Neural stimulation can reduce the frequency of seizures in persons with epilepsy, but rates of seizure-free outcome are low. Vagus nerve stimulation prevents seizures by continuously activating noradrenergic projections from the brainstem to the cortex. Cortical norepinephrine then increases GABAergic transmission and increases seizure threshold. Another approach, responsive nervous stimulation, prevents seizures by reactively shocking the seizure onset zone in precise synchrony with seizure onset. The electrical shocks abort seizures before they can spread and manifest clinically. The goal of this study was to determine whether a hybrid platform in which brainstem activation triggered in response to impending seizure activity could prevent seizures. We chose the zebrafish as a model organism for this study because of its ability to recapitulate human disease, in conjunction with its innate capacity for tightly controlled high-throughput experimentation. We first set out to determine whether electrical stimulation of the zebrafish hindbrain could have an anticonvulsant effect. We found that pulse train electrical stimulation of the hindbrain significantly increased the latency to onset of pentylenetetrazole-induced seizures, and that this apparent anticonvulsant effect was blocked by noradrenergic antagonists, as is also the case with rodents and humans. We also found that the anticonvulsant effect of hindbrain stimulation could be potentiated by reactive triggering of single pulse electrical stimulations in response to impending seizure activity. Finally, we found that the rate of stimulation triggering was directly proportional to pentylenetetrazole concentration and that the stimulation rate was reduced by the anticonvulsant valproic acid and by larger stimulation currents. Taken as a whole, these results show that that the anticonvulsant effect of brainstem activation can be efficiently utilized by reactive triggering, which suggests that alternative stimulation paradigms for vagus nerve stimulation might be useful. Moreover, our results show that the zebrafish epilepsy model can be used to advance our understanding of neural stimulation in the treatment of epilepsy.
To ascertain the frequency of self-reported anger and depression in levetiracetam (LEV).
To evaluate the risk of severe cutaneous adverse drug reactions (SCAR) after exposure to multi-indication antiepileptic drugs for in Korean elderly patients.
The relationship between monogenic and polygenic forms of epilepsy is poorly understood and the extent to which the genetic and acquired epilepsies share common pathways is unclear. Here, we use an integrated systems-level analysis of brain gene expression data to identify molecular networks disrupted in epilepsy.
Antiepileptic drug treatment can induce psychosis in some patients. However, there are no agreed definitions or diagnostic criteria for antiepileptic drug-induced psychotic disorder in the classification systems of either epileptology or psychiatry. In this study we investigated the clinical spectrum of antiepileptic drug-induced psychotic disorder in patients with epilepsy. The medical records of all patients with epilepsy who were diagnosed by a neuropsychiatrist as having a psychotic disorder at the Royal Melbourne Hospital from January 1993 to June 2015 were reviewed. Data were extracted regarding epilepsy and its treatment, psychotic symptoms profile and outcome. The diagnosis of epilepsy was established in accordance to the classification system of the International League Against Epilepsy while that of psychotic disorder was made according to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition and the proposal on neuropsychiatric disorders in epilepsy. Patients with antiepileptic drug-induced psychotic disorder were compared to those with psychotic disorders unrelated to antiepileptic drugs assessed over the same period (non-antiepileptic drug induced psychotic disorder group). Univariate comparisons were performed and variables with a value of P < 0.1 were selected for the multivariate logistic regression analysis. The records of 2630 in-patients and outpatients with epilepsy were screened, from which 98 (3.7%) with psychotic disorders were identified. Among these, 14 (14.3%) were diagnosed to have antiepileptic drug-induced psychotic disorder. Excluding one patient who developed psychosis after valproate withdrawal, 76.9% in the non-antiepileptic drug induced psychotic disorder group were female and the percentage of temporal lobe involvement was higher in the non-antiepileptic drug induced psychotic disorder group (69.2% versus 38.1%, P < 0.05). Current use of levetiracetam was higher in antiepileptic drug-induced psychotic disorder group (84.6% versus 20.2%, P < 0.01) while use of carbamazepine was higher in the comparator group (15.4% versus 44.0%, P < 0.05). Multivariate logistic regression confirmed four factors associated with antiepileptic drug-induced psychotic disorder: female gender, temporal lobe involvement and use of levetiracetam, and a negative association with carbamazepine. Disorganized behaviours and thinking were more common in the antiepileptic drug-induced psychotic disorder group (100% versus 72.6% and 76.9% versus 38.1%, respectively; P < 0.05). The percentage of continuous treatment with antipsychotic drugs was lower in the antiepileptic drug-induced psychotic disorder group (15.4% versus 66.7%, P < 0.01). No patients experienced a chronic course in antiepileptic drug-induced psychotic disorder group whereas 40.5% did in non-antiepileptic drug induced psychotic disorder (P < 0.05). Our findings indicated that one in seven patients with epilepsy who developed psychosis had antiepileptic drug-induced psychotic disorder. In these patients, female gender, temporal lobe involvement and current use of levetiracetam were significantly associated with antiepileptic drug induced psychotic disorder compared to other types of psychosis, while carbamazepine had a negative association. Disorganized behaviours and thinking were predominant in antiepileptic drug-induced psychotic disorder. Patients with antiepileptic drug-induced psychotic disorder differed from non-antiepileptic drug-induced psychotic disorders in having better outcome.
