Antiepileptic drug combinations--have newer agents altered clinical outcomes?

Presynaptic antiseizure medications - basic mechanisms and clues for their rational combinations

Among clinically highly efficient antiseizure medications (ASMs) there are modifiers of the presynaptic release machinery. Of them, levetiracetam and brivaracetam show a high affinity to the synaptic vesicle protein type 2 A (SV2A), whereas pregabalin and gabapentin are selective ligands for the α2δ1 subunits of the voltage-gated calcium channels. In this paper, we present recent progress in understanding the significance of presynaptic release machinery in the neurochemical mechanisms of epilepsy and ASMs. Furthermore, we discuss whether the knowledge of the basic mechanisms of the presynaptically acting ASMs might help establish a rational polytherapy for drug-resistant epilepsy.

Effectiveness analysis of three-drug combination therapies for refractory focal epilepsy

Selecting appropriate antiseizure medications (ASMs) for combination therapy in patients with drug-resistant epilepsy (DRE) is a complex task that requires an empirical approach, especially in patients receiving polytherapy. We aimed to analyze the effectiveness of various three-drug combinations in a group of patients with DRE under real-world conditions. This single-center, longitudinal observational study investigated patients with drug-resistant focal epilepsy who received three-drug regimens in the outpatient clinic of Tongji Hospital from September 2019 to December 2022. The effectiveness of each triple regimen was evaluated by the seizure-free rate and within-patient ratio of the seizure frequency (a seizure frequency ratio [SFR]<1 indicated superior efficacy). The independent t-test or Mann-Whitney U test was used for effectiveness analysis, and P values were adjusted by the Benjamini-Hochberg method for multiple comparisons. A total of 511 triple trials comprising 76 different regimens were conducted among 323 enrolled patients. Among these triple regimens, lamotrigine (LTG)/valproic acid (VPA)/topiramate (TPM) was the most frequently prescribed (29.4%, n ​= ​95). At the last clinical visit, 14.9% (n ​= ​48) of patients achieved seizure freedom after receiving triple therapy. LTG/VPA/TPM and LTG/VPA/levetiracetam (LEV) exhibited the highest seizure-free rates at 17.9% and 12.8%, respectively. These two regimens also had significantly lower median SFRs of 0.48 (interquartile range [IQR], 0.17-0.85; adjusted P ​< ​0.001) and 0.63 (IQR, 0.21-1.04; adjusted P ​< ​0.01), respectively. LTG/VPA/perampanel (PER) was another promising regimen that showed marginal effectiveness (median SFR ​= ​0.67; adjusted P ​= ​0.053). LTG/VPA/phenobarbital had the highest incidence of regimen-specific side effects (40.0%, 4/10), while the incidence of side effects from LTG/VPA/LEV was minimal (5.1%, 2/39). In conclusion, LTG/VPA/TPM and LTG/VPA/LEV exhibited superior efficacy and good tolerability in treating patients with DRE. Our results provide preliminary insights into the selection of ASMs for three-drug combination therapies in this clinically challenging population.

Imperatorin interacts additively with novel antiseizure medications in the mouse maximal electroshock-induced seizure model: an isobolographic transformation

BACKGROUND

Anticonvulsant effects of imperatorin (IMP) have been experimentally confirmed earlier, but no information is available on the interaction profiles of this naturally occurring coumarin when combined with novel antiseizure medication (ASMs). This study aimed to determine the effects of IMP on the anticonvulsant effects of lacosamide (LCM), oxcarbazepine (OXC), pregabalin (PGB), and topiramate (TPM) in the maximal electroshock-induced seizure (MES) model in mice.

METHODS

The anticonvulsant effects exerted by novel ASMs (LCM, OXC, PGB, and TPM) when combined with constant doses of IMP (25 and 50 mg/kg) underwent isobolographic transformation to precisely classify the observed interactions in the mouse MES model. Total brain concentrations of ASMs were measured with high-pressure liquid chromatography to exclude the pharmacokinetic nature of interactions among IMP and the tested ASMs.

RESULTS

IMP (50 mg/kg) significantly enhanced (p < 0.01) the anticonvulsant potency of LCM, OXC, PGB, and TPM in the mouse MES model. IMP (25 mg/kg) mildly potentiated the anticonvulsant action of LCM, OXC, PGB, and TPM, but no statistical significance was reported for these combinations. The isobolographic transformation of data from the MES test revealed that the interactions of novel ASMs with IMP were additive. Moreover, IMP (50 mg/kg) did not affect the total brain content of any of the novel ASMs in experimental mice.

CONCLUSIONS

The additive interactions of IMP with LCM, OXC, PGB, and TPM in the mouse MES model accompanied by no pharmacokinetic changes in the total brain content of ASMs are worthy of recommendation for further studies.

Canagliflozin alleviates valproic acid-induced autism in rat pups: Role of PTEN/PDK/PPAR-γ signaling pathways

Autism is complex and multifactorial, and is one of the fastest growing neurodevelopmental disorders. Canagliflozin (Cana) is an antidiabetic drug that exhibits neuroprotective properties in various neurodegenerative syndromes. This study investigated the possible protective effect of Cana against the valproic acid (VPA)-induced model of autism. VPA was injected subcutaneously (SC) into rat pups at a dose of 300 mg/kg, twice daily on postnatal day-2 (PD-2) and PD-3, and once on PD-4 to induce an autism-like syndrome. Graded doses of Cana were administered (5 mg/kg, 7.5 mg/kg, and 10 mg/kg, P.O.) starting from the first day of VPA injections and continued for 21 days. At the end of the experiment, behavioral tests and histopathological alterations were assessed. In addition, the gene expression of peroxisome proliferator-activated receptor γ (PPAR γ), lactate dehydrogenase A (LDHA), pyruvate dehydrogenase kinase (PDK), cellular myeloctomatosis (c-Myc) with protein expression of glucose transporter-1 (GLUT-1), phosphatase and tensin homolog (PTEN), and level of acetylcholine (ACh) were determined. Treatment with Cana significantly counteracted histopathological changes in the cerebellum tissues of the brain induced by VPA. Cana (5 mg/kg, 7.5 mg/kg, and 10 mg/kg) improved sociability and social preference, enhanced stereotypic behaviors, and decreased hyperlocomotion activity, in addition to its significant effect on the canonical Wnt/β-catenin pathway via the downregulation of gene expression of LDHA (22%, 64%, and 73% in cerebellum tissues with 51%, 60%, and 75% in cerebrum tissues), PDK (27%, 50%, and 67% in cerebellum tissues with 34%, 66%, and 77% in cerebrum tissues), c-Myc (35%, 44%, and 72% in cerebellum tissues with 19%, 58%, and 79% in cerebrum tissues), protein expression of GLUT-1 (32%, 48%, and 49% in cerebellum tissues with 30%, 50%, and 54% in cerebrum tissues), and elevating gene expression of PPAR-γ (2, 3, and 4 folds in cerebellum tissues with 1.5, 3, and 9 folds in cerebrum tissues), protein expression of PTEN (2, 5, and 6 folds in cerebellum tissues with 6, 6, and 10 folds in cerebrum tissues), and increasing the ACh levels (4, 5, and 7 folds) in brain tissues. The current study confirmed the ameliorating effect of Cana against neurochemical and behavioral alterations in the VPA-induced model of autism in rats.

