Psychiatric and behavioral adverse events in randomized clinical studies of the noncompetitive AMPA receptor antagonist perampanel
Perampanel, a selective, noncompetitive α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) glutamate receptor antagonist, is indicated for adjunctive treatment of partial seizures in patients ≥12 years based on three phase III clinical studies. The perampanel U.S. Prescribing Information includes a boxed warning for serious psychiatric and behavioral adverse reactions. To provide context for this warning, detail on psychiatric and behavioral safety data from perampanel clinical studies is presented.Methods
An analysis of pooled safety data from three phase III studies in patients with partial seizures is presented. Data from phase I and phase II studies in patients with and without epilepsy were also analyzed. Psychiatric and behavioral treatment-emergent adverse events (TEAEs) were evaluated according to Medical Dictionary for Regulatory Activities (MedDRA) terms, using “narrow” and “narrow-and-broad” standardized MedDRA queries (SMQs) for TEAEs suggestive of hostility/aggression.Results
From the three phase III partial-seizure studies, the overall rate of psychiatric TEAEs was higher in the 8 mg (17.2%) and 12 mg (22.4%) perampanel groups versus placebo (12.4%). In the “narrow” SMQ, hostility/aggression TEAEs were observed in 2.8% for 8 mg and 6.3% for 12 mg perampanel groups, versus 0.7% of placebo patients. “Narrow-and-broad” SMQs for hostility/aggression TEAE rates were 12.3% for 8 mg and 20.4% for 12 mg perampanel groups, versus 5.7% for placebo; rates for events resulting in discontinuation were perampanel = 1.6% versus placebo = 0.7%. For events reported as serious AEs (SAEs), rates were perampanel = 0.7% versus placebo = 0.2%. In nonepilepsy patients, psychiatric TEAEs were similar between patients receiving perampanel and placebo. In phase I subjects/volunteers, all psychiatric TEAEs were mild or moderate. These analyses suggest that psychiatric adverse effects are associated with use of perampanel.Significance
Patients and caregivers should be counseled regarding the potential risk of psychiatric and behavioral events with perampanel in patients with partial seizures; patients should be monitored for these events during treatment, especially during titration and at higher doses.
KCNT1 mutations have been found in epilepsy of infancy with migrating focal seizures (EIMFS; also known as migrating partial seizures in infancy), autosomal dominant nocturnal frontal lobe epilepsy, and other types of early onset epileptic encephalopathies (EOEEs). We performed KCNT1-targeted next-generation sequencing (207 samples) and/or whole-exome sequencing (229 samples) in a total of 362 patients with Ohtahara syndrome, West syndrome, EIMFS, or unclassified EOEEs. We identified nine heterozygous KCNT1 mutations in 11 patients: nine of 18 EIMFS cases (50%) in whom migrating foci were observed, one of 180 West syndrome cases (0.56%), and one of 66 unclassified EOEE cases (1.52%). KCNT1 mutations occurred de novo in 10 patients, and one was transmitted from the patient's mother who carried a somatic mosaic mutation. The mutations accumulated in transmembrane segment 5 (2/9, 22.2%) and regulators of K+ conductance domains (7/9, 77.8%). Five of nine mutations were recurrent. Onset ages ranged from the neonatal period (<1 month) in five patients (5/11, 45.5%) to 1–4 months in six patients (6/11, 54.5%). A generalized attenuation of background activity on electroencephalography was seen in six patients (6/11, 54.5%). Our study demonstrates that the phenotypic spectrum of de novo KCNT1 mutations is largely restricted to EIMFS.
