Evaluation of perampanel in patients with intellectual disability and epilepsy

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.

The Cognitive and Behavioural Effects of Perampanel in Children with Neurodevelopmental Disorders: A Systematic Review

In children and adolescents with epilepsy, neurodevelopmental comorbidities can impair the quality of life more than seizures. The aim of this review was to evaluate the cognitive and behavioural effects of perampanel (PER) in the paediatric population. We performed a systematic search of the literature, selecting studies published in English including children and adolescents with epilepsy treated with PER. Cognitive and behavioural outcomes were assessed through validated neuropsychological standardised scales. Eighteen studies involving 3563 paediatric patients were included. Perampanel did not impair general cognitive functions and visuospatial skills, whereas a slight improvement in verbal memory and a decline in attentional power were detected. In adolescents with refractory epilepsies, high doses and/or rapid titration of PER and an underlying psychiatric disorder were risk factors for developing or worsening psychiatric outcomes such as anger, aggressiveness, and irritability. Data on children and adolescents treated with new antiseizure medications are scant, and neuropsychiatric effects are tricky to be detected during developmental age. According to the currently available evidence, PER showed an overall favourable risk-benefit profile. Pharmacodynamics, co-administration of other antiseizure medications, and family and personal history of neuropsychiatric disorders should be considered before PER treatment.

Acute inhibition of AMPA receptors by perampanel reduces amyloid β-protein levels by suppressing β-cleavage of APP in Alzheimer's disease models

Hippocampal hyperexcitability is a promising therapeutic target to prevent Aβ deposition in AD since enhanced neuronal activity promotes presynaptic Aβ production and release. This article highlights the potential application of perampanel (PER), an AMPA receptor (AMPAR) antagonist approved for partial seizures, as a therapeutic agent for AD. Using transgenic AD mice combined with in vivo brain microdialysis and primary neurons under oligomeric Aβ-evoked neuronal hyperexcitability, the acute effects of PER on Aβ metabolism were investigated. A single oral administration of PER rapidly decreased ISF Aβ40 and Aβ42 levels in the hippocampus of J20, APP transgenic mice, without affecting the Aβ40 /Aβ42 ratio; 5 mg/kg PER resulted in declines of 20% and 31%, respectively. Moreover, PER-treated J20 manifested a marked decrease in hippocampal APP βCTF levels with increased FL-APP levels. Consistently, acute treatment of PER reduced sAPPβ levels, a direct byproduct of β-cleavage of APP, released to the medium in primary neuronal cultures under oligomeric Aβ-induced neuronal hyperexcitability. To further evaluate the effect of PER on ISF Aβ clearance, a γ-secretase inhibitor was administered to J20 1 h after PER treatment. PER did not influence the elimination of ISF Aβ, indicating that the acute effect of PER is predominantly on Aβ production. In conclusion, acute treatment of PER reduces Aβ production by suppressing β-cleavage of amyloid-β precursor protein effectively, indicating a potential effect of PER against Aβ pathology in AD.

Does a psychiatric history play a role in the development of psychiatric adverse events to perampanel… and to placebo?

OBJECTIVE

The purpose of this study was to establish whether a past psychiatric history could play a role in the development of psychiatric treatment-emergent adverse events (PTEAEs) in patients randomized to perampanel (PER) or placebo.

METHODS

The development of PTEAEs was compared between patients with/without a psychiatric history in a post hoc analysis from four randomized placebo-controlled trials (RPCTs) of PER (304/305/306/335) in patients with treatment-resistant focal epilepsy.

RESULTS

Among the 2,187 patients enrolled in the RPCTs, 352 (16.1%) had a psychiatric history (PER n = 244; placebo n = 108), while 1835 patients (83.9%) did not (PER n = 1325; placebo n = 510). Compared to patients without a psychiatric history, those with a positive history reported more PTEAEs for both patients randomized to PER (11.8% vs. 29.9%, p < 0.01) or to placebo (9.2% vs. 19.4%, p < 0.01). The prevalence of PTEAEs was not higher among patients randomized to 2 mg and 4 mg/day doses than placebo in both those with and without psychiatric history. Rather, the higher prevalence rates were among subjects randomized to 8 mg (29.8%) and 12 mg (36.4%) PER doses in patients with a past psychiatric history.