Budget Impact Analysis of Treatment Flow Optimization in Epilepsy Patients: Estimating Potential Impacts with Increased Referral Rate to Specialized Care

Objectives: We developed a Markov model to simulate a treatment flow of epilepsy patients who refer to specialized care from non-specialized care, and to surgery from specialized care for estimation of patient distributions and expenditures caused by increasing the referral rate for specialized care. Methods: This budget impact analysis of treatment flow optimization in epilepsy patients was performed as a long-term simulation using the Markov model by comparing the current treatment flow and the optimized treatment flow. In the model, we simulated the prognosis of new onset 5-year-old epilepsy patients (assuming to represent epilepsy occurring between 0 and 10 years of age) treated over a lifetime period. Direct costs of pharmacotherapies, management fees and surgeries are included in the analysis to evaluate the annual budget impact in Japan. Results: In the current treatment flow, the number of refractory patients treated with four drugs by non-specialized care were estimated as 8766 and yielded JPY5.8 billion annually. However, in the optimized treatment flow, the number of patients treated with four drugs by non-specialized care significantly decreased and who continued the monotherapy increased. The costs for the four-drug therapy by non-specialized care were eliminated. Hence cost-saving of JPY9.5 billion (-5% of the current treatment flow) in total national expenditures would be expected. Conclusion: This study highlights that any policy decision-making for referral optimization to specialized care in appropriate epilepsy patients would be feasible with a cost-savings or very few budget impacts. However, important information in the decision-making such as transition probability to the next therapy or excuse for sensitive limitations is not available currently. Therefore, further research with reliable data such as big data analysis or a national survey with real-world treatment patterns is needed.

Interactions among Lacosamide and Second-Generation Antiepileptic Drugs in the Tonic-Clonic Seizure Model in Mice

Combination therapy with two or three antiseizure medications (ASMs) is sometimes a preferred method of treatment in epilepsy patients. (1) Background: To detect the most beneficial combination among three ASMs, a screen test evaluating in vivo interactions with respect to their anticonvulsant properties, was conducted on albino Swiss mice; (2) Methods: Classification of interactions among lacosamide (LCM) and selected second-generation ASMs (lamotrigine (LTG), pregabalin (PGB), oxcarbazepine (OXC), and topiramate (TPM)) was based on the isobolographic analysis in the mouse maximal electroshock-induced seizure (MES) model. Interactions among LCM and second-generation ASMs were visualized using a polygonogram; (3) Results: In the mouse MES model, synergy was observed for the combinations of LCM + TPM + PGB and LCM + OXC + PGB. Additivity was reported for the other combinations tested i.e., LCM + LTG + TPM, LCM + LTG + PGB, LCM + LTG + OXC, and LCM + OXC + TPM in this seizure model. No adverse effects associated with triple ASM combinations, containing LCM and second-generation ASMs were observed in mice; (4) Conclusions: The combination of LCM + TPM + PGB was the most beneficial combination among the tested in this study, offering synergistic suppression of tonic-clonic seizures in mice subjected to the MES model. Both the isobolographic analysis and polygonogram method can be recommended for experimental epileptology when classifying interactions among the ASMs.

Evaluation of Factors Impacting the Efficacy of Single or Combination Therapies of Valproic Acid, Carbamazepine, and Oxcarbazepine: A Longitudinal Observation Study

Objective: This study aimed to determine the efficacy and clinical factors related to the pharmacodynamics of single or combination therapies of valproic acid (VPA), carbamazepine (CBZ), and oxcarbazepine (OXC), three commonly used anti-epileptic drugs (AEDs) in China.

Methods: The study evaluated the records of 2027 outpatients in a Changsha hospital, located in China, from December 23, 2015 to October 28, 2019. The baseline seizure frequency was assessed during the first visit. AED efficacy was determined based on the reduction in seizures from baseline at the subsequent visits. Multivariable ordinal regression analysis was used to determine the association between the clinical factors (demographic characteristics, clinical features, and medication situation) and AED efficacy. For validation, the clinical efficacies of AEDs were compared as both single agents and in combinations. Differences in adverse effect (AEs) categories were analyzed by Chi-square between AED groups.

Results: Records of patients receiving VPA, CBZ, and OXC were evaluated. Serum concentrations of VPA and CBZ is significantly correlated with efficacy (OR 1.030 [1.024–1.037], p < 0 0.0001; OR 1.250 [1.146–1.63], p < 0.0001, respectively) and OXC efficacy correlated to the serum concentration of the metabolite 10,11-dihydro-10-hydroxy-carbazepine (monohydroxy derivative, MHD) serum concentrations (OR 1.060 [1.031–1.089], p < 0.0001). Significant differences existed between females and males in VPA efficacy (OR 1.318 [1.033–1.682], p = 0.027). After validation, VPA, in combination with OXC (OR 1.93 [1.38–2.70], p<0.001), or with VGB (Vigabatrin) (OR 2.36 [1.38–2.70], p = 0.002), showed significantly better efficacy than as a single agent. OXC efficacy was also affected by the duration of epilepsy (OR 0.965 [0.946–0.984], p < 0.001). Additionally, the efficacies of OXC and VPA were also affected by the seizure type. Seizure reduction improved significantly with an increasing number of pharmacists’ educations in the first three visits period. There were no differences in AEs incidence among these 3 AEDs except for Psychiatric (0.02) and nervous system disorders (0.0001).

Conclusion: Serum concentrations of VPA and CBZ may positively affect their efficacies, while OXC efficacies are correlated to MHD serum concentrations. The efficacy of VPA was higher in females compared to males. VPA-OXC and VPA-VGB combinations had higher efficacies compared to monotherapy. Besides, OXC efficacy is probably reducing by the duration of epilepsy. Additionally, VPA efficacy for focal or generalized seizures is superior to mixed-type seizures. OXC was more effective for focal seizures compared to mixed-type ones. Education provided by pharmacists improved the seizures to some extent, and there were no significant differences between most categories of adverse effects for the investigated AEDs.

