Old versus new antiepileptic drugs: the SANAD study

Drug resistant epilepsies: A multicentre case series of steroid therapy

PURPOSE

Our study aimed to evaluate the effectiveness of corticosteroids on seizure control in drug-resistant epilepsies (DREs). Our primary goal was to assess the response to steroids for various underlying etiologies, interictal electroencephalographic (EEG) patterns and electroclinical seizure descriptions. Our second goal was to compare steroid responsiveness to different treatment protocols.

METHODS

This is a retrospective multicentre cohort study conducted according to the STROBE guidelines (Strengthening the Reporting of Observational Studies in Epidemiology). The following data were collected for each patient: epilepsy etiology, interictal EEG pattern, seizure types and type of steroid treatment protocol administered.

RESULTS

Thirty patients with DRE were included in the study. After 6 months of therapy, 62.7 % of patients experienced reduced seizure frequency by 50 %, and 6.6 % of patients experienced complete seizure cessation. Findings associated with favourable response to steroids included structural/lesional etiology of epilepsy, immune/infectious etiology and focal interictal abnormalities on EEG. Comparing four different steroid treatment protocols, the most effective for seizure control was treatment with methylprednisolone at the dose of 30 mg/kg/day administered for 3 days, leading to greater than 50 % seizure reduction at 6 months in 85.7 % of patients. Treatment with dexamethasone 6 mg/day for 5 days decreased seizure frequency in 71.4 % of patients. Hydrocortisone 10 mg/kg administered for 3 months showed a good response to treatment in 71 %.

CONCLUSIONS

In our study, two-thirds of patients with DRE experienced a significant seizure reduction following treatment with steroids. We suggest considering steroids as a potential therapeutic option in children with epilepsy not responding to conventional antiseizure medicines (ASM).

Neuroprotective effect of Berberine Nanoparticles Against Seizures in Pentylenetetrazole Induced Kindling Model of Epileptogenesis: Role of Anti-Oxidative, Anti-Inflammatory, and Anti-Apoptotic Mechanisms

There is an unmet need to develop alternative therapeutic strategies to not only restrain seizures but also to alleviate the underlying pathologies and sequelae. Berberine (BBR), an isoquinoline alkaloid, has shown promising effect in the kindling model of epileptogenesis, but due to the poor oral bioavailability its clinical application is limited. So, the present study was designed to study the neuroprotective effect of BBR nanoparticles (enhanced bioavailability as compared to BBR) against seizures in pentylenetetrazole (PTZ) induced kindling model of epileptogenesis. Kindling model was established in male Wistar rats by intraperitoneal (i.p.) administration of PTZ (30 mg/kg) on every alternate day till the animal became fully kindled or till 6 weeks. Three doses of BBR (50, 100, and 200 mg/kg) and nano-BBR (25, 50, 100 mg/kg) were studied for seizure score, percentage of animal kindled, histopathological score, oxidative stress, inflammation, and apoptosis in PTZ treated rats by conducting cytokines, gene expression and protein expression analysis. BBR nanoparticles showed significant effect on the seizure score and percentage of animal kindled, histopathological score, neurobehavioral parameters (Forced swim test, Rotarod), oxidative (MDA, SOD, GSH, GPx) and inflammatory (IL-1beta, TNF-alpha) parameters, apoptotic parameters (Bax and iNOS), and gene (Nrf2, NQO1, HO1) and protein expression (Nrf2) as compared to both PTZ and BBR. BBR nanoparticles showed neuroprotective effect in PTZ induced kindling model of epileptogenesis and proves to be a promising antiepileptogenic therapy for the patients who are at high risk of developing seizures.

Perampanel add-on therapy for drug-refractory epilepsy: A single-center retrospective study based on 6-month treatment outcomes in Central China

OBJECTIVE

To systematically evaluate the efficacy, tolerability and retention of perampanel (PER) for treating drug-refractory epilepsy (DRE), and to investigate the independent factors affecting efficacy and retention. We hope this will provide clinicians with guidelines for the use of PER to treat patients with DRE.

