On Seizures and Knives: Perampanel-Induced Psychosis: A Case Report and Literature Review.

Managing epilepsy in the context of intellectual disability can be complicated as this population is known to have higher rates of drug resistance and sensitivity to side effects of antiseizure medications (ASMs). Perampanel is a novel ASM recently approved as an adjunctive treatment for drug resistant focal seizures. It carries a black-box warning for serious psychiatric and behavioral adverse reactions of aggression, irritability, et cetera. However, psychosis is a seldom reported side effect of perampanel. We herein describe a case of a 15-year-old girl with moderate intellectual disability who presented with refractory seizures managed successfully after using perampanel. Around 2 months later, she developed psychosis and aggression. The patient's history lacked any significant family or personal history of mental illness. Managing psychotic symptoms was difficult in this case; as perampanel was needed for proper seizure control, and both psychosis and seizures were severe and significantly endangering the patient and people around her. Thus, symptoms were addressed by adding a low-dose risperidone, an atypical antipsychotic. This paper highlights the importance of pre-treatment counselling and monitoring for the emergence of psychiatric side effects including the rarely occurring psychosis while using perampanel, particularly in highly sensitive patients, e.g., those with intellectual disability. We also emphasize on the importance of accurate weighing of risks and benefits while managing psychosis as an adverse event to ASMs in the background of drug-resistant epilepsy.

Effects of CYP3A4 genetic polymorphisms on the pharmacokinetics and efficacy of perampanel in Chinese pediatric patients with epilepsy.

OBJECTIVE: This study was the first to evaluate the effect of CYP3A4 gene polymorphisms on the plasma concentration and effectiveness of perampanel (PER) in Chinese pediatric patients with epilepsy. METHODS: We enrolled 102 patients for this investigation. The steady-state concentration was determined after patients maintained a consistent PER dosing regimen for at least 21 days. Plasma PER concentrations were measured using liquid chromatography-tandem mass spectrometry. Leftover samples from standard therapeutic drug monitoring were allocated for genotyping analysis. The primary measure of efficacy was the rate of seizure reduction with PER treatment at the final check-up. RESULTS: The CYP3A4×10 GC phenotype exhibited the highest average plasma concentration of PER at 491.1 ±â€¯328.1 ng/mL, in contrast to the CC phenotype at 334.0 ±â€¯161.1 ng/mL. The incidence of adverse events was most prominent in the CYP3A4×1 G TT and CYP3A4×10 GC groups, with rates of 77.8 % (7 of 9 patients) and 50.0 % (46 of 92 patients), respectively. Moreover, the percentage of patients for whom PER was deemed ineffective was least in the CYP3A4×1 G TT and CYP3A4×10 CC groups, recorded at 11.1 % (1 of 9 patients) and 10.0 % (1 of 10 patients), respectively. There was a significant correlation between PER plasma concentration and either exposure or toxicity (both with p < 0.05). We suggest a plasma concentration range of 625-900 ng/mL as a suitable reference for PER in Chinese patients with epilepsy. CONCLUSION: The CYP3A4×10 gene's genetic polymorphisms influence plasma concentrations of PER in Chinese pediatric patients with epilepsy. Given that both efficacy and potential toxicity are closely tied to plasma PER levels, the CYP3A4 genetic phenotype should be factored in when prescribing PER to patients with epilepsy.

Efficacy of perampanel by etiology in Japanese patients with epilepsy-subpopulation analysis of a prospective post-marketing observational study.