Clinical Management of Drug Resistant Epilepsy: A Review on Current Strategies

Drug resistant epilepsy (DRE) is defined as the persistence of seizures despite at least two syndrome-adapted antiseizure drugs (ASD) used at efficacious daily dose. Despite the increasing number of available ASD, about a third of patients with epilepsy still suffer from drug resistance. Several factors are associated with the risk of evolution to DRE in patients with newly diagnosed epilepsy, including epilepsy onset in the infancy, intellectual disability, symptomatic epilepsy and abnormal neurological exam. Pharmacological management often consists in ASD polytherapy. However, because quality of life is driven by several factors in patients with DRE, including the tolerability of the treatment, ASD management should try to optimize efficacy while anticipating the risks of drug-related adverse events. All patients with DRE should be evaluated at least once in a tertiary epilepsy center, especially to discuss eligibility for non-pharmacological therapies. This is of paramount importance in patients with drug resistant focal epilepsy in whom epilepsy surgery can result in long-term seizure freedom. Vagus nerve stimulation, deep brain stimulation or cortical stimulation can also improve seizure control. Lastly, considering the effect of DRE on psychologic status and social integration, comprehensive care adaptations are always needed in order to improve patients' quality of life.

Developing precision treatments for epilepsy using patient and animal models

Introduction: Phenytoin was the first antiepileptic drug (AED) discovered in an animal model of seizures whose clinical efficacy was subsequently confirmed. This clearly indicated that a search for other AEDs had to consider animal studies.Areas covered: Main seizure tests used for the evaluation of possible anticonvulsive activity of potential anticonvulsants and their predictive values have been reviewed. Procedures used for the estimation of antiepileptogenic effects have been also included.Expert opinion: First-line seizure models comprise maximal electroshock (MES)-, pentylenetetrazol (PTZ)- and kindling-induced convulsions in rodents. The MES test may be considered as a convenient and easy model of generalized tonic-clonic seizures, PTZ test - as a model of generalized myoclonic seizures and to a certain degree - absence seizures. Kindled seizures (for example, from amygdala) may be regarded as a model of focal seizures. Some tests have been suggested for the search of AEDs effective in drug-resistant seizures - for instance, 6 Hz (44 mA) test or intrahippocampal kainate model of mesial temporal lobe epilepsy. There are also recommendations from experimental epileptology on synergistic AED combinations for patients with drug-resistant seizures. The clinical evidence on this issue is scarce and favors a combined treatment with valproate + lamotrigine.

Is the mechanism of action of antiseizure drugs a key element in the choice of treatment?

About 25 antiseizure drugs are available for the treatment of patients with epilepsy. The choice of the most suited drug for a specific patient is primarily based on the results of the pivotal randomized clinical trials and on the patient's characteristics and comorbidities. Whether or not the mechanism of action of the antiseizure drugs should be also taken into account to better predict the patient's response to the treatment remains a matter of debate. Despite the apparent complexity and diversity of antiseizure drug mechanisms of action, the reality unfortunately remains that they are very close, in particular with regard to their relationship with the pathophysiology of epilepsy. With the only exception of the association between lamotrigine and sodium valproate, there are no clinical data that formally support a synergistic association between certain antiseizure drugs in terms of efficacy. However, anticipating risk of adverse events by limiting as far as possible the combination of drugs, which share the same mechanisms of action, is undoubtedly an important driver of daily therapeutic decisions.

Polygonogram with isobolographic synergy for three-drug combinations of phenobarbital with second-generation antiepileptic drugs in the tonic-clonic seizure model in mice

Background

Combination therapy consisting of two or more antiepileptic drugs (AEDs) is usually prescribed for patients with refractory epilepsy. The drug–drug interactions, which may occur among currently available AEDs, are the principal criterion taken by physicians when prescribing the AED combination to the patients. Unfortunately, the number of possible three-drug combinations tremendously increases along with the clinical approval of novel AEDs.

Aim

To isobolographically characterize three-drug interactions of phenobarbital (PB) with lamotrigine (LTG), oxcarbazepine (OXC), pregabalin (PGB) and topiramate (TPM), the maximal electroshock-induced (MES) seizure model was used in male albino Swiss mice.

Materials and method

The MES-induced seizures in mice were generated by alternating current delivered via auricular electrodes. To classify interactions for 6 various three-drug combinations of AEDs (i.e., PB + TPM + PGB, PB + OXC + TPM, PB + LTG + TPM, PB + OXC + PGB, PB + LTG + PGB and PB + LTG + OXC), the type I isobolographic analysis was used. Total brain concentrations of PB were measured by fluorescent polarization immunoassay technique.

Results

The three-drug mixtures of PB + TPM + PGB, PB + OXC + TPM, PB + LTG + TPM, PB + OXC + PGB, PB + LTG + PGB and PB + LTG + OXC protected the male albino Swiss mice from MES-induced seizures. All the observed interactions in this seizure model were supra-additive (synergistic) (p < 0.001), except for the combination of PB + LTG + OXC, which was additive. It was unable to show the impact of the studied second-generation AEDs on total brain content of PB in mice.

Conclusions

The synergistic interactions among PB and LTG, OXC, PGB and TPM in the mouse MES model are worthy of being transferred to clinical trials, especially for the patients with drug resistant epilepsy, who would benefit these treatment options.

Sub-additive (antagonistic) interaction of lacosamide with lamotrigine and valproate in the maximal electroshock-induced seizure model in mice: an isobolographic analysis

BACKGROUND

Launching polytherapy with two or three antiseizure drugs (ASDs) in patients with epilepsy is still problematic. The choice of ASDs to combine them together is usually based on clinicians' experience and it requires knowledge about mechanisms of action of the studied ASDs and their drug-drug interactions, whose nature may be favorable, neutral or unfavorable. To characterize three-drug interaction among lacosamide (LCM), lamotrigine (LTG) and valproate (VPA), the type I isobolographic analysis was used. The antiseizure effects of three-drug combination were analyzed in a model of maximal electroshock-induced seizures (MES) in albino Swiss mice.

MATERIALS AND METHODS

The seizure activity in mice was evoked by alternating current stimulation (25 mA, 500 V, 50 Hz, 0.2 s). Both, the type I isobolographic analysis and the test of parallelism of dose-response effects of the ASDs were used so as to properly classify interaction among three ASDs, administered in a fixed ratio combination of 1:1:1.

RESULTS

The three-drug mixture of LCM, LTG and VPA at the fixed ratio of 1:1:1 protected the experimental mice from MES-induced seizures; however, the reported interaction was sub-additive (antagonistic; p < 0.01) with isobolography.

CONCLUSION

The antagonistic pharmacodynamic interaction among LCM, LTG and VPA in the MES test in mice cannot be transferred to clinical settings and this unfavorable combination should not be recommended for patients with epilepsy.

