Rescue therapies for seizure clusters: Pharmacology and target of treatments

The primary goal of treatment for seizure clusters is cessation of the cluster to avoid progression to more severe conditions, such as prolonged seizures and status epilepticus. Rescue therapies are key components of treatment plans for patients with seizure clusters. Three rescue therapies are approved in the United States for the treatment of seizure clusters: diazepam rectal gel, midazolam nasal spray, and diazepam nasal spray. This review characterizes the pharmacological function of rescue therapies for seizure clusters, as well as describing γ‐aminobutyric acid A (GABAA) receptor functions. GABAA receptors are heteropentamers, consisting primarily of α1‐6, β1‐3, γ2, and δ subunits in the central nervous system. These subunits can traffic to and from the membrane to regulate membrane potential. Benzodiazepines, such as diazepam and midazolam, are positive allosteric modulators of GABAA receptors, the activation of which leads to an increase in intracellular chloride, hyperpolarization of the cell membrane, and a reduction in excitation. GABAA receptor subunit mutations, dysregulation of trafficking, and degradation are associated with epilepsy. Although benzodiazepines are effective GABAA receptor modulators, individual formulations have unique profiles in practice. Diazepam rectal gel is an effective rescue therapy for seizure clusters; however, adults and adolescents may have social reservations regarding its administration. Intranasal delivery of midazolam or diazepam is a promising alternative to rectal administration because these formulations offer easy, socially acceptable administration and exhibit a rapid onset. Off‐label benzodiazepines, such as orally disintegrating lorazepam and intranasal use of an intravenous formulation of midazolam via nasal atomizer, are less well characterized regarding bioavailability and tolerability compared with approved agents

Cannabidiol for Epilepsy: New Hope on the Horizon?

Epilepsy is a common neurologic disorder; it is estimated that ∼50million people are affected worldwide. About one third of those patients are drug resistant, defined as failure to stop all seizures despite adequate trials of at least 2 appropriate medications. There has been an enormous interest in developing antiepileptic drugs with novel mechanisms of action. This review discusses the evidence supporting the anticonvulsant properties of cannabis in humans, focusing on cannabidiol. We begin by exploring the early and somewhat anecdotal evidence that was recently replaced by high-quality data from randomized controlled studies, which subsequently led to the US Food and Drug Administration approval of a purified cannabidiol extract for the treatment of 2 highly refractory pediatric epilepsy syndromes (Dravet and Lennox-Gastaut)

The unmet need for rapid epileptic seizure termination (REST)

•Rapid epileptic seizure termination (REST) treatment aims to abort an ongoing seizure.•Current outpatient rescue medications have not been sufficiently studied as REST treatment.•Successful REST medication requires IV-like pharmacokinetics.•Novel drug delivery systems suitable for REST treatment are in development. Approximately 40% of epilepsy patients will continue to experience breakthrough seizures despite stable antiepileptic drug regimens. Rescue treatments have demonstrated efficacy and safety for select seizure emergencies. Outpatient administered intranasal and rectally delivered medications are regulatory approved for acute repetitive seizures (ARS), and injectable benzodiazepines are indicated for parenteral treatment of established status epilepticus. Despite these advances, no studies have been shown to abort an ongoing seizure following patient or caregiver home administration of therapy at the first clinical sign of seizure onset. Such treatment would require rapid systemic absorption without intravenous access, and evidence of seizure cessation within minutes of administration that is superior to placebo (eg, seizure self-regulation). Rapid epileptic seizure termination (REST) treatment may apply to multiple seizure emergencies beyond ARS, including focal or generalized seizures preceded by an aura, flurries of absence or myoclonic seizures, or prolonged focal and generalized seizures at high risk of progression to status epilepticus. Novel investigational drug delivery systems have demonstrated feasibility of intraictal delivery and seizure cessation by two minutes. Ongoing randomized trials of REST treatment for diverse seizure emergencies hold the potential to decrease bouts of mental and physical incapacitation in patients with drug-resistant epilepsy

Assessment of Treatment Side Effects and Quality of Life in People with Epilepsy

Epilepsy impairs quality of life in physical, psychological, cognitive, social, and occupational domains. In people who are not seizure free, depression and adverse medication effects have a predominant role in determining quality of life. The assessment of these factors and other comorbidities is essential for maximizing quality of life in epilepsy. There are multiple tools available to assess medication effects and quality of life in a structured format. Such tools can provide superior assessments and allow clinicians to have a greater impact on their patients' quality of life

