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.

(1) Background: Increasing evidence supports the anti-inflammatory and neuroprotective role of perampanel (PER), mediated by decreased expression of pro-inflammatory cytokines and by interference with apoptosis processes. Therefore, the use of PER to treat status epilepticus (SE) with suspected inflammatory etiology is appealing and deserves further investigation. (2) Methods: We retrospectively analyzed seven patients (five F, two M; median age: 62 years) with refractory and super-refractory SE due to a probable or defined inflammatory etiology and treated with PER. (3) Results: PER was administered as the third (4/7) or fourth drug (3/7), with a median loading dose of 32 mg/day (range: 16-36 mg/day) and a median maintenance dose of 10 mg/day (range: 4-12 mg/day). In five cases, SE was focal, while in two patients, it was generalized. SE was caused by systemic inflammation in three patients, while in the other four subjects, it was recognized to have an autoimmune etiology. SE resolution was observed after PER administration in all cases, particularly within 24 h in the majority of patients (4/7, 57.1%). (4) Conclusions: Our data support the efficacy of PER in treating SE when first- and second-line ASMs have failed and suggest a possible earlier use in SE cases that are due to inflammatory/autoimmune etiology.

BACKGROUND: Dravet syndrome is a severe epilepsy disorder characterized by drug-resistant seizures and cognitive dysfunction, often caused by SCN1A gene mutations. It leads to neurodevelopmental delays and motor, behavioral, and cognitive impairments, with a high mortality rate. Treatment options include sodium valproate, clobazam, and newer agents such as cannabidiol and fenfluramine. Zonisamide, which is used in some cases, can cause hyperthermia and oligohydrosis. Herein, we present a case of a patient with Dravet syndrome whose seizures were controlled by treating infections and switching from zonisamide to perampanel.
METHODS: A 24-year-old Japanese man with Dravet syndrome presented to our department with aspiration pneumonia. The patient had been treated with valproate, sodium bromide, and zonisamide for a long time. His seizures were triggered by hyperthermia. The patient was experiencing a sustained pattern of hyperthermia caused by infection, zonisamide, and persistent convulsions, which caused a vicious cycle of further seizures. In this case, the control of infection and switching from zonisamide to perampanel improved seizure frequency.
CONCLUSIONS: Dravet syndrome usually begins with generalized clonic seizures in its infancy because of fever and progresses to various seizure types, often triggered by fever or seizure-induced heat due to mutations in the SCN1A gene that increases neuronal excitability. Seizures usually diminish with age, but the heat sensitivity remains. In this case, seizures were increased by repeated infections, and hyperthermia was induced by zonisamide, resulting in status epilepticus. Perampanel, an aminomethylphosphonic acid receptor antagonist, decreased seizures but caused psychiatric symptoms. It was effective in suppressing seizures of Dravet syndrome in this patient.

This study reported the first case of Kohlschütter-Tönz syndrome (KTS) in China and reviewed the literature of the reported cases.
This patient was registered at the Children\'s Hospital of Chongqing Medical University. The patient\'s symptoms and treatments were recorded in detail, and the patient was monitored for six years. We employed a combination of the following search terms and Boolean operators in our search strategy: Kohlschütter-Tönz syndrome, KTS, and ROGDI. These terms were carefully selected to capture a broad range of relevant publications in PubMed, Web of Science, WHO Global Health Library, and China National Knowledge Infrastructure, including synonyms, variations, and specific terms related to KTS. The pathogenicity of the variants was predicted using SpliceAI and MutationTaster, and the structures of the ROGDI mutations were constructed using I-TASSER.
This is the first case report of KTS in China. Our patient presented with epilepsy, global developmental delay, and amelogenesis imperfecta. A trio-WES revealed homozygous mutations in ROGDI (c.46-37_46-30del). The brain magnetic resonance imaging (MRI) and video electroencephalogram (VEEG) were normal. The efficacy of perampanel (PMP) in treating seizures and intellectual disability was apparent. Furthermore, 43 cases of ROGDI-related KTS were retrieved. 100% exhibited epilepsy, global developmental delay, and amelogenesis imperfecta. 17.2% received a diagnosis of attention deficit hyperactivity disorder (ADHD), and 3.4% were under suspicion of autism spectrum disorder (ASD). Language disorders were observed in all patients. Emotional disorders, notably self-harm behaviors (9.1%), were also reported.
ROGDI-related KTS is a rare neurodegenerative disorder, characterized by three classic clinical manifestations: epilepsy, global developmental delay, and amelogenesis imperfecta. Moreover, patients could present comorbidities, including ADHD, ASD, emotional disorders, and language disorders. PMP may be a potential drug with relatively good efficacy, but long-term clinical trials are still needed.

