Conventional MRI scan and DTI imaging show more severe brain injury in neonates with hypoxic-ischemic encephalopathy and seizures

BACKGROUND

Neonates with hypoxic-ischemic encephalopathy (HIE) and seizures have poorer outcome for undetermined reasons.

AIMS

Our aim was to determine if brain imaging was more abnormal in neonates with HIE and electrographically confirmed seizures and whether this was impacted by seizure burden.

STUDY DESIGN

Single center retrospective review.

SUBJECTS

Forty-eight term neonates with HIE (with and without seizures) underwent MRI brain scans before age 14 days between the years 2008 and 2013.

OUTCOME MEASURES

Images were rated using a MRI injury score and fractional anisotropy (FA) values were extracted from diffusion tensor imaging (DTI).

RESULTS

The seizure group (n = 25) had significantly more injury within white matter, basal ganglia, posterior limb of internal capsule, and watershed areas compared to the group without seizures (n = 23). The severity of injury in all measured areas increased with increasing seizure severity. The seizure group also had lower FA values in posterior limb of the internal capsule and the splenium of corpus callosum.

CONCLUSIONS

Neonates with HIE and seizures had more brain injury that occurred in areas typically affected by HIE and was greater with higher seizure burden. Seizures may be a marker of more severe brain injury or seizures themselves may amplify brain damage from HIE.

Electrocorticographic high-gamma modulation with passive listening paradigm for pediatric extraoperative language mapping

OBJECTIVE

This prospective study compared the topography of high-gamma modulation (HGM) during a story-listening task requiring negligible patient cooperation, with the conventional electrical stimulation mapping (ESM) using a picture-naming task, for presurgical language localization in pediatric drug-resistant epilepsy.

METHODS

Patients undergoing extraoperative monitoring with subdural electrodes were included. Electrocorticographic signals were recorded during quiet baseline and a story-listening task. The likelihood of 70- to 150-Hz power modulation during the listening task relative to the baseline was estimated for each electrode and plotted on a cortical surface model. Sensitivity, specificity, accuracy, and diagnostic odds ratio (DOR) were estimated compared to ESM, using a meta-analytic framework.

RESULTS

Nineteen patients (10 with left hemisphere electrodes) aged 4-19 years were analyzed. HGM during story listening was observed in bilateral posterior superior temporal, angular, supramarginal, and inferior frontal gyri, along with anatomically defined language association areas. Compared to either cognitive or both cognitive and orofacial sensorimotor interference with naming during ESM, left hemisphere HGM showed high specificity (0.82-0.84), good accuracy (0.66-0.70), and DOR of 2.23 and 3.24, respectively. HGM was a better classifier of ESM language sites in the left temporoparietal cortex compared to the frontal lobe. Incorporating visual naming with the story-listening task substantially improved the accuracy (0.80) and DOR (13.61) of HGM mapping, while the high specificity (0.85) was retained. In the right hemisphere, no ESM sites for aphasia were seen, and the results of HGM and ESM comparisons were not significant.

SIGNIFICANCE

HGM associated with story listening is a specific determinant of left hemisphere ESM language sites. It can be used for presurgical language mapping in children who cannot cooperate with conventional language tasks requiring active engagement. Incorporation of additional language tasks, if feasible, can further improve the diagnostic accuracy of language localization with HGM.

Online Transcranial Magnetic Stimulation Protocol for Measuring Cortical Physiology Associated with Response Inhibition

We describe the development of a reproducible, child-friendly motor response inhibition task suitable for online Transcranial Magnetic Stimulation (TMS) characterization of primary motor cortex (M1) excitability and inhibition. Motor response inhibition prevents unwanted actions and is abnormal in several neuropsychiatric conditions. TMS is a non-invasive technology that can quantify M1 excitability and inhibition using single- and paired-pulse protocols and can be precisely timed to study cortical physiology with high temporal resolution. We modified the original Slater-Hammel (S-H) stop signal task to create a "racecar" version with TMS pulses time-locked to intra-trial events. This task is self-paced, with each trial initiating after a button push to move the racecar towards the 800 ms target. GO trials require a finger-lift to stop the racecar just before this target. Interspersed randomly are STOP trials (25%) during which the dynamically adjusted stop signal prompts subjects to prevent finger-lift. For GO trials, TMS pulses were delivered at 650 ms after trial onset; whereas, for STOP trials, the TMS pulses occurred 150 ms after the stop signal. The timings of the TMS pulses were decided based on electroencephalography (EEG) studies showing event-related changes in these time ranges during stop signal tasks. This task was studied in 3 blocks at two study sites (n=38) and we recorded behavioral performance and event-related motor-evoked potentials (MEP). Regression modelling was used to analyze MEP amplitudes using age as a covariate with multiple independent variables (sex, study site, block, TMS pulse condition [single- vs. paired-pulse], trial condition [GO, successful STOP, failed STOP]). The analysis showed that TMS pulse condition (p<0.0001) and its interaction with trial condition (p=0.009) were significant. Future applications for this online S-H/TMS paradigm include the addition of simultaneous EEG acquisition to measure TMS-evoked EEG potentials. A potential limitation is that in children, the TMS pulse sound could affect behavioral task performance.