OBJECTIVE: To examine the efficacy and safety of perampanel (PER) in patients with post-stroke epilepsy (PSE), brain tumor-related epilepsy (BTRE), and post-traumatic epilepsy (PTE) using Japanese real-world data. METHODS: The prospective post-marketing observational study included patients with focal seizures with or without focal to bilateral tonic-clonic seizures who received PER combination therapy. The observation period was 24 or 52 weeks after the initial PER administration. The safety and efficacy analysis included 3716 and 3272 patients, respectively. This post hoc analysis examined responder rate (50% reduction in seizure frequency), seizure-free rate (proportion of patients who achieved seizure-free), and safety in patients included in the post-marketing study who had PSE, BTRE, and PTE in the 4 weeks prior to the last observation. RESULTS: Overall, 402, 272, and 186 patients were included in the PSE, BTRE, and PTE subpopulations, and 2867 controls in the "Other" population (etiologies other than PSE, BTRE, or PTE). Mean modal dose (the most frequently administered dose) values at 52 weeks were 3.38, 3.36, 3.64, and 4.04 mg/day for PSE, BTRE, PTE, and "Other," respectively; PER retention rates were 56.2%, 54.0%, 52.6%, and 59.7%, respectively. Responder rates (% [95% confidence interval]) were 82% (76.3%-86.5%), 78% (70.8%-83.7%), 67% (56.8%-75.6%), and 50% (47.9%-52.7%) for PSE, BTRE, PTE, and "Other," respectively, and seizure-free rates were 71% (64.5%-76.5%), 62% (54.1%-69.0%), 50% (40.6%-60.4%), and 28% (25.8%-30.1%), respectively. Adverse drug reactions tended to occur less frequently in the PSE (14.7%), BTRE (16.5%), and PTE (16.7%) subpopulations than in the "Other" population (26.3%). SIGNIFICANCE: In real-world clinical conditions, efficacy and tolerability for PER combination therapy were observed at low PER doses for the PSE, BTRE, and PTE subpopulations. PLAIN LANGUAGE SUMMARY: To find out how well the medication perampanel works and whether it is safe for people who have epilepsy after having had a stroke, brain tumor, or head injury, we used information from real-life medical situations in Japan. We looked at the data of about 3700 Japanese patients with epilepsy who were treated with perampanel. We found that perampanel was used at lower doses and better at controlling seizures, and had fewer side effects for patients with epilepsy caused by these etiologies than the control group.

Perampanel as an Add-On Therapy in Patients with Refractory Status Epilepticus and Postanoxic Encephalopathy: A Real-Life Single-Center Retrospective Cohort Study.

BACKGROUND: Data on the efficacy of perampanel in refractory status epilepticus (RSE) and postanoxic encephalopathy (PAE) are limited; its use in such conditions is currently off-label. METHODS: We conducted a retrospective cohort study of consecutive adult patients with RSE, including PAE, exhibiting electroencephalographic patterns indicative of status epilepticus who were treated at our center (January 2018 to December 2022) with assessment of clinical and electroencephalographic outcomes. RESULTS: Thirty-six patients were included in the study, of whom 29 had nonanoxic RSE and 7 had PAE. Within the nonanoxic RSE subgroup, 45% (13 of 29; 95% confidence interval [CI] 27-63%) of study participants were responders, 34% (10 of 29; 95% CI 17-52%) were partial responders, and 21% (6 of 29; 95% CI 6-35%) were nonresponders. In the PAE subgroup (n = 7), no patients fully responded to perampanel; 43% (3 of 7; 95% CI 6-80%) were partial responders, and 57% (4 of 7; 95% CI 20-95%) were nonresponders. Responder and nonresponder study participants exhibited overlapping baseline characteristics. No significant differences in duration of hospitalization were observed between responders and nonresponders in both subgroups. Responders in the RSE subgroup had a median discharge modified Rankin Scale score of 3 (interquartile range 3-4), and nonresponders had a median discharge modified Rankin Scale score of 5 (interquartile range 5-6). CONCLUSIONS: Despite limitations from the retrospective design and the small population size, this study suggests that perampanel use in nonanoxic RSE appears to yield promising results at moderate doses, including a tendency toward a better functional outcome at discharge, without significant adverse effects. However, in patients with PAE, the drug seems to show suboptimal performance. Perampanel appears to have promising efficacy as an add-on therapy in nonanoxic RSE. However, in patients with PAE, its efficacy seems to be lower. Further studies are warranted to confirm these observations.

Redefined giant somatosensory evoked potentials: Evoked epileptic complexes of excitatory and inhibitory components.

OBJECTIVE: Giant somatosensory evoked potentials (SEPs) are observed in patients with cortical myoclonus. Short-latency components (SLC), are regarded as evoked epileptic activities or paroxysmal depolarization shifts (PDSs). This study aimed to reveal the electrophysiological significance of the middle-latency component (MLC) P50 of the SEPs. METHODS: Twenty-two patients with cortical myoclonus having giant SEPs (patient group) and 15 healthy controls were included in this study. Waveform changes in SEPs before and after perampanel (PER) treatment were evaluated in the patient group. The wide range, time-frequency properties underlying the waveforms were compared between the groups. RESULTS: After PER treatment, SLC was prolonged and positively correlated with PER concentration, whereas MLC showed no correlation with PER concentration. Time-frequency analysis showed a power increase (156 Hz in all patients, 624 Hz in benign adult familial myoclonus epilepsy patients) underlying SLC and a power decrease (156 Hz, 624 Hz) underlying MLC in the patient group. CONCLUSIONS: The high-frequency power increase in SLCs and decrease in MLCs clearly reflected PDS and subsequent hyperpolarization, respectively. This relationship was similar to that of interictal epileptiform discharges, suggesting that giant SEPs evoke epileptic complexes of excitatory and inhibitory components. SIGNIFICANCE: MLCs of giant SEPs reflected inhibitory components.