Summary of recommendations for the management of infantile seizures: Task Force Report for the ILAE Commission of Pediatrics
Evidence-based guidelines, or recommendations, for the management of infants with seizures are lacking. A Task Force of the Commission of Pediatrics developed a consensus document addressing diagnostic markers, management interventions, and outcome measures for infants with seizures. Levels of evidence to support recommendations and statements were assessed using the American Academy of Neurology Guidelines and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. The report contains recommendations for different levels of care, noting which would be regarded as standard care, compared to optimal care, or “state of the art” interventions. The incidence of epilepsy in the infantile period is the highest of all age groups (strong evidence), with epileptic spasms the largest single subgroup and, in the first 2 years of life, febrile seizures are the most commonly occurring seizures. Acute intervention at the time of a febrile seizure does not alter the risk for subsequent epilepsy (class 1 evidence). The use of antipyretic agents does not alter the recurrence rate (class 1 evidence), and there is no evidence to support initiation of regular antiepileptic drugs for simple febrile seizures (class 1 evidence). Infants with abnormal movements whose routine electroencephalography (EEG) study is not diagnostic, would benefit from video-EEG analysis, or home video to capture events (expert opinion, level U recommendation). Neuroimaging is recommended at all levels of care for infants presenting with epilepsy, with magnetic resonance imaging (MRI) recommended as the standard investigation at tertiary level (level A recommendation). Genetic screening should not be undertaken at primary or secondary level care (expert opinion). Standard care should permit genetic counseling by trained personal at all levels of care (expert opinion). Genetic evaluation for Dravet syndrome, and other infantile-onset epileptic encephalopathies, should be available in tertiary care (weak evidence, level C recommendation). Patients should be referred from primary or secondary to tertiary level care after failure of one antiepileptic drug (standard care) and optimal care equates to referral of all infants after presentation with a seizure (expert opinion, level U evidence). Infants with recurrent seizures warrant urgent assessment for initiation of antiepileptic drugs (expert opinion, level U recommendation). Infantile encephalopathies should have rapid introduction and increment of antiepileptic drug dosage (expert opinion, level U recommendation). There is no high level evidence to support any particular current agents for use in infants with seizures. For focal seizures, levetiracetam is effective (strong evidence); for generalized seizures, weak evidence supports levetiracetam, valproate, lamotrigine, topiramate, and clobazam; for Dravet syndrome, strong evidence supports that stiripentol is effective (in combination with valproate and clobazam), whereas weak evidence supports that topiramate, zonisamide, valproate, bromide, and the ketogenic diet are possibly effective; and for Ohtahara syndrome, there is weak evidence that most antiepileptic drugs are poorly effective. For epileptic spasms, clinical suspicion remains central to the diagnosis and is supported by EEG, which ideally is prolonged (level C recommendation). Adrenocorticotropic hormone (ACTH) is preferred for short-term control of epileptic spasms (level B recommendation), oral steroids are probably effective in short-term control of spasms (level C recommendation), and a shorter interval from the onset of spasms to treatment initiation may improve long-term neurodevelopmental outcome (level C recommendation). The ketogenic diet is the treatment of choice for epilepsy related to glucose transporter 1 deficiency syndrome and pyruvate dehydrogenase deficiency (expert opinion, level U recommendation). The identification of patients as potential candidates for epilepsy surgery should be part of standard practice at primary and secondary level care. Tertiary care facilities with experience in epilepsy surgery should undertake the screening for epilepsy surgical candidates (level U recommendation). There is insufficient evidence to conclude if there is benefit from vagus nerve stimulation (level U recommendation). The key recommendations are summarized into an executive summary. The full report is available as Supporting Information. This report provides a comprehensive foundation of an approach to infants with seizures, while identifying where there are inadequate data to support recommended practice, and where further data collection is needed to address these deficits.
Autosomal dominant mutations in the sodium-gated potassium channel subunit gene KCNT1 have been associated with two distinct seizure syndromes, nocturnal frontal lobe epilepsy (NFLE) and malignant migrating focal seizures of infancy (MMFSI). To further explore the phenotypic spectrum associated with KCNT1, we examined individuals affected with focal epilepsy or an epileptic encephalopathy for mutations in the gene. We identified KCNT1 mutations in 12 previously unreported patients with focal epilepsy, multifocal epilepsy, cardiac arrhythmia, and in a family with sudden unexpected death in epilepsy (SUDEP), in addition to patients with NFLE and MMFSI. In contrast to the 100% penetrance so far reported for KCNT1 mutations, we observed incomplete penetrance. It is notable that we report that the one KCNT1 mutation, p.Arg398Gln, can lead to either of the two distinct phenotypes, ADNFLE or MMFSI, even within the same family. This indicates that genotype–phenotype relationships for KCNT1 mutations are not straightforward. We demonstrate that KCNT1 mutations are highly pleiotropic and are associated with phenotypes other than ADNFLE and MMFSI. KCNT1 mutations are now associated with Ohtahara syndrome, MMFSI, and nocturnal focal epilepsy. They may also be associated with multifocal epilepsy and cardiac disturbances.
