Language and social functioning in children and adolescents with epilepsy.

Individuals with epilepsy have difficulties with social function that are not adequately accounted for by seizure severity or frequency. This study examined the relationship between language ability and social functioning in 193 children with epilepsy over a period of 36months following their first recognized seizure. The findings show that children with persistent seizures have poorer language function, even at the onset of their seizures, than do their healthy siblings, children with no recurrent seizures, and children with recurrent but not persistent seizures. They continue to demonstrate poorer language function 36months later. This poor language function is associated with declining social competence. Intervention aimed at improving social competence should include consideration of potential language deficits that accompany epilepsy and social difficulty.

Design and implementation of the first randomized controlled trial of coenzyme CoQ10 in children with primary mitochondrial diseases.

We report the design and implementation of the first phase 3 trial of CoenzymeQ10 (CoQ10) in children with genetic mitochondrial diseases. A novel, rigorous set of eligibility criteria was established. The trial, which remains open to recruitment, continues to address multiple challenges to the recruitment of patients, including widely condoned empiric use of CoQ10 by individuals with proven or suspected mitochondrial disease and skepticism among professional and lay mitochondrial disease communities about participating in placebo-controlled trials. These attitudes represent significant barriers to the ethical and scientific evaluation--and ultimate approval--of nutritional and pharmacological therapies for patients with life-threatening inborn errors of energy metabolism.

Cyclocreatine treatment improves cognition in mice with creatine transporter deficiency.

The second-largest cause of X-linked mental retardation is a deficiency in creatine transporter (CRT; encoded by SLC6A8), which leads to speech and language disorders with severe cognitive impairment. This syndrome, caused by the absence of creatine in the brain, is currently untreatable because CRT is required for creatine entry into brain cells. Here, we developed a brain-specific Slc6a8 knockout mouse (Slc6a8-/y) as an animal model of human CRT deficiency in order to explore potential therapies for this syndrome. The phenotype of the Slc6a8-/y mouse was comparable to that of human patients. We successfully treated the Slc6a8-/y mice with the creatine analog cyclocreatine. Brain cyclocreatine and cyclocreatine phosphate were detected after 9 weeks of cyclocreatine treatment in Slc6a8-/y mice, in contrast to the same mice treated with creatine or placebo. Cyclocreatine-treated Slc6a8-/y mice also exhibited a profound improvement in cognitive abilities, as seen with novel object recognition as well as spatial learning and memory tests. Thus, cyclocreatine appears promising as a potential therapy for CRT deficiency.

Importance of muscle light microscopic mitochondrial subsarcolemmal aggregates in the diagnosis of respiratory chain deficiency.

The purpose of this study was to evaluate relationships between subsarcolemmal mitochondrial aggregates and electron transport chain deficiencies in skeletal muscle with the objective of establishing an association between mitochondrial accumulation and electron transport chain complex deficiency. We conducted a large-scale, retrospective study to evaluate factors associated with subsarcolemmal mitochondrial aggregates (percent) in pediatric patients who received muscle biopsies for suspected respiratory chain disorders. Patients were included if they had histochemical stains for assessment of mitochondrial pathology and had biochemical testing for muscle electron transport chain complex activities. Significant positive bivariate correlations (n = 337) were found between subsarcolemmal mitochondrial aggregate percentage and electron transport chain complexes II, IV, I + III, and II + III activities. Evaluation showed that a cutoff value of > 2% subsarcolemmal mitochondrial aggregates had poor overall diagnostic accuracy (mean, 32%), compared with a < 5% cutoff (mean, 60%). To better evaluate the effects of subsarcolemmal mitochondrial aggregates percentages, patients were stratified according to lower one-third (group 1, n = 120 plus ties) and upper one-third (group 2, n = 115 plus ties) of subsarcolemmal mitochondrial aggregates values. Although only minor clinical and pathologic differences were observed, group 1 participants had significantly lower electron transport chain complex activities than group 2 for all enzymes except complex III. Logistic regression showed over 2-fold greater odds of deficiency for electron transport chain complexes I + III (P = .01) and II + III (P = .03) for group 1 participants compared with group 2. We conclude that, contrary to the previous > 2.0% subsarcolemmal mitochondrial aggregates cutoff for respiratory chain disorder, patients with a low subsarcolemmal mitochondrial aggregates percentage (≤4%) are significantly more likely to have electron transport chain complex deficiency than patients with increased subsarcolemmal mitochondrial aggregates percentage (≥10%). This morphological approach for assessment of mitochondrial proliferation may assist clinicians to select further testing to rule out an electron transport chain complex deficiency in children by other methods, including direct biochemical testing of electron transport chain complex activities, measurement of muscle coenzyme Q10 content, or evaluation for a mitochondrial DNA depletion syndrome.