Polygonogram and isobolographic analysis of interactions between various novel antiepileptic drugs in the 6-Hz corneal stimulation-induced seizure model in mice

Pharmacotherapy with two antiepileptic drugs in combination is usually prescribed to epilepsy patients with refractory seizures. The choice of antiepileptic drugs in combination should be based on synergistic cooperation of the drugs with respect to suppression of seizures. The selection of synergistic interactions between antiepileptic drugs is challenging issue for physicians, especially, if 25 antiepileptic drugs are currently available and approved to treat epilepsy patients. The aim of this study was to determine all possible interactions among 5 second-generation antiepileptic drugs (gabapentin (GBP), lacosamide (LCM), levetiracetam (LEV), pregabalin (PGB) and retigabine (RTG)) in the 6-Hz corneal stimulation-induced seizure model in adult male albino Swiss mice. The anticonvulsant effects of 10 various two-drug combinations of antiepileptic drugs were evaluated with type I isobolographic analysis associated with graphical presentation of polygonogram to visualize the types of interactions. Isobolographic analysis revealed that 7 two-drug combinations of LEV+RTG, LEV+LCM, GBP+RTG, PGB+LEV, GBP+LEV, PGB+RTG, PGB+LCM were synergistic in the 6-Hz corneal stimulation-induced seizure model in mice. The additive interaction was observed for the combinations of GBP+LCM, GBP+PGB, and RTG+LCM in this seizure model in mice. The most beneficial combination, offering the highest level of synergistic suppression of seizures in mice was that of LEV+RTG, whereas the most additive combination that protected the animals from seizures was that reporting additivity for RTG+LCM. The strength of interaction for two-drug combinations can be arranged from the synergistic to the additive, as follows: LEV+RTG > LEV+LCM > GBP+RTG > PGB+LEV > GBP+LEV > PGB+RTG > PGB+LCM > GBP+LCM > GBP+PGB > RTG+LCM.

Gestational exposure to valproic acid upregulates total Stat3 protein expression while downregulating phosphorylated Stat3 in CD-1 mouse embryos with neural tube defects

Valproic acid (VPA), a widely prescribed antiepileptic drug and an effective treatment for psychiatric disorders, is teratogenic causing neural tube defects (NTDs) and other defects in the exposed embryo. Signal transducer and activator of transcription 3 (Stat3) is a transcription factor that is activated via tyrosine phosphorylation. Stat3, as well as its active form (pYStat3), is expressed during neural tube closure in murine development. This study investigated the effects of in utero VPA exposure on embryonic Stat3 mRNA and protein expression during the critical period of neural tube closure in CD-1 mouse embryos. Following the exposure of CD-1 pregnant mice to the teratogenic dose of 400 mg/kg VPA or saline on gestational day (GD) 9, embryos were harvested at 1, 3, 6, or 24 hr and on GD13. Stat3 mRNA levels remained unchanged at all time points. Total Stat3 protein levels were significantly (p < .05) increased in GD9 embryos at 1 and 6 hr post-exposure and in GD13 exposed nonexencephalic and exencephalic embryo heads. In contrast, phosphorylated Stat3 levels were significantly (p < .05) downregulated in GD9 embryos at the 3 and 6 hr time points with an overall trend of downregulation in the GD10 and GD13 groups. Total and phosphorylated Stat3 protein levels remained unchanged in nuclear extracts of the exposed nonexencephalic and exencephalic GD13 embryo heads. The reported significant downregulation of phosphorylated Stat3 levels suggests its possible role in VPA-induced NTDs in mouse embryos.

Pharmacological Management of the Genetic Generalised Epilepsies in Adolescents and Adults

Common genetic generalised epilepsy syndromes encountered by clinicians include childhood and juvenile absence epilepsies, juvenile myoclonic epilepsy and generalised tonic-clonic seizures on awakening. Treatment of these syndromes involves largely the use of broad-spectrum antiseizure drugs. Those effective for the generalised epilepsies include sodium valproate, phenobarbital, ethosuximide, clobazam, clonazepam, lamotrigine, levetiracetam, topiramate, zonisamide and, more recently, perampanel and brivaracetam. Results from the few rigorous studies comparing outcomes with drugs for genetic generalised epilepsies show valproate to be the most effective. The majority of patients with genetic generalised epilepsy syndromes will become seizure free on antiseizure monotherapy; those for whom control proves elusive may benefit from combination regimens. Early counselling regarding management may assist the patient to come to terms with their diagnosis and improve long-term outcomes. Treatment can be lifelong in some individuals, although others may remain seizure free without medication. Choice of antiseizure medication depends on the efficacy for specific seizure types, as well as tolerability. For patients prescribed comedication, drug interactions should be considered. In particular, for young women taking oral hormonal contraceptives, ≥ 200 mg/day of topiramate can decrease the circulating concentration of ethinylestradiol and ≥ 12 mg/day of perampanel can induce levonorgestrel metabolism. The use of valproate in women of childbearing potential is limited by associated teratogenic and neurodevelopmental effects in offspring. Given that valproate is often the antiseizure drug of choice for genetic generalised epilepsies, this creates a dilemma for patients and clinicians. Decision making can be aided by comprehensive assessment and discussion of treatment options. Psychiatric comorbidities are common in adolescents and adults with genetic generalised epilepsies. These worsen the prognosis, both in terms of seizure control and quality of life. Attendant lifestyle issues can impact significantly on the individual and society. Frontal lobe dysfunction, which can present in patients with juvenile myoclonic epilepsy, can adversely affect the long-term outlook, regardless of the nature of seizure control. Ongoing management requires consideration of psychosocial and behavioural factors that can complicate diagnosis and treatment. An assured supportive attitude by the neurologist can be an important contributor to a positive outcome. The mechanisms underlying genetic generalised epilepsies, including genetic abnormalities, are unclear at present. As the pathophysiology is unravelled, this may lead to the development of novel therapies and improved outcomes for patients with these syndromes.

Aspects of cAMP Signaling in Epileptogenesis and Seizures and Its Potential as Drug Target

Epilepsy is one of the most common chronic neurological conditions. Today, close to 30 different medications to prevent epileptic seizures are in use; yet, far from all patients become seizure free upon medical treatment. Thus, there is a need for new pharmacological approaches including novel drug targets for the management of epilepsy. Despite the fact that a role for cAMP signaling in epileptogenesis and seizures was first suggested some four decades ago, none of the current medications target the cAMP signaling system. The reasons for this are probably many including limited knowledge of the underlying biology and pathology as well as difficulties in designing selective drugs for the different components of the cAMP signaling system. This review explores selected aspects of cAMP signaling in the context of epileptogenesis and seizures including cAMP response element binding (CREB)-mediated transcriptional regulation. We discuss the therapeutic potential of targeting cAMP signaling in epilepsy and point to an increased knowledge of the A-kinase anchoring protein-based signaling hubs as being of seminal importance for future drug discovery within the field. Further, in terms of targeting CREB, we argue that targeting upstream cAMP signals might be more fruitful than targeting CREB itself. Finally, we point to astrocytes as cellular targets in epilepsy since cAMP signals may regulate astrocytic K⁺ clearance affecting neuronal excitability.

