Phenobarbital, midazolam, bumetanide, and neonatal seizures: The devil is in the details

High Effectiveness of Midazolam and Lidocaine in the Treatment of Acute Neonatal Seizures

PURPOSE

To assess the clinical effectiveness of treating acute seizures with midazolam and lidocaine infusion.

METHODS

This single-center historical cohort study included 39 term neonates with electrographic seizures who underwent treatment with midazolam (1st line) and lidocaine (2nd line). Therapeutic response was measured using continuous video-EEG monitoring. The EEG measurements included total s eizure burden (minutes), maximum ictal fraction (minutes/hour), and EEG-background (normal/slightly abnormal vs. abnormal). Treatment response was considered good (seizure control with midazolam infusion), intermediate (need to add lidocaine to the control), or no response. Using clinical assessments supplemented by BSID-III and/or ASQ-3 at 2 to 9 years old age, neurodevelopment was classified as normal, borderline, or abnormal.

RESULTS

A good therapeutic response was obtained in 24 neonates, an intermediate response in 15, and no response in any of the neonates. Babies with good response showed lower values in maximum ictal fraction compared with those with intermediate response (95% CI: 5.85-8.64 vs. 9.14-19.14, P = 0.002). Neurodevelopment was considered normal in 24 children, borderline in five, and abnormal in other 10 children. Abnormal neurodevelopment was significantly associated with an abnormal EEG background, maximum ictal fraction >11 minutes, and total s eizure burden >25 minutes (odds ratio 95% CI: 4.74-1708.52, P = 0.003; 1.72-200, P = 0.016; 1.72-142.86, P = 0.026, respectively) but not with the therapeutic response. Serious adverse effects were not recorded.

CONCLUSIONS

This retrospective study suggests that the midazolam/lidocaine association could potentially be efficacious in decreasing seizure burden in term neonates with acute seizures. These results would justify testing the midazolam/lidocaine combination as a first-line treatment for neonatal seizures in future clinical trials.

NKCC1 in human diseases: is the SLC12A2 gene haploinsufficient?

Mutations in the SLC12A2 gene, which encodes the Na-K-2Cl cotransporter-1 (NKCC1), are linked to various conditions such as neurodevelopmental deficits, deafness, and fluid secretion in different epithelia. Cases of complete NKCC1 deficiency in young patients are straightforward, leading to clinical presentations that overlap with the phenotypes observed in NKCC1 knockout mouse models. However, cases involving deleterious variants in one allele are more difficult, as the clinical presentation is variable, and the cause-effect relationship is not always clear. For instance, we worked on a single patient's case from multiple angles and published six related papers to convince ourselves of the cause-and-effect relationship between her NKCC1 mutation and her clinical presentations. The cluster of mutations in a small portion of the carboxyl terminus and its association with deafness point to a cause-and-effect relationship, even if the molecular mechanism is unknown. Overall, the preponderance of evidence suggests that the SLC12A2 gene is a human disease-causing and likely haploinsufficient gene that requires further investigation.

Effects of Midazolam on Antioxidant Levels, Biochemical and Metabolic Parameters in Eurygaster integriceps Puton (Hemiptera: Scutelleridae) Eggs Parasitized by Trissolcus semistriatus Nees (Hymenoptera: Scelionidae)

Eurygaster integriceps Puton (Hemiptera: Scutelleridae) is among the most important insect pests of wheat (Triticum sativum L.) and barley (Hordeum vulgare L.) grown in the Middle East. Biological and chemical methods are insufficient to control E. integriceps populations below economic thresholds. In this study, we investigated the effects of midazolam, a clinical drug, on selected metabolic enzyme activity, antioxidant levels, and biochemical parameters in E. integriceps eggs parasitized by Trissolcus semistriatus Nees (Hymenoptera: Scelionidae). Increasing concentrations of midazolam caused cell damage in the parasitized eggs due to its oxidative effects. Transferase enzymes, such as, aspartate transferase, alanine transferase, and gamma glutamyl transferase activities were altered following exposure. Metabolic enzymes, such as, creatine kinase, alkaline phosphatase, amylase, and lactate dehydrogenase also were adversely affected. Levels of the non-enzymatic antioxidants uric acid, bilirubin, and albumin also were altered.

Effects of Mutations in TSC Genes on Neurodevelopment and Synaptic Transmission

Mutations in TSC1 or TSC2 genes are linked to alterations in neuronal function which ultimately lead to the development of a complex neurological phenotype. Here we review current research on the effects that reduction in TSC1 or TSC2 can produce on the developing neural network. A crucial feature of the disease pathophysiology appears to be an early deviation from typical neurodevelopment, in the form of structural abnormalities. Epileptic seizures are one of the primary early manifestation of the disease in the CNS, followed by intellectual deficits and autism spectrum disorders (ASD). Research using mouse models suggests that morphological brain alterations might arise from the interaction of different cellular types, and hyperexcitability in the early postnatal period might be transient. Moreover, the increased excitation-to-inhibition ratio might represent a transient compensatory adjustment to stabilize the developing network rather than a primary factor for the development of ASD symptoms. The inhomogeneous results suggest region-specificity as well as an evolving picture of functional alterations along development. Furthermore, ASD symptoms and epilepsy might originate from different but potentially overlapping mechanisms, which can explain recent observations obtained in patients. Potential treatment is determined not only by the type of medicament, but also by the time point of treatment.

Reply to the commentary by Ben-Ari and Delpire: Bumetanide and neonatal seizures: Fiction versus reality

In this response to a commentary by Ben-Ari and Delpire on our recent study on the pharmacology of neonatal seizures in a novel, physiologically validated rat model of birth asphyxia, we wish to rectify their inaccurate descriptions of our model and data. Furthermore, because Ben-Ari and Delpire suggest that negative data on bumetanide from preclinical and clinical trials of neonatal seizures have few implications for (alleged) bumetanide actions on neurons in other brain disorders, we will discuss this topic as well. Based on the poor brain penetration of bumetanide, combined with the extremely wide cellular expression patterns of the target protein NKCC1, it is obvious that the numerous actions of systemically applied bumetanide described in the literature are not mediated by the drug's effects on central neurons.