Intermittent dosing of rapamycin maintains antiepileptogenic effects in a mouse model of tuberous sclerosis complex
Inhibitors of the mechanistic target of rapamycin (mTOR) pathway have antiepileptogenic effects in preventing epilepsy and pathologic and molecular mechanisms of epileptogenesis in mouse models of tuberous sclerosis complex (TSC). However, long-term treatment with mTOR inhibitors may be required to maintain efficacy and potentially has chronic side effects, such as immunosuppression. Attempts to minimize drug exposure will facilitate translational efforts to develop mTOR inhibitors as antiepileptogenic agents for patients with TSC. In this study, we tested intermittent dosing paradigms of mTOR inhibitors for antiepileptogenic properties in a TSC mouse model.Methods
Western blot analysis of phosphorylation of S6 protein was used to assess the dose- and time-dependence of mTOR inhibition by rapamycin in control mice and conditional knockout mice with inactivation of the Tsc1 gene in glial fibrillary acidic protein (GFAP)–expressing cells (Tsc1GFAPCKO mice). Based on the Western blot studies, different dosing paradigms of rapamycin starting at postnatal day 21 were tested for their ability to prevent epilepsy or pathologic abnormalities in Tsc1GFAPCKO mice: 4 days of rapamycin only (4–∞), 4 days on–24 days off (4–24), and 4 days on–10 days off (4–10).Results
mTOR activity was inhibited by rapamycin in a dose-dependent fashion and recovered to baseline by about 10 days after the last rapamycin dose. The 4–10 and 4–24 dosing paradigms almost completely prevented epilepsy and the 4–10 paradigm inhibited glial proliferation and megalencephaly in Tsc1GFAPCKO mice.Significance
Intermittent dosing of rapamycin, with drug holidays of more than 3 weeks, maintains significant antiepileptogenic properties in mouse models of TSC. These findings have important translational applications in developing mTOR inhibitors as antiepileptogenic agents in TSC patients by minimizing drug exposure and potential side effects.
Self-management challenges facing adults with epilepsy include limited understanding of the condition and treatment, associated psychosocial issues, and lack of community integration. Self-management interventions improve patients' medical, life role, and emotional management. Previous interventions, developed from expert opinion, indicated issues with participant engagement/retention, and limited follow-up periods. PACES in Epilepsy addressed methodologic concerns by utilizing patient needs assessment data (n = 165) to derive self-management content and program features for evaluation via randomized controlled trial (RCT).Methods
Participants were adults with chronic epilepsy (n = 83), without serious mental illness or substantive intellectual impairment, who were recruited from two epilepsy centers. Participants were assigned randomly to intervention or treatment-as-usual groups. Outcomes included the Epilepsy Self-Management Scale (ESMS), Epilepsy Self-Efficacy Scale (ESES), Quality of Life in Epilepsy-31 (QOLIE-31), Patient Health Questionnaire-9 (PHQ-9), and the Generalized Anxiety Disorder-7 (GAD-7), administered at baseline, postintervention (8 weeks), and 6 months postintervention. The intervention was an 8-week group of 6–8 adults co-led by a psychologist and trained peer with epilepsy that met one evening per week at a hospital for 75 min. Topics included medical, psychosocial, cognitive, and self-management aspects of epilepsy, in addition to community integration and optimizing epilepsy-related communication. The treatment group provided satisfaction ratings regarding program features.Results
PACES participants (n = 38) improved relative to controls (n = 40) on the ESMS (p < 0.001) and subscales [Information (p < 0.001); Lifestyle (p < 0.002)]; ESES (p < 0.001); and QOLIE-31 (p = 0.002). At 6-month follow up, PACES participants remained improved on the ESMS (p = 0.004) and Information subscale (p = 0.009); and Energy/Fatigue (p = 0.032) and Medication Effects (p = 0.005) of the QOLIE-31. Attrition in both groups was low (8% in each group) and all program satisfaction ratings exceeded 4.0/5.0, with leadership (4.76), topics (4.53), and location (4.30) as the most highly rated aspects.Significance
A consumer generated epilepsy self-management program appears to be a promising intervention from multiple perspectives, particularly in relation to disability management.
