Status epilepticus: Role for etiology in determining response to benzodiazepines.

OBJECTIVE: Clinical factors contributing to benzodiazepine failure in treating status epilepticus (SE) include suboptimal dosing and seizure duration. As many benzodiazepine-refractory episodes of SE arise from acute etiologies, we sought to determine whether etiology impacts SE treatment. METHODS: The potency of diazepam to terminate SE induced by lithium-pilocarpine (LiPilo-SE) or kainic acid (KA-SE) in 3-week-old rats was studied by video-electroencephalography. Synaptic γ-aminobutyric acid type A receptor (GABAR)-mediated currents were recorded from dentate granule cells using voltage-clamp electrophysiology. Surface expression of γ2 subunit-containing GABARs and Kv4.2 potassium channels in hippocampal slices was determined using a biotinylation assay. Expression of phosphorylated forms of ß2/3 and γ2 subunits was determined using phosphospecific antibodies and Western blotting. RESULTS: Diazepam failed to terminate late SE in LiPilo-SE animals but was successful in terminating KA-SE of 1- and 3-hour duration. One hour after SE onset, GABAR-mediated synaptic inhibition and γ2 subunit-containing GABAR surface expression were reduced in LiPilo-SE animals. These were unchanged in KA-SE animals at 1 and 3 hours. Phosphorylation of γ2 subunit residue S327 was unchanged in both models, although GABAR ß3 subunit S408/409 residues were dephosphorylated in the LiPilo-SE animals. Kv4.2 potassium channel surface expression was increased in LiPilo-SE animals but reduced in KA-SE animals. INTERPRETATION: SE-model-dependent differences support a novel hypothesis that the development of benzodiazepine pharmacoresistance may be etiologically predetermined. Further studies are required to investigate the mechanisms that underlie such etiological differences during SE and whether etiology-dependent protocols for the treatment of SE need to be developed. Ann Neurol 2018;83:830-841.

Phosphatase inhibition prevents the activity-dependent trafficking of GABAA receptors during status epilepticus in the young animal.

OBJECTIVES: To determine if the activity-dependent trafficking of γ2 subunit-containing γ-aminobutyric acid type A receptors (GABAA Rs) that has been observed in older animals and posited to contribute to benzodiazepine pharmacoresistance during status epilepticus (SE) is age-dependent, and to evaluate whether blockade of protein phosphatases can inhibit or reverse the activity-dependent plasticity of these receptors. METHODS: The efficacy and potency of diazepam 0.2-10 mg/kg administered 3 or 60 min after the onset of a lithium/pilocarpine-induced seizure in postnatal day 15-16 rats was evaluated using video-electroencephalography (EEG) recordings. The surface expression of γ2 subunit-containing GABAA Rs was assessed using a biotinylation assay, and GABAA R-mediated miniature inhibitory postsynaptic currents (mIPSCs) were recorded using whole-cell patch-clamp recording techniques from dentate granule cells in hippocampal slices acutely obtained 60 min after seizure onset (SE-treated). The effect of the protein phosphatase inhibitors FK506 and okadaic acid (OA) on the surface expression of these receptors was determined in organotypic slice cultures exposed to high potassium and N-methyl-d-aspartate (NMDA) or in SE-treated slices. RESULTS: Diazepam terminated seizures of 3 min but not 60 min duration, even at the highest dose. In the SE-treated slices, the surface expression of γ2 subunit-containing GABAA Rs was reduced and the amplitude of the mIPSCs was diminished. Inhibition of protein phosphatases prevented the activity-induced reduction of the γ2 subunit-containing GABAA Rs in organotypic slice cultures. Furthermore, treatment of SE-treated slices with FK506 or OA restored the surface expression of the γ2 subunit-containing GABAA Rs and the mIPSC amplitude. SIGNIFICANCE: This study demonstrates that the plasticity of γ2 subunit-containing GABAA Rs associated with the development of benzodiazepine resistance in young and adult animals is similar. The findings of this study suggest that the mechanisms regulating the activity-dependent trafficking of GABAA Rs during SE can be targeted to develop novel adjunctive therapy for the treatment of benzodiazepine-refractory SE.

