Katrina Peariso

Gaps and opportunities in refractory status epilepticus research in children: A multi-center approach by the Pediatric Status Epilepticus Research Group (pSERG)

Purpose: Status epilepticus (SE) is a life-threatening condition that can be refractory to initial treatment. Randomized controlled studies to guide treatment choices, especially beyond first-line drugs, are not available. This report summarizes the evidence that guides the management of refractory convulsive SE (RCSE) in children, defines gaps in our clinical knowledge and describes the development and works of the ‘pediatric Status Epilepticus Research Group’ (pSERG). Methods: A literature review was performed to evaluate current gaps in the pediatric SE and RCSE literature. In person and online meetings helped to develop and expand the pSERG network. Results: The care of pediatric RCSE is largely based on extrapolations of limited evidence derived from adult literature and supplemented with case reports and case series in children. No comparative effectiveness trials have been performed in the pediatric population. Gaps in knowledge include risk factors for SE, biomarkers of SE and RCSE, second-and third-line treatment options, and long-term outcome. Conclusion: The care of children with RCSE is based on limited evidence. In order to address these knowledge gaps, the multicenter pSERG was established to facilitate prospective collection, analysis, and sharing of de-identified data and biological specimens from children with RCSE. These data will allow identification of treatment strategies associated with better outcomes and delineate evidence-based interventions to improve the care of children with SE.

Time from convulsive status epilepticus onset to anticonvulsant administration in children

Objective: To describe the time elapsed from onset of pediatric convulsive status epilepticus (SE) to administration of antiepileptic drug (AED). Methods: This was a prospective observational cohort study performed from June 2011 to June 2013. Pediatric patients (1 month–21 years) with convulsive SE were enrolled. In order to study timing of AED administration during all stages of SE, we restricted our study population to patients who failed 2 or more AED classes or needed continuous infusions to terminate convulsive SE. Results: We enrolled 81 patients (44 male) with a median age of 3.6 years. The first, second, and third AED doses were administered at a median (p25–p75) time of 28 (6–67) minutes, 40 (20–85) minutes, and 59 (30–120) minutes after SE onset. Considering AED classes, the initial AED was a benzodiazepine in 78 (96.3%) patients and 2 (2–3) doses of benzodiazepines were administered before switching to nonbenzodiazepine AEDs. The first and second doses of nonbenzodiazepine AEDs were administered at 69 (40–120) minutes and 120 (75–296) minutes. In the 64 patients with out-of-hospital SE onset, 40 (62.5%) patients did not receive any AED before hospital arrival. In the hospital setting, the first and second in-hospital AED doses were given at 8 (5–15) minutes and 16 (10–40) minutes after SE onset (for patients with in-hospital SE onset) or after hospital arrival (for patients with out-of-hospital SE onset). Conclusions: The time elapsed from SE onset to AED administration and escalation from one class of AED to another is delayed, both in the prehospital and in-hospital settings.

Recent applications of MCD spectroscopy to metalloenzymes

Magnetic circular dichroism (MCD) continues to be a powerful probe of metalloenzyme electronic and geometric structure, in addition to playing a major role in the determination of heme enzyme coordination geometries. Excited state electronic structure contributions to enzyme activity have been gleaned from C-term MCD studies, which are usually interpreted in the context of other spectroscopies, including electronic absorption and resonance Raman. The recent development of sophisticated methods for the analysis of variable-temperature, variable-field MCD have allowed the ground states of metalloenzyme active sites to be studied in detail, providing information on the electronic and geometric structure of the site. This has been especially informative for non-heme iron enzymes. In the past two years X-ray MCD has been shown to be a promising technique for the study of metalloenzymes.

EXAFS studies of the zinc sites of UDP-(3-O-acyl)-N-acetylglucosamine deacetylase (LpxC).