Enzyme inducing antiepileptic drugs are associated with mitochondrial proliferation and increased cytochrome c oxidase activity in muscle of children with epilepsy.

PURPOSE: To evaluate the effects of epilepsy-related factors associated with mitochondrial pathology and function in skeletal muscle of children with suspected mitochondrial disorders. METHODS: This case-control study evaluated patients and age-matched controls with muscle biopsies at Cincinnati Children's Hospital Medical Center obtained between January, 2000 and December, 2008. RESULTS: A total of 65 epilepsy patients and 65 age-matched controls met the inclusion criteria. No significant clinical, pathological, or biochemical differences were found between the epilepsy and control groups. Treatment resistance was associated with decreased electron transport chain (ETC) complex II+III activity compared to treatment-responsive patients. Only patients receiving enzyme inducer antiepileptic drugs (AEDs) had ETC complex activities equivalent to or greater than other study groups. Robust regression modeling found a significant effect between percentage of myofibers with subsarcolemmal mitochondrial aggregates (SSMA) and ETC complex IV activity for the enzyme inducer AED group. Least squares regression showed that only complex IV/citrate synthase ratio was strongly correlated with SSMA percentage for the enzyme inducer AED group. As far as we can determine this is the first study to show an association between enzyme inducer AED treatment and enhanced ETC complex IV activity. CONCLUSIONS: In skeletal muscle mitochondrial density, assessed by SSMA percentage, and ETC complex IV activity are positively correlated in patients receiving enzyme inducer AED treatment.

Creatine transporter (CrT; Slc6a8) knockout mice as a model of human CrT deficiency.

Mutations in the creatine (Cr) transporter (CrT; Slc6a8) gene lead to absence of brain Cr and intellectual disabilities, loss of speech, and behavioral abnormalities. To date, no mouse model of CrT deficiency exists in which to understand and develop treatments for this condition. The purpose of this study was to generate a mouse model of human CrT deficiency. We created mice with exons 2-4 of Slc6a8 flanked by loxP sites and crossed these to Cre:CMV mice to create a line of ubiquitous CrT knockout expressing mice. Mice were tested for learning and memory deficits and assayed for Cr and neurotransmitter levels. Male CrT(⁻/y) (affected) mice lack Cr in the brain and muscle with significant reductions of Cr in other tissues including heart and testes. CrT(⁻/y) mice showed increased path length during acquisition and reversal learning in the Morris water maze. During probe trials, CrT(⁻/y) mice showed increased average distance from the platform site. CrT(⁻/y) mice showed reduced novel object recognition and conditioned fear memory compared to CrT(+/y). CrT(⁻/y) mice had increased serotonin and 5-hydroxyindole acetic acid in the hippocampus and prefrontal cortex. Ubiquitous CrT knockout mice have learning and memory deficits resembling human CrT deficiency and this model should be useful in understanding this disorder.

Self-esteem and symptoms of depression in children with seizures: relationships with neuropsychological functioning and family variables over time.