UNASSIGNED: Preclinical studies in a mouse model have shown that SYNGAP1 haploinsufficiency results in an epilepsy phenotype with excessive GluA2-AMPA insertion specifically on the soma of fast-spiking parvalbumin-positive interneurons associated with significant dysfunction of cortical gamma homeostasis that was rescued by perampanel (PER), an AMPA receptor blocker. In this single case, we aimed to investigate the presence of dysregulated cortical gamma in a toddler with a pathogenic SYNGAP1 variant and report on the effect of low-dose PER on electroencephalogram (EEG) and clinical profile.
UNASSIGNED: Clinical data from physician\'s clinic notes; genetic testing reports; developmental scores from occupational therapy, physical therapy, speech and language therapy evaluations; and applied behavioral analysis reports were reviewed. Developmental assessments and EEG analysis were done pre- and post-PER.
UNASSIGNED: Clinically, the patient showed improvements in the developmental profile and sleep quality post-PER. EEG spectral power analysis in our patient revealed a loss of gamma power modulation with behavioral-state transitions similar to what was observed in Syngap1+/- mice. Furthermore, the administration of low-dose PER rescued the dysfunctional cortical gamma homeostasis, similar to the preclinical study. However, as in the epileptic mice, PER did not curb epileptiform discharges or clinical seizures.
UNASSIGNED: Similar to the Syngap1+/- mice, cortical gamma homeostasis was dysregulated in the patient. This dysfunction was rescued by PER. These encouraging results necessitate further validation of gamma dysregulation as a potential translational EEG biomarker in SYNAP1-DEE. Low-dose PER can be explored as a therapeutic option through clinical trials.

Perampanel (Fycompa) is a glutamate receptor antagonist known to be a safe, effective, and well-tolerated medication; nevertheless, adverse effects are possible. This case report aims to raise the suspicion of perampanel-induced thrombocytopenia and discuss its possible pathways implicated. Here, we present the case of a 66-year-old female patient with a generalized tonic-clonic seizure initially managed with levetiracetam, valproic acid, and lacosamide; however, the patient continued to have seizures clinically as well as on the electroencephalogram. The patient was initiated on 2 mg of perampanel and reached up to 12 mg within a week, after which the seizure was controlled. Nevertheless, after perampanel initiation, a gradual platelet count reduction was observed. Upon withdrawal of perampanel, the platelet count dramatically improved reaching up to her baseline. Although perampanel is known to be a safe medication, a hematological complication such as thrombocytopenia is possible. The exact mechanism remains unclear. Further studies are required to understand the association between thrombocytopenia and perampanel to identify high-risk populations and prevent this condition sequentially.

BACKGROUND: N-methyl-d-aspartate receptors (NMDARs) are ligand-gated ion channels that mediate excitatory synaptic transmission and brain development in the central nervous system. Mutations in GRIN2D encoding the NMDAR subunit GluN2D are associated with a wide spectrum of neurodevelopmental disorders.
METHODS: We report a novel de novo GRIN2D variant (NM_000836.2: c.2024C > T, p.Ala675Val) in an infant with severe developmental and epileptic encephalopathy. Clinical characteristics and treatment outcomes of patients with GRIN2D-related developmental and epileptic encephalopathy were summarized by reviewing the literature.
RESULTS: In silico analysis suggested this p.Ala675Val variant residing in the highly conserved M3 helix of GluN2D would interfere with channel gating. Therapeutic options including multiple anticonvulsants, oral corticosteroid therapy, and ketogenic diet failed to achieve seizure control. Eventually, adjunctive therapy with perampanel led to marked electroclinical improvement.
CONCLUSIONS: Perampanel can be beneficial adjuvant therapy for patients with GRIN2D-related intractable epilepsy. Mechanistic understanding and case-per-se analysis are required to enable more individualized treatment for the patients.