Fosphenytoin pre-medication for pediatric extra-operative electrical stimulation brain mapping

PURPOSE

We studied the effect of fosphenytoin (FOS) pre-medication on the incidence and thresholds of after-discharges (ADs), seizures, and functional responses during electrical stimulation mapping (ESM).

METHODS

As individualized by the attending epileptologist, FOS was given intravenously at 2 mg-phenytoin-equivalents (PE)/kg/min or 150 mg-PE/min (whichever slower). Patients who received and did not receive FOS were compared for the incidence and thresholds of ADs, seizures, and functional responses.

RESULTS

Before ESM, 40 and 82 patients respectively were pre-medicated/not pre-medicated with FOS. The incidence of ESM-induced seizures was significantly lower in FOS pre-medicated patients (22.5% vs. 42.7%, p = 0.044), whereas temporal language threshold was higher (9.2 vs. 6.5 mA, p = 0.032). FOS was more efficacious in preventing ESM-induced seizures in patients with symptomatogenic zone ipsilateral to the side of ESM. Although FOS dose had no significant effect on minimum language, minimum motor, or AD thresholds; seizure and temporal language thresholds showed trends approaching significance, intersecting at 12.2 mg-PE/kg. The incidence of ESM-induced seizures was significantly lower in those who received FOS at a dose of ≤12 mg/kg (9.1%) compared to those who did not receive any FOS (42.7%, p = 0.046), while the temporal language thresholds were not significantly different (6.3 vs. 6.5 mA, p = 0.897).

CONCLUSIONS

This study provides class III evidence that FOS pre-medication before ESM decreases the incidence of ESM-induced seizures, but increases temporal language threshold. FOS pre-medication may thus be considered before ESM. Future studies should prospectively verify these observations and characterize dose-response relationships.

The Diagnostic Accuracy of Video Electroencephalography Without Event Capture

OBJECTIVE

The aim of this study was to quantify the accuracy of 24-hour video electroencephalography (vEEG) for the diagnosis of epilepsy when a patient's typical paroxysmal event was not captured (no-event vEEG).

METHODS

We performed a retrospective chart review of all first-time 24 hour no-event vEEG studies at Cincinnati Children's Hospital Medical Center. Clinician diagnosis of epilepsy with a minimum of one year follow-up was used as the reference standard to calculate diagnostic accuracy. Sensitivity and specificity of routine EEG (rEEG) and vEEG were compared in patients with both studies, and factors affecting the accuracy of vEEG were explored with a multivariable analysis.

RESULTS

No-event vEEG showed sensitivity of 0.54 (95% confidence interval [CI] 0.44 to 0.64) and specificity of 0.88 (95% CI 0.84 to 0.92) respectively, with a diagnostic odds ratio of 7.53 (95% CI 4.45 to 12.76). The sensitivity of vEEG was statistically superior to that of rEEG, whereas specificity was comparable. Age emerged as the only factor that affected the diagnostic accuracy of no-event vEEG.

CONCLUSION

Even in the absence of a typical seizure or spell, video EEG is a useful test for predicting or excluding epilepsy, with diagnostic accuracy that is superior to rEEG and unaffected by the presence of a chronic neurological condition.

Utility of the Autism Observation Scale for Infants in Early Identification of Autism in Tuberous Sclerosis Complex

BACKGROUND

Tuberous sclerosis complex (TSC) is a genetic disorder with high prevalence of associated autism spectrum disorder (ASD). Our primary objectives were to determine early predictors of autism risk to identify children with TSC in most need of early interventions. The Autism Observation Scale for Infants (AOSI) was evaluated as a measure of ASD-associated behaviors in infants with TSC at age 12 months and its ability to predict ASD at 24 months.

METHODS

Children ages 0 to 36 months with TSC were enrolled in the TSC Autism Center of Excellence Research Network (TACERN), a multicenter, prospective observational study to identify biomarkers of ASD. The AOSI was administered at age 12 months and the Autism Diagnostic Observation Schedule-2 (ADOS-2) and Autism Diagnostic Interview-Revised (ADI-R) at 24 months. Developmental functioning was assessed using the Mullen Scales of Early Learning. Children were classified as ASD or non-ASD according to the ADOS-2.