PURPOSE: To test over time the relationships of neuropsychological functioning to mental health in children following a first recognized seizure and, of primary importance, to determine if the strength of these relationships differs based on risk and protective factors. METHODS: In a larger prospective study, 135 children with a first seizure (ages 8-14 years) and 73 healthy sibling controls completed neuropsychological testing at baseline and 36 months. Structured telephone interviews were used to obtain data from children on mental health and family environment; major caregiving parents provided data on demographic and family variables. Data analyses included correlation coefficients and linear regression models. RESULTS: Children with seizures showed an overall trend for improvement in mental health. More children with seizures than siblings had declines in processing speed. Declines in neuropsychological functioning were correlated with worse mental health. With regard to risk and protective factors, higher parent education protected against decline in self-esteem related to decline in processing speed. Better family functioning and greater parental support protected against decline in self-esteem related to decrease in verbal memory and learning. Older child age protected against increase in depressive symptoms related to decline in processing speed. DISCUSSION: Seizure onset had a negative impact on mental health in children with declines in cognitive functioning except for older children and those with more family resources. Children should be assessed for declines in processing speed and, if found, those subgroups of children with less educated or more anxious parents and those in less supportive families should be targeted for interventions.

The effect of temperament and neuropsychological functioning on behavior problems in children with new-onset seizures.

The present study is part of a larger project that seeks to identify factors that predict children's behavioral, social, and cognitive adaptation to epilepsy. Children with seizures are more likely to have internalizing and externalizing behavior problems than either healthy children or children with other chronic illnesses. The present research examines risk factors for behavior problems. Early temperament and neuropsychological functioning, specifically executive function and language abilities, are evaluated as unique and moderating predictors of adverse behavioral outcomes in 229 children with a first recognized seizure. Parents assessed temperament, children were administered neuropsychological tests, and teachers evaluated behavior 36 months after seizure onset. Results revealed that early temperament and neuropsychological functioning, specifically executive function, predicted behavioral outcomes 3 years after seizure onset.

Megalencephalic leukoencephalopathy with subcortical cysts: a third confirmed case with literature review.

Megalencephalic leukoencephalopathy with subcortical cysts (MLC) causes early-onset, slowly progressive central nervous system white matter disease, macrocephaly, and later cognitive and motor decline. We describe brain structure in a patient with MLC and proven MLC1 mutations. A male, normal at birth, had macrocephaly at 6 months followed by developmental delay. Magnetic resonance imaging showed extensive signal abnormality in cerebral white matter and subcortical progressive cystic changes in the bilateral temporal and right frontal areas. Biopsy of frontal gyrus at age 15 months showed normal gray matter. The subcortical white matter was pale due to prominent fine uniform 2- to 4-mu-thick vacuoles with a few interspersed myelinated axons and rare microglia. The vacuoles had a single-, double-, or, rarely, triple-unit membrane (resembling myelin) and contained occasional organelles but no intermediate filaments. Both normal myelinated and thinly myelinated axons were observed. The outer and occasionally the inner layers of myelin surrounding intact axons formed blebs that may represent a source for vacuoles. Genetic analysis identified 2 heterozygous mutations of intron 3 (c.322-1 G>A) and intron 7 (c.597+1G>A), the 1st leading to deletion of amino acids 60 to 89 and the 2nd to deletion of amino acids 194 to 199. Fine uniform vacuolation of white matter with wide separation of myelinated axons is the hallmark of MLC in early childhood.

Magnetic resonance imaging findings in children with a first recognized seizure.

This study characterized structural abnormalities associated with onset of seizures in children, using magnetic resonance imaging and a standardized classification system in a large prospective cohort. Two hundred eighty-one children aged 6-14 years completed magnetic resonance imaging within 6 months of their first recognized seizure. Most examinations were performed with a standardized, dedicated seizure protocol; all were scored using a standard scoring system. At least one magnetic resonance imaging abnormality was identified in 87 of 281 (31%) children with a first recognized seizure. Two or more abnormalities were identified in 34 (12%). The commonest abnormalities were ventricular enlargement (51%), leukomalacia/gliosis (23%), gray-matter lesions such as heterotopias and cortical dysplasia (12%), volume loss (12%), other white-matter lesions (9%), and encephalomalacia (6%). Abnormalities defined as significant, or potentially related to seizures, occurred in 40 (14%). Temporal lobe and hippocampal abnormalities were detected at a higher frequency than in previous studies (13/87). Magnetic resonance imaging and a standardized, reliable, valid scoring system demonstrated a higher rate of abnormal findings than previously reported, including findings formerly considered incidental. Practice parameters may need revision, to expand the definition of significant abnormalities and support wider use of magnetic resonance imaging in children with newly diagnosed seizures.