The medium chain triglyceride ketogenic diet is an established treatment for drug-resistant epilepsy that increases plasma levels of decanoic acid and ketones. Recently, decanoic acid has been shown to provide seizure control in vivo, yet its mechanism of action remains unclear. Here we show that decanoic acid, but not the ketones β-hydroxybutryate or acetone, shows antiseizure activity in two acute ex vivo rat hippocampal slice models of epileptiform activity. To search for a mechanism of decanoic acid, we show it has a strong inhibitory effect on excitatory, but not inhibitory, neurotransmission in hippocampal slices. Using heterologous expression of excitatory ionotropic glutamate receptor AMPA subunits in Xenopus oocytes, we show that this effect is through direct AMPA receptor inhibition, a target shared by a recently introduced epilepsy treatment perampanel. Decanoic acid acts as a non-competitive antagonist at therapeutically relevant concentrations, in a voltage- and subunit-dependent manner, and this is sufficient to explain its antiseizure effects. This inhibitory effect is likely to be caused by binding to sites on the M3 helix of the AMPA-GluA2 transmembrane domain; independent from the binding site of perampanel. Together our results indicate that the direct inhibition of excitatory neurotransmission by decanoic acid in the brain contributes to the anti-convulsant effect of the medium chain triglyceride ketogenic diet.
Approximately 30% of epilepsy patients do not respond to antiepileptic drugs, representing an unmet medical need. There is evidence that neuroinflammation plays a pathogenic role in drug-resistant epilepsy. The high-mobility group box 1 (HMGB1)/TLR4 axis is a key initiator of neuroinflammation following epileptogenic injuries, and its activation contributes to seizure generation in animal models. However, further work is required to understand the role of HMGB1 and its isoforms in epileptogenesis and drug resistance. Using a combination of animal models and sera from clinically well-characterized patients, we have demonstrated that there are dynamic changes in HMGB1 isoforms in the brain and blood of animals undergoing epileptogenesis. The pathologic disulfide HMGB1 isoform progressively increased in blood before epilepsy onset and prospectively identified animals that developed the disease. Consistent with animal data, we observed early expression of disulfide HMGB1 in patients with newly diagnosed epilepsy, and its persistence was associated with subsequent seizures. In contrast with patients with well-controlled epilepsy, patients with chronic, drug-refractory epilepsy persistently expressed the acetylated, disulfide HMGB1 isoforms. Moreover, treatment of animals with antiinflammatory drugs during epileptogenesis prevented both disease progression and blood increase in HMGB1 isoforms. Our data suggest that HMGB1 isoforms are mechanistic biomarkers for epileptogenesis and drug-resistant epilepsy in humans, necessitating evaluation in larger-scale prospective studies.
The syndrome of malignant migrating partial seizures of infancy (MMPSI) is characterized by early onset of multiple seizure types and overall poor prognosis. Seizures are markedly drug resistant and few reports have suggested the efficacy of some antiepileptic drugs. We report one case of MMPSI in which prolonged seizure control is obtained with an association of clonazepam, levetiracetam and stiripentol, confirming thus the possibility of complete sustained seizure control in this epileptic syndrome. Of more than 60 cases reported to date, ours is the forth in which sustained complete control of seizures was obtained.
PURPOSE: Although differences in illness perceptions between neurologists and patients with epilepsy or psychogenic nonepileptic seizures (PNES) are likely to be clinically relevant, this is the first study to attempt a direct comparison. In addition, this study compares the illness perceptions of patients with epilepsy with those of patients with PNES. METHODS: Thirty-four patients with epilepsy, 40 patients with PNES, and 45 neurologists were recruited. All patient participants completed versions of the illness perception questionnaire revised (IPQ-R) adapted for epileptic or nonepileptic seizure disorders, single-item symptom attribution question (SAQ), Hospital Anxiety and Depression Scale (HADS), Quality of Life in Epilepsy-31 (QOLIE-31), and Liverpool Seizure Severity Scale (LSSS). Participating neurologists completed two versions of the IPQ-R and two SAQs for epileptic and nonepileptic seizure disorders. KEY FINDINGS: Differences in illness perceptions between patients with epilepsy and patients with PNES were minor compared to those between patients with either seizure disorder and neurologists. Neurologists considered both seizure disorders more treatable and more amenable to personal control than did the patients themselves. Neurologists had much more polarized views of the etiology of both conditions; whereas patients mostly considered the causes of their seizure disorders as partially “physical” and partially “psychological,” neurologists perceived epilepsy as an essentially “physical” and PNES as a clearly “psychological” problem. SIGNIFICANCE: There are considerable differences between the illness perceptions of patients with seizure disorders and their doctors, which could represent barriers to successful clinical management. In particular, a discrepancy between neurologists' and patients' beliefs about the personal control that patients may be able to exert over PNES could contribute to the confusion or anger some patients report after the diagnosis has been explained to them. Furthermore, patients' endorsement of “physical” causes for PNES may reflect an unrealistic faith in the effectiveness of “physical” treatments and could be a cause of tension in patients' relationship with their doctor, for instance when the neurologist attempts to withdraw antiepileptic drug treatment or refers patients for psychological interventions.
To evaluate the clinical efficacy and safety of the newer antiepileptic drugs (AEDs), namely, Eslicarbazepine (ESL), Retigabine/Ezogabine (RTG), Carisbamate (CAR), Lacosamide (LAC), Brivaracetam (BRI) or Perampanel (PER) as adjunctive therapy for adults with partial-onset seizures (POS).