Clinical opinion: Earlier employment of polytherapy in sequential pharmacotherapy of epilepsy

Modern pharmacotherapy for epilepsy consists of orderly, sequential drug trials, in which antiepileptic drugs (AEDs) are chosen under the concept of individual patient-oriented (or - tailored) pharmacotherapy. Although monotherapy has been established as the preferred mode of AEDs therapy in both newly diagnosed and drug resistant epilepsies, there are still lack of evidence to favor either monotherapy or polytherapy in epilepsy, which has generated continuing controversies on the preferred mode of pharmacotherapy. However, each mode of pharmacotherapy may have both advantages and disadvantages, which are different and variable related to individual case scenario. We conducted a brief comparative overview between monotherapy and polytherapy to provide clues for earlier employment of polytherapy in each steps of sequential drug trials. Previous claims about the advantages of monotherapy over polytherapy are not supported but gradually losing its ground by the introduction of a large number of drugs carrying pharmacological advantages for combination therapy. Current evidence stresses the importance of combining drugs having synergistic interactions for better outcome of polytherapy, which has not been considered in previous clinical investigations comparing monotherapy and polytherapy. It is likely that a significant improvement in the outcome of current AEDs therapy is feasible by earlier employment of polytherapy as well as identification of combination drug regimens carrying synergistic interactions. At present, lamotrigine(LTG) and valproate(VPA) combination regimen is the only well documented synergistic regimen, but there are a long-list of candidate regimens requiring future trials in appropriate designs.

A viewpoint on rational and irrational fixed-drug combinations

INTRODUCTION

Considering that there are around 30% of patients with epilepsy resistant to monotherapy, the use of synergistic combinations of antiepileptic drugs is of particular importance. This review shows most beneficial as well as irrational combined treatments both from an experimental and clinical point of view. Areas covered: Preferably, experimental data derived from studies evaluating synergy, additivity, or antagonism by relevant methods, in terms of anticonvulsant or neurotoxic effects and pharmacokinetic data have been considered. Although there have been no randomized clinical trials on this issue, the clinical data have been analyzed from studies on considerable numbers of patients. Case-report studies have been not considered. Expert commentary: The experimental data provide a strong support that co-administration of lamotrigine with carbamazepine is negative, considering the anticonvulsant and neurotoxic effects. Clinical reports do not entirely support this conclusion. Other experimentally documented negative combinations comprise lamotrigine+ oxcarbazepine and oxcarbazepine+ phenytoin. From the experimental and clinical point of view, a combination of lamotrigine+ valproate may deserve recommendation. Other most positive experimental and clinical combinations include carbamazepine+valproate, phenytoin+phenobarbital, carbamazepine+gabapentin, carbamazepine+topiramate, levetiracetam+valproate, levetiracetam+carbamazepine. Certainly, experimental data have some limitations (non-epileptic animals, acute administration of antiepileptic drugs) so all experimental recommendations need a careful clinical evaluation.

Combination of phenobarbital with phenytoin and pregabalin produces synergy in the mouse tonic-clonic seizure model: An isobolographic analysis

AIMS

Despite many antiepileptic drugs (AEDs) are available to treat epilepsy, there is still about 30% of epilepsy patients inadequately treated with these AEDs. For these patients, polytherapy with two or three AEDs to fully control their seizure attacks is recommended. Unfortunately, polytherapy is always associated with drug interactions, whose nature may be beneficial, neutral or unfavorable. To determine a type of interaction for the combination of three AEDs (i.e., phenobarbital [PB], phenytoin [PHT] and pregabalin [PGB]) at the fixed-ratio of 1:1:1, we used a model of tonic-clonic seizures in male albino Swiss mice.

MATERIALS AND METHOD

Tonic-clonic seizures in mice were evoked by a current (sine-wave, 25 mA, 500 V, 0.2 s stimulus duration) delivered via auricular electrodes. The anticonvulsant effects of the three-drug combination (PB, PHT and PGB) in terms of suppression of tonic-clonic seizures in mice were assessed with type I isobolographic analysis. Potential acute side effects for the mixture of PB, PHT and PGB along with total brain concentrations of the AEDs were determined to confirm pharmacodynamic nature of observed interaction.

RESULTS

The three-drug combination of PB, PHT and PGB (at the fixed-ratio of 1:1:1) exerted synergistic interaction (at P < 0.01) in the mouse model of tonic-clonic seizures. The combination of PB, PHT and PGB did not produce any side effects in experimental animals, when measuring long-term memory, muscular strength and motor coordination. The measurement of total brain concentrations of PB, PHT and PGB was conducted to confirm that none of the three AEDs significantly influenced total brain concentrations (pharmacokinetic profiles) of the other co-administered AEDs in mice.

CONCLUSIONS

The synergistic pharmacodynamic interaction for the combination of PB, PHT and PGB observed in this preclinical study can be translated into clinical settings and this favorable AED combination is worthy of being recommended to some patients with refractory epilepsy.

Sodium valproate in pregnancy: what are the risks and should we use a shared decision-making approach?

BACKGROUND

Despite significant teratogenic risks, sodium valproate is still widely prescribed in many countries to women of childbearing age, as a mood stabiliser in bipolar disorder and also in epilepsy. The UK has recently banned valproate use in women who are not in a pregnancy prevention programme. Whilst this ruling reflects prevailing clinical practice, it also highlights an ongoing debate about when (if ever) a woman who is or could become pregnant should be allowed to choose to take valproate.

MAIN BODY

We review the benefits and harms of drugs available for bipolar disorder and epilepsy in women of childbearing age, with a particular focus on teratogenic risk. We speculate on hypothetical rare situations in which potential benefits of valproate may outweigh potential harms in such women. We also review the literature on shared decision-making - on which there is now a NICE guideline and numerous evidence-based decision tools. Drawing on previous work by experts in shared decision-making, we offer a list of 'frequently asked questions' and a matrix of options to support conversations with women about continuing or discontinuing the drug in (or in anticipation of) pregnancy. We also consider whether shared decision-making is an appropriate paradigm when considering whether to continue a teratogenic drug.

CONCLUSION

We conclude that because valproate in pregnancy remains the subject of such debate, there is scope for further research - not only into the relative efficacy and safety of alternatives to it - but also into the dynamics of communication and shared decision-making in this situation.

Unblinded, randomized multicenter trial comparing lamotrigine and valproate combination with controlled-release carbamazepine monotherapy as initial drug regimen in untreated epilepsy

PURPOSE

To compare controlled-release carbamazepine monotherapy (CBZ-CR) with lamotrigine and valproate combination therapy (LTG + VPA) in equivalent total drug load, as initial drug regimen in untreated patients with partial and/or generalized tonic-clonic seizures (GTCS).