METHODS

We conducted a single-center retrospective observational study of patients with DRE who received PER as add-on therapy at the Epilepsy Center of the People's Hospital of Henan Province, China, between 2020 Mar. and 2021 Sep. We collected clinical data from these patients. The observation period was 6 months. The observation endpoint is the drug response and retention rate at 6 months of PER use. Regression analyses were used to compare the differences in efficacy and retention rates, respectively.

RESULTS

Clinical data were obtained for 72 patients with DRE (mean duration of treatment: 10.6 months). At 6 months, 25% of patients (n = 18) were seizure free; 18.1% of patients (n = 13) remained seizure free for 6 months after the addition of PER. 22.2% of patients (n = 16) had a response (One of the patients was withdrawn 5 months after adding PER due to financial difficulties). The retention rate of PER at 6 months was 77.8%. Adverse effects tended to be dominated by neuropsychiatric symptoms. Multifactorial logistic regression analysis showed significant differences in whether the baseline seizure frequency exceeded 4 seizures/month (OR = 0.232, 95%CI: 0.077-0.702, p = 0.01) and whether the number of previously failed ASMs exceeded 3 (OR = 0.316; 95%CI:0.109-0.920, p = 0.035). This indicates that the risk of experiencing a nonresponse is higher with a higher baseline seizure frequency as well as with a higher number of previous ASM failures. Therefore, a baseline frequency exceeding four seizures/month and more than three previous ASM failures were independent influencing factors for PER addition treatment for patients with DRE. Multifactorial COX regression showed that patients with DRE due to infection had a lower retention rate (OR = 15.957, 95% CI: 3.692-68.972, P < 0.001) than patients with DRE due to other noninfectious etiologies. Patients with DRE who only had a single seizure type (OR = 0.053, 95% CI:0.006-0.476, P = 0.009), and patients who did not have cognitive impairment (OR = 134.253, 95% CI:5.623-3205.104, P = 0.002) showed longer durations of PER use. Infection-related epilepsy etiology, experiencing multiple types of seizures, and with cognitive impairment were independent influencing factors on PER use retention in patients with DRE.

CONCLUSION

Our study demonstrated the efficacy of PER for reducing seizure frequency in patients with DRE and found significant differences in efficacy and retention rate, respectively. This provides a basis for assessing the expected efficacy and duration of use of PER for patients with DRE.

Effect and tolerability of perampanel in patients with drug-resistant epilepsy

OBJECTIVE

Perampanel is one of the most recently approved antiseizure medications. The aim of the present study was to assess clinical efficacy and tolerability, in combination with pharmacokinetic variability, of perampanel treatment in patients at a tertiary referral center for epilepsy.

METHODS

We performed a retrospective observational study of patients given perampanel as adjunctive treatment in the period January 2013 - February 2019 at the National Center for Epilepsy at Oslo University Hospital, Norway.

RESULTS

Clinical data were available for 175 mainly adult patients with drug-resistant epilepsy with mean treatment duration of 16.1 months. We found that 23% (40 patients) were responders (i.e., achieving more than 50% reduction in seizure frequency), four of whom became seizure free, 29% (51 patients) experienced a modest effect, whereas for 29% (50 patients) perampanel had no seizure-reducing effect. A paradoxical effect, with seizure aggravation, was reported in 9% (15 patients). The responder rate was significantly higher in those with slow vs. fast dosage titration. Logistic regression analysis showed better efficacy among those with generalized vs. those with focal epilepsy. Adverse effects were reported by 135 patients (77%), ranging from mild (34%), to moderate (41%) and severe (2%). In 55 patients (41%), these adverse effects resulted in discontinuation of treatment with perampanel. The most frequent adverse effects were psychiatric symptoms (34%), dizziness (31%), and sleepiness (26%). Of the 31 patients for whom serum concentration measurements were available, the mean daily perampanel dose was 6.3 mg (SD 3.0), with a mean serum concentration at steady state of 1.03 μmol/L (range: 0.15-3.59 μmol/L). There were pronounced differences between patients, as demonstrated by a 12-fold variability in the range of concentration/dose (C/D)-ratios (0.06 to 0.69 μmol/L/mg), where enzyme inducers contributed.