Serum perampanel levels in patients with seizures are not affected by hemodialysis.

Perampanel belongs to a novel class of antiseizure medications (ASMs). Studies examining the effect of hemodialysis on perampanel serum levels in clinical settings are lacking. We aimed to evaluate the changes in serum perampanel levels during hemodialysis. We studied patients with seizures who received oral perampanel between April 2020 and March 2023 and whose serum concentration of perampanel was measured before and after hemodialysis. We analyzed the serum concentrations of levetiracetam and lacosamide for comparison. Fourteen patients, with a mean age of 76.1 ± 7.88 years, were included. The dose of perampanel was 2.14 ± 1.27 mg. The hemodialysis clearance rate of perampanel, levetiracetam, and lacosamide was 0 ± 13%, 69 ± 11%, and 59.6 ± 8.2%, respectively. The post-dialysis CD ratio decreased significantly with levetiracetam but not with perampanel. Adverse but acceptable effects of perampanel were observed in two patients. The serum concentrations of several ASMs have been shown to be reduced during hemodialysis. Our study revealed that the serum perampanel concentration does not decrease during hemodialysis. Owing to the low rate of adverse effects and the stability of perampanel serum concentration during hemodialysis, perampanel could be a favorable choice as an ASM for patients with seizures undergoing hemodialysis. PLAIN LANGUAGE SUMMARY: Our study looked at how hemodialysis affects the serum levels of perampanel, a new type of medication for seizures. In 14 patients who started treatment between April 2020 and March 2023, perampanel serum levels did not decrease during hemodialysis, unlike other seizure medications. This shows that perampanel can be a good option for patients with seizures who need hemodialysis, with fewer side effects compared to other medications.

Differences in factors associated with insomnia symptoms between patients with epilepsy with and without depressive symptoms.

OBJECTIVE: To determine if insomnia-related factors differ depending on the presence of depression in patients with epilepsy. METHODS: This cross-sectional multicenter study collected data on depressive symptoms, insomnia symptoms, and excessive daytime sleepiness, which were defined as a Patient Health Questionnaire-9 (PHQ-9) score of ≥ 10, an Insomnia Severity Index (ISI) score of ≥ 15, and an Epworth Sleepiness Scale (ESS) of ≥ 11, respectively. Further, uncontrolled seizures were defined as one or more seizures per month during antiseizure medications treatment. A stepwise logistic regression analysis was conducted, with a logistic regression with interaction terms performed to identify differences in insomnia-related factors depending on depressive symptoms. RESULTS: Of 282 adults with epilepsy (men, 58 %; mean age, 40.4 ± 13.9 years), a PHQ-9 score ≥ 10, an ISI score ≥ 15, an ESS score ≥ 11 were noted in 23.4 % (n = 66), 20.2 % (n = 57), and 12.8 % (n = 36), respectively. More patients with depressive symptoms had an ISI score ≥ 15 (56.1 % vs. 9.3 %; p < 0.001) than those without. In multiple logistic regression, uncontrolled seizures (odds ratio [OR], 4.896; p < 0.01), daytime sleepiness (OR, 5.369; p < 0.05), and a history of psychiatric disorders (OR, 3.971; p < 0.05) were identified as significant factors that were more likely to be associated with an ISI score ≥ 15; however, this was only true in patients without depressive symptoms. In contrast, use of perampanel (OR, 0.282; p < 0.05) was less likely associated, while female sex (OR, 3.178; p < 0.05) was more likely associated with an ISI score ≥ 15 only in patients with depressive symptoms. CONCLUSIONS: Insomnia-related factors in patients with epilepsy may differ between patients with and without depression. Our findings of different insomnia-related factors based on the presence of depression may facilitate the management of patients with epilepsy.

Tolerability of perampanel: A retrospective study at the department of psychiatry.