SIGNIFICANCE

A psychiatric history appears to increase the risk of PTEAEs in patients randomized to placebo and to PER at doses of 8 and 12 mg/day. It should be identified in all patients considered for treatment with PER, particularly when prescribed at doses above 4 mg/day.

Reduced efficacy of perampanel in patients with severe motor and intellectual disabilities syndrome and drug-resistant epilepsy: A single-center analysis from Japan

People with severe motor and intellectual disabilities syndrome (SMIDS) have multiple comorbidities and high mortality rates. This study examined whether there is a difference in the efficacy and tolerability of perampanel (PER) between patients with drug-resistant epilepsy with or without SMIDS. The study identified 65 patients with drug-resistant epilepsy who underwent PER treatment as adjunctive therapy. The 50 % responder rate was 22 % (14/65) overall and 11 % (5/44) in patients with SMIDS versus 43 % (9/21) in patients without SMIDS (p <0.01). Although the overall 50 % responder rate was similar to those of previous reports, PER was less efficacious in the patients with SMIDS; nevertheless, PER was tolerated in the patients with SMIDS.

Perampanel treatment in highly drug-resistant epilepsies including nonsurgical candidates and failed surgery

OBJECTIVE

To evaluate the effectiveness and tolerability of perampanel (PER) treatment for patients with highly drug-resistant epilepsies (HDRE) including nonsurgical candidates and failed surgery in real-world setting.

METHODS

All patients who were treated with PER during June 2015 to August 2019 were selected. Primary outcomes were percentage of seizure reduction, responder rate, and seizure freedom rate. Seizure frequency after taking PER at 3 and 12 months were compared with baseline seizure frequency within the same time period prior to starting PER. Secondary outcomes were retention rate, side effects, and predictors for a response to PER. Descriptive statistics and the Kernel regression model were employed.

RESULTS

Forty-one patients received PER treatment during the study period. Six patients who had no baseline seizure frequency recordings were excluded, for a total of 35 patients included for analysis. Mean age was 40.06 years (SD 12.34). All were highly resistant to several antiseizure drugs (ASDs) with a median number of previously failed ASDs of 8 items. Eleven, 16, 5, and 3 patients were lesional, nonlesional focal epilepsy, nonsurgical candidate, and failed surgery, respectively. At 3 months after PER treatment, the median percentage of seizure reduction was 20 % (-35.71, 100), the responder rate was 22.86 % (8/35), and the seizure freedom rate was 17.14% (6/35). At 12 months after PER treatment, the corresponding outcomes were 25% (-20.57, 91.60), 22.58% (7/31), and 9.68% (3/31), respectively. Retention rates at 3 and 12 months were 100% and 91.43% (32/35), respectively. Nineteen patients (54.29%) experienced side effects from PER. Side effects were somnolence (6/35), dizziness (3/35), irritability (2/35), and ataxia (2/35), and one each for weight loss, nausea, headache, insomnia, verbal aggressivity, and depression. Median duration for 2-mg dose increment was 2.2 months.

CONCLUSIONS

In real-world practice, slow-titration PER regimen is well-tolerable and shows benefit in helping control seizures in patients with very difficult-to-treat HDRE.

Differences in levetiracetam and perampanel treatment-related irritability in patients with epilepsy

PURPOSE

The present study evaluated whether patients with epilepsy who received both levetiracetam (LEV) and perampanel (PER) therapy showed side effects of irritability. The study also examined the relationship between patient characteristics and irritability when it occurred as a side effect.

METHODS

We retrospectively examined medical records of 98 patients with epilepsy who were treated with both LEV and PER at the Department of Psychiatry in the Epilepsy Center of Nishiniigata Chuo National Hospital in Japan. We performed multiple regression analyses with the presence/absence of irritability due to LEV or PER as the dependent variables and clinical characteristics of the patients as independent variables.

RESULTS

LEV and PER caused irritability in 7 and 17 of 98 patients, respectively. LEV- and PER-related irritability did not occur in the same patients. A logistic multiple regression analysis revealed that EEG findings of temporal focal epileptic discharge were significantly associated with increased incidence of irritability due to LEV. LEV-related irritability decreased significantly with higher dosages of LEV. Another logistic multiple regression analysis revealed that a psychiatric comorbidity of irritability and EEG findings of nontemporal focal epileptic discharge were significantly associated with increased incidence of irritability due to PER.

CONCLUSIONS

LEV and PER cause irritability in different patient groups. Additionally, irritability as a side effect was present only at low dosages of LEV, but PER tended to cause irritability even at high dosages.