CONCLUSION

Our results demonstrate that perampanel had a modest seizure-reducing effect in this very treatment-resistant patient group. Predictors of treatment success were generalized epilepsy and slow dosage titration. In patients without a history of psychiatric problems, clinicians could consider increasing dose of perampanel beyond 6 mg daily, taking co-medication and serum concentrations into account.

Feasibility of implantable iron oxide nanoparticles in detecting brain activity-proof of concept in a rat model

BACKGROUND

Precise detection of zones of increased brain activity is a crucial aspect in the delineation of the cortical region responsible for epilepsy (epileptic focus). When possible, removal of this area can lead to improved control of epilepsy or even its cure. This study explores a new method of detection of electrical brain activity based on the surgical implantation of iron oxide superparamagnetic nanoparticles (SPIONs). By their magnetic nature, SPIONs tend to aggregate in the presence of magnetic fields. This study aims to demonstrate if brain's magnetic fields could change the aggregation status of SPIONs in a rat model.

METHODS

Plastic containers (capsules) containing SPIONs in aqueous suspension were implanted over the cortex of either rats rendered epileptic or naive rats (sham). A model of focal epilepsy using cortical penicillin injection was used for the epileptic rats. Capsules not implanted in rats served as control. Using magnetic resonance imaging (MRI), the aggregation status of SPIONs contained in the capsules was assessed via measurement of the T₂ relaxivity time of the solutions.

RESULTS

Eight Rats were used for the experiments, with 4 rats in each group (epileptic and sham). One Rat in the sham group died immediately after surgery and 3 rats failed to demonstrate the expected behavior after intervention (2 rats in epileptic group with limited observable seizures and 1 rat in the sham group having repeated seizures). T₂ of the control capsules were significantly lower than those implanted in rats (146 ms vs 7.6 ms, p < 0.001), suggesting a higher degree of SPIONs aggregation in the implanted capsules. No significant difference in T₂ could be demonstrated between epileptic and sham rats.

CONCLUSIONS

SPIONs implanted over the cortex of active brain showed an increased aggregation status, confirming their potential as a new marker for brain activity. One of the main advantages of SPIONs is that their aggregation status can be measured at a distance with MRI, taking advantage of its high spatial resolution and imaging capacities. The current model was suboptimal to confirm if epileptic activity can be differentiated from normal brain activity using SPIONs.

Treatment outcome after failure of a first antiepileptic drug

OBJECTIVES

We assessed the likelihood of 12-month seizure remission and treatment failure after failure of a first antiepileptic drug, and identified factors influencing these outcomes.

METHODS

SANAD (Standard and New Antiepileptic Drug) was a randomized controlled trial comparing monotherapy with standard and new antiepileptic drugs. Patients were followed up to study completion, even if they were switched from their randomized treatment. After a first treatment failure, we assessed the probability of 12-month seizure remission and treatment failure. Prognostic modeling identified predictors of these outcomes.

RESULTS

Forty-four percent of patients in the SANAD trial had a first treatment failure. Seventy-five percent of these subsequently achieved 12-month remission by 6 years of follow-up. Significant prognostic factors included sex, age at treatment failure, time on randomized treatment at treatment failure, neurologic insult, total number of tonic-clonic seizures at treatment failure, reason for treatment failure, seizure type, and CT/MRI scan result. After a first treatment failure, young patients without tonic-clonic seizures, with a normal CT/MRI scan and failing their treatment because of unacceptable adverse events, had the highest likelihood of 12-month remission. Approximately 50% of patients who failed a first treatment also failed their second. Significant prognostic factors included total number of tonic-clonic seizures at first treatment failure, reason for first treatment failure, and CT/MRI scan result. Patients with tonic-clonic seizures and failing because of inadequate seizure control had the highest risk of a second treatment failure.

CONCLUSIONS

A high proportion of patients will achieve 12-month remission after a first treatment failure. Clinical factors can stratify patients according to likely outcome.