RESULTS

Analysis included 79 children who had been administered the AOSI at 12 months and ADOS-2 and ADI-R at 24 months. The ASD group had a mean AOSI total score at 12 months significantly higher than the non-ASD group (11.8 ± 7.4 vs 6.3 ± 4.7; P < 0.001). An AOSI total score cutoff of 13 provided a specificity of 0.89 to detect ASD with the ADOS-2. AOSI total score at 12 months was similarly associated with exceeding cutoff scores on the ADI-R.

CONCLUSIONS

The AOSI is a useful clinical tool in determining which infants with TSC are at increased risk for developing ASD.

Language and motor function thresholds during pediatric extra-operative electrical cortical stimulation brain mapping

OBJECTIVE

To examine current thresholds and their determinants for language and motor mapping with extra-operative electrical cortical stimulation (ECS).

METHODS

ECS electrocorticograph recordings were reviewed to determine functional thresholds. Predictors of functional thresholds were found with multivariable analyses.

RESULTS

In 122 patients (age 11.9±5.4years), average minimum, frontal, and temporal language thresholds were 7.4 (± 3.0), 7.8 (± 3.0), and 7.4 (± 3.1) mA respectively. Average minimum, face, upper and lower extremity motor thresholds were 5.4 (± 2.8), 6.1 (± 2.8), 4.9 (± 2.3), and 5.3 (± 3.3) mA respectively. Functional and after-discharge (AD)/seizure thresholds were significantly related. Minimum, frontal, and temporal language thresholds were higher than AD thresholds at all ages. Minimum motor threshold was higher than minimum AD threshold up to 8.0years of age, face motor threshold was higher than frontal AD threshold up to 11.8years age, and lower subsequently. UE motor thresholds remained below frontal AD thresholds throughout the age range.

CONCLUSIONS

Functional thresholds are frequently above AD thresholds in younger children.

SIGNIFICANCE

These findings raise concerns about safety and neurophysiologic validity of ECS mapping. Functional and AD/seizure thresholds relationships suggest individual differences in cortical excitability which cannot be explained by clinical variables.

After-discharges and seizures during pediatric extra-operative electrical cortical stimulation functional brain mapping: Incidence, thresholds, and determinants

OBJECTIVE

This study examined the incidence, thresholds, and determinants of electrical cortical stimulation (ECS)-induced after-discharges (ADs) and seizures.

METHODS

Electrocorticograph recordings were reviewed to determine incidence of ECS-induced ADs and seizures. Multivariable analyses for predictors of AD/seizure occurrence and their thresholds were performed.

RESULTS

In 122 patients, the incidence of ADs and seizures was 77% (94/122) and 35% (43/122) respectively. Males (odds ratio [OR] 2.92, 95% CI 1.21-7.38, p=0.02) and MRI-negative patients (OR 3.69, 95% CI 1.24-13.7, p=0.03) were found to have higher odds of ECS-induced ADs. A significant trend for decreasing AD thresholds with age was seen (regression co-efficient -0.151, 95% CI -0.267 to -0.035, p=0.011). ECS-induced seizures were more likely in patients with lateralized functional imaging (OR 6.62, 95% CI 1.36-55.56, p=0.036, for positron emission tomography) and presence of ADs (OR 3.50, 95% CI 1.12-13.36, p=0.043).

CONCLUSIONS

ECS is associated with a high incidence of ADs and seizures. With age, current thresholds decrease and the probability for AD/seizure occurrence increases.

SIGNIFICANCE

ADs and seizures during ECS brain mapping are potentially hazardous and affect its functional validity. Thus, safer method(s) for brain mapping with improved neurophysiologic validity are desirable.

Parent and Patient Perceptions of Functional Impairment Due to Tourette Syndrome: Development of a Shortened Version of the Child Tourette Syndrome Impairment Scale

The Child Tourette Syndrome Impairment Scale (CTIM) rates 37 problems in school, social, and home domains separately for tics and for comorbid diagnoses. However, a shorter version would be easier to implement in busy clinics. Using published data from 85 children with Tourette syndrome, 92 controls, and parents, factor analysis was used to generate a "mini-CTIM" composed of 12 items applied to tic and comorbid diagnoses. Child- and parent-rated mini-CTIM scores were compared and correlated across raters and accounting for clinician-rated tic severity and presence of attention-deficit hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD). The mini-CTIM achieved domain Cronbach alphas ranging from 0.71 to 0.94 and intra-item correlation coefficients ranging from 0.84 to 0.96. The resulting scale correlated with clinician-rated tic severity and reflected the presence of ADHD and OCD. The mini-CTIM appears promising as a practical assessment tool for tic- and non-tic-related impairment in children with Tourette syndrome.