European perspective of perampanel response in people with Intellectual Disability

BACKGROUND

Epilepsy prevalence is over 20% for those with ID. It is difficult to diagnose and treat and more likely to be treatment resistant. The evidence informing prescribing is sparse, particularly for new drugs such as perampanel (PMP).

AIMS OF THE STUDY

This study seeks to strengthen the research evidence regarding PMP for people with ID by pooling information from two isolated and separately conducted studies: the UK-based Epilepsy Database Register (Ep-ID) and the data from the Kempenhaeghe clinic in the Netherlands.

METHODS

A single data set of comparable data was created and analysed under agreement and supervision of a UK statistician.

RESULTS

Seizure reduction within twelve months was evident in 62% of Dutch and 47% of UK patients. Retention rates were higher for those in the UK (P = .01) and for patients with moderate to profound ID, whilst side effects were more prominent in the Dutch cohort.

CONCLUSIONS

Comparable rates of seizure reduction are in line with estimates for non-ID patients, adding to the evidence suggesting that PMP has a similar impact on those with ID. Taking a European perspective and sharing data across centres can help strengthen the evidence for prescribing antiepileptic drugs in the ID population.

Epilepsy, anti-seizure medication, intellectual disability and challenging behaviour - Everyone's business, no one's priority

PURPOSE

People with Intellectual Disability (ID) and epilepsy are more likely to experience psychiatric conditions, challenging behaviour (CB), treatment resistance and adverse effects of anti-seizure medications (ASM) than those without. This population receives care from various professionals, depending on local care pathways. This study evaluates the training status, confidence, reported assessment and management practices of different professional groups involved in caring for people with ID, epilepsy and CB.

METHODS

A cross sectional survey using a questionnaire developed by expert consensus which measured self-reported training status, confidence, and approaches to assessment and management of CB in people with ID and epilepsy was distributed to practitioners involved in epilepsy and/or ID.

RESULTS

Of the 83 respondents, the majority had either a psychiatry/ID (n = 39), or Neurology/epileptology background (n = 31). Psychiatry/ID and Neurology/epileptology had similar confidence in assessing CB in ID-epilepsy cases, but Psychiatry/ID exhibited higher self-rated confidence in the management of these cases. While assessing and managing CB, Psychiatry/ID appeared more likely to consider mental health aspects, while Neurology/epileptology typically focused on ASM.

CONCLUSION

Psychiatry/ID and Neurology/epileptology professionals had varying training levels in epilepsy, ID and CB, had differing confidence levels in managing this patient population, and considered different factors when approaching assessment and management. As such, training opportunities in ID should be offered to neurology professionals, and vice versa. Based on the findings, a best practice checklist is presented, which aims to provide clinicians with a structured framework to consider causal explanations for CB in this population.

Effects of perampanel on secondary bilateral synchrony and behavioral problems in adolescents with epilepsy showing insufficient response with levetiracetam

PURPOSE

The purpose of this study was to determine the efficacy of perampanel (PER) on secondary bilateral synchrony (SBS) and behavioral problems in adolescents with epilepsy who showed insufficient response to levetiracetam (LEV).

METHODS

The primary criterion for patient selection was the presence of SBS. The criteria such as age between 12 and 18 years, seizures refractory to antiseizure medications including LEV, at least four seizures a month, neuropsychological impairments, and at least 12 months of follow-up also had to be fulfilled. Patients were given PER at an initial dose of 2 mg/day, followed by increments of +2 mg/day every 2 weeks. Concomitant medications remained unchanged during evaluation period. Responders for electroencephalogram (EEG) and seizures were identified as showing a ≥50 % reduction from the baseline SBS on EEG and seizure frequency, respectively. Neuropsychological impairments as per the Japanese manuals for the Aberrant Behavior Checklist (ABC-J) were evaluated before and after PER administration.

RESULTS

Eight of 14 patients were considered responders for seizures. Among these 8 responders, 6 patients were considered responders for EEG and behavioral problems. Mean ABC-J scores in both EEG non-responders and responders were decreased significantly at 12 months (p < 0.05 and p < 0.05, respectively). ABC-J scores were significantly lower in EEG responders than in EEG non-responders at 12 months (p < 0.01). Moreover, among patients with decreased ABC-J scores, the degree of decrease was larger in EEG responders than in EEG non-responders (p < 0.01).