Seizure cluster: Definition, prevalence, consequences, and management

•Seizure clusters are common in patients with refractory epilepsy.•There is no agreed upon definition for seizure clusters.•Rescue medications are underutilized in seizure clusters.•Non-rectal, non-IV benzodiazepines are safe and effective in the outpatient management of seizure clusters. To summarize definitions, prevalence, risk factors, consequences, and acute management of seizure clusters using rescue medications. We searched MEDLINE for studies that assessed definitions, clinical characteristics, outcomes, and use of rescue medication for aborting seizure clusters. Different clinical and statistical definitions for seizure clusters have been proposed, including: ≥3 seizures in 24 h, ≥2 seizures in 24 h, and ≥2 seizures in 6 h. Most studies of seizure clusters have been conducted in tertiary epilepsy centers, with refractory epilepsy patients. Patients with severe and poorly controlled epilepsy are more likely to experience seizure clusters. Seizure clusters can result in increased health care utilization and have negative impact on the quality of life of patients and caregivers. Use of benzodiazepine rescue medications in acute management of seizure clusters can help avoid progression to status epilepticus and reduce emergency room visits. Rescue medications are underutilized in seizure clusters. Currently, rectal diazepam gel is the only FDA approved rescue medication for seizure clusters. In addition, buccal midazolam is approved in European countries for treatment of prolonged seizures. However, various non-rectal non-IV benzodiazepines are safe and effective in treating acute seizures and clusters. Most patients and caregivers preferred non-rectal routes. Identifying patients that are at high risk for seizure clusters, providing them with formal action plans and educating them about use of rescue medication for seizure clusters can help ameliorate the outcomes in this group of epilepsy patients

A De Novo HECW2 Variant in a Patient with Acetazolamide-Responsive Episodic Ataxia

To the best of our knowledge, this is the first case to address episodic ataxia (EA) as a possible phenotypic feature of HECW2-related disorder. This single case study describes a 26-year-old female born at term with mild intellectual disability, neonatal hypotonia, and a history of febrile seizures who presented with paroxysmal events since the age of 2. These episodes include frequent falls due to imbalance, dilated pupils, vertigo, diaphoresis, nausea, vomiting, and nystagmus. Brain imaging was normal. A prolonged electroencephalogram (EEG) revealed interictal epileptiform discharges but failed to capture her clinical events. For several years, she was treated for presumed focal seizures with preserved awareness and trialed on adequate dosing of several antiepileptic medications without improvement. After 25 years, given the more prolonged nature of her episodes and the mild interictal cerebellar signs, empiric treatment with acetazolamide was initiated for a presumed diagnosis of EA. Acetazolamide treatment led to a dramatic reduction in event frequency and severity. The initial EA genetic panel was negative. Clinical exome sequence analysis revealed a novel pathogenic de novo missense variant in the HECW2 gene [c.3829 T > C;(p.Tyr1277His)], located in the HECT domain. HECW2 variants are associated with neurodevelopmental delay, hypotonia, and epilepsy. This study expands the genetic and clinical spectrum of HECW2-related disorder and adds EA to the phenotypic spectrum in affected individuals

Concurrent Autoimmune Encephalitis, Diabetes, and Thyroiditis After a Single Dose of Pembrolizumab

Objective We describe the case of a patient with an extensive autoimmune response after one dose of pembrolizumab, emphasizing the importance of early recognition of the diverse presentation of autoimmune complications from checkpoint inhibitors. Background A 55-year-old woman with a myxoid chondrosarcoma of the right hand, previously treated with chemotherapy that received one dose of pembrolizumab, with an excellent tumor response. One month later she developed progressive memory impairment and new onset of severe hyperglycemia (glucose > 700 mg/dL) and profound hypothyroidism (TSH of 90 mcIU/mL), attributed to pembrolizumab. She was treated with hormone replacement for autoimmune diabetes and hypothyroidism. Shortly after, she had her first generalized convulsive seizure. Initial MRI brain was unremarkable. Formal neurological evaluation two weeks later was concerning for fluctuating cognitive impairment and staring spells, for which she was admitted. EEG demonstrated focal status epilepticus of the left posterior quadrant. She required multiple agents to control her refractory seizures. MRI brain showed FLAIR hyperintensities in the bilateral hippocampi and cerebral hemispheres. CSF: WBC 3 (76% lymph), normal protein and glucose, negative infectious workup, 7 CSF specific oligoclonal bands, and positive anti-Hu (1:8 CSF and 1:400 serum) and positive serum anti-GAD-65 antibodies (>1:4800). Anti-TPO antibodies were 103 IU/ml. She received 1 gram of intravenous solumedrol for 5 days. Due to partial response, she received five sessions of plasma exchange. Follow up MRI brain showed worsening FLAIR hyperintensities in the bilateral hippocampi, therefore, she was started on IVIG. Patient's mental status continued to improve, and she was discharged to acute rehabilitation on a slow prednisone taper. Design/Methods N/A. Results N/A. Conclusions Checkpoint inhibitor therapy is associated with a variety of systemic and neurological autoimmune complications. A high level of suspicion is needed for early identification of these syndromes and prompt management. Monitoring of treatment response is crucial as it may require treatment escalation