Comparison and optimization of in silico algorithms for predicting the pathogenicity of sodium channel variants in epilepsy

OBJECTIVE

Variants in neuronal voltage-gated sodium channel α-subunits genes SCN1A, SCN2A, and SCN8A are common in early onset epileptic encephalopathies and other autosomal dominant childhood epilepsy syndromes. However, in clinical practice, missense variants are often classified as variants of uncertain significance when missense variants are identified but heritability cannot be determined. Genetic testing reports often include results of computational tests to estimate pathogenicity and the frequency of that variant in population-based databases. The objective of this work was to enhance clinicians' understanding of results by (1) determining how effectively computational algorithms predict epileptogenicity of sodium channel (SCN) missense variants; (2) optimizing their predictive capabilities; and (3) determining if epilepsy-associated SCN variants are present in population-based databases. This will help clinicians better understand the results of indeterminate SCN test results in people with epilepsy.

METHODS

Pathogenic, likely pathogenic, and benign variants in SCNs were identified using databases of sodium channel variants. Benign variants were also identified from population-based databases. Eight algorithms commonly used to predict pathogenicity were compared. In addition, logistic regression was used to determine if a combination of algorithms could better predict pathogenicity.

RESULTS

Based on American College of Medical Genetic Criteria, 440 variants were classified as pathogenic or likely pathogenic and 84 were classified as benign or likely benign. Twenty-eight variants previously associated with epilepsy were present in population-based gene databases. The output provided by most computational algorithms had a high sensitivity but low specificity with an accuracy of 0.52-0.77. Accuracy could be improved by adjusting the threshold for pathogenicity. Using this adjustment, the Mendelian Clinically Applicable Pathogenicity (M-CAP) algorithm had an accuracy of 0.90 and a combination of algorithms increased the accuracy to 0.92.

SIGNIFICANCE

Potentially pathogenic variants are present in population-based sources. Most computational algorithms overestimate pathogenicity; however, a weighted combination of several algorithms increased classification accuracy to >0.90.

Pediatric Epilepsy Surgery: The Prognostic Value of Central Nervous System Comorbidities in Patients and their Families

Central nervous system comorbidities have been identified in patients with epilepsy. Several of these comorbidities have been correlated with poor surgery outcomes in patient cohorts. The authors sought to determine if prevalence of comorbidities in pediatric epilepsy surgery patients and their families correlate with long-term seizure outcome in a cross-sectional analysis. Three-generation pedigrees were elicited to compare family history of epilepsy, ADHD, anxiety, autism, bipolar disorder, cognitive disability, depression, migraine, and motor disability to surgery outcomes in 52 patients. Proportions of affected patients and relatives were compared to general population comorbidity rates and the patients' most recent seizure outcome classification. Patients and families had significantly higher rates of comorbidities than the general population. Poorer long-term seizure outcomes following resective surgery were associated with autism or cognitive disability in patients. Together these data support evidence for a common pathophysiological mechanism between epilepsy and central nervous system comorbidities.

Epilepsy prevalence and severity predictors in MRI-identified focal cortical dysplasia

OBJECTIVES

To determine the prevalence of epilepsy and drug-resistant epilepsy in pediatric patients with focal cortical dysplasia (FCD) identified by magnetic resonance imaging (MRI). To determine clinical and imaging differences between those with drug-resistant epilepsy, drug-responsive epilepsy, and no epilepsy among children with MRI-identified FCD.

METHODS

A keyword search of a hospital radiology database identified 97 study participants for inclusion in this retrospective study. Participants were included if they were under 18 years of age at time of database query and had an MRI between 2004 and 2013 showing FCD. Exclusion was based on imaging and clinical characteristics. Data was gathered using a chart review and supplemental questionnaire.

RESULTS

In this cohort of patients with imaging findings compatible with FCD, 29% had not developed epilepsy. The prevalence of epilepsy and drug-resistant epilepsy was 71.13% (95% C.I.=61.05-79.89%) and 32.99% (95% C.I.=23.78-43.27%), respectively. Patients with epilepsy were more likely to have temporal (p=0.029) or frontal (p=0.044) lobe lesions and a family history of seizures (p=0.003) than those without epilepsy. Age of seizure onset was later in those with drug-responsive epilepsy than those with drug-resistant epilepsy (p=0.0002). A later age of seizure onset (OR=1.22, p=0.0441, 95% C.I.=1.00-1.486) and absence of developmental delay (OR=3.624, p=0.0497, 95% C.I.=1.002-13.110) predicted a less severe epilepsy phenotype.

CONCLUSIONS

Previous studies have only assessed patient cohorts with FCD and epilepsy, limiting the data on "asymptomatic" or "atypically presenting" FCD. Identifying a surprisingly large, novel cohort of children with FCD that had not developed epilepsy helps define prognosis and inform clinical management of children with FCD on imaging.