CONCLUSIONS

PER may be useful in reducing SBS on EEG, seizure frequency, and behavioral problems.

Perampanel in brain tumor-related epilepsy: Observational pilot study

OBJECTIVE

Possible loss of efficacy and potential interactions between antiepileptic drugs (AEDs) and chemotherapy could complicate the management of patients with brain tumor-related epilepsy (BTRE) that may expose patients to an increased risk of adverse events. Perampanel (PER) is a highly selective, noncompetitive, alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)-type glutamate receptor antagonist. This study evaluates the effectiveness, QoL, cognition, and mood of PER in add-on therapy in BTRE patients.

MATERIAL AND METHODS

Observational pilot study on the effectiveness of PER as add-on therapy in BTRE patients with uncontrolled seizures with a 6-month follow-up.

RESULTS

We recruited 26 BTRE patients. During the follow-up, 16 underwent chemotherapy and 11 radiotherapy; 11 had disease progression. Five patients dropped out. Mean daily PER dosage was 6.6 mg in the 21 patients who completed the follow-up and 6.4 mg in the ITT population. The mean number of seizures/month decreased from 10.8 ± 15.03 at baseline to 1.7 ± 4.34 in the 21 patients who reached the final follow-up. Responder rate was 88.4%: Eight patients were seizure-free, 15 had ≥50% seizure reduction, and 3 remained stable. Four patients (15.4%) reported AEs: 2 required PER dose reduction, and 2 dropped out. Neuropsychological, mood, and QoL questionnaires were not statistically different compared to baseline. There were no significant differences in seizure control in patients with/without IDH1 mutation and with/without MGMT methylation.

CONCLUSIONS

Perampanel proved to be effective on seizure control in BRTE patients and to be well tolerated without negative effects on cognition and QoL. Perampanel could be a valid therapeutic option in BTRE.

Efficacy and tolerability of perampanel in patients with genetic generalized epilepsy (GGE): A retrospective, single-center study from the United Arab Emirates (UAE)

•52.4% achieved seizure freedom at six months from baseline in our cohort of PWE from the UAE.•38.1% achieved ≥50% reduction in seizure frequency at six months from baseline.•90.5% remained on perampanel treatment beyond the six-month period.•33.3% maintained perampanel monotherapy beyond six months.•9.5% discontinued perampanel treatment due to treatment-induced adverse events.

Clinical profiles associated with serum perampanel concentrations in children with refractory epilepsy

BACKGROUND

Perampanel (PER) is a new antiepileptic drug (AED) with a novel mechanism of action. Investigations of the efficacy and safety of PER in pediatric and adult patients have increased recently. Although the clinical usefulness and pharmacokinetics of PER have been investigated in adolescent and adult populations, similar studies have not been performed in children.

PATIENTS AND METHODS

We retrospectively reviewed the medical records of patients treated with PER for more than 6 months in the Department of Pediatrics, Hiroshima University Hospital, between September 2016 and November 2018. We obtained demographic and clinical data including age, sex, epilepsy type, seizure type, seizure frequency before and after treatment initiation, adverse events, reasons for discontinuing PER treatment, doses at evaluation points, serum concentrations, concomitant AEDs, intellectual status, and epilepsy etiology. Seizure types and epilepsy syndromes were classified according to the criteria of the International League Against Epilepsy.

RESULTS

The study included 44 patients (22 males) between the ages of 6 months and 16 years. Of those, 10 patients discontinued PER therapy. The 50% response rate was 52.3% in patients treated with PER, and four patients achieved complete seizure control. Perampanel was highly effective in patients with generalized and focal epilepsy (50% responder rates, 52.9% and 50.0%, respectively). Favorable response rates were observed for tonic-clonic, focal nonmotor, and absence seizures with 50% response rates of 54.5%, 50.0%, and 66.7%, respectively. The 50% responder rate was 31.3 for epileptic spasms (ES). Treatment-emergent adverse events (TEAEs) included somnolence (n = 8), irritability (n = 2), ataxia (n = 2), and one case each of dizziness, compulsiveness, and enuresis. Serum concentrations of PER were compared in patients taking concomitant enzyme-inducing antiepileptic drugs (EIAEDs; carbamazepine, phenytoin, and phenobarbital) and those taking concomitant non-EIAEDs. Serum PER concentrations were correlated with dose per body weight in both groups (EIAED: r = 0.765, p = 0.00000212; non-EIAED: r = 0.71, p = 0.0000158). The mean concentration-to-dose (CD) ratio was 2398.4 ng mL^-1 mg^-1 kg^-1 (range: 800-4524.7) in the non-EIAED group and 693.7 ng mL^-1 mg^-1 kg^-1 (range: 344-1309.7) in the EIAED group. Serum PER levels were lower in the EIAED group than in the non-EIAED group. All patients with serum PER concentrations above 400 ng/mL experienced somnolence.

