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ObjectiveTo systematically review and evaluate the available evidence supporting or refuting clinical use of therapeutic drug monitoring (TDM) of antiepileptic drugs (AEDs) in patients with epilepsy.MethodsWe searched MEDLINE, Embase, BIOSIS, Cochrane, PubMed, Africa-Wide Information, Web of Science, and grey literature. Randomized controlled studies and observational studies that compared the clinical outcomes of TDM vs non-TDM were included. Two reviewers independently extracted the data. The primary outcome was seizure control; adverse effects were considered as secondary outcomes. The PROSPERO ID of this systematic review's protocol is CRD42018089925.ResultsSixteen studies were identified meeting eligibility requirements. Four randomized controlled trials (RCTs), 1 meta-analysis, and 11 quasiexperimental (QE) studies were included in the systematic review. Results from the analysis of RCTs showed no significant positive effect of TDM on seizure outcome (only 25% positive effect of phenytoin). However, some of the QE studies found that TDM was associated with better seizure control or lower rates of adverse effects. The existing evidence from various designs has shown various methodological implications, which warrants inconclusive results and highlights the requirement of more number of studies in this line.ConclusionsIf optimally implemented, TDM may enhance clinical care, particularly for phenytoin and other AEDs with complex pharmacokinetics. However, the ideal method for implementation is unclear, and serum drug levels should be considered in context with patient-reported clinical data regarding seizure control and adverse events.

Background Headaches with marked, specific response to indomethacin occur in children, but the phenotypic spectrum of this phenomenon has not been well-studied. Methods We reviewed pediatric patients with headache showing ≥80% improvement with indomethacin, from seven academic medical centers. Results We included 32 pediatric patients (16 females). Mean headache onset age was 10.9 y (range 2–16 y). Headache syndromes included hemicrania continua (n = 13), paroxysmal hemicrania (n = 10), primary stabbing headache (n = 2), short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (n = 1), primary exercise headache (n = 1) and primary cough headache (n = 1). Adverse events were reported in 13, most commonly gastrointestinal symptoms, which often improved with co-administration of gastro-protective agents. Conclusion Indomethacin-responsive headaches occur in children and adolescents, and include headache syndromes, such as primary cough headache, previously thought to present only in adulthood. The incidence of adverse events is high, and patients must be co-treated with a gastroprotective agent.

Koolen-de Vries syndrome (KdVS) is a genetic condition caused by 17q21.31 microdeletions or pathogenic variants in KANSL1. Affected patients most commonly exhibit some or all of the following: neonatal hypotonia, developmental impairment, facial dysmorphic features, and congenital malformations. Epilepsy occurs in approximately half, often with phenotypes on the epilepsyaphasia spectrum. We describe six children with KdVS found to have continuous spike-wave in sleep (CSWS) on EEG, four of whom were diagnosed with epileptic encephalopathy with CSWS and two with Landau-Kleffner syndrome. When compared with other children with CSWS on EEG, patients with KdVS may present at slightly later ages and with a longer interval between seizure diagnosis and identification of CSWS. There is no clear best treatment for children with CSWS, but two patients in our cohort were trialed on a variation of the ketogenic diet, and both reported clinical improvement. In one of the patients, the response was dramatic, and CSWS recurred when weaning of the ketogenic diet was attempted. Based on our findings, an EEG capturing a prolonged period of sleep should be arranged in any child with KdVS presenting with developmental regression or plateau, particularly if they have a preceding history of seizures.