Preliminary evaluation of child self-rating using the Child Tourette Syndrome Impairment Scale

AIM

To evaluate and compare how children with Tourette syndrome and parents rate tic and non-tic behavioral related impairment in home, school, and social domains; to compare these with clinician tic ratings; and to identify factors that may predict greater impairment.

METHOD

In a sample of 85 Tourette syndrome and 92 healthy control families, the Child Tourette Syndrome Impairment Scale, designed for parent-report and which includes 37 items rated for tic and non-tic impairment, was administered to parents and, with the referent modified, to children ages 9 to 17 years. Tic severity was rated using the Yale Global Tic Severity Scale (YGTSS). Analyses utilized descriptive and multivariate statistics.

RESULTS

Tourette syndrome children's and parents' impairment ratings were higher than HC (p<0.001) and correlated moderately (r=0.46 to 0.54; p<0.001). Children's and parents' tic impairment ratings correlated with YGTSS (r=0.36 to 0.37; p<0.001). Parents' average ratings were higher than children's for 19 tic and all 37 non-tic impairment items. For 29 items, children self-rated impairment higher for tics than non-tics. Diagnoses of attention-deficit-hyperactivity disorder and obsessive-compulsive disorder had larger effects on parent impairment ratings.

INTERPRETATION

The Child Tourette Syndrome Impairment Scale appears informative for child self-rating in Tourette syndrome.

Presurgical language localization with visual naming associated ECoG high- gamma modulation in pediatric drug-resistant epilepsy

OBJECTIVE

This prospective study compared presurgical language localization with visual naming-associated high-γ modulation (HGM) and conventional electrical cortical stimulation (ECS) in children with intracranial electrodes.

METHODS

Patients with drug-resistant epilepsy who were undergoing intracranial monitoring were included if able to name pictures. Electrocorticography (ECoG) signals were recorded during picture naming (overt and covert) and quiet baseline. For each electrode the likelihood of high-γ (70-116 Hz) power modulation during naming task relative to the baseline was estimated. Electrodes with significant HGM were plotted on a three-dimensional (3D) cortical surface model. Sensitivity, specificity, and accuracy were calculated compared to clinical ECS.

RESULTS

Seventeen patients with mean age of 11.3 years (range 4-19) were included. In patients with left hemisphere electrodes (n = 10), HGM during overt naming showed high specificity (0.81, 95% confidence interval [CI] 0.78-0.85), and accuracy (0.71, 95% CI 0.66-0.75, p < 0.001), but modest sensitivity (0.47) when ECS interference with naming (aphasia or paraphasic errors) and/or oral motor function was regarded as the gold standard. Similar results were reproduced by comparing covert naming-associated HGM with ECS naming sites. With right hemisphere electrodes (n = 7), no ECS-naming deficits were seen without interference with oral-motor function. HGM mapping showed a high specificity (0.81, 95% CI 0.78-0.84), and accuracy (0.76, 95% CI 0.71-0.81, p = 0.006), but modest sensitivity (0.44) compared to ECS interference with oral-motor function. Naming-associated ECoG HGM was consistently observed over Broca's area (left posterior inferior-frontal gyrus), bilateral oral/facial motor cortex, and sometimes over the temporal pole.

SIGNIFICANCE

This study supports the use of ECoG HGM mapping in children in whom adverse events preclude ECS, or as a screening method to prioritize electrodes for ECS testing.

Multiple Antipsychotic Medication Use in Autism Spectrum Disorder

OBJECTIVE

The purpose of this study was to explore the use of multiple antipsychotic medications in patients with autism spectrum disorder (ASD) by reviewing the longitudinal medication management of 1100 patients consecutively treated for behavioral symptoms associated with ASD at a tertiary care specialty clinic.

METHODS

We identified all patients with ASD treated with daily doses of two or more antipsychotics for at least two visits at our clinic. For each patient meeting inclusion criteria, diagnostic and demographic data were collected. To evaluate clinical need and effectiveness of antipsychotic medications in this sample, we reviewed symptoms targeted with each antipsychotic medication and concomitant medications prescribed. Clinical Global Impressions-Severity (CGI-S) and Clinical Global Impressions-Improvement (CGI-I) scale ratings had been completed at the time of each visit, and the duration of treatment with antipsychotic medications was determined. To evaluate the safety and tolerability of antipsychotic medication use in ASD, we reviewed reported adverse effects and calculated body mass index (BMI) change with treatment.

RESULTS

Seventy patients met the inclusion criteria (6.4% of our sample). The majority of patients were moderately to severely ill Caucasian males, as determined by baseline mean CGI-S of 4.7 (SD = 0.8), and were diagnosed with autistic disorder and comorbid intellectual disability. The mean age was 15.1 years (SD = 10.9), the primary targeted symptoms were agitation/irritability, physical aggression, and self-injury. The majority of patients remained on two or more antipsychotics for >1 year. In this population, patients demonstrated greater symptomatic improvement and generally tolerated treatment without significant adverse effects.