The relationship between sleep problems and neuropsychological functioning in children with first recognized seizures.

Epilepsy is associated with sleep disturbance, but little is known about how early this relationship develops and how it affects neuropsychological functioning. This study documented the frequency and types of sleep problems and examined how sleep problems are associated with seizures and neuropsychological functioning in 332 children following their first recognized seizure (ages 6-14) and in 225 sibling controls. Formal neuropsychological batteries were administered to all subjects. Sleep was measured using the Sleep Behavior Questionnaire and the Child Behavior Checklist. Sleep problems were more frequent in the seizure sample relative to siblings and previously published norms; bedtime difficulties, daytime somnolence, and parasomnias were the most frequently occurring sleep problems. In the seizure group, sleep problems were related to seizure parameters and to neuropsychological functioning. Seizure patients with significant sleep problems had worse neuropsychological functioning on all measures. Findings demonstrate the significant impact of sleep disturbance on children with newly recognized seizures.

Seizure recurrence risk following a first seizure in neurologically normal children.

PURPOSE: To define seizure recurrence rates in normal children who had had a single seizure and to define electroencephalography (EEG) or magnetic resonance imaging (MRI) utility in predicting seizure recurrence. METHODS: We studied 150 children (6 to 14 years) with a first afebrile, unprovoked seizure. Inclusion criteria were: Normal physical and neurological examination, undergone EEG and MRI studies of the brain, and followed for at least 27 months. These children participated in an ongoing prospective study of new onset seizures in childhood. RESULTS: The seizure recurrence rate was 66.4%. An abnormal EEG had no association with seizure recurrence at 9, 18, or 27 months (p = 0.1806, p = 0.2792, and p = 0.2379, respectively). A "significant" MRI abnormality, which occurred in 16.0% of patients, was associated with an increased seizure recurrence risk at 9 months (p = 0.0389) but not at 18 or 27 months. DISCUSSION: EEG findings poorly predict recurrence after a single seizure. The high rate of MRI abnormalities suggests that MRI may need consideration as a routine test to evaluate epilepsy in normal children.

The association of MRI findings and neuropsychological functioning after the first recognized seizure.

PURPOSE: To explore relationships between MRI abnormalities of the brain and neuropsychological functioning in children who were evaluated following their first recognized seizure. METHODS: Subjects were children aged 6 to 14 years with a first recognized seizure within the past 3 months who participated in a larger prospective study of child adaptation. The 249 children with neuropsychological testing and neuroimaging were studied. Children underwent neuropsychological examination an average of 2.8 months and MRI examination an average of 1.3 months after the first recognized seizure. On factor analysis four factors were found for neuropsychological function: LANG = Language, PS = Processing Speed, EC = Executive/ Construction, VMEM = Verbal Memory and Learning. For analysis, structural abnormalities found on MRI were classified as significant (yes/no) based on whether they were presumed to be related to the seizure condition. RESULTS: On MRI, 34 (14%) had structural abnormalities that were judged to be significant in that they were possibly related to their seizures. Children with significant abnormalities had significantly lower estimated IQ scores and significantly lower language, processing speed, executive/constructional ability, and verbal memory and learning factor scores than did children without significant abnormalities. CONCLUSIONS: Children who have structural brain abnormalities at onset have slightly lower cognitive functioning overall, and all neuropsychological domains seemed to be affected relatively equally. This pattern was apparent even when we restricted the analysis to children with intellectual functioning in the broadly normal range.