METHODS

This unblinded, randomized, 60-week superiority trial recruited patients having two or more unprovoked seizures with at least one seizure during previous three months. After randomization into CBZ-CR or LTG + VPA, patients entered into eight-week titration phase (TP), followed by 52-week maintenance phase (MP). Median doses of CBZ-CR and LTG + VPA were 600 mg/day and 75 mg/day + 500 mg/day, respectively. Primary outcome measure was completion rate (CR), a proportion of patients who have completed the 60-week study as planned. Secondary efficacy measures included seizure-free rate (SFR) for 52-week of MP and time to first seizure (TTFS) during MP.

RESULTS

Among 207 randomized patients, 202 underwent outcome analysis (104 in CBZ-CR, 98 in LTG + VPA). CR was 62.5% in CBZ-CR and 65.3% in LTG + VPA (p = 0.678). SFR during MP was higher in LTG + VPA (64.1%) than CBZ-CR (47.8%) (P = 0.034). TTFS was shorter with CBZ-CR (p = 0.041). Incidence of adverse effects (AEs) were 57.7% in CBZ-CR and 60.2% in LTG + VPA and premature drug withdrawal rates due to AEs were 12.5% and 7.1%, respectively, which were not significantly different.

CONCLUSION

CR was comparable between LTG + VPA and CBZ-CR, however, both SFR for 52-week MP and TTFS during MP were in favor of LTG + VPA than CBZ-CR. The study suggested that LTG + VPA can be an option as initial drug regimen for untreated patients with partial seizures and/or GTCS except for women of reproductive age.

Beneficial Combination of Lacosamide with Retigabine in Experimental Animals: An Isobolographic Analysis

BACKGROUND/AIM

To isobolographically determine the types of interactions that occur between retigabine and lacosamide (LCM; two third-generation antiepileptic drugs) with respect to their anticonvulsant activity and acute adverse effects (sedation) in the maximal electroshock-induced seizures (MES) and chimney test (motor performance) in adult male Swiss mice.

METHODS

Type I isobolographic analysis for nonparallel dose-response effects for the combination of retigabine with LCM (at the fixed-ratio of 1:1) in both the MES and chimney test in mice was performed. Brain concentrations of retigabine and LCM were measured by high-pressure liquid chromatography (HPLC) to characterize any pharmacokinetic interactions occurring when combining these drugs.

RESULTS

Linear regression analysis revealed that retigabine had its dose-response effect line nonparallel to that of LCM in both the MES and chimney tests. The type I isobolographic analysis illustrated that retigabine combined with LCM (fixed-ratio of 1:1) exerted an additive interaction in the mouse MES model and sub-additivity (antagonism) in the chimney test. With HPLC, retigabine and LCM did not mutually change their total brain concentrations, thereby confirming the pharmacodynamic nature of the interaction.

CONCLUSION

LCM combined with retigabine possesses a beneficial preclinical profile (benefit index ranged from 2.07 to 2.50) and this 2-drug combination is worth recommending as treatment plan to patients with pharmacoresistant epilepsy.

Treatment of refractory epilepsy patients with autologous mesenchymal stem cells reduces seizure frequency: An open label study

PURPOSE

Existing anti-epileptic drugs (AED) have limited efficiency in many patients, necessitating the search for alternative approaches such as stem cell therapy. We report the use of autologous patient-derived mesenchymal stem cells (MSC) as a therapeutic agent in symptomatic drug-resistant epilepsy in a Phase I open label clinical trial (registered as NCT02497443).

PATIENTS AND METHODS

The patients received either standard treatment with AED (control group), or AED supplemented with single intravenous administration of undifferentiated autologous MSC (target dose of 1×10⁶cells/kg), followed by a single intrathecal injection of neurally induced autologous MSC (target dose of 0.1×10⁶cells/kg).

RESULTS

MSC injections were well tolerated and did not cause any severe adverse effects. Seizure frequency was designated as the main outcome and evaluated at 1 year time point. 3 out of 10 patients in MSC therapy group achieved remission (no seizures for one year and more), and 5 additional patients became responders to AEDs, while only 2 out of 12 patients became responders in control group (difference significant, P=0.0135).

CONCLUSIONS

MSC possess unique immunomodulatory properties and are a safe and promising candidate for cell therapy in AED resistant epilepsy patients.

Pharmacological Treatment of Drug-Resistant Epilepsy in Adults: a Practical Guide

More than 30 % of adults with epilepsy do not fully control on the currently available antiepileptic drugs (AEDs). For these and many other patients, combinations of agents, often possessing different mechanisms of actions, are employed with the aim of achieving seizure freedom or the best available prognosis in terms of reduced seizure numbers and severity. This review discusses my own approach to optimising outcomes in as many of these patients as possible by adjusting the drug burden using a combination of two, three or sometimes four or more AEDs. Modes of drug action are reviewed and practical strategies for treating different patients with drug-resistant epilepsy have been explored. Only for sodium valproate with lamotrigine is there good evidence of synergism. The final part of this practical paper consists of six individual illustrative cases with appropriate comments.

Adjunctive eslicarbazepine acetate: A pooled analysis of three phase III trials

OBJECTIVE

To assess the safety and efficacy of once-daily (QD) adjunctive eslicarbazepine acetate (ESL).

METHODS

This post-hoc pooled analysis of three randomized, placebo-controlled trials (2093-301, -302, -304) involved adults with refractory partial-onset seizures (POS) receiving 1-3 antiepileptic drugs (AEDs). All studies included 8-week baseline, 2-week titration, and 12-week maintenance periods. Patients were randomized equally to placebo, ESL 400mg (studies 301, 302), 800mg, or 1200mg QD. The primary endpoint was standardized seizure frequency (SSF; per 4weeks); secondary endpoints included responder rates (maintenance period), and incidence of treatment-emergent adverse events (TEAEs), TEAEs leading to discontinuation, serious AEs (SAEs), and deaths.

RESULTS

The safety and efficacy analysis populations totaled 1447 and 1410 patients, respectively. SSF was significantly reduced versus placebo with ESL 800mg (p=0.0001) and 1200mg (p<0.0001) but not 400mg (p=0.81). There were no significant interactions between treatment effect and age, gender, race/ethnicity, geographic region, epilepsy duration, or concomitant AED use. Incidences of TEAEs and TEAEs leading to discontinuation increased with ESL dose. Incidences of the most frequent TEAEs were lower for patients who initiated dosing at 400 versus 800mg QD, regardless of titration regimen and maintenance dose. SAE incidence was <10%; there were 3 deaths (placebo, n=2; ESL 800mg, n=1).

CONCLUSIONS

ESL (800 and 1200mg QD) was effective and well tolerated as adjunctive therapy for adults with refractory POS.