CONCLUSIONS

The use of two or more antipsychotic medications may be increasingly common in patients with ASD. This retrospective study demonstrates that this treatment approach may be of some clinical benefit, and is generally well tolerated. Prospective studies focusing on the efficacy and safety of concomitant antipsychotic medication usage in ASD should be considered.

d-Cycloserine enhances durability of social skills training in autism spectrum disorder

BACKGROUND

d-Cycloserine (DCS) enhances extinction learning across species, but it has proven challenging to identify consistent benefit of DCS when added to therapeutic interventions. We conducted a placebo-controlled trial of DCS to potentiate social skills training in autism spectrum disorder (ASD) but found substantial improvement in both the DCS and placebo groups at the conclusion of active treatment. Here, we assess the impact of DCS 11 weeks following active treatment to evaluate the impact of DCS on treatment response durability.

METHODS

Study participants included 60 outpatient youth with ASD, ages 5-11 years, all with IQ above 70, and significantly impaired social functioning who completed a 10-week active treatment phase during which they received weekly single doses of 50 mg of DCS or placebo administered 30 min prior to group social skills training. Following the 10-week active treatment phase, blinded follow-up assessments occurred at week 11 and week 22. The primary outcome measure for our durability of treatment evaluation was the parent-rated social responsiveness scale (SRS) total raw score at week 22.

RESULTS

Analysis of the SRS total raw score demonstrated significant decrease for the DCS group compared to the placebo group (p = 0.042) indicating greater maintenance of treatment effect in the DCS group. DCS was well tolerated, with irritability being the most frequently reported adverse effect in both groups.

CONCLUSIONS

The findings of this study suggest that DCS may help youth with ASD to maintain skills gained during sort-term social skills training. Larger-scale studies with longer follow-up will be necessary to further understand the long-term impact of DCS paired with structured social skills training.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01086475.

Child Neurology Recruitment and Training: Views of Residents and Child Neurologists From the 2015 AAP/CNS Workforce Survey

BACKGROUND

To assess and compare resident and practicing child neurologists' attitudes regarding recruitment and residency training in child neurology.

METHODS

A joint task force of the American Academy of Pediatrics and the Child Neurology Society conducted an electronic survey of child neurology residents (n = 305), practicing child neurologists (n = 1290), and neurodevelopmental disabilities specialists (n = 30) in 2015. Descriptive and multivariate analyses were performed.

RESULTS

Response rates were 32% for residents (n = 97; 36% male; 65% Caucasian) and 40% for practitioners (n = 523; 63% male; 80% Caucasian; 30% lifetime certification). Regarding recruitment, 70% (n = 372) attributed difficulties recruiting medical students to insufficient early exposure. Although 68% (n = 364) reported that their medical school required a neurology clerkship, just 28% (n = 152) reported a child neurology component. Regarding residency curriculum, respondents supported increased training emphasis for genetics, neurodevelopmental disabilities, and multiple other subspecialty areas. Major changes in board certification requirements were supported, with 73% (n = 363) favoring reduced adult neurology training (strongest predictors: fewer years since medical school P = 0.003; and among practicing child neurologists, working more half-day clinics per week P = 0.005). Furthermore, 58% (n = 289) favored an option to reduce total training to 4 years, with 1 year of general pediatrics. Eighty-two percent (n = 448) would definitely or probably choose child neurology again.

CONCLUSIONS

These findings provide support for recruitment efforts emphasizing early exposure of medical students to child neurology. Increased subspecialty exposure and an option for major changes in board certification requirements are favored by a significant number of respondents.

Drug-resistant epilepsy in children with partial onset epilepsy treated with carbamazepine

OBJECTIVE

To evaluate the outcome, including drug-resistant epilepsy (DRE) in children with newly diagnosed partial onset epilepsy treated with carbamazepine (CBZ).

METHODS

A retrospective medical records review and telephone questionnaire were undertaken on a total of 100 subjects.

RESULTS

Long-term follow-up was obtained on 79 children with a mean duration of 7.1 years from CBZ initiation. A total of 66 (83.5%) subjects achieved 2-year seizure remission, 48 (72.7%) subjects did so with CBZ monotherapy. Seven (10.6%) had seizure recurrence after 2-year seizure remission. DRE was diagnosed in seven (8.9%) subjects and five subjects had epilepsy surgery. The mean duration from seizure onset to epilepsy surgery was 5.3 (±2.1) years. Contributing factors for the prolonged duration from seizure onset to epilepsy surgery were identified including: relapsing-remitting course of seizure, family reluctance for epilepsy surgery and uncontrolled psychological problems.