Extended X-ray absorption fine structure (EXAFS) spectroscopy has been used to determine the structure of the Zn(II) sites in UDP-(3-O-acyl)-N-acetylglucosamine deacetylase (LpxC) from Aquifex aeolicus and Pseudomonas aeruginosa. The active site Zn(II) is four coordinate, with exclusively low-Z (nitrogen and oxygen) ligation in both enzymes. The amplitude of the outer-shell scattering from the histidine ligands is best fit using two histidine ligands, suggesting a ZnO(2)(His)(2) site, where O most likely represents a conserved aspartate and a solvent molecule. The same structure was found for Co(II)-substituted A. aeolicus LpxC, although in this case it is possible that the coordination sphere may expand to include a fifth low-Z ligand. EXAFS data were also measured for the Escherichia coli LpxC enzyme. When a single Co(II) is substituted for Zn(II) in the active site of E. coli LpxC, EXAFS data show the same ligand environment as is found for the P. aeruginosa and A. aeolicus enzymes. However, the EXAFS data for E. coli LpxC with two zinc ions bound per protein, with the second Zn(II) acting as an inhibitory metal, demonstrates that the inhibitory metal is bound to at least two high-Z (sulfur, presumably thiolate, or chlorine) ligands. Results of the outer-shell scattering analysis, combined with previous studies of the LpxC enzyme, indicate a novel zinc binding motif not found in any previously studied zinc metalloproteins.

Association of Time to Treatment With Short-term Outcomes for Pediatric Patients With Refractory Convulsive Status Epilepticus.

Importance Treatment delay for seizures can lead to longer seizure duration. Whether treatment delay is associated with major adverse outcomes, such as death, remains unknown. Objective To evaluate whether untimely first-line benzodiazepine treatment is associated with unfavorable short-term outcomes. Design, Setting, and Participants This multicenter, observational, prospective cohort study included 218 pediatric patients admitted between June 1, 2011, and July 7, 2016, into the 11 tertiary hospitals in the United States within the Pediatric Status Epilepticus Research Group. Patients, ranging in age from 1 month to 21 years, with refractory convulsive status epilepticus (RCSE) that did not stop after the administration of at least 2 antiseizure medications were included. Patients were divided into 2 cohorts: those who received the first-line benzodiazepine treatment in less than 10 minutes and those who received it 10 or more minutes after seizure onset (untimely). Data were collected and analyzed from June 1, 2011, to July 7, 2016. Main Outcomes and Measures The primary outcome was death during the related hospital admission. The secondary outcome was the need for continuous infusion for seizure termination. Multivariate analysis of mortality controlled for structural cause, febrile RCSE, age, and previous neurological history (including previous RCSE events). Use of continuous infusions was additionally adjusted for generalized RCSE, continuous RCSE, and 5 or more administrations of antiseizure medication. Results A total of 218 patients were included, among whom 116 (53.2%) were male and the median (interquartile range) age was 4.0 (1.2-9.6) years. The RCSE started in the prehospital setting for 139 patients (63.8%). Seventy-four patients (33.9%) received their first-line benzodiazepine treatment in less than 10 minutes, and 144 (66.1%) received untimely first-line benzodiazepine treatment. Multivariate analysis showed that patients who received untimely first-line benzodiazepine treatment had higher odds of death (adjusted odds ratio [AOR], 11.0; 95% CI, 1.43 to ∞; P = .02), had greater odds of receiving continuous infusion (AOR, 1.8; 95% CI, 1.01-3.36; P = .047), had longer convulsive seizure duration (AOR, 2.6; 95% CI, 1.38-4.88; P = .003), and had more frequent hypotension (AOR 2.3; 95% CI, 1.16-4.63; P = .02). In addition, the timing of the first-line benzodiazepine treatment was correlated with the timing of the second-line (95% CI, 0.64-0.95; P < .001) and third-line antiseizure medications (95% CI, 0.25-0.78; P < .001). Conclusions and Relevance Among pediatric patients with RCSE, an untimely first-line benzodiazepine treatment is independently associated with a higher frequency of death, use of continuous infusions, longer convulsion duration, and more frequent hypotension. Results of this study raise the question as to whether poor outcomes could, in part, be prevented by earlier administration of treatment.

Refractory Status Epilepticus in Children: Intention to Treat With Continuous Infusions of Midazolam and Pentobarbital.