Rapid brief feedback intracerebral stimulation based on real-time desynchronization detection preceding seizures stops the generation of convulsive paroxysms
To investigate the abortion of seizure generation using “minimal” intervention in hippocampi using two rat models of human temporal lobe epilepsy.Methods
The recording or stimulation electrodes were implanted into both hippocampi (CA1 area). Using the kainic acid (chronic: experiment duration 24 days) and the 4-aminopyridine (acute: experiment duration 2 h) models of paroxysms in rats, a real-time feedback stimulation paradigm was implemented, which triggered a short periodic electrical stimulus (5 Hz for 5 s) upon detecting a seizure precursor. Our seizure precursor detection algorithm relied on the monitoring of the real-time phase synchronization analysis, and detected/anticipated electrographic seizures as early as a few seconds to a few minutes before the behavioral and electrographic seizure onset, with a very low false-positive rate of the detection.Results
The baseline mean seizure frequencies were 5.39 seizures per day (chronic) and 13.2 seizures per hour (acute). The phase synchrony analysis detected 88% (434 of 494) of seizures with a mean false alarm of 0.67 per day (chronic) and 83% (86 of 104) of seizures with a mean false alarm of 0.47 per hour (acute). The feedback stimulation reduced the seizure frequencies to 0.41 seizures per day (chronic) and 2.4 seizures per hour (acute). Overall, the feedback stimulation paradigm reduced seizure frequency by a minimum of 80% to a maximum of 100% in 10 rats, with 83% of the animals rendered seizure-free.Significance
This approach represents a simple and efficient manner for stopping seizure development. Because of the short on-demand stimuli, few or no associated side effects are expected in clinical application in patients with epilepsy. Abnormal synchrony patterns are common features in epilepsy and other neurologic and psychiatric syndromes; therefore, this type of feedback stimulation paradigm could be a novel therapeutic modality for use in various neurologic and psychiatric disorders.
Seizure characteristics of epilepsy in childhood after acute encephalopathy with biphasic seizures and late reduced diffusion
The aim of this study was to clarify characteristics of post-encephalopathic epilepsy (PEE) in children after acute encephalopathy with biphasic seizures and late reduced diffusion (AESD), paying particular attention to precise diagnosis of seizure types.Methods
Among 262 children with acute encephalopathy/encephalitis registered in a database of the Tokai Pediatric Neurology Society between 2005 and 2012, 44 were diagnosed with AESD according to the clinical course and magnetic resonance imaging (MRI) findings and were included in this study. Medical records were reviewed to investigate clinical data, MRI findings, neurologic outcomes, and presence or absence of PEE. Seizure types of PEE were determined by both clinical observation by pediatric neurologists and ictal video–electroencephalography (EEG) recordings.Results
Of the 44 patients after AESD, 10 (23%) had PEE. The period between the onset of encephalopathy and PEE ranged from 2 to 39 months (median 8.5 months). Cognitive impairment was more severe in patients with PEE than in those without. Biphasic seizures and status epilepticus during the acute phase of encephalopathy did not influence the risk of PEE. The most common seizure type of PEE on clinical observation was focal seizures (n = 5), followed by epileptic spasms (n = 4), myoclonic seizures (n = 3), and tonic seizures (n = 2). In six patients with PEE, seizures were induced by sudden unexpected sounds. Seizure types confirmed by ictal video-EEG recordings were epileptic spasms and focal seizures with frontal onset, and all focal seizures were startle seizures induced by sudden acoustic stimulation. Intractable daily seizures remain in six patients with PEE.Significance
We demonstrate seizure characteristics of PEE in children after AESD. Epileptic spasms and startle focal seizures are common seizure types. The specific seizure types may be determined by the pattern of diffuse subcortical white matter injury in AESD and age-dependent reorganization of the brain network.