CONCLUSIONS

Over 80% of children with newly diagnosed partial onset epilepsy who were initially treated with CBZ achieved 2-year seizure remission, and more than 70% of this group did so with CBZ monotherapy. The majority of these patients maintained seizure remission overtime. However, 8.9% of this population met the criteria for DRE and most of them had epilepsy surgery. The duration from seizure onset to epilepsy surgery is an important potential area for improvement in DRE patient care.

Weight Gain Effects of Second-Generation Antipsychotic Treatment in Autism Spectrum Disorder

OBJECTIVE

Irritability (aggression, self-injury, and severe tantrums) associated with autism spectrum disorder (ASD) is often treated with second-generation antipsychotics (SGAs), which are well known for their associated risk of weight gain in youth. Recent reports suggest that youth with ASD treated with SGAs may suffer more pronounced weight gain than typically developing children. In this study, we present a comprehensive comparison of weight gain effects of five SGAs in a clinical population of youth with ASD.

METHODS

We completed a subanalysis of demographic and treatment data describing 202 youth with ASD treated at two large, subspecialty psychiatry clinics. Included subjects were between 2 and 20 years of age and were treated with one of five SGAs (risperidone, aripiprazole, olanzapine, quetiapine, or ziprasidone) for up to 4 years. We calculated change in each participant's body-mass index (BMI) z-score during the treatment period using a linear model where the dependent variable was change in BMI z-score and the independent variables were SGA used and duration of treatment. First, these models were run for each drug separately, then the SGA groups were run together to estimate differences between groups. We also adjusted these models for weight gain-attenuating concomitant medications.

RESULTS

Treatment with risperidone, aripiprazole, and olanzapine resulted in statistically significant increase in BMI z-score (p = 0.03, 0.05, and <0.01 respectively). Ziprasidone and quetiapine were not associated with an increase in BMI z-score in this analysis (p = 0.47 and p = 0.11). Subjects treated with olanzapine showed a statistically significant greater increase in BMI z-score when compared with the other SGAs (all p-values <0.05). These results did not change when adjusted for multiple testing or weight gain-attenuating medication as covariate.

CONCLUSION

Clinicians treating youth with ASD may be able to use this information to balance the risks and benefits of SGA treatment when managing ASD-associated irritability.

The Clinical Predictors That Facilitate a Clinician's Decision to Order Genetic Testing for Rett Syndrome

BACKGROUND

Rett syndrome is a common genetic cause of intellectual disability in girls caused by a mutation in the MECP2 gene. Diagnosis is based on clinical criteria. The aim was to compare the frequencies of the clinical criteria in patients with and without MECP2 mutations.

METHODS

We performed a retrospective review at a children's hospital of patients who underwent MECP2 testing from 2008 to 2013. Logistic regression was performed to determine which criteria were most predictive of MECP2 status.

RESULTS

Of 169 patients who met inclusion criteria, 46 (27.2%) were MECP2 positive. Loss of language skills (MECP2+ 100% versus MECP2- 87.8%; P = 0.012) was the most common finding among both groups. Other main criteria were more common in MECP2 patients: gait abnormalities (84.8% versus 27.6%; P < 0.0001); stereotypic hand movements (76.1% versus 15.5%; P < 0.0001); loss of hand skills (71.7% versus 4.9%; P < 0.0001). Logistic regression analysis including all four criteria demonstrated language loss was not predictive.

CONCLUSIONS

Loss of hand skills resulted in the highest odds of having a positive genetic test. Gait abnormalities and stereotypic hand movements were also strong predictors of MECP2+ testing. Many individuals with language delay had genetic testing; however, this is the least specific of the major criteria. These findings have implications for which patients should have genetic testing.

Abnormal Cortical Plasticity in Youth with Autism Spectrum Disorder: A Transcranial Magnetic Stimulation Case-Control Pilot Study

OBJECTIVE

This case-control study investigated the use of a low-intensity repetitive transcranial magnetic stimulation (rTMS) protocol to measure motor cortex (M1) plasticity in youth with autism spectrum disorder (ASD) compared with typically developing children (TDC). We hypothesized that impairments in long-term potentiation-like properties represent a neurophysiological biomarker of abnormal cortical function in ASD.

METHODS

We studied youth with ASD aged 11-18 years and matched controls (TDC). Intermittent theta burst stimulation (iTBS) was delivered to the dominant M1 at an intensity of 70% of resting motor threshold. Suprathreshold single-pulse TMS was performed to compare amplitudes of motor-evoked potentials (MEP) measured from surface electromyography electrodes on a target muscle before (20 pulses) and after (10 pulses/time point) iTBS at predefined timepoints (up to 30 minutes) to measure any potentiation effects. A linear mixed model was used to examine group differences in MEP amplitudes over time following iTBS.