PURPOSE: We aimed to identify factors that contribute to the discontinuation of perampanel. METHODS: We retrospectively analyzed patients with epilepsy at the Department of Psychiatry, Hokkaido University Hospital. We evaluated the factors contributing to perampanel discontinuation as primary outcomes using Cox proportional hazards regression. Then, we explored the components contributing to the primary outcomes using logistic regression analysis. RESULTS: A total of 118 patients were included, 44.9% of whom discontinued participation, 22.0% had intellectual disability, and 23.7% had a psychiatric disorder other than intellectual disability. Adverse effects occurred in 65% of the patients, 23.7% had psychiatric adverse effects (PAE), and 49.2% had common adverse effects (CAE). The effect of PER to suppress seizures was confirmed in 65.3% of them. Discontinuation was influenced by non-response (Hazard Ratio (HR) 6.70, 95% Confidence Interval (CI) 3.42-13.1), the occurrence of PAE (HR 3.68, 95% CI 1.89-7.16), CAE (HR 1.90, 95% CI 1.06-3.41), and comorbid psychiatric disorders (HR 2.35, 95% CI 1.21-4.59). Moreover, comorbid intellectual disability correlated with a low risk of PAE (OR 0.19, 95% CI 0.04-0.89). CONCLUSION: The discontinuation of perampanel is influenced by poor efficacy and the occurrence of common/psychiatric adverse effects. The discontinuation of perampanel is influenced by poor efficacy and the occurrence of common/psychiatric adverse effects. Consideration of factors contributing to perampanel discontinuation may assist in determining the indication for perampanel treatment.

Use of perampanel oral suspension for the treatment of refractory and super-refractory status epilepticus.

INTRODUCTION: Status epilepticus (SE) is a medical emergency associated with a significant risk of disability and death. The treatment of SE follows a step-wise approach, with limited data on ideal antiseizure medications (ASMs) for refractory and super refractory SE (RSE/SRSE). Perampanel (PER), an AMPA receptor antagonist, has shown promise in animal models but still has limited data in humans. This study tried to evaluate optimal dosage and safety of PER in RSE and SRSE patients. MATERIALS AND METHODS: We retrospectively analysed 17 adult patients with RSE (1) or SRSE (16) treated with PER. Demographic and clinical data, including EEG patterns, ASMs administered, PER dosages, and PER plasma concentrations, were collected. For patients receiving a 24 mg PER loading dose (full dose group), the following treatment regimen was applied: 24 mg per day for 48 h following by 16 mg per day. The response to PER was assessed based on electroencephalographic (EEG) improvement from high to low epileptiform activity or from low to the absence of epileptiform activities. Safety was evaluated monitoring hepatic and renal function. RESULTS: A response rate of 58.82 % was observed, with significantly higher responses in the full dose group (81.82 %) compared to those receiving PER doses below 24 mg (low dose group) (16.67 %) (p-value = 0.004; OR 0.044, 95 % CI 0.003 to 0.621, p = 0.021). No other clinical factors significantly influenced treatment response. Hepatic enzymes become elevated in most patients (70.59 %) but spontaneously decreased. DISCUSSION: Our findings suggest that a 24 mg PER dose administered for 48 h may be more effective in managing RSE and SRSE compared to doses below 24 mg, potentially due to pharmacokinetic factors. CONCLUSION: More robust data on PER in RSE and SRSE, including standardized dosing procedures and plasma level monitoring are needed. PER's potential benefits should be explored further, particularly in patients with RSE and SRSE.

Perampanel as monotherapy or first adjunctive therapy in pediatric and adult patients with epilepsy: the first United States-based phase IV open-label ELEVATE study.

ELEVATE (Study 410; NCT03288129) is the first prospective, multicenter, open-label, Phase IV study of perampanel as monotherapy or first adjunctive therapy in patients aged ≥ 4 years with focal-onset seizures or generalized tonic-clonic seizures in the United States. The study included Screening, Titration (≤ 13 weeks), Maintenance (39 weeks), and Follow-up (4 weeks) Periods. During Titration, perampanel was initiated at 2 mg/day and up-titrated to 4 mg/day at Week 3. Depending on response and tolerability, optional up-titrations to a maximum of 12 mg/day occurred. The primary endpoint was retention rate; additional endpoints included seizure-freedom rate, 50% responder rate, and incidence of treatment-emergent adverse events (TEAEs). At baseline, 10 (18.5%) patients were assigned to the monotherapy group and 44 (81.5%) patients to the first adjunctive therapy group. However, due to the addition of an anti-seizure medication along with perampanel on the first day of treatment, one patient was excluded from the monotherapy subgroup analyses. The mean perampanel exposure duration was 39.8 weeks and 32 (59.3%) patients completed the study. Retention rate at 12 months (or study completion) was 63.0% (monotherapy, 77.8%; first adjunctive therapy, 59.1%). Seizure-freedom rate during the Maintenance Period was 32.7% (monotherapy, 44.4%; first adjunctive therapy, 29.5%) and the 50% responder rate was 78.7% (monotherapy, 85.7%; first adjunctive therapy, 76.9%). TEAEs and serious TEAEs were reported by 88.9% (n = 48/54) and 7.4% (n = 4/54) of patients, respectively. Overall, the efficacy and safety of perampanel as monotherapy or first adjunctive therapy support the use of perampanel as early-line treatment for epilepsy.

