" and "epileptiform". Patients were divided into two groups based on the absence of all (group 1) or presence of any (group 2) of the following criteria: mental retardation, cerebral palsy, neurological deficits, abnormal MRI and/or intractable epilepsy. Special attention was given to the spike/sharp wave amplitude/duration and background slowing. RESULTS: A total of 44 children (eight months to 15 years) were studied. Groups 1 and 2 were each composed of 22 children. Background slowing was more frequent in group 2 (10/22, 45%) compared to group 1 (1/22, 4.5%; p = 0.002). In group 2, 8/22 (36%) had spikes or sharp waves with amplitudes below 50 microV or above 150 microV with a positive predictive value of 89%, and a negative predictive value of 39%. Only 1/22 (4.5%) in group 1 had epileptiform activity outside of the 50-150 microV range. CONCLUSIONS: The presence of very high or low-amplitude occipital epileptiform abnormalities or background slowing may be indicative of encephalopathy.

Persistent focal seizures after cat scratch encephalopathy.

This report describes a 9-year-old child with status epilepticus and cat scratch disease. This patient's focal seizures and electroencephalographic changes persisted for 18 months after status epilepticus. This patient represents the third reported case of persistent focal seizures or electroencephalographic changes after status epilepticus secondary to cat scratch disease. This finding suggests that cat scratch encephalopathy may be a cause of localization-related epilepsy, and should be investigated when evaluating a patient with new-onset partial seizures.

Assessment of the QT interval in the electroencephalography (EEG) of children with syncope, epilepsy, and attention-deficit hyperactivity disorder (ADHD).

The interpretation of QT interval is often neglected during electroencephalography (EEG) reading. We compared the incidence of prolonged QT interval, as seen in the electrocardiography (ECG) recording lead of the EEG, in children presenting with seizure, syncope, or attention-deficit hyperactivity disorder (ADHD). Abnormal QT was defined as >460 ms. The incidence of prolonged QT in the seizure, syncope, and ADHD groups was 1/50 (2%), 7/50 (14%), and 2/50 (4%), respectively (P = .036, chi-square). The mean +/- SD of QT were 405 +/- 34, 424 +/- 39, and 414 +/- 36, respectively (P = .035, analysis of variance [ANOVA], syncope group, compared with seizure group). The incidence of prolonged QT as measured in the EEG was unexpectedly high in children presenting with seizure, syncope, or ADHD. These data support the concept that QT evaluation should be emphasized during routine EEG reading, as it may aid in identifying cases of undiagnosed cardiac conduction abnormalities. Prospective studies comparing EEG-ECG tracings with 12-lead ECG are warranted.