RESULTS

Nine youth with ASD (mean age 15.6; 7 males; 6 right-hand dominant) and 9 TDC (mean age 14.5; 5 males; 9 right-hand dominant) participated. All subjects tolerated the procedure well. Both groups had a mean increase in excitability after iTBS for 30 minutes; however, the time course of excitability changes differed (F9,144 = 2.05; p = 0.038). Post-hoc testing identified a significant decrease in amplitude of the ASD group at 20 minutes following iTBS compared with the TDC after correcting for multiple comparisons.

CONCLUSION

In this study, we demonstrate early evidence for a potential physiological biomarker of cortical plasticity in youth with ASD using a rapid low-intensity rTMS protocol with a discriminate measure at 20 minutes following stimulation. The procedure was well tolerated by all 18 participants. Future work will include modification of the protocol to improve the ability to distinguish subtypes of ASD based on behavioral and cognitive testing.

Correlation Among Genotype, Phenotype, and Histology in Neuronal Ceroid Lipofuscinoses: An Individual Patient Data Meta-Analysis

BACKGROUND

Neuronal ceroid lipofuscinoses (NCL) are heterogeneous neurodegenerative disorders. A better understanding of genotype-phenotype-histology correlation is expected to improve patient care and enhance understanding for phenotypic variability. This meta-analysis studies the correlation of NCL genotypes with clinical phenotypes, ages of onset, and pathologic findings.

METHODS

A structured MEDLINE search was performed using search strings incorporating relevant Medical Subject Headings (MeSH) terms. Studies of NCL patients with genetic, clinical, and histologic data were included. Individual patient data were extracted. Chi-square statistic was used to test the genotype differences in clinical phenotypes and histology. The distribution of age(s) of onset as a function of genotype was explored. Pairwise comparisons were performed with robust analysis of variance.

RESULTS

Sixty-eight studies including a total of 440 individuals with NCL were analyzed. Genetic testing was performed on 395 patients, and a pathologic mutation was identified in 372 of 395 of them. A significant clustering of genotypes into juvenile-onset (only CLN3) and infantile-onset (all others) phenotypes was observed (P < 0.0001). However, the CLN6 genotype showed a bimodal onset and included 14 of 17 subjects with the adult-onset phenotype. The estimated age of onset was respectively lower for subjects with CLN1 mutation (3.01 years, 95% confidence interval [CI] = 2.54 to 3.49) and higher for those with CLN6 mutation (16.33 years, 95% CI = 15.68 to 16.98), compared with other genotypes (P < 0.05 for pairwise comparisons). There was a significant (P < 0.0001) clustering of genotype observed according to the sampled tissue types and electron microscopic findings.

CONCLUSIONS

NCL genotypes significantly differ in terms of ages of onset and clinical phenotypes. There is a distinct segregation of genotypes and electron microscopic findings and high-yield tissue types for pathologic study. This information can possibly facilitate testing and diagnosis in resource-limited settings.

Patellofemoral instability in children: T2 relaxation times of the patellar cartilage in patients with and without patellofemoral instability and correlation with morphological grading of cartilage damage

BACKGROUND

Patellofemoral instability is one of the most common causes of cartilage damage in teenagers.

OBJECTIVE

To quantitatively evaluate the patellar cartilage in patients with patellofemoral instability using T2 relaxation time maps (T2 maps), compare the values to those in patients without patellofemoral instability and correlate them with morphological grades in patients with patellofemoral instability.

MATERIALS AND METHODS

Fifty-three patients with patellofemoral instability (mean age: 15.9 ± 2.4 years) and 53 age- and gender-matched patients without patellofemoral instability were included. Knee MR with axial T2 map was performed. Mean T2 relaxation times were obtained at the medial, central and lateral zones of the patellar cartilage and compared between the two groups. In the patellofemoral instability group, morphological grading of the patellar cartilage (0-4) was performed and correlated with T2 relaxation times.

RESULTS

Mean T2 relaxation times were significantly longer in the group with patellofemoral instability as compared to those of the control group across the patellar cartilage (Student's t-test, P<0.05) with the longest time at the central area. Positive correlation was seen between mean T2 relaxation time and morphological grading (Pearson correlation coefficiency, P<0.001). T2 increased with severity of morphological grading from 0 to 3 (mixed model, P<0.001), but no statistical difference was seen between grades 3 and 4.

CONCLUSION

In patellofemoral instability, patellar cartilage damage occurs across the entire cartilage with the highest T2 values at the apex. T2 relaxation times directly reflect the severity in low-grade cartilage damage, which implies an important role for T2 maps in differentiating between normal and low-grade cartilage damage.