CONCLUSIONS

Perampanel is effective against various types of seizures, including ES, in pediatric patients with refractory epilepsy. Furthermore, PER has good tolerability when the dose is adjusted based on serum concentrations. The PER CD ratio was lower in pediatric patients than in adolescents and adults; therefore, clinicians must consider the CD ratio when treating children with PER.

Perampanel-induced weight gain depends on level of intellectual disability and its serum concentration

BACKGROUND

Body weight (BW) gain may be induced by perampanel (PER) administration, similar to the well-known adverse effects of valproic acid and gabapentin. Intellectual disability (ID) and serum PER concentration may be risk factors of BW gain.

PURPOSE

This study investigated how ID and serum PER concentration are associated with PER-induced BW gain.

METHODS

Subjects were 76 patients with epilepsy (41 men, aged 16-70 years). All patients were divided by intelligence quotient (IQ) into no ID (IQ ≥ 70, n = 24), mild to moderate ID (70 > IQ ≥35, n = 31), and severe to profound ID (IQ < 35, n = 21) groups. BW was measured before and 2, 4, 6, and 12 months after initiation of PER treatment, and serum PER concentration at 12 months.

RESULTS

BW gains in the mild to moderate ID group at 4, 6, and 12 months were significantly (p <  0.05) higher than in the no ID and in the severe to profound ID groups. At 12 months, BW gain was associated with serum PER concentrations in the no ID (p =  0.034) and the mild to moderate ID (p =  0.001) groups but not in the severe to profound ID group. Multiple linear regression analysis found BW gain at 12 months was positively correlated with the mild to moderate ID group (β = 0.373, p =  0.002) and serum PER concentration (β = 0.241, p =  0.047).

CONCLUSIONS

The mild to moderate ID group gained more BW than the no ID group, suggesting that PER-induced food intake was greater due to weaker behavioral control in the mild to moderate ID group. The present study suggests a linear correlation between serum PER concentration and BW change.

Clinical Experience with Perampanel in Intractable Focal Epilepsy Over 12 Months of Follow-Up

Background and Purpose

There are only limited studies on perampanel (PER), one of the latest antiepileptic drug. This study aimed to evaluate the long-term efficacy and tolerability of perampanel as an add-on therapy in patients with intractable focal epilepsy.

Methods

The medical records of 97 patients (age, 12-30 years) were retrospectively reviewed and analyzed. The patients had been diagnosed with focal epilepsy, treated with PER, and regularly followed up over 12 months.

Results

All patients had uncontrolled seizures despite treatment with two or more antiepileptic drugs. The mean age of seizure onset was 5.2 years (range, 0-17.0). PER was first prescribed at an average age of 15.7 years (range, 12.0-25.3), and mean follow-up duration after PER initiation was 15.9 months (range, 12-20). The responder rate was 41.7%, with over 75% seizure reduction obtained in 11 cases (15.3%), including three seizure-free cases (4.2%). The retention rates at 3, 6, 12, and 18 months of follow-up were 82.5% (80/97), 72.1% (70/97), 60.8% (59/97), and 37.5% (6/16), respectively. Forty-four patients (44/97, 45.4%) discontinued PER, because of treatment-related adverse events in 20 (20.6%) and no efficacy in 24 (24.7%). Treatment-related adverse events were reported by 52 patients (53.6%). The most common adverse event was somnolence or lethargy, reported by 17 patients (17/97, 23%), followed by dizziness (15/97, 20%) and psychological problems such as aggressiveness or irritability (15/97, 20%). Thirty-three patients (33/52, 63.4%) showed their first adverse symptom for 2 or 4 mg/day of PER.

Conclusions

PER would be an effective therapeutic option for patients with intractable focal epilepsy. However, careful monitoring of adverse events is essential from treatment initiation, with particular attention to psychological problems in adolescents and young adults.