The relationship between pharmacokinetic parameters of carbamazepine and therapeutic response in epileptic patients

INTRODUCTION

The prescribed dose and carbamazepine plasma concentration to achieve the optimal therapeutic efficacy are highly variable from one patient to the other. Our study aimed to determine whether biological parameters may be used as plasma markers that can individually adjust the carbamazepine dose necessary to optimize therapeutic efficacy.

MATERIAL AND METHODS

Ninety-four epileptic patients under carbamazepine monotherapy and who have never used combination therapy were recruited from the consecutive admissions at the Department of Neurology "CHU Sahloul" of Sousse Central Hospital in Tunisia from February 2010 to April 2011. The patients were monitored for epilepsy for three years on average. Carbamazepine and 10,11-epoxide-carbamazepine concentrations were analyzed through high-performance liquid chromatography. Simultaneously, therapeutic efficacy was assessed through the annual number of seizures in each patient.

RESULTS

Our results showed the absence of any significant correlations between specific dose (mg/kg/day), carbamazepine plasma concentrations and therapeutic efficacy (r = 0.0025, p = 0.30; r = 0.1584, p = 0.38 respectively), whereas both plasma 10,11-epoxide-carbamazepine concentration and 10,11-epoxide-carbamazepine to plasma carbamazepine ratio were closely correlated with therapeutic efficacy (r = 0.34, p = 0.03; r = 0.45, p = 0.008 respectively). The optimum therapeutic response was observed among patients who simultaneously had a plasma concentration of 0.8 μg/ml of metabolite and 5.5 μg/ml of carbamazepine.

CONCLUSIONS

The results suggest that plasma levels of both carbamazepine and of 10,11-epoxide-carbamazepine must be set to achieve an optimum therapeutic response.

Tolerability and Safety of Commonly Used Antiepileptic Drugs in Adolescents and Adults: A Clinician's Overview

This paper discusses the issues surrounding the tolerability and safety of the commonly used antiepileptic drugs (AEDs) in adolescents and adults. The content includes dose-related adverse effects, idiosyncratic reactions, behavioural and psychiatric comorbidities, chronic problems, enzyme induction and teratogenesis. Twenty-one AEDs are discussed in chronological order of their introduction into the UK, starting with phenobarbital and ending with brivaracetam. Wherever possible, advice is given on anticipating, recognising and managing these issues and thereby improving the lives of people with epilepsy, most of whom will need to take one or more of these agents for life. Avoidance of side effects will increase the possibility of achieving and maintaining long-term seizure freedom. Alternatively, adverse events from AEDs will substantially reduce quality of life and often result in higher healthcare costs.

Prospective audit with adjunctive perampanel: Preliminary observations in focal epilepsy

PURPOSE

Perampanel (PER) was first licensed in the United Kingdom in 2012 for the adjunctive treatment of focal seizures with or without secondary generalization in adults and children over 12years of age. It has recently also been approved for use as add-on therapy for patients with primary generalized tonic-clonic seizures. This prospective audit reports preliminary outcomes with adjunctive PER in patients with focal-onset seizures in everyday clinical practice using a standard design.

METHODS

To date, 54 patients (38 males, 16 females; 21-65years, median: 48years) have completed the study. The median monthly seizure frequency was 4 (range: 1-60). At baseline, patients were taking a median of 2 other antiepileptic drugs (range: 1-4 drugs), with their seizures having previously failed to improve on a median of 3 schedules (range: 1-15 schedules). After 12weeks of stable dosing, PER was added, aiming at a target range of 6-12mg/daily. Review took place every 6-8weeks until one of 4 endpoints was reached: seizure freedom for ≥6months on a given PER dose, ≥50% (responder) or <50% (marginal effect) seizure reduction over 6months, compared with the prospective baseline, on the highest tolerated PER dose, or withdrawal of PER due to a lack of efficacy or side effects.

RESULTS

Three (5.6%) patients have remained seizure-free, with 8 (14.8%) demonstrating a ≥50% response and a further 17 (31.5%) reporting a marginal effect. Of the 26 (48.1%) dropping out of PER treatment, 21 (38.9%) did so because of side effects. The commonest problems were nausea, vomiting, ataxia, dizziness, and sedation. Overall, 6 (11%) patients developed neuropsychiatric problems, with 3 reporting irritability and/or aggression. Two patients had substantial weight gain, and another patient suffered recurrent falls. Treatment with enzyme-inducing AEDs had no effect on PER dosing in patients responding to PER or withdrawing due to side effects.

SIGNIFICANCE

These data support the value of adjunctive PER in some patients with pharmacoresistant epilepsy in everyday clinical practice.

Practical Use of Newer Antiepileptic Drugs as Adjunctive Therapy in Focal Epilepsy

This article lays the background for, and discusses the practical issues surrounding, the adjunctive use of the last four antiepileptic drugs (AEDs) to be licensed for the treatment of pharmacoresistant focal seizures in the UK and elsewhere. More than 30% of adolescent and adult patients will not be fully controlled on the currently available therapeutic armamentarium. After not responding to their first three AED schedules, only a handful of patients attained seizure freedom on subsequent regimens. To optimise the response to any new AED in this setting, it is often necessary to reduce the existing drug burden. The pharmacology, tolerability and safety, and everyday use of lacosamide, eslicarbazepine acetate, retigabine (ezogabine) and perampanel will be reviewed and discussed. This will be accompanied by data from prospective audits with each drug undertaken at the Western Infirmary in Glasgow, Scotland, and a report of their successful introduction in an illustrative case. Overall, there is a large variation in the course of refractory epilepsy and the effect of AED therapy on this process seems minimal. Nevertheless, a number of patients will benefit from the introduction of each new AED, with some becoming seizure-free.

Third International Congress on Epilepsy, Brain, and Mind: Part 2

Epilepsy is both a disease of the brain and the mind. Here, we present the second of two papers with extended summaries of selected presentations of the Third International Congress on Epilepsy, Brain and Mind (April 3-5, 2014; Brno, Czech Republic). Humanistic, biologic, and therapeutic aspects of epilepsy, particularly those related to the mind, were discussed. The extended summaries provide current overviews of epilepsy, cognitive impairment, and treatment, including brain functional connectivity and functional organization; juvenile myoclonic epilepsy; cognitive problems in newly diagnosed epilepsy; SUDEP including studies on prevention and involvement of the serotoninergic system; aggression and antiepileptic drugs; body, mind, and brain, including pain, orientation, the "self-location", Gourmand syndrome, and obesity; euphoria, obsessions, and compulsions; and circumstantiality and psychiatric comorbidities.