Objective: To describe pediatric patients with convulsive refractory status epilepticus in whom there is intention to use an IV anesthetic for seizure control. Design: Two-year prospective observational study evaluating patients (age range, 1 mo to 21 yr) with refractory status epilepticus not responding to two antiepileptic drug classes and treated with continuous infusion of anesthetic agent. Setting: Nine pediatric hospitals in the United States. Patients: In a cohort of 111 patients with refractory status epilepticus (median age, 3.7 yr; 50% male), 54 (49%) underwent continuous infusion of anesthetic treatment. Main Results: The median (interquartile range) ICU length of stay was 10 (3–20) days. Up to four “cycles” of serial anesthetic therapy were used, and seizure termination was achieved in 94% by the second cycle. Seizure duration in controlled patients was 5.9 (1.9–34) hours for the first cycle and longer when a second cycle was required (30 [4–120] hr; p = 0.048). Midazolam was the most frequent first-line anesthetic agent (78%); pentobarbital was the most frequently used second-line agent after midazolam failure (82%). An electroencephalographic endpoint was used in over half of the patients; higher midazolam dosing was used with a burst suppression endpoint. In midazolam nonresponders, transition to a second agent occurred after a median of 1 day. Most patients (94%) experienced seizure termination with these two therapies. Conclusions: Midazolam and pentobarbital remain the mainstay of continuous infusion therapy for refractory status epilepticus in the pediatric patient. The majority of patients experience seizure termination within a median of 30 hours. These data have implications for the design and feasibility of future intervention trials. That is, testing a new anesthetic anticonvulsant after failure of both midazolam and pentobarbital is unlikely to be feasible in a pediatric study, whereas a decision to test an alternative to pentobarbital, after midazolam failure, may be possible in a multicenter multinational study.

Refractory status epilepticus in children with and without prior epilepsy or status epilepticus

Objective: To compare refractory convulsive status epilepticus (rSE) management and outcome in children with and without a prior diagnosis of epilepsy and with and without a history of status epilepticus (SE). Methods: This was a prospective observational descriptive study performed from June 2011 to May 2016 on pediatric patients (1 month–21 years of age) with rSE. Results: We enrolled 189 participants (53% male) with a median (25th–75th percentile) age of 4.2 (1.3–9.6) years. Eighty-nine (47%) patients had a prior diagnosis of epilepsy. Thirty-four (18%) patients had a history of SE. The time to the first benzodiazepine was similar in participants with and without a diagnosis of epilepsy (15 [5–60] vs 16.5 [5–42.75] minutes, p = 0.858). Patients with a diagnosis of epilepsy received their first non-benzodiazepine (BZD) antiepileptic drug (AED) later (93 [46–190] vs 50.5 [28–116] minutes, p = 0.002) and were less likely to receive at least one continuous infusion (35/89 [39.3%] vs 57/100 [57%], p = 0.03). Compared to patients with no history of SE, patients with a history of SE received their first BZD earlier (8 [3.5–22.3] vs 20 [5–60] minutes, p = 0.0073), although they had a similar time to first non-BZD AED (76.5 [45.3–124] vs 65 [32.5–156] minutes, p = 0.749). Differences were mostly driven by the patients with an out-of-hospital rSE onset. Conclusions: Our study establishes that children with rSE do not receive more timely treatment if they have a prior diagnosis of epilepsy; however, a history of SE is associated with more timely administration of abortive medication.

Presentation, diagnosis and treatment of bilateral Rasmussen's encephalitis in a 12-year-old female