Sudden unexplained death in childhood: A comparison of cases with and without a febrile seizure history
We considered whether a subset of children with sudden unexplained death in childhood (SUDC) and a history of febrile seizures (FS) may parallel those in sudden unexpected death in epilepsy (SUDEP). The prevalence of a history of FS was examined, and factors that may distinguish SUDC cases with and without FS were described.Methods
Characteristics were assessed in 123 consecutive children with SUDC reported to the SUDC program (4/1/11-3/31/14) by their parents. Parental interview covered the decedent's medical history, circumstances of death, environmental factors, cause of death, and family medical history. Features of SUDC cases were compared by FS history.Results
Overall, 31.7% of SUDC cases had a history of FS, among which 74.4% had simple FS. Compared to those without a history of FS, a history of FS was associated with a greater median age at death (p = 0.03) and death during the weekdays (p = 0.02). Terminal fever was similar in those with and without FS. The median time from FS to death was 6.0 months (interquartile range [IQR] 3.0–10.0). In all SUDC cases, prone position at death, death during sleep, and unwitnessed deaths predominated.Significance
There are parallels among SUDC, sudden infant deaths, and sudden unexpected death in epilepsy (SUDEP) with regard to prone position, unwitnessed deaths mostly during sleep, and male predominance. In children with SUDC and a history of FS, terminal fever may increase the risk for an unwitnessed terminal seizure. The greater than expected prevalence of a FS history and the proportion with terminal fever or illness in this cohort suggests that some SUDC deaths may be seizure related and therefore have potential commonalities with SUDEP.
Epilepsy and hippocampal neurodegeneration induced by glutamate decarboxylase inhibitors in awake rats
Fycompa (perampanel) receives European MA for PGTC seizures in patients with idiopathic generalised epilepsy
Under an expanded access investigational new drug (IND) trial, cannabidiol (CBD) is being studied as a possible adjuvant treatment of refractory epilepsy in children. Of the 25 subjects in the trial, 13 were being treated with clobazam (CLB). Because CLB and CBD are both metabolized in the cytochrome P450 (CYP) pathway, we predicted a drug–drug interaction, which we evaluate in this article.Methods
Thirteen subjects with refractory epilepsy concomitantly taking CLB and CBD under IND 119876 were included in this study. Demographic information was collected for each subject including age, sex, and etiology of seizures, as well as concomitant antiepileptic drugs (AEDs). CLB, N-desmethylclobazam (norclobazam; nCLB), and CBD levels were measured over the course of CBD treatment. CLB doses were recorded at baseline and at weeks 4 and 8 of CBD treatment. Side effects were monitored.Results
We report elevated CLB and nCLB levels in these subjects. The mean (± standard deviation [SD]) increase in CLB levels was 60 ± 80% (95% confidence interval (CI) [−2–91%] at 4 weeks); the mean increase in nCLB levels was 500 ± 300% (95% CI [+90–610%] at 4 weeks). Nine of 13 subjects had a >50% decrease in seizures, corresponding to a responder rate of 70%. The increased CLB and nCLB levels and decreases in seizure frequency occurred even though, over the course of CBD treatment, CLB doses were reduced for 10 (77%) of the 13 subjects. Side effects were reported in 10 (77%) of the 13 subjects, but were alleviated with CLB dose reduction.Significance
Monitoring of CLB and nCLB levels is necessary for clinical care of patients concomitantly on CLB and CBD. Nonetheless, CBD is a safe and effective treatment of refractory epilepsy in patients receiving CLB treatment.