Efficacy and tolerability of perampanel in pediatric patients with Dravet syndrome.

Background: In 1978, Charlotte Dravet first described a form of epilepsy termed Dravet syndrome (DS). It is a form of genetic epilepsy with early-onset, intractable epilepsy episodes, and neurodevelopmental delay. In children, DS can lead to refractory seizures that are resistant to standard therapy. Recently, perampanel (PER) was approved as an antiepileptic drug for patients as young as 4 years old. Methods: The medical records were retrospectively reviewed and patients with DS who used PER were included in this study. The diagnosis was established using whole-exome sequencing, and the collected data included the patients' demographic characteristics, seizure pattern, PER dosage, laboratory and imaging findings. Results: This study included 18 pediatric patients with a clinical diagnosis of DS. The mean age of PER initiation was 7.67±3.865. Most patients had two types of seizures (61.1%) followed by three types (22.2%), with generalized tonic-clonic being the most frequently reported type of seizure. The mean efficacy of PER was 29.17%±29.368%, and only one patient had an efficacy of 100%. Moreover, patients aged 8 years and younger presented with higher efficacy than those who were older (49.17%±34.120% vs. 19.17%±21.829%, P=0.03). Conclusions: This study presented supporting evidence of the promising therapeutic effect of PER among patients with DS. PER can be considered one of the treatment options for this group of patients. However, several patients presented with unfavorable side effects that led to medication cessation. Future multicenter studies are required to explore further treatment options for patients with DS.

Efficacy and safety of adjunctive perampanel treatment in pediatric patients with epilepsy aged 4-12 years: a real-world study.

OBJECTIVE: To determine the efficacy and safety of perampanel (PER) as an adjunctive therapy in children aged 4-12 years with epilepsy. METHODS: We performed a non-randomized, open-label, placebo-uncontrolled, real-world self-controlled study that included 216 young children (aged 4-12 years) with epilepsy who received PER as adjunctive therapy at the children's hospital affiliated with Chongqing Medical University from July 4, 2020, to September 20, 2023. RESULTS: (1) The efficacy rates of adjunctive PER therapy at 3, 6, 9, and 12 months were 62.8%, 67.8%, 65.3%, and 61.2%, respectively. PER showed efficacy in alleviating focal seizures, generalized tonic-clonic seizures, myoclonic seizures, and absence seizures. The efficacy rates for variants of self-limited epilepsy with centrotemporal spikes (SeLECTS) and Lennox-Gastaut syndrome (LGS) were 89.5% and 66.7%, respectively. (2) Focal non-motor onset seizures with or without impaired awareness, focal to bilateral tonic-clonic seizures (FBTCS), LGS, variants of SeLECTS, the number of concomitant antiseizure medications (ASMs), a family history of epilepsy, and focal lesions on cranial magnetic resonance imaging were independent factors affecting efficacy. The order of PER addition did not affect efficacy. The retention rates at 3, 6, 9, and 12 months were 90.7%, 84.7%, 74.7%, 64.9%, respectively. (3) Adverse reactions occurred in 45 patients (45/216, 20.8%), with irritability/aggressive behavior (18/216, 8.3%) and somnolence (14/216, 6.5%) being the most common. Twelve patients (12/216, 5.6%) withdrew from the study because of adverse reactions. CONCLUSION: In young Chinese children with epilepsy, PER is effective, safe, and well-tolerated as an adjunctive therapy, making it a viable option for use with broad-spectrum ASMs.

Optimizing perampanel monotherapy for surgically resected brain tumors.