Drosophila sodium channel mutations: Contributions to seizure-susceptibility

This paper reviews Drosophila voltage-gated Na(+) channel mutations encoded by the para (paralytic) gene and their contributions to seizure disorders in the fly. Numerous mutations cause seizure-sensitivity, for example, para(bss1), with phenotypes that resemble human intractable epilepsy in some aspects. Seizure phenotypes are also seen with human GEFS+ spectrum mutations that have been knocked into the Drosophila para gene, para(GEFS+) and para(DS) alleles. Other para mutations, para(ST76) and para(JS) act as seizure-suppressor mutations reverting seizure phenotypes in other mutants. Seizure-like phenotypes are observed from mutations and other conditions that cause a persistent Na(+) current through either changes in mRNA splicing or protein structure.

Systems biology, complexity, and the impact on antiepileptic drug discovery

The number of available anticonvulsant drugs increased in the period spanning over more than a century, amounting to the current panoply of nearly two dozen so-called antiepileptic drugs (AEDs). However, none of them actually prevents/reduces the post-brain insult development of epilepsy in man, and in no less than a third of patients with epilepsy, the seizures are not drug-controlled. Plausibly, the enduring limitation of AEDs' efficacy derives from the insufficient understanding of epileptic pathology. This review pinpoints the unbalanced reductionism of the analytic approaches that overlook the intrinsic complexity of epilepsy and of the drug resistance in epilepsy as the core conceptual flaw hampering the discovery of truly antiepileptogenic drugs. A rising awareness of the complexity of epileptic pathology is, however, brought about by the emergence of nonreductionist systems biology (SB) that considers the networks of interactions underlying the normal organismic functions and of SB-based systems (network) pharmacology that aims to restore pathological networks. By now, the systems pharmacology approaches of AED discovery are fairly meager, but their forthcoming development is both a necessity and a realistic prospect, explored in this review.

Network meta-analyses of antiepileptic drug efficacy and tolerability in drug-resistant focal epilepsies: a clinical perspective

PURPOSE

Network meta-analysis (NMA) is a new technique that allows multiple treatment comparisons and provides estimates of effect sizes for all possible pair-wise comparisons. Several NMAs of antiepileptic drug (AED) efficacy and tolerability in individuals with refractory focal epilepsy, however, came to non-specific and, in some cases, divergent conclusions. We review some clinical factors that may be responsible for these inconsistent findings.

RESULTS

A major issue is the small number of individuals included in the meta-analyses with consequent wide confidence intervals and lack of ability to achieve significant results. Further issues are lack of robustness of the measured efficacy outcome-the responder ratio (the percentage of individuals with a >50 % improvement in seizure frequency); the selection of randomized studies (RCTs) included, i.e., the inclusion of studies with heterogeneous populations (children and adults); and inclusion of people treated with different doses of the experimental drug. Some methods of analysing data from RCTs, such as the last observation carried forward (LOCF) analysis, the choice of different phases of the study to compare to baseline, and the year in which the trial was conducted, selectively affect measurement of efficacy outcomes. Titration speed and other methodological aspects selectively affect tolerability.

CONCLUSION

Several factors restrict the analysis of clinically useful estimates of the comparative efficacy of AEDs, while analysis of tolerability may be easier to accomplish.

Prospective audits with newer antiepileptic drugs in focal epilepsy: insights into population responses?

Despite the availability of a wide range of new antiepileptic drugs (AEDs), there is little evidence that their introduction has substantially altered outcomes. This paper reviews data from 5 consecutive prospective audits with new AEDs using similar methodology. Prospective audits with topiramate (TPM; n=135), levetiracetam (LEV; n=136), zonisamide (ZNS; n=141), pregabalin (PGB; n=135), and lacosamide (LCM; n=160) were undertaken in treated patients with uncontrolled partial-onset seizures. Follow-up continued until one of four endpoints was reached: seizure freedom for ≥6months on unchanged dosing; ≥50% reduction (responder) in seizure frequency on the highest tolerated dose compared with baseline; <50% seizure frequency reduction (marginal response) compared with baseline in patients wishing to continue treatment with the new AED; or withdrawal due to lack of efficacy, side effects, or both. A greater proportion of seizure-free patients occurred with LEV (23.5%), LCM (21.9%), and TPM (20.7%) than with ZNS (12.8%) and PGB (10.4%). A higher percentage discontinued treatment with ZNS (41.8%) and PGB (50.4%) than with LEV (32.4%), TPM (31.1%), and LCM (22.5%). Most seizure-free patients responded to the new agent as first or second add-on (TPM 96%; LEV 97%; ZNS 89%; PGB 86%; LCM 97%) often at modest or moderate dosing (TPM 68%, ≤200mg/day; LEV 63%, ≤1000mg/day; ZNS 61%, ≤100mg/day; PGB 86%, ≤300mg/day; LCM 74%, ≤200mg/day). With <10% of patients discontinuing all AEDs due to lack of efficacy, tolerability was the major factor influencing the number of patients remaining on treatment. Lacosamide was the best (77% patients continued treatment), while PGB was the worst (50% continued treatment) tolerated AED. Overall, seizure freedom was achieved in <25% of patients in each audit, mainly as a first or second add-on, with best tolerated AEDs producing a higher number of good outcomes. Seizures in very few patients with drug-resistant epilepsy, as defined by the International League Against Epilepsy task force, responded to any of the 5 newer AEDs. These data support the suggestion that the introduction of modern agents has not importantly impacted the outcomes in refractory epilepsy.

[Development of neurology in Germany after 1960]

The still continuing accelerated development of neurology in Germany is described in this article by a contemporary witness who was active in this field from 1965 to 2005. The personal experiences of the author are obviously only reflected over these 40 years so that the glorious antecedents in the period up to 1933, the era in which our predecessors were the world leaders in neurology, is not sufficiently covered. This dominance was lost by the anti-Semitism during the era of National Socialism and the sequelae of World War II. As a result of the war, German neurologists became effectively isolated and their participation in international congresses was forbidden so that a gradual reestablishment of alignment only became possible after 1960. In this brief description no attempt at completeness has been made and only subjectivity and brevity have been considered. An attempt is made to retrospectively convey what essentially happened. An exact dating of advances over the period was sometimes difficult. The readership will have the opportunity to share the surprise of the author on how meagre the neurological knowledge and diagnostic methods were 50 years ago, how rapidly the subsequent development happened, how rapidly things became obvious which 20 years ago nobody was aware of and despite the progress how pleased we were to find ourselves at the most recent state of error and probably still find ourselves nowadays. In particular, how powerless and untested the therapeutic efforts were at that time. The progress can only be measured by a comparison between then, 50 years ago and the present. A projection of the future based on these experiences is not attempted but it seems to be certain that many conceptions, diagnostic advances and therapy options are still undiscovered and that further exciting times can be expected.

Control of seizures in different stages of partial epilepsy: LACO-EXP, a Spanish retrospective study of lacosamide

Lacosamide is approved as adjunctive therapy for focal epilepsies. The number of antiepileptic drugs (AEDs) tried is associated with prognosis. This multicenter, retrospective, observational study (LACO-EXP) in Spