Developmental factors in the pathogenesis of neonatal seizures

Efficacy and safety of ketamine for neonatal refractory status epilepticus: case report and systematic review

Background

Evidence-based data on treatment of neonatal status epilepticus (SE) are scarce. We aimed to collect data on the efficacy and safety of ketamine for the treatment of neonatal SE and to assess its possible role in the treatment of neonatal SE.

Methods

We described a novel case and conducted a systematic literature review on neonatal SE treated with ketamine. The search was carried out in Pubmed, Cochrane, Clinical Trial Gov, Scopus and Web of Science.

Results

Seven published cases of neonatal SE treated with ketamine were identified and analyzed together with our novel case. Seizures typically presented during the first 24 h of life (6/8). Seizures were resistant to a mean of five antiseizure medications. Ketamine, a NMDA receptor antagonist, appeared to be safe and effective in all neonates treated. Neurologic sequelae including hypotonia and spasticity were reported for 4/5 of the surviving children (5/8). 3/5 of them were seizure free at 1-17 months of life.

Discussion

Neonatal brain is more susceptible to seizures due to a shift towards increased excitation because of a paradoxical excitatory effect of GABA, a greater density of NMDA receptors and higher extracellular concentrations of glutamate. Status epilepticus and neonatal encephalopathy could further enhance these mechanisms, providing a rationale for the use of ketamine in this setting.

Conclusions

Ketamine in the treatment of neonatal SE showed a promising efficacy and safety profile. However, further in-depth studies and clinical trials on larger populations are needed.

Status Epilepticus in the Neonate: Updates in Treatment Strategies

PURPOSE OF REVIEW

The purpose of this review is to report recent advances in treatment of neonatal seizures, with a specific focus on new literature since a 2013 systematic review performed by this author (Slaughter) and others. There is a paucity of data with regard to well-defined status epilepticus (SE) in neonates, so treatment of recurrent seizures was also included in this inquiry. We aimed to summarize the efficacy and safety profiles of current therapeutic options as well as describe trends in medication selection in the neonatal intensive care unit (NICU) setting.

RECENT FINDINGS

Phenobarbital remains first-line therapy in practice, though there is increasing evidence of its neurotoxicity and long-term sequelae. Bumetanide failed an open-label trial for efficacy, demonstrated an increased risk for hearing loss, and has since fallen out of favor for use in this population. New agents, such as levetiracetam and topiramate, still have very limited data but appear to be as efficacious as older medications, with more favorable side effect profiles. There are limited high-level evidence-based data to guide treatment of neonatal seizures. Emerging research focusing on drug mechanisms and safety profiles may provide additional information to guide decisions; however, further research is needed.

Complex spectrum of phenobarbital effects in a mouse model of neonatal hypoxia-induced seizures

Seizures in neonates, mainly caused by hypoxic-ischemic encephalopathy, are thought to be harmful to the brain. Phenobarbital remains the first line drug therapy for the treatment of suspected neonatal seizures but concerns remain with efficacy and safety. Here we explored the short- and long-term outcomes of phenobarbital treatment in a mouse model of hypoxia-induced neonatal seizures. Seizures were induced in P7 mice by exposure to 5% O₂ for 15 minutes. Immediately after hypoxia, pups received a single dose of phenobarbital (25 mg.kg^-1) or saline. We observed that after administration of phenobarbital seizure burden and number of seizures were reduced compared to the hypoxic period; however, PhB did not suppress acute histopathology. Behavioural analysis of mice at 5 weeks of age previously subjected to hypoxia-seizures revealed an increase in anxiety-like behaviour and impaired memory function compared to control littermates, and these effects were not normalized by phenobarbital. In a seizure susceptibility test, pups previously exposed to hypoxia, with or without phenobarbital, developed longer and more severe seizures in response to kainic acid injection compared to control mice. Unexpectedly, mice treated with phenobarbital developed less hippocampal damage after kainic acid than untreated counterparts. The present study suggests phenobarbital treatment in immature mice does not improve the long lasting functional deficits induces by hypoxia-induced seizures but, unexpectedly, may reduce neuronal death caused by exposure to a second seizure event in later life.

Short-Term Effects of Phenobarbitone on Electrographic Seizures in Neonates

BACKGROUND

Phenobarbitone is the most common first-line anti-seizure drug and is effective in approximately 50% of all neonatal seizures.

OBJECTIVE

To describe the response of electrographic seizures to the administration of intravenous phenobarbitone in neonates using seizure burden analysis techniques.

METHODS

Multi-channel conventional EEG, reviewed by experts, was used to determine the electrographic seizure burden in hourly epochs. The maximum seizure burden evaluated 1 h before each phenobarbitone dose (T-1) was compared to seizure burden in periods of increasing duration after each phenobarbitone dose had been administered (T+1, T+2 to seizure offset). Differences were analysed using linear mixed models and summarized as means and 95% CI.

