Treatment responsive GABA(B)-receptor limbic encephalitis presenting as new-onset super-refractory status epilepticus (NORSE) in a deployed U.S. soldier
- Epileptic disorders : international epilepsy journal with videotape
- Published about 5 years ago
A 23-year-old, previously healthy, deployed U.S. soldier presented with bilateral temporal lobe seizures recalcitrant to multiple antiepileptic drugs and anti-seizure anaesthetic agents. He received methylprednisolone, intravenous immunoglobulins, plasma exchange, and rituximab for presumed autoimmune encephalitis before achieving seizure freedom. Six weeks after presentation, the aetiology of his refractory seizures was found to be due to autoantibodies targeting the anti-GABA(B)-receptor. This case is noteworthy for being the first reported case of anti-GABA(B)-receptor limbic encephalitis presenting with new-onset refractory status epilepticus (NORSE), a clinical syndrome that often carries a grave prognosis and in which a treatable aetiology is often never discovered. Our case also supports testing for GABA-receptor autoantibodies and the upfront use of multi-modal immunotherapy in patients presenting with limbic encephalitis and new refractory seizures.
Status epilepticus is a common pediatric neurological emergency. Management includes prompt administration of appropriately selected anti-seizure medications, identification and treatment of seizure precipitant(s), as well as identification and management of associated systemic complications. This review discusses the definitions, classification, epidemiology and management of status epilepticus and refractory status epilepticus in children.
Dogs with spontaneous diseases can exhibit a striking similarity in etiology, clinical manifestation, and disease course when compared to human patients. Therefore, dogs are intensely discussed as a translational model of human disease. In particular, genetic studies in selected dog breeds serve as an excellent tool to identify epilepsy disease genes. In addition, canine epilepsy is discussed as a translational platform for drug testing. On one hand, epileptic dogs might serve as an interesting model by allowing the evaluation of drug efficacy and potency under clinical conditions with a focus on chronic seizures resistant to standard medication, preventive strategies, or status epilepticus. On the other hand, several limitations need to be considered including owner-based seizure monitoring, species differences in pharmacokinetics and drug interactions, as well as cost-intensiveness. The review gives an overview on the current state of knowledge regarding the etiology, clinical manifestation, pathology, and drug response of canine epilepsy, also pointing out the urgent need for further research on specific aspects. Moreover, the putative advantages, the disadvantages, and limitations of antiepileptic drug testing in canine epilepsy are critically discussed.
Comorbid anxiety and depressive disorders in people with epilepsy (PWE) are highly prevalent and associated with various adverse outcomes. However, the prevalence of anxiety disorders in PWE across studies is highly variable. Our aim was to estimate the prevalence and moderating factors of anxiety and depressive disorders in PWE.
Diazepam (Valium) is among the most successful drugs from the onset of the psychopharmacological revolution that began during the 1950’s. Efficacious in treating a wide-spectrum of CNS disorders, including anxiety and epilepsy, it set the standard for pharmacotherapy in terms of potency, onset of action, and safety. In this Viewpoint, the legacy of diazepam to chemical neuroscience will be considered along with its synthesis, pharmacology, drug metabolism, adverse events and dependence, clinical use, and regulatory issues.
Refractory status epilepticus (RSE) occurs when status epilepticus (SE) fails to respond to appropriate therapy with typical antiepileptic drugs (AEDs). Animal studies have shown ketamine to be a highly efficacious agent in this setting, but very few case reports describe use of ketamine in human SE or RSE. We report a retrospective review of 11 patients who were treated for RSE with ketamine infusion in addition to other standard AEDs over a nine-year period. Data collection included age, gender, history of epilepsy, etiology of RSE, daily dose of ketamine, co-therapeutic agents, duration of seizures, treatment response, and disposition. RSE was successfully terminated in all 11 patients treated with ketamine. Dosing ranged from 0.45mg/kg/h to 2.1mg/kg/h based upon the preference of the treating clinician and response to therapy, with maximal daily doses ranging from 1392mg to 4200mg. Ketamine was the last AED used prior to resolution of RSE in 7/11 (64%) cases. In the remaining four cases, one other AED was added after ketamine infusion had begun. Time from ketamine initiation to seizure cessation ranged from 4 to 28 days (mean=9.8, SD=8.9). In 7/11 patients, RSE was resolved within one week of starting therapy. Administration of ketamine was uniformly associated with improvement in hemodynamic stability. Six of the seven patients (85%) who required vasopressors during early treatment for RSE were able to be weaned from vasopressors during ketamine infusion. No acute adverse effects were noted. These findings suggest that ketamine may be a safe and efficacious adjunctive agent in the treatment of RSE.