Mechanisms Underlying Aggressive Behavior Induced by Antiepileptic Drugs: Focus on Topiramate, Levetiracetam, and Perampanel

Antiepileptic drugs (AEDs) are effective against seizures, but their use is often limited by adverse effects, among them psychiatric and behavioral ones including aggressive behavior (AB). Knowledge of the incidence, risk factors, and the underlying mechanisms of AB induced by AEDs may help to facilitate management and reduce the risk of such side effects. The exact incidence of AB as an adverse effect of AEDs is difficult to estimate, but frequencies up to 16% have been reported. Primarily, levetiracetam (LEV), perampanel (PER), and topiramate (TPM), which have diverse mechanisms of action, have been associated with AB. Currently, there is no evidence for a specific pharmacological mechanism solely explaining the increased incidence of AB with LEV, PER, and TPM. Serotonin (5-HT) and GABA, and particularly glutamate (via the AMPA receptor), seem to play key roles. Other mechanisms involve hormones, epigenetics, and “alternative psychosis” and related phenomena. Increased individual susceptibility due to an underlying neurological and/or a mental health disorder may further explain why people with epilepsy are at an increased risk of AB when using AEDs. Remarkably, AB may occur with a delay of weeks or months after start of treatment. Information to patients, relatives, and caregivers, as well as sufficient clinical follow-up, is crucial, and there is a need for further research to understand the complex relationship between AED mechanisms of action and the induction/worsening of AB.

Safety and tolerability profile of new antiepileptic drug treatment in children with epilepsy

INTRODUCTION

Treatment of pediatric epilepsy requires a careful evaluation of the safety and tolerability profile of antiepileptic drugs (AEDs) to avoid or minimize as much as possible adverse events (AEs) on various organs, hematological parameters, and growth, pubertal, motor, cognitive and behavioral development.

AREAS COVERED

Treatment-emergent AEs (TEAEs) reported in the literature 2000-2018 regarding second- and third-generation AEDs used in the pediatric age, with exclusion of the neonatal period that exhibits specific peculiarities, have been described on the basis of their frequency, severity/tolerability, and particular association with a given AED.

EXPERT OPINION

Somnolence/sedation and behavioral changes, like irritability and nervousness, are among the most commonly observed TEAEs associated with almost all AEDs. Lamotrigine, Gabapentin, Oxcarbazepine, and Levetiracetam appear to be the best-tolerated AEDs with a ≤2% withdrawal rate, while Tiagabine and Everolimus are discontinued in up to >20% of the patients because of intolerable TEAEs. For some AEDs, literature data are scanty to draw a high-level evidence on their safety and tolerability profile. The reasons are: insufficient population size, short duration of treatments, or lack of controlled trials. A future goal is that of identifying clearer, easier, and more homogeneous methodological strategies to facilitate AED testing in pediatric populations.

Perampanel as adjunctive therapy in highly refractory epilepsies: Real-world data from an Italian tertiary care epilepsy centre

Perampanel (PER) is a selective non-competitive α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor antagonist, licensed as adjunctive therapy in focal epilepsy and primary generalized tonic-clonic seizures (pGTCSs). We performed a retrospective study on highly refractory adult patients taking PER, with 1-year follow-up. Retention rate represented the primary outcome of our work; seizure frequency reduction (≥50%), "switch rate" and proportion of adverse events (AEs) were evaluated as secondary endpoints. Eighty-nine subjects (47 females, age range: 19-78 years) were included. Seventy-three had focal epilepsy (FE), 9 generalized epilepsy and 7 epileptic encephalopathy. All patients were highly drug-resistant (medication failures: 5-17). Retention rate was 87.6%, 63% and 51.7% at 3, 6 and 12 months. Responders were 27/89 (30.3%), with 8/27 seizure-free. The number of previous treatment failures and the concomitant use of enzyme inducers negatively influenced clinical response, whereas no correlation was documented between PER dose and outcome. Responder proportion was more satisfying in structural FE than in FE of unknown etiology (33% versus 20%), and in secondarily GTCSs than focal seizures (54% vs 28%), whereas pGTCSs showed a lower reponse rate (25%). Mild-to-moderate AEs (mainly dizziness, gait disturbances and psychiatric effects) were reported by 40% of patients; serious psychiatric AEs usually occurred in subjects with psychiatric comorbidities. Our study confirms the tolerability and effectiveness of PER in highly drug-resistant patients with different epilepsy syndromes and aetiologies.

