Midazolam fails to prevent neurological damage in children with convulsive refractory febrile status epilepticus

Prognostic effects of treatment protocols for febrile convulsive status epilepticus in children

Background

Febrile status epilepticus is the most common form of status epilepticus in children. No previous reports compare the effectiveness of treatment strategies using fosphenytoin (fPHT) or phenobarbital (PB) and those using anesthetics as second-line anti-seizure medication for benzodiazepine-resistant convulsive status epilepticus (CSE). We aimed to examine the outcomes of various treatment strategies for febrile convulsive status epilepticus (FCSE) in a real-world setting while comparing the effects of different treatment protocols and their presence or absence.

Methods

This was a single-center historical cohort study that was divided into three periods. Patients who presented with febrile convulsive status epilepticus for ≥60 min even after the administration of at least one anticonvulsant were included. During period I (October 2002–December 2006), treatment was performed at the discretion of the attending physician, without a protocol. During period II (January 2007–February 2013), barbiturate coma therapy (BCT) was indicated for FCSE resistant to benzodiazepines. During period III (March 2013–April 2016), BCT was indicated for FCSE resistant to fPHT or PB.

Results

The rate of electroencephalogram monitoring was lower in period I than period II+III (11.5% vs. 85.7%, p<0.01). Midazolam was administered by continuous infusion more often in period I than period II+III (84.6% vs. 25.0%, p<0.01), whereas fPHT was administered less often in period I than period II+III (0% vs. 27.4%, p<0.01). The rate of poor outcome, which was determined using the Pediatric Cerebral Performance Category scale, was higher in period I than period II+III (23.1% vs. 7.1%, p=0.03). The rate of poor outcome did not differ between periods II and III (4.2% vs. 11.1%, p=0.40).

Conclusions

While the presence of a treatment protocol for FCSE in children may improve outcomes, a treatment protocol using fPHT or PB may not be associated with better outcomes.

Growth and differentiation factor-15 as a potential prognostic biomarker for status-epilepticus-associated-with-fever: A pilot study

OBJECTIVE

Biomarkers predicting poor outcomes of status-epilepticus-associated-with-fever (SEF) at an early stage may contribute to treatment guidance. However, none have been reported thus far. We investigated the dynamics of serum growth and differentiation factor (GDF)-15 after seizure onset in patients with SEF and determined whether GDF-15 can predict poor outcomes, particularly in the first 6 h after seizure onset.

METHODS

We enrolled 37 pediatric patients with SEF and eight patients with simple febrile seizures (SFS) and collected their blood samples within 24 h of seizure onset and eight febrile control patients between March 1, 2017 and September 30, 2020. All patients were aged ≤15 years.

RESULTS

In the SEF group, the median post-seizure serum GDF-15 values were 1,065 (<6h), 2,720 (6-12 h), and 2,411 (12-24 h) pg/mL. The median serum GDF-15 in the first 6 h was measured in patients with SEF without a significant past medical history (n = 21) and was found to be statistically significantly higher (1,587 pg/mL) than in the febrile control (551 pg/mL) and SFS (411 pg/mL) groups. The median serum GDF-15 was statistically significantly higher in patients with SEF with sequelae (n = 5) and patients with acute encephalopathy with biphasic seizures/reduced diffusion/hemorrhagic shock and encephalopathy syndrome (n = 6) than in patients with SEF without sequelae (n = 16) (15,898 vs 756 pg/mL) and patients with prolonged FS (n = 15) (9,448 vs 796 pg/mL).

CONCLUSIONS

This study demonstrates the dynamics of serum GDF-15 in patients with SEF and indicates the potential of GDF-15 as an early predictor of poor outcomes.

Early non-convulsive seizures are associated with the development of acute encephalopathy with biphasic seizures and late reduced diffusion

INTRODUCTION

Children with either febrile seizure or acute encephalopathy exhibit seizures and/or impaired consciousness accompanied by fever of unknown etiology (SICF). Among children with SICF, we previously reported those who have refractory status epilepticus or prolonged neurological abnormalities with normal AST levels are at a high risk for the development of acute encephalopathy with biphasic seizures and late reduced diffusion (AESD), considered to be caused by excitotoxicity. Non-convulsive seizures (NCS) are common in critically ill children and cause excitotoxic neuronal injury. The aim of this study was to elucidate the prevalence of NCS in the acute phase of children at a high risk for developing AESD and the relationship between NCS in the acute phase and neurological outcomes.

METHODS

We studied 137 children with SICF at a high risk for developing AESD and who underwent continuous electroencephalogram monitoring (cEEG) upon admission to a tertiary pediatric care center at Hyogo Prefectural Kobe Children's Hospital between October 2007 and August 2018. Patient characteristics and outcomes were compared between patients with NCS and without NCS.

RESULTS

Of the 137 children, NCS occurred in 30 children; the first NCS were detected in cEEG at the beginning in 63.3%, during the first hour in 90%, and within 12 h in 96.7%. Neurological sequelae were more common in NCS patients (20.0%) than in non-NCS patients (1.9%; p = 0.001). Five in 30 NCS patients (16.7%) and 3 in 107 non-NCS patients (2.8%) developed AESD (p = 0.013).

CONCLUSION

The occurrence of NCS is associated with subsequent neurological sequelae, especially the development of AESD.