Status epilepticus (SE) continues to be a challenging neurological emergency with high morbidity and mortality. During treatment, different regimens are practiced encompassing all known seizure termination mechanisms. To our knowledge, this is the first case series report describing EEG patterns and clinical outcomes in patients treated with ketamine and perampanel (PER) concomitantly.
To assess clinical and electrographic outcomes in patients receiving dual antiglutamatergic therapy in SE.
Twenty-one out of twenty five patients were treated with ketamine, and four patients with ketamine were associated with PER. In the ketamine plus PER group, three out of four patients had convulsive SE, and one had non-convulsive status epilepticus (NCSE), whereas eight patients in the ketamine group had NCSE. The incidence of beta pattern appearance on EEG after starting patients on ketamine and PER was achieved in all four patients (100%) compared to (61.9%) in the other group. A burst suppression pattern was recorded in 75% of patients treated with ketamine and PER, in comparison to 28.5% of patients in patients treated with a different regimen. The time to resolution of SE was significantly shorter in the ketamine group (median 24 (24-64) h vs. 6 (05-144) h p > 0.05). Moreover, the average number of days on IV anesthetic was slightly lower in a patient treated with PER concomitantly. In terms of morbidity, the average increase in mRS was also lower in the ketamine and PER group, although it was not statistically significant.
Dual anti-glutamatergic therapy could provide a favorable approach to treating SE, which yet needs to be further investigated through larger randomized control studies.

BACKGROUND: Perampanel (PER), a third-generation antiepileptic drug, is a selective and noncompetitive α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor antagonist, and has been approved for the treatment of adults and adolescents with focal epilepsy. However, there are only a few studies about the efficacy and tolerability of PER in young children with multidrug-resistant epilepsy. In this case, we aimed to share our clinical experience in this group.
METHODS: A 4-year-old boy without perinatal asphyxia and familial history of epilepsy began to have ictal seizures from age 14 mo, with jerky movement of four limbs and head nodding. Abnormal multifocal discharge and background activity were recorded through electroencephalography, and no pathogenic mutation was found in the whole exome sequencing for the patient and his parents. He had received valproate, levetiracetam, topiramate, oxcarbazepine, clonazepam and lacosamide sequentially at different times, but he still had frequent seizures even after vagus nerve stimulation (VNS) implantation. He was diagnosed with idiopathic multidrug-resistant epilepsy. However, his seizure frequency was significantly reduced after PER administration in a dose-dependent manner, and better cognitive behavior was observed. In addition, the adverse reactions of anger and aggression also appeared.
CONCLUSIONS: PER is effective as add-on therapy for young children with multidrug-resistant epilepsy who have previously undergone VNS implantation.

Epilepsy is known to comorbid with Alzheimer\'s disease. It can promote cognitive decline, and eventually worsen their prognosis and mortality. It is sometimes difficult to find a suitable drug because of the adverse effects. Perampanel has a unique mechanism of action that antagonizes α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid type glutamate receptor. Here, we report a case of severe dementia due to Alzheimer\'s disease with intractable epilepsy, which perampanel effected for controlling seizures with less adverse effects. The subject is an 89-year-old Japanese woman with severe dementia due to Alzheimer\'s disease and intractable myoclonic epilepsy. She also had psychiatric symptoms, such as circadian rhythm disorder and irritability. Valproic acid, lacosamide, or carbamazepine were prescribed, but none of them was effective. Shortly after perampanel started, however, myoclonus and these psychiatric symptoms improved. Moreover, it did not cause any obvious adverse effects, which made it possible to continue perampanel until the end of her life. Perampanel may be useful for controlling intractable epilepsy accompanied by Alzheimer\'s disease. It may also improve psychiatric symptoms with less adverse effect. Accumulation of studies is necessary to evaluate the effectiveness of perampanel on the epilepsy of Alzheimer\'s disease patients and further understand that mechanism.