HMGB1 mediates microglia activation via the TLR4/NF-κB pathway in coriaria lactone induced epilepsy

Epilepsy is a chronic and recurrent disease of the central nervous system, with a complex pathology. Recent studies have demonstrated that the activation of glial cells serve an important role in the development of epilepsy. The objective of the present study was to investigate the role of high‑mobility group box‑1 (HMGB1) in mediating the activation of glial cells through the toll‑like receptor 4 (TLR4)/nuclear factor (NF)‑κB signaling pathway in seizure, and the underlying mechanism. The brain tissue of post‑surgery patients with intractable epilepsy after resection and the normal control brain tissue of patients with craniocerebral trauma induced intracranial hypertension were collected. The expression level and distribution pattern of HMGB1, OX42 and NF‑κB p65 were detected by immunohistochemistry. HMGB1, TLR4, receptor for advanced glycation end products (RAGE), NF‑κB p65 and inducible nitric oxide synthase (iNOS) expression levels were detected by western blotting, and serum cytokine levels of interleukin (IL)‑1, IL‑6, tumor necrosis factor (TNF)‑α, transforming growth factor (TGF)‑β and IL‑10 in patients with epilepsy and craniocerebral trauma were detected by ELISA. And cell model of epilepsy was established by coriaria lactone (CL)‑stimulated HM cell, and the same factors were measured. The potential toxic effect of HMGB1 on HM cells was evaluated by MTT and 5‑ethynyl‑2‑deoxyuridine assays. The results demonstrated that compared with the control group, levels of HMGB1, TLR4, RAGE, NF‑κB p65 and iNOS in the brain of the epilepsy group were significantly increased, and increased cytokine levels of IL‑1, IL‑6, TNF‑α, TGF‑β and IL‑10 in patients with epilepsy were also observed. At the same time, the above results were also observed in HM cells stimulated with CL. Overexpression of HMGB1 enhanced the results, while HMGB1 small interfering RNA blocked the function of CL. There was no significant toxic effect of HMGB1 on HM cells. In conclusion, overexpression of HMGB1 potentially promoted epileptogenesis. CL‑induced activation of glial cells may act via up‑regulation of HMGB1 and TLR4/RAGE receptors, and the downstream transcription factor NF‑κB.

Comparing Safety and Efficacy of "Third-Generation" Antiepileptic Drugs: Long-Term Extension and Post-marketing Treatment

Four "third-generation" antiepileptic drugs (AEDs) were approved for adjunctive treatment of refractory focal onset seizures during the past 10 years. Long-term efficacy and safety of the drugs were demonstrated in large extension studies and in reports of subgroups of patients not studied in pivotal trials. Reviewing extension study and post-marketing outcome series for the four newer AEDs-lacosamide, perampanel, eslicarbazepine acetate and brivaracetam-can guide clinicians in treating and monitoring patients. AED extension studies evaluate treatment retention, drug tolerability, and drug safety during individualized treatment with flexible dosing and thus provide information not available in rigid pivotal trials. Patient retention in the studies ranged from 75 to 80% at 1 year and from 36 to 68% at 2-year treatment intervals. Safety findings were generally similar to those of pivotal trials, with no major safety risks identified and with several specific adverse drug effects, such as hyponatremia, reported. The third-generation AEDs, some through new mechanisms and others with improved tolerability compared to related AEDs, provide new options in efficacy and tolerability.

The retention of lacosamide in patients with epilepsy and intellectual disability in three specialised institutions

PURPOSE

We describe the effectiveness of lacosamide as adjunctive therapy in patients with epilepsy and an intellectual disability. This information is relevant, as few data exist pertaining to this population with a high prevalence of (intractable) epilepsy.

METHODS

We performed a retrospective study in three specialised institutions. Inclusion criteria were (1) focal onset or symptomatic generalized (2) therapy-resistant epilepsy, (3) intellectual disability and (4) residence in a care-facility for people with intellectual disabilities (PWID). The primary outcome variables were the retention rates of lacosamide, estimated through Kaplan-Meier survival analysis. Secondary outcomes were reported seizure control, side effects and clinical factors influencing discontinuation.