Perampanel (PER) is an antiseizure medication (ASM) with a unique mechanism of action, which was approved in Japan for use in combination therapy in 2016 and as a monotherapy in 2020. It has exerted antitumor effects against several types of tumors in vitro. However, the efficacy of PER monotherapy for seizure control is not well-established in patients with brain tumor. In the present study, 25 patients with brain tumor treated using PER monotherapy at our institution were analyzed and compared with 45 patients treated using the most commonly prescribed ASM, levetiracetam (LEV). The PER group was younger and had a higher frequency of glioma cases. During drug administration, seizures were observed in two patients from the PER group (8.0%) and five patients from the LEV group (11.1%); however, the difference was not significant. The incidence of adverse effects did not significantly differ between the groups (12.0 and 2.2%, respectively). In the PER group, mild liver dysfunction was observed in two patients and drug rash in one. In the LEV group, a drug-induced rash was observed in one patient. PER monotherapy may be safe and effective for seizure treatment or prophylaxis in patients with brain tumor. Further large-scale clinical studies are warranted.

Effects of the AMPAR Antagonist, Perampanel, on Cognitive Function in Rats Exposed to Neonatal Iron Overload.

Iron accumulation has been associated with the pathogenesis of neurodegenerative diseases and memory decline. As previously described by our research group, iron overload in the neonatal period induces persistent memory deficits and increases oxidative stress and apoptotic markers. The neuronal insult caused by iron excess generates an energetic imbalance that can alter glutamate concentrations and thus trigger excitotoxicity. Drugs that block glutamatergic receptor eligibly mitigate neurotoxicity; among them is perampanel (PER), a reversible AMPA receptor (AMPAR) antagonist. In the present study, we sought to investigate the neuroprotective effects of PER in rats subjected to iron overload in the neonatal period. Recognition and aversive memory were evaluated, AMPAR subunit phosphorylation, as well as the relative expression of genes such as GRIA1, GRIA2, DLG4, and CAC, which code proteins involved in AMPAR anchoring. Male rats received vehicle or carbonyl iron (30 mg/kg) from the 12th to the 14th postnatal day and were treated with vehicle or PER (2 mg/kg) for 21 days in adulthood. The excess of iron caused recognition memory deficits and impaired emotional memory, and PER was able to improve the rodents' memory. Iron increased the phosphorylation of GLUA1 subunit, which was reversed by PER. Furthermore, iron overload increased the expression of the GRIA1 gene and decreased the expression of the DLG4 gene, demonstrating the influence of metal accumulation on the metabolism of AMPAR. These results suggest that iron can interfere with AMPAR functionality, through altered phosphorylation of its subunits, and the expression of genes that code for proteins critically involved in the assembly and anchoring of AMPAR. The blockade of AMPAR with PER is capable of partially reversing the cognitive deficits caused by iron overload.

Structural connectivity as a predictive factor for perampanel response in patients with epilepsy.

OBJECTIVES: This study aimed to identify clinical characteristics that could predict the response to perampanel (PER) and determine whether structural connectivity is a predictive factor. METHODS: We enrolled patients with epilepsy who received PER and were followed-up for a minimum of 12 months. Good PER responders, who were seizure-free or presented with more than 50 % seizure reduction, were classified separately from poor PER responders who had seizure reduction of less than 50 % or non-responders. A graph theoretical analysis was conducted based on diffusion tensor imaging to calculate network measures of structural connectivity among patients with epilepsy. RESULTS: 106 patients with epilepsy were enrolled, including 26 good PER responders and 80 poor PER responders. Good PER responders used fewer anti-seizure medications before PER administration compared to those by poor PER responders (3 vs. 4; p = 0.042). Early PER treatment was more common in good PER responders than poor PER responders (46.2 vs. 21.3 %, p = 0.014). Regarding cortical structural connectivity, the global efficiency was higher and characteristic path length was lower in good PER responders than in poor PER responders (0.647 vs. 0.635, p = 0.006; 1.726 vs. 1,759, p = 0.008, respectively). For subcortical structural connectivity, the mean clustering coefficient and small-worldness index were higher in good PER responders than in poor PER responders (0.821 vs. 0.791, p = 0.009; 0.597 vs. 0.560, p = 0.009, respectively). CONCLUSION: This study demonstrated that early PER administration can predict a good PER response in patients with epilepsy, and structural connectivity could potentially offer clinical utility in predicting PER response.

Phase IV PROVE study: Perampanel in real-world clinical care of pediatric patients with epilepsy.