Thiamylal anaesthetic therapy for febrile refractory status epilepticus in children

PURPOSE

To evaluate barbiturate anaesthetic therapy using thiamylal for febrile refractory status epilepticus (fRSE) in children.

METHODS

This was a review of a prospectively-collected database between April 2012-March 2016 for fRSE cases treated with thiamylal anaesthetic therapy in a single paediatric hospital in Japan. The sample comprised 23 children (median age, 23 months) with fRSE that underwent thiamylal anaesthetic therapy for convulsive seizures lasting longer than 60 min, sustained after intravenous administration of benzodiazepine and non-benzodiazepine anticonvulsants. The intervention comprised protocol-based thiamylal anaesthetic therapy with bolus administration. We measured the dose and time required to achieve the burst suppression pattern (BSP) on electroencephalography, seizure recurrence, death, neurological sequelae, and complications.

RESULTS

All patients except one reached the BSP. The thiamylal median dose until reaching the BSP was 27.5 mg/kg, and the median time from thiamylal administration to reaching the BSP was 109.5 min. There was one case of immediate treatment failure and one of withdrawal seizure, but no breakthrough seizure. No deaths occurred during treatment, and neurological sequelae occurred in four cases (17%). Vasopressors were administered in all cases. Other complications included 11 cases of pneumonia and one of enterocolitis.

CONCLUSION

We revealed the time and dose required to reach the BSP with thiamylal anaesthetic therapy using bolus administration in children. Our results suggested that reaching the BSP with bolus administration requires markedly less time than without bolus administration, rarely causes seizure recurrence in paediatric fRSE, and causes haemodynamic dysfunction and infections as often as observed without bolus administration.

Detailed characteristics of acute encephalopathy with biphasic seizures and late reduced diffusion: 18-year data of a single-center consecutive cohort

OBJECTIVE

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is a syndrome characterized by biphasic seizures with impaired consciousness. AESD is rare outside Asia, and consecutive cohort studies are therefore scarce. Herein, we aimed to describe the detailed characteristics of AESD, including clinical course, electroencephalogram data, laboratory data, imaging findings, treatment, and outcomes.

METHODS

We reviewed the clinical database and medical charts of 43 consecutive pediatric patients (<18 years old) who developed AESD between October 1, 2002, and September 30, 2019.

RESULTS

We found that AESD occurred even though patients did not develop prolonged seizures. A comparison between the two groups (first seizure duration <30 min and first seizure duration ≥30 min) revealed three main findings: first, patients with AESD who had shorter seizures had better prognosis than those with prolonged seizures; second, patients with AESD who had shorter seizures tended to have earlier occurrence of a second seizure; and third, high signal intensity on diffusion-weighted magnetic resonance imaging was observed mainly in frontal areas, not diffusely, in patients with shorter seizures, and in a broader area in patients with prolonged seizures.

CONCLUSIONS

Our description of the detailed clinical picture of AESD may add new insight into its pathophysiology.

Septic Encephalopathy Characterized by Acute Encephalopathy with Biphasic Seizures and Late Reduced Diffusion and Early Nonconvulsive Status Epilepticus

Infection, whether viral or bacterial, can result in various forms of brain dysfunction (encephalopathy). Septic encephalopathy (SE) is caused by an excessive immune reaction to infection, with clinical features including disturbed consciousness and seizures. Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is usually accompanied by viral infection in children and is characterized by biphasic seizures and impaired consciousness. The initial neurologic symptom of AESD is typically a febrile seizure that frequently lasts longer than 30 minutes. However, the possible forms this seizure takes are unclear. For example, it is unknown if nonconvulsive status epilepticus (NCSE) could be an early seizure symptomatic of AESD. In addition, thus far no cases of combined SE and AESD have been reported. Here, we describe the first reported case of SE with AESD that notably demonstrated NCSE as an early seizure.

Benzodiazepines induce sequelae in immature mice with inflammation-induced status epilepticus

OBJECTIVE

Since benzodiazepines (BZPs) became clinically available for the treatment of status epilepticus (SE) in children, the incidence of neurological sequelae has increased. However, the cause-effect relationship is poorly understood. In this paper, we examined the effect of BZPs on an inflammation-induced SE (iSE) animal model.

METHOD

Inflammation was induced by injecting poly(I:C) (pIC 10 mg/kg, postnatal day 12-14), seizure was induced by injecting pilocarpine hydrochloride (PILO 200 mg/kg, postnatal day 15) into C57BL/6J mice, and the pIC+PILO mice were used as the iSE model (miSE). The GABA-A receptor agonist midazolam (MDL 0.5 mg/kg) was used to inhibit seizures. Sequelae were evaluated by performing behavior and immunohistochemical analyses in the chronic phase.

RESULT

The exploratory activity of mice in the miSE plus MDL group increased significantly, indicating that hyperactivity was newly induced by MDL in miSE mice. The contextual fear memory of the miSE mice was also significantly increased and that of miSE treated with MDL returned to the normal level. The parvalbumin-positive GABA neurons were decreased in number by pIC+PILO which was rescued by MDL. Apoptosis marker ssDNA-positive cells were increased by pIC+PILO which could not be rescued by MDL. Therefore, we propose that BZP-dependent therapy for SE needs to be rethought from the perspective of using other treatment approaches.