Efficacy of hypnosis on pain, wound-healing, anxiety, and stress in children with acute burn injuries: a randomized controlled trial.

No randomized controlled trial has investigated the efficacy of hypnosis for reducing pain and improving wound-healing in children with burns. This randomized controlled trial aimed to investigate whether hypnosis decreases pain, anxiety, and stress and accelerates wound-healing in children undergoing burn wound procedures. Children (4-16 years) with acute burns presenting for their first dressing change were randomly assigned to a Hypnosis Group who received hypnosis plus standard care or a Standard Care Group who received standard pharmacological and nonpharmacological intervention. Repeated measures of pain intensity, anxiety, stress, and wound-healing were taken at dressing changes until ≥95% wound re-epithelialization. Data for 62 children were analyzed on an intent-to-treat basis using Generalized Estimating Equations (n = 35 Standard Care Group; n = 27 Hypnosis Group). An effect on the primary outcomes of pain and wound healing was not supported {self-reported pain intensity largest Mean Difference [MD] = -0.85 (95% confidence interval [CI]: -1.91 to 0.22), P = 0.12; MD for re-epithelialization = -0.46 [95% CI: -4.27 to 3.35], P = 0.81}. Some support was found for an effect on the secondary outcomes of preprocedural anxiety (MD = -0.80 [95% CI: -1.50 to -0.10], P = 0.03 before the second dressing change) and heart rate as a measure of stress (MD = -15.20 [-27.20 to -3.20], P = 0.01 and MD = -15.39 [-28.25 to -2.53], P = 0.02 before and after the third dressing change). Hypnosis may be effective for decreasing preprocedural anxiety and heart rate in children undergoing repeated pediatric wound care procedures but not for reducing pain intensity or accelerating wound healing.

Effectiveness of medical hypnosis for pain reduction and faster wound healing in pediatric acute burn injury: study protocol for a randomized controlled trial.

BACKGROUND: Burns and the associated wound care procedures can be extremely painful and anxiety-provoking for children. Burn injured children and adolescents are therefore at greater risk of experiencing a range of psychological reactions, in particular posttraumatic stress disorder, which can persist for months to years after the injury. Non-pharmacological intervention is critical for comprehensive pain and anxiety management and is used alongside pharmacological analgesia and anxiolysis. However, effective non-pharmacological pain and anxiety management during pediatric burn procedures is an area still needing improvement. Medical hypnosis has received support as a technique for effectively decreasing pain and anxiety levels in adults undergoing burn wound care and in children during a variety of painful medical procedures (e.g., bone marrow aspirations, lumbar punctures, voiding cystourethrograms, and post-surgical pain). Pain reduction during burn wound care procedures is linked with improved wound healing rates. To date, no randomized controlled trials have investigated the use of medical hypnosis in pediatric burn populations. Therefore this study aims to determine if medical hypnosis decreases pain, anxiety, and biological stress markers during wound care procedures; improves wound healing times; and decreases rates of traumatic stress reactions in pediatric burn patients. METHODS/DESIGN: This is a single-center, superiority, parallel-group, prospective randomized controlled trial. Children (4 to 16 years, inclusive) with acute burn injuries presenting for their first dressing application or change are randomly assigned to either the (1) intervention group (medical hypnosis) or (2) control group (standard care). A minimum of 33 participants are recruited for each treatment group. Repeated measures of pain, anxiety, stress, and wound healing are taken at every dressing change until ≥95 % wound re-epithelialization. Further data collection assesses impact on posttraumatic stress symptomatology, speed of wound healing, and parent perception of how easy the dressing change is for their child. DISCUSSION: Study results will elucidate whether the disease process can be changed by using medical hypnosis with children to decrease pain, anxiety, and stress in the context of acute burn wounds. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12615000419561.