INTRODUCTION: The non-interventional Phase IV PROVE study (NCT03208660) assessed retention, efficacy, safety and tolerability, and perampanel dosing in patients with epilepsy during routine clinical care. This analysis evaluated final data from patients aged <4 years and 4-<12 years. METHODS: Data were obtained retrospectively from medical/pharmacy records of patients in the United States initiating perampanel after January 1, 2014, according to treating clinician recommendations. Retention rate was the primary endpoint. Secondary assessments included median percent changes in seizure frequency, seizure-freedom rates, investigator impression of seizure effect, and safety and tolerability. RESULTS: The Safety Analysis Set (SAS) included 41 patients (<4 years; mean maximum dose, 3.5 mg/day) and 203 patients (4-<12 years; mean maximum dose, 5.3 mg/day); 24-month retention rates were 35.7% (n = 5/14) and 42.0% (n = 47/112), respectively. In the Full Analysis Set, during Months 1-3, median percent reductions in seizure frequency were 33.3% (n = 8 [<4 years]) and 26.0% (n = 32 [4-<12 years]), and seizure-freedom rates were 12.5% in both groups (n = 1/8 and n = 4/32); patient numbers were low at later time points. Most patients showed improvements in seizure control (45.9% [<4 years] versus 52.4% [4-<12 years]) or no change (45.9% versus 34.5%) (SAS). Treatment-emergent adverse events (TEAEs) were reported in 12 (<4 years: 29.3%; most common, irritability [7.3%]) and 64 patients (4-<12 years: 31.5%; most common, aggression [6.9%]). CONCLUSIONS: Perampanel was generally well tolerated with <21% of TEAEs leading to withdrawal at 24 months, had favorable retention rates (≥50% and >35% at 12 and 24 months, respectively), and sustained efficacy in pediatric patients during routine clinical care.

Population pharmacokinetics and dosing optimization of perampanel in children with epilepsy: A real-world study.

OBJECTIVE: The purposes of this study were to explore the pharmacokinetics of perampanel (PER) in children with epilepsy, identify factors that contribute to pharmacokinetic variations among subjects, evaluate the connection between PER exposure and clinical outcome, and establish an evidence-based approach for tailoring individualized antiepileptic treatment in this specific population. METHODS: In this prospective study, PER plasma concentrations and genetic information on metabolic enzymes were obtained from 194 patients younger than 18 years. The disposition kinetics of PER in pediatric patients following oral dosing were characterized using nonlinear mixed effect models. The effective range for the plasma concentration of PER was determined by assessing the efficacy and safety of PER treatment and analyzing the relationship between drug exposure and clinical response. Monte Carlo simulations were then performed to evaluate and optimize the current dosing regimens. RESULTS: The pharmacokinetic profile of PER was adequately described by a one-compartment model with first-order absorption and elimination. Body weight, total bilirubin level, and concomitant oxcarbazepine were found to have significant influences on PER pharmacokinetics. Model estimates of apparent clearance and volume of distribution were .016 ± .009 L/h/kg and 1.47 ± .78 L/kg, respectively. The effective range predicted from plasma concentration data in responders was 215-862 µg/L. Dosing scenarios stratified according to essential covariates were proposed through simulation analysis. SIGNIFICANCE: In this study, we captured the pharmacokinetic/pharmacodynamic characteristics of PER in pediatric epilepsy patients through analysis of real-world data and adopted a pharmacometric approach to support an individualized dosing strategy for PER in this specific population.

Irregular Tremulous Movements and Infrequent Seizures: A Clinical-Electrophysiological Diagnosis of Benign Adult Familial Myoclonus Epilepsy.

We report a case involving a 31-year-old male without any known precipitating injuries presenting with involuntary finger movements and rare seizures. There was a noted family history of tremulous movements. Yet the characteristics of his finger movements were irregular and not typical of essential tremor (ET). Electrophysiological examinations, including video EEG, showed no epileptic discharges, and brain MRI results were normal. However, somatosensory evoked potentials (SEP) revealed the presence of giant SEP, and a positive cortical (C)-reflex was observed, leading to a clinical diagnosis of benign adult familial myoclonus epilepsy (BAFME). Management with valproic acid and perampanel resulted in a significant reduction of symptoms. This case highlights the necessity of considering BAFME in the differential diagnosis for atypical tremorous finger movements, especially with a relevant family history, and the critical role of electrophysiological findings indicative of cortical hyperexcitability.