AimTo describe the clinical course and pathological diagnosis of a 12-year-old female who presented with an acute syndrome of right hemispheric epilepsy and cortical dysfunction and brain MRI demonstrating atrophy of the left cerebral and right cerebellar hemispheres.ResultsThe patient presented with occasional partial seizures consisting of a left calf sensation followed by left leg clonic jerking. Initial brain MRI showed left cerebral and right cerebellar atrophy with T2 hyperintensity in the left parietal region. After six months, the seizure frequency increased and semiology evolved to include frequent clonic movements of the left side of the face, arm and leg and epilepsia partialis continua (EPC) of the left arm and leg. There was progressive weakness of the left leg and, to a lesser extent, her left arm. MRI at this time demonstrated an additional T2 hyperintensity in the right frontal lobe. An extensive evaluation for paraneoplastic, mitochondrial, and genetic epilepsy syndromes was unrevealing. On biopsy evaluation, chronic T-cell mediated encephalitis was demonstrated within bilateral frontal lobes. Treatment with immunomodulatory therapy resulted in some improvement in her seizure frequency and motor function.ConclusionRasmussen’s encephalitis can be a challenging diagnosis. The patient’s clinical history, including EPC, with bilateral frontal lobe biopsies confirming a T-cell mediated encephalitis supports a diagnosis of bilateral Rasmussen encephalitis. This case highlights the diagnostic challenges and treatment dilemmas that arise in an adolescent presenting with bilateral inflammatory lesions of Rasmussen’s encephalitis.

Efficacy and safety of ketogenic diet for treatment of pediatric convulsive refractory status epilepticus

PURPOSE To describe the efficacy and safety of ketogenic diet (KD) for convulsive refractory status epilepticus (RSE). METHODS RSE patients treated with KD at the 6/11 participating institutions of the pediatric Status Epilepticus Research Group from January-2011 to December-2016 were included. Patients receiving KD prior to the index RSE episode were excluded. RSE was defined as failure of ≥2 anti-seizure medications, including at least one non-benzodiazepine drug. Ketosis was defined as serum beta-hydroxybutyrate levels >20 mg/dl (1.9 mmol/l). Outcomes included proportion of patients with electrographic (EEG) seizure resolution within 7 days of starting KD, defined as absence of seizures and ≥50% suppression below 10 μV on longitudinal bipolar montage (suppression-burst ratio ≥50%); time to start KD after onset of RSE; time to achieve ketosis after starting KD; and the proportion of patients weaned off continuous infusions 2 weeks after KD initiation. Treatment-emergent adverse effects (TEAEs) were also recorded. RESULTS Fourteen patients received KD for treatment of RSE (median age 4.7 years, interquartile range [IQR] 5.6). KD was started via enteral route in 11/14 (78.6%) patients. KD was initiated a median of 13 days (IQR 12.5) after the onset of RSE, at 4:1 ratio in 8/14 (57.1%) patients. Ketosis was achieved within a median of 2 days (IQR 2.0) after starting KD. EEG seizure resolution was achieved within 7 days of starting KD in 10/14 (71.4%) patients. Also, 11/14 (78.6%) patients were weaned off their continuous infusions within 2 weeks of starting KD. TEAEs, potentially attributable to KD, occurred in 3/14 (21.4%) patients, including gastro-intestinal paresis and hypertriglyceridemia. Three month outcomes were available for 12/14 (85.7%) patients, with 4 patients being seizure-free, and 3 others with decreased seizure frequency compared to pre-RSE baseline. CONCLUSIONS This series suggests efficacy and safety of KD for treatment of pediatric RSE.

Olfactory Bulbectomy Leads to the Development of Epilepsy in Mice.

There is a clear link between epilepsy and depression. Clinical data demonstrate a 30–35% lifetime prevalence of depression in patients with epilepsy, and patients diagnosed with depression have a three to sevenfold higher risk of developing epilepsy. Traditional epilepsy models partially replicate the clinical observations, with the demonstration of depressive traits in epileptic animals. Studies assessing pro-epileptogenic changes in models of depression, however, are more limited. Here, we examined whether a traditional rodent depression model—bilateral olfactory bulbectomy—predisposes the animals towards the development of epilepsy. Past studies have demonstrated increased neuronal excitability after bulbectomy, but continuous seizure monitoring had not been conducted. For the present study, we monitored control and bulbectomized animals by video-EEG 24/7 for approximately two weeks following the surgery to determine whether they develop spontaneous seizures. All seven bulbectomized mice exhibited seizures during the monitoring period. Seizures began about one week after surgery, and occurred in clusters with severity increasing over the monitoring period. These results suggest that olfactory bulbectomy could be a useful model of TBI-induced epilepsy, with advantages of relatively rapid seizure onset and a high number of individuals developing the disease. The model may also be useful for investigating the mechanisms underlying the bidirectional relationship between epilepsy and depression.