Functional characterization of missense variants in the creatine transporter gene (SLC6A8): improved diagnostic application.

Creatine transporter deficiency is an X-linked mental retardation disorder caused by mutations in the creatine transporter gene (SLC6A8). So far, 20 mutations in the SLC6A8 gene have been described. We have developed a diagnostic assay to test creatine uptake in fibroblasts. Additionally, we expanded the assay to characterize novel SLC6A8 missense variants. A total of 13 variants were introduced in the SLC6A8 cDNA by site-directed mutagenesis. All variants were transiently transfected in SLC6A8-deficient fibroblasts and tested for restoration of creatine uptake in deficient primary fibroblasts. Thus, we proved that nine variants (p.Gly87Arg, p.Phe107del, p.Tyr317X, p.Asn336del, p.Cys337Trp, p.Ile347del, p.Pro390Leu, p.Arg391Trp, and p.Pro554Leu) are pathogenic mutations and four variants (p.Lys4Arg, p.Gly26Arg, p.Met560Val, and p.Val629Ile) are nonpathogenic. The present study provides an improved diagnostic tool to classify sequence variants of unknown significance.

Temperament, family environment, and behavior problems in children with new-onset seizures.

Children with epilepsy, even those with new-onset seizures, exhibit relatively high rates of behavior problems. The purpose of this study was to explore the relationships among early temperament, family adaptive resources, and behavior problems in children with new-onset seizures. Our major goal was to test whether family adaptive resources moderated the relationship between early temperament dimensions and current behavior problems in 287 children with new-onset seizures. Two of the three temperament dimensions (difficultness and resistance to control) were positively correlated with total, internalizing, and externalizing behavior problems (all P<0.0001). The third temperament dimension, unadaptability, was positively correlated with total and internalizing problems (P<0.01). Family adaptive resources moderated the relationships between temperament and internalizing and externalizing behavior problems at school. Children with a difficult early temperament who live in a family environment with low family mastery are at the greatest risk for behavior problems.

Magnetic resonance imaging (MRI) and electroencephalographic (EEG) findings in a cohort of normal children with newly diagnosed seizures.

In the initial assessment of children with new-onset seizures, the suggestion that electroencephalography (EEG) should be standard and that magnetic resonance imaging (MRI) should be optional has been questioned. The purposes of this study were to (1) describe the frequency of EEG and MRI abnormalities and (2) explore relationships between MRI and EEG findings to determine their relevance in the assessment of children with new-onset seizures who are otherwise developing normally. As part of an ongoing, prospective study of children with new-onset seizures, we studied 181 children (90 girls and 91 boys). Children were entered into the study within 3 months of their first-recognized seizure. The association between EEG and MRI abnormalities was explored using a chi-square test. Abnormal MRI findings were found in 32.6% (n = 59) of the sample. The EEG and MRI results agreed with respect to classification into normal or abnormal in 37% (n = 67). Of the 50 children with a normal EEG, however, 21 (42%) were found to have an abnormal MRI. We found an unexpectedly high frequency of imaging abnormalities in our sample of otherwise normal children, although the significance of these findings is not clear. Follow-up of these patients will help us interpret the importance of the abnormalities. Despite our relatively small sample, however, our findings indicate that a normal EEG does not reliably predict a normal MRI in children with first seizures.

Overexpression of wild-type creatine transporter (SLC6A8) restores creatine uptake in primary SLC6A8-deficient fibroblasts.

In the study reported, we prove that mutations in the SLC6A8 gene are responsible for SLC6A8 deficiency, a cerebral creatine deficiency syndrome (CCDS), since overexpression of the wild-type SLC6A8 open reading frame (ORF) restores the creatine uptake profile in SLC6A8-deficient fibroblasts.

Comprehensive mutation analysis of GLDC, AMT, and GCSH in nonketotic hyperglycinemia.