Perampanel for the treatment of epilepsy with genetic aetiology: Real-world evidence from the PERMIT Extension study.

Genetic factors contribute to the aetiology of epilepsy in >50% of cases, and information on the use of antiseizure medications in people with specific aetiologies will help guide treatment decisions. The PERMIT Extension study pooled data from two real-world studies (PERMIT and PROVE) to investigate the effectiveness and safety/tolerability of perampanel (PER) when used to treat people with focal and generalised epilepsy in everyday clinical practice. This post-hoc analysis of PERMIT Extension explored the use of PER when used to treat individuals presumed to have epilepsy with a genetic aetiology. Assessments included retention rate (evaluated at 3, 6 and 12 months), effectiveness (responder and seizure freedom rates; evaluated at 3, 6, 12 months and the last visit [last observation carried forward) and tolerability (adverse events [AEs]). Of the 6822 people with epilepsy included in PERMIT Extension, 1012 were presumed to have a genetic aetiology. The most common genetic aetiologies were idiopathic generalised epilepsy (IGE; 58.2%), tuberous sclerosis (1.1%), Dravet syndrome (0.8%) and genetic epilepsy with febrile seizures plus (GEFS+; 0.5%). Retention rates at 3, 6 and 12 months in the total genetic aetiology population were 89.3%, 79.7% and 65.9%, respectively. In the total genetic aetiology population, responder rates at 12 months and the last visit were 74.8% and 68.3%, respectively, and corresponding seizure freedom rates were 48.9% and 46.5%, respectively. For the specific aetiology subgroups, responder rates at 12 months and the last visit were, respectively: 90.4% and 84.4% (IGE), 100% and 57.1% (tuberous sclerosis), 100% and 71.4% (Dravet syndrome), and 33.3% and 20.0% (GEFS+). Corresponding seizure freedom rates were, respectively: 73.1% and 64.6% (IGE), 33.3% and 22.2% (tuberous sclerosis), 20.0% and 28.6% (Dravet syndrome), and 0% and 0% (GEFS+). The incidence of AEs was 46.5% for the total genetic aetiology population, 48.8% for IGE, 27.3% for tuberous sclerosis, 62.5% for Dravet syndrome, and 20% for GEFS+. Tolerability findings were consistent with PER's known safety profile. PER was effective and generally well tolerated when used in individuals with a presumed genetic epilepsy aetiology in clinical practice. PER was effective across a wide range of genetic aetiologies.

Psychiatric and behavioral concerns of perampanel with concomitant levetiracetam in children with epilepsy.

PURPOSE: Perampanel (PER) is expanding the therapeutic scope for pediatric epilepsy owing to its efficacy and favorable safety profile. However, concerns about psychiatric and behavioral adverse events (PBAEs) in combination therapy with levetiracetam (LEV) continue to contribute to hesitation in its prescription. We investigated the risk profiles for PBAEs when adding PER to pediatric epilepsy treatment and analyzed the differences according to the presence of concomitant LEV. METHODS: We retrospectively reviewed the medical records of children aged 4-18 years with epilepsy who were prescribed PER as adjunctive therapy from March 2016 to February 2023. We compared the occurrence and management of PBAEs between the PER without LEV and PER with LEV groups. The risk factors for PBAEs were also analyzed. RESULTS: Ninety-four patients (53 boys and 41 girls) were included in this study. The median age of total patients at the time of adding PER was 14.9 years (12.3-16.4 years), and 53 patients (56.4 %) had concomitant LEV. Forty-seven PBAEs occurred in 34 patients (36.2 %), with no significant differences depending on whether concomitant LEV is present or not. The most common PBAEs were aggression (14.9 %), irritability (9.6 %), affect lability (7.4 %), and acute psychosis (6.4 %). PBAEs occurred at a lower dosage (2-6 mg/day) in 70.6 % of the patients. In addition, 73.5 % of patients with PBAEs continued PER treatment by follow-up observation or by reducing the PER dosage. No risk factors, such as the presence of concomitant LEV or lamotrigine, any comorbid conditions, higher PER dosage (8-12 mg/day), two or more concomitant anti-seizure medications, and younger age (<13 years) at PER add-on, showed significant associations. CONCLUSION: When expanding the use of anti-seizure medications in pediatric patients, real-world evidence on safety issues is crucial for pediatric epileptologists. We confirmed that combination therapy with PER and LEV did not increase the risk profile of PBAEs.