Joint modelling of longitudinal and competing risks data

Available methods for joint modelling of longitudinal and survival data typically have only one failure type for the time to event outcome. We extend the methodology to allow for competing risks data. We fit a cause-specific hazards sub-model to allow for competing risks, with a separate latent association between longitudinal measurements and each cause of failure.The method is applied to data from the SANAD trial of anti-epileptic drugs (AEDs), as a means of investigating the effect of drug titration on the relative effects of lamotrigine (LTG) and carbamazepine (CBZ) on treatment failure. Concern had been expressed that differential titration rates may have been to the disadvantage of CBZ. The beneficial effect of LTG on unacceptable adverse events leading to drug withdrawal did not lessen and indeed increased slightly when a calibrated dose was accounted for in the joint model. Adjustment for the titration rate of LTG relative to CBZ resulted in an unchanged effect of the former on drug withdrawals due to inadequate seizure control. LTG remains the AED of choice from this analysis.

Topiramate monotherapy in the treatment of newly or recently diagnosed epilepsy

BACKGROUND

The efficacy of topiramate (TPM) as an adjunctive treatment for epilepsy has been established in placebo-controlled clinical trials. Clinical trials of antiepileptic monotherapy usually evaluate low and high doses of study drug or compare study drug with another active agent.

OBJECTIVE

This article reviews available evidence for the use of TPM as monotherapy in patients with newly or recently diagnosed epilepsy.

METHODS

A search of MEDLINE, EMBASE, BIOSIS, SCISEARCH, and the Cochrane Database of Systematic Reviews (all years) for reports of controlled trials of TPM monotherapy in patients with recently diagnosed (within the previous 3 years) epilepsy was conducted in January 2008 using the terms topiramate, epilepsy, newly diagnosed, recently diagnosed, and monotherapy. Identified trials were included in the review if they were published in peer-reviewed journals and enrolled > or = 20 patients.

RESULTS

Three randomized, double-blind, controlled trials met the criteria for inclusion in the review. In a comparison of TPM 50 and 500 mg/d, the higher dose was associated with significantly greater freedom from seizures at 6 months compared with the lower dose (54% vs 39%, respectively; P = 0.02). The time to first seizure was significantly associated with mean plasma TPM concentrations (P = 0.015). In a comparison of TPM 50 and 400 mg/d, the time to first seizure was significantly longer with the higher dose compared with the lower dose (P<0.001, Kaplan-Meier analysis), and the probability of 12-month seizure freedom was significantly higher (76% vs 59%, respectively; P = 0.001). Again, the time to first seizure was significantly associated with mean plasma TPM concentrations (P = 0.029). In a comparative study of TPM 100 and 200 mg/d, carbamazepine 600 mg/d, and valproate 1250 mg/d, there was no significant difference in rates of 6-month seizure freedom with TPM 100 and 200 mg/d (49% and 44%, respectively), carbamazepine (44%), and valproate (44%). Adverse events in the 3 studies were similar between TPM dose groups, although the incidence generally increased with increasing doses, occurred early in treatment, and decreased with prolonged therapy. In a pooled analysis of the 3 trials, the most commonly occurring adverse events during dose titration were paresthesia (25%), fatigue (16%), dizziness (13%), somnolence (13%), and nausea (10%); the most frequent adverse events during maintenance therapy were headache (20%), decreased appetite (11%), and weight loss (11%).

CONCLUSION

In the 3 studies reviewed, TPM monotherapy was effective and generally well tolerated in patients with newly diagnosed epilepsy.

Topiramate: a review of its use in the treatment of epilepsy

Topiramate (Topamax) is a structurally novel broad-spectrum antiepileptic drug (AED) with established efficacy as monotherapy or adjunctive therapy in the treatment of adult and paediatric patients with generalised tonic-clonic seizures, partial seizures with or without generalised seizures, and seizures associated with Lennox-Gastaut syndrome. The incidence and severity of many adverse events, including CNS-related events, may be reduced through the use of slow titration to effective and well tolerated dosages. It is associated with few clinically significant interactions with other drugs, is effective when used with other AEDs, is not associated with drug-induced weight gain and, at lower dosages, does not interfere with the effectiveness of oral contraceptives. Therefore, topiramate is a valuable option as monotherapy or adjunctive therapy in the treatment of epilepsy in adult and paediatric patients.