RESULTS

Nineteen neonates had electrographic seizures and met the inclusion criteria for the study. Thirty-one doses were studied. The maximum seizure burden was significantly reduced 1 h after the administration of phenobarbitone (T+1) [-14.0 min/h (95% CI: -19.6, -8.5); p < 0.001]. The percentage reduction was 74% (IQR: 36-100). This reduction was temporary and not significant within 4 h of administrating phenobarbitone. Subgroup analysis showed that only phenobarbitone doses at 20 mg/kg resulted in a significant reduction in the maximum seizure burden from T-1 to T+1 (p = 0.002).

CONCLUSIONS

Phenobarbitone significantly reduced seizures within 1 h of administration as assessed with continuous multi-channel EEG monitoring in neonates. The reduction was not permanent and seizures were likely to return within 4 h of treatment.

The Etiology and Clinical Evaluations of Neonatal Seizures in Kashan, IRAN

OBJECTIVE

Detection of seizure, its etiology, and clinical types is important for guiding therapy. This study was designed to evaluate the etiology and clinical evaluations of neonatal seizures in Kashan, Iran.

MATERIALS AND METHODS

The data of 100 hospitalized neonates with a complaint of seizures in Kashan City, from January 2006 to January 2011 were evaluated. The pediatric neurologist made the final diagnosis. The gestational age, neonate admission age, type of delivery, and laboratory and radiological investigations were reviewed from the medical records. The relation of seizure etiology and other variables were compared using the Chi-square test. All the statistical analyses were performed using SPSS (ver 11.5).

RESULTS

A total of 100 neonates were hospitalized with a diagnosis of seizures. The overall incidence rate of seizures was 2.6 per 1,000 live births. A total of 59% of seizures happened in the first three days of life. The etiologies of seizures were hypoxicischemic encephalopathy (HIE) (36%), hyponatremia (12%), hypoglycemia (11%), intracranial hemorrhage (11%), infections (10%), hypocalcemia (8%), metabolic disorders (7%), the structural anomalies (5%), and hypomagnesaemia (4%). In 23% of neonates, no specific etiology was found and 23% had multiple etiologies. In 45% of neonates, the EEG was not recorded. The type of the seizures were focal-clonic (26%), tonic (25%), multifocal clonic (34%), subtle (11%), and myoclonic (4%). The types of the seizure were unrelated to the paraclinical findings.

CONCLUSION

Neonatal seizures are common and HIE was the main cause of seizures in this study. The clinical evaluation of neonatal seizures needs improvement.

Treadmill exercise protects against pentylenetetrazol-induced seizures and oxidative stress after traumatic brain injury

Traumatic brain injury (TBI) is a major cause of acquired epilepsy, and significant resources are required to develop a better understanding of the pathologic mechanism as targets for potential therapies. Thus, we decided to investigate whether physical exercise after fluid percussion injury (FPI) protects from oxidative and neurochemical alterations as well as from behavioral electroencephalographic (EEG) seizures induced by subeffective convulsive doses of pentylenetetrazol (PTZ; 35 mg/kg). Behavioral and EEG recordings revealed that treadmill physical training increased latency to first clonic and tonic-clonic seizures, attenuated the duration of generalized seizures, and protected against the increase of PTZ-induced Racine scale 5 weeks after neuronal injury. EEG recordings also revealed that physical exercise prevented PTZ-induced amplitude increase in TBI animals. Neurochemical analysis showed that exercise training increased glutathione/oxidized glutathione ratio and glutathione levels per se. Exercise training was also effective against alterations in the redox status, herein characterized by lipid peroxidation (thiobarbituric acid reactive substances), protein carbonyl increase, as well as the inhibition of superoxide dismutase and Na⁺,K⁺-ATPase activities after FPI. On the other hand, histologic analysis with hematoxylin and eosin revealed that FPI induced moderate neuronal damage in cerebral cortex 4 weeks after injury and that physical exercise did not protect against neuronal injury. These data suggest that the ability of physical exercise to reduce FPI-induced seizures is not related to its protection against neuronal damage; however, the effective protection of selected targets, such as Na⁺/K⁺-ATPase elicited by physical exercise, may represent a new line of treatment for post-traumatic seizure susceptibility.

AED Treatment Through Different Ages: As Our Brains Change, Should Our Drug Choices Also?

Patient age can impact selection of the optimal antiepileptic drug for a number of reasons. Changes in brain physiology from neonate to elderly, as well as changes in underlying etiologies of epilepsy, could potentially affect the ability of different drugs to control seizures. Unfortunately, much of this is speculative, as good studies demonstrating differences in efficacy across age ranges do not exist. Beyond the issue of efficacy, certain drugs may be more or less appropriate at different ages because of differing pharmacokinetics, including changes in hepatic metabolism, absorption, and elimination. Lack of appropriate drug formulations (such as liquid forms) may be a barrier to using drugs in the very young. Finally, some serious adverse events are seen either exclusively or preferentially at different ages.