Nonketotic hyperglycinemia (NKH) is an inborn error of metabolism characterized by accumulation of glycine in body fluids and various neurological symptoms. NKH is caused by deficiency of the glycine cleavage multi-enzyme system with three specific components encoded by GLDC, AMT, and GCSH. We undertook the first comprehensive screening for GLDC, AMT, and GCSH mutations in 69 families (56, six, and seven families with neonatal, infantile, and late-onset type NKH, respectively). GLDC or AMT mutations were identified in 75% of neonatal and 83% of infantile families, but not in late-onset type NKH. No GCSH mutation was identified in this study. GLDC mutations were identified in 36 families, and AMT mutations were detected in 11 families. In 16 of the 36 families with GLDC mutations, mutations were identified in only one allele despite sequencing of the entire coding regions. The GLDC gene consists of 25 exons. Seven of the 32 GLDC missense mutations were clustered in exon 19, which encodes the cofactor-binding site Lys754. A large deletion involving exon 1 of the GLDC gene was found in Caucasian, Oriental, and black families. Multiple origins of the exon 1 deletion were suggested by haplotype analysis with four GLDC polymorphisms. This study provides a comprehensive picture of the genetic background of NKH as it is known to date.

Stability of salivary concentrations of the newer antiepileptic drugs in the postal system.

Saliva antiepileptic drug (AED) concentrations strongly correlate with serum concentrations. Saliva collection is painless and noninvasive, and untrained personnel can easily be taught the collection process. Remote patients could mail saliva samples to a laboratory for monitoring, and samples could be obtained in the immediate postictal state to provide a "real-time" concentration. The objectives of this study were to assess the stability of saliva lamotrigine (LMT), levetiracetam (LEV), oxcarbazepine (OXC), topiramate (TPM), and zonsiamide (ZNS) concentrations sent through the United States Postal Service (USPS) and to quantify the amount of time needed for patients and the USPS to return samples to clinic. Saliva samples were obtained from patients currently taking 1 of the targeted AEDs. Samples were split into 2 storage vials. One sample was sealed in an addressed envelope, which the patient mailed from home, whereas the other sample was frozen immediately. Postmark date and day returned were collected for mailed samples. Saliva concentrations were determined using HPLC. Wilcoxon rank sum tests were used to compare the immediately-frozen and mailed sample means. Correlations were determined by the Spearman test. Thirty-seven patients were enrolled in the study. The median time between collection and postmark was 1 day (range 0-6 days); and between collection and receipt was 4 days (range 1-160 days). The mean concentrations for mailed and immediately frozen samples were similar for each AED (P > 0.15). Spearman rank order correlations between mailed and immediately frozen aliquots were strong (LMT rs = 1, LEV rs = 1, OXC rs = 0.964, TPM rs = 0.90, and ZNS rs = 1). Saliva samples mailed by patients maintain stability and can be returned in a reasonable length of time. Further studies are needed to assess patient/caretaker capability of obtaining an adequate sample.

Incidence of brain creatine transporter deficiency in males with developmental delay referred for brain magnetic resonance imaging.

Several case reports describe children with global developmental delay who have brain creatine deficiency, where the deficiency was due to a lack of creatine transport into the brain or altered creatine synthesis. The purpose of this study was to determine what percentage of males with developmental delay referred for brain magnetic resonance imaging (MRI) at the authors' institution in a 12-month period was found to have brain creatine deficiency due to a defect in the creatine transporter gene. In the authors' facility, single voxel proton magnetic resonance spectroscopy (MRS) is routinely performed on any male child age 2 to 18 years with a history of language and/or developmental delay referred for a brain MRI. Charts for the 12-month time period were retrospectively reviewed. Fourteen subjects met inclusion criteria for global developmental delay. Two of the 14 patients had brain creatine deficiency on MRS. In the remaining 12, other structural and white matter abnormalities were identified. This study suggests that brain creatine deficiency is an important consideration in the differential diagnosis of males with global developmental delay referred for brain MRI; brain MRS should be considered in such cases.