FGIN-1-27 is an agonist at the translocator protein 18 kDa (TSPO), a cholesterol transporter that is associated with neurosteroidogenesis. This protein has been identified as a peripheral binding site for benzodiazepines; in anamniotes, however, a second TSPO isoform that is absent in amniotes has been implicated in erythropoiesis. Functional conservation of the central benzodiazepine-binding site located in the GABAA receptors has been demonstrated in anamniotes and amniotes alike; however, it was not previously demonstrated for TSPO. The present investigation explored the behavioral effects of FGIN-1-27 on an anxiety test in zebrafish (Danio rerio, Family: Cyprinide) and on a mixed anxiety/panic test on wall lizards (Tropidurus oreadicus, Family: Tropiduridae). Results showed that FGIN-1-27 reduced anxiety-like behavior in the zebrafish light/dark preference test similar to diazepam, but with fewer sedative effects. Similarly, FGIN-1-27 also reduced anxiety- and fear-like behaviors in the defense test battery in wall lizards, again producing fewer sedative-like effects than diazepam; the benzodiazepine was also unable to reduce fear-like behaviors in this species. These results A) underline the functional conservation of TSPO in defensive behavior in anamniotes; B) strengthen the proposal of using anamniote behavior as models in behavioral pharmacology; and C) suggest TSPO/neurosteroidogenesis as a target in treating anxiety disorders.
The development of new antiepileptic drugs is a high-risk/high-cost research field, which is made even riskier if the behavioral epileptic seizure profile is the unique approach on which the development is based. In order to increase the effectiveness of the screening conducted in the zebrafish model of status epilepticus (SE), the evaluation of neurochemical markers of SE would be of great relevance. Epilepsy is associated with changes in the glutamatergic system, and glutamate uptake is one of the critical parameters of this process. In this study therefore, we evaluated the levels of glutamate uptake in the zebrafish brain and analyzed its correlation with the progression of behavioral changes in zebrafish at different times after the administration of kainic acid 5 mg/kg). The results showed that the zebrafish suffered with lethargy while swimming for up to 72 h after SE, had reduced levels of GFAP cells 12 h after SE, reduced levels of S100B up to 72 h after SE, and reduced levels of glutamate uptake in the forebrain between 3 h and 12 h after SE. The forebrain region of adult zebrafish after SE is similar to the neurochemical limbic alterations that are seen in rodent models of SE. This study demonstrated that there is a time window in which to use the KA zebrafish model of SE to explore some of the known neurochemical alterations that have been observed in rodent models of epilepsy and epileptic human patients.
The prevalence of epilepsy is estimated 5-10 per 1000 population and around 70% of patients with epilepsy can be sufficiently controlled by antiepileptic drugs (AEDs). Epileptogenesis is the process responsible for converting normal into an epileptic brain and mechanisms responsible include among others: inflammation, neurodegeneration, neurogenesis, neural reorganization and plasticity. Some AEDs may be antiepileptiogenic (diazepam, eslicarbazepine) but the correlation between neuroprotection and inhibition of epileptogenesis is not evident. Antiepileptogenic activity has been postulated for mTOR ligands, resveratrol and losartan. So far, clinical evidence gives some hope for levetiracetam as an AED inhibiting epileptogenesis in neurosurgical patients. Biomarkers for epileptogenesis are needed for the proper selection of patients for evaluation of potential antiepileptogenic compounds.
Nonconvulsive status epilepticus (NCSE) is present in multiple pediatric neurogenetic syndromes with epileptic encephalopathies. While intravenous (IV) medications are used inpatient for treatment of critical illness-related NCSE, there is no consensus on treatment of ambulatory NCSE. Up to 50% of patients with Angelman syndrome (AS) have NCSE with myoclonic or atypical absence status. Here we report our experience in pediatric patients with AS and NCSE treated outpatient with a tapering course of oral diazepam. We conducted a chart review of 104 patients seen in the Angelman Syndrome Clinic at Massachusetts General Hospital from January 2008 to March 2017, who met the criteria. Response to treatment was defined as cessation of NCSE symptoms with electroencephalogram (EEG) confirmation when possible. Twenty-one patients with NCSE were identified, and 13 patients (9 male) with 25 episodes of NCSE were included. Mean age at NCSE episode was 5years 4months (15months-12years). Six patients had one episode of NCSE, and 7 patients had recurrent episodes (mean: 2.7; range: 2-4). Median diazepam treatment was 6days (4-12days), with a mean dose of 0.32mg/kg/day divided over 2-3 administrations, decreased every 2days. Nine episodes required multiple courses; however, oral diazepam alone was ultimately successful in 80% (20/25) of NCSE episodes. Oral diazepam was well-tolerated with no major side effects. A short course of oral diazepam is well-tolerated and effective in patients with AS who have ambulatory NCSE. It may be considered prior to escalating to inpatient care in AS and possibly other epilepsy syndromes.