Pharmacokinetics and Proposed Dosing of Levetiracetam in Children With Obesity.

OBJECTIVE: Characterize levetiracetam pharmacokinetics (PK) in children with obesity to inform dosing. METHODS: Children 2 to <21 years old receiving standard of care oral levetiracetam across two opportunistic studies provided blood samples. Levetiracetam plasma PK data were analyzed with a nonlinear mixed-effects modeling approach. Indirect measures for body size and covariates were tested for model inclusion. Individual empirical Bayesian estimates using the final model parameters were compared by obesity status. Monte Carlo simulation using total body weight was performed in children with normal estimated glomerular filtration rate to identify dosing for children with obesity that resulted in comparable exposures to normal weight adults and children after receiving label dosing. RESULTS: The population PK model was developed from 341 plasma concentrations from 169 children. A 1-compartment model best fit the data with fat-free mass as a significant covariate. Compared with children with normal weight, children with obesity had significantly lower body weight-normalized clearance (median [range], 4.77 [1.49-10.44] and 3.71 [0.86-13.55] L/h/70 kg, respectively). After label dosing with the oral formulation in children with obesity 4 to <16 years old, maximum and minimum steady-state concentrations were higher (25% and 41%, respectively [oral solution] and 27% and 19%, respectively [tablet]) compared with children with normal weight. Comparable exposures between children with and without obesity were achieved with weight-tiered dosing regimens of <75 kg or ≥75 kg. CONCLUSIONS: Weight-tiered dosing for levetiracetam oral solution and tablets for children with obesity 4 to <16 years old results in more comparable exposures to children of normal weight.

Epilepsy and Electroencephalographic Abnormalities in SATB2-Associated Syndrome.

BACKGROUND: Seizures are an under-reported feature of the SATB2-associated syndrome phenotype. We describe the electroencephalographic findings and seizure semiology and treatment in a population of individuals with SATB2-associated syndrome. METHODS: We performed a retrospective review of 101 individuals with SATB2-associated syndrome who were reported to have had a previous electroencephalographic study to identify those who had at least one reported abnormal result. For completeness, a supplemental survey was distributed to the caregivers and input from the treating neurologist was obtained whenever possible. RESULTS: Forty-one subjects were identified as having at least one prior abnormal electroencephalography. Thirty-eight individuals (93%) had epileptiform discharges, 28 (74%) with central localization. Sleep stages were included as part of the electroencephalographies performed in 31 individuals (76%), and epileptiform activity was recorded during sleep in all instances (100%). Definite clinical seizures were diagnosed in 17 individuals (42%) with a mean age of onset of 3.2 years (four months to six years), and focal seizures were the most common type of seizure observed (42%). Six subjects with definite clinical seizures needed polytherapy (35%). Delayed myelination and/or abnormal white matter hyperintensities were seen on neuroimaging in 19 individuals (61%). CONCLUSIONS: Epileptiform abnormalities are commonly seen in individuals with SATB2-associated syndrome. A baseline electroencephalography that preferably includes sleep stages is recommended during the initial evaluation of all individuals with SATB2-associated syndrome, regardless of clinical suspicion of epilepsy.

Validation of a Concussion Screening Battery for Use in Medical Settings: Predicting Centers for Disease Control Concussion Symptoms in Children and Adolescents.

OBJECTIVE: Effective screening for concussion is increasingly important, and medical professionals play a critical role in diagnostic and return-to-play decisions. However, few well-validated measures are available to assist in those decisions. This study aims to determine whether previously validated measures assessing neurocognitive and neurobehavioral abilities can predict Centers for Disease Control (CDC) concussion symptom endorsement in a sample of child or youth athletes. METHOD: Participants were 113 individuals, aged 6-17, representing 29 consecutive cases undergoing a post-concussion evaluation by a pediatric neurologist and 84 consecutive cases completing standardized baseline assessments (i.e., not being evaluated as a follow-up to a concussion). All participants completed the same standardized battery of tests comprised of the Connors' Continuous Performance Test (CPT 3), the Balance Error Scoring System (BESS), and the NIH 4-Meter Gait Test as well as completing a checklist of CDC concussion symptoms. RESULTS: Regression analyses indicate that the screening battery explained 33% of the variance (d = 1.4) in concussion symptom endorsement, after controlling for age. The neurocognitive test alone (CPT 3) accounts for 21.5% of the variance (d = 1.05) in symptoms after controlling for age, and the neurobehavioral measures (BESS and NIH 4-Meter Gait) then account for an additional 11.5% variance (accounting for 18.6% variance, d = .96, when entered first). These effect sizes are considered large to very large and reflect a marked increase in predictive validity relative to existing measures commonly used in concussion assessments. CONCLUSIONS: A relatively brief screening battery can function in medical settings to predict significant and substantial variability in CDC concussion symptoms in a pediatric sample.

Safety and pharmacokinetics of ribavirin for the treatment of la crosse encephalitis.

BACKGROUND: La Crosse viral encephalitis (LACVE) is associated with residual epilepsy and neurocognitive deficits in survivors. This report summarizes 3 phases of clinical studies of children treated with intravenous (IV) ribavirin (RBV), each one exploring a different phase (I, IIA, IIB) of clinical trial development. METHODS: In phase I, 7 children with life-threatening LACVE were treated with emergency use RBV using a moderate IV dose (8.33 mg/kg/dose q 8 hours day 1, 5 mg/kg/dose q 8 hours days 2-10). In phase IIA, 12 children with severe LACVE were enrolled: 8 treated with RBV (same dose as phase I) and 4 with placebo. In phase IIB an escalated dose was used (33 mg/kg dose 1, then 16 mg/kg/dose q 6 hours for 4 days, and 8 mg/kg/dose q 8 hours for 3 days). RESULTS: In a group of 15 children treated in phase I and phase IIA, RBV appeared safe at moderate dose, but based on steady-state RBV levels of 9.3 µM, estimated cerebrospinal fluid levels were less than 20% of the EC50 of RBV for LACVE. At the escalated dose used in phase IIB, adverse events occurred, likely related to RBV, and therefore the trial was discontinued. Nevertheless, valuable pharmacokinetic (PK) and safety data were obtained at moderate dose, with potential treatment implications for other indications. CONCLUSIONS: Although the results do not support the use of RBV for LACVE, this nevertheless is the largest study of antiviral treatment for LACVE to date and the largest pharmacokinetic analysis of IV RBV in children for any indication.