RESULTS

One hundred and thirty-two patients were included. The median retention time of lacosamide in our cohort was four years. The estimated one-, two- and three-year retention rates of lacosamide were 64%, 57% and 56% respectively. Severity of intellectual disability and seizure type did not influence whether lacosamide was continued. In 48.5% of patients, a reduction of seizure activity was reported. Side effects were at least part of the reason for discontinuing treatment in 26.5% of all patients. Common side effects were tiredness/somnolence (in 30.3%), aggression/agitation (24.2%), and instable gait (15.2%). Five deaths during follow-up were considered unlikely to be related to the use of lacosamide. One patient died unexpectedly within two months of treatment onset, probably this was a case of SUDEP.

CONCLUSION

These retention rates of lacosamide in PWID are similar to rates of previously registered anti-epileptic drugs in PWID. Behavioural side effects were noted in a high proportion compared to the general literature on lacosamide. Other side effects were in line with this literature. Lacosamide seems effective and safe for PWID and refractory epilepsy.

AMPA receptors and perampanel behind selected epilepsies: current evidence and future perspectives

INTRODUCTION

The alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors are the major mediators of glutamate-mediated excitatory neurotransmission, and are critical for synchronization and spread of epileptic activity. Areas covered: AMPA receptor antagonists have been also developed as antiepileptic drugs and perampanel (PER) is the first highly selective, non-competitive AMPA-type glutamate receptor antagonist that is available on the market. It is approved as adjunctive therapy for the treatment of partial-onset seizures with or without secondary generalization, and for primary generalized tonic-clonic seizures in idiopathic generalized epilepsy, in patients aged ≥ 12 years. This article reviews the role of AMPA receptors in the neuronal hyperexcitability underlying epilepsy, the mechanism of action and clinical experience on the anti-seizure activity of PER. Moreover, the rationale for targeting AMPA receptor in specific epileptic disorders, including brain tumor-related epilepsy, mesial temporal lobe epilepsy with/without hippocampal sclerosis, and status epilepticus is evaluated. Finally, the pharmacological rationale for the development of AMPA receptor antagonists in other neurological disorders beyond epilepsy is considered. Expert opinion: Further research aimed at better understanding the pharmacology and blocking mechanism of PER and other AMPA receptor antagonists will drive future development of therapeutic agents that target epilepsy and other neurological diseases.

Spotlight on perampanel in the management of seizures: design, development and an update on place in therapy

Purpose

Perampanel is a first-in-class antiepileptic medication approved for the treatment of partial (focal) seizures, and as adjunctive treatment for primarily generalized tonic–clonic seizures. The pharmacology, efficacy data, adverse-effect profile, pharmacokinetics and place in therapy are reviewed.

Summary

Perampanel is indicated for use in patients with epilepsy who are 12 years of age or older. It is the first medication designed specifically to be a non-competitive antagonist at post-synaptic α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptors. Efficacy in refractory seizures has been established, and ongoing efficacy demonstrated by post-marketing data. The drug is completely absorbed, and exhibits a half-life that allows for once-daily administration in doses up to 12 mg/day. Drug interactions are minimal, but increased doses may be necessary when given with strong inducers of cytochrome P450 enzymes, including when perampanel is co-administered with other antiepileptics that exhibit this property. The most common adverse effects noted in both clinical trials and post-marketing are dizziness and somnolence. Psychiatric and behavioral adverse events have been documented in both adult and pediatric patients, including those with no corresponding diagnostic history.

Conclusion

Perampanel is a novel adjunctive antiepileptic medication that is an effective option for adolescents and adults with partial seizures, and primarily generalized tonic–clonic seizures uncontrolled with other medications.

Current role of perampanel in pediatric epilepsy

Perampanel is among the latest AEDs approved, indicated for the treatment of partial-onset seizures with or without secondary generalization, and for primary generalized tonic-clonic seizures, in patients aged 12 years and older. This paper summarizes the clinical recommendations on the current role of perampanel in the treatment of pediatric epilepsies and future directions for research. The optimal dosage should be comprised between 4 and 12 mg/day, with 8 mg/day being the most common dosage used. The rate and severity of adverse events, including psychiatric symptoms, can be decreased by starting at low doses, and titrating slowly. Overall, perampanel presents an acceptable risk/benefit ratio, but special caution should be made to the risk of seizure aggravation and behavioral problems. The favorable cognitive profile, the ease of use of the titration scheme and the once-daily formulation offer advantage over other AEDs and make this drug particularly suitable for adolescent population. Perampanel is a welcome addition to the armamentarium of the existing AEDs, as it represents a new approach in the management of epilepsy, with a novel mechanism of action and a potential to have a considerable impact on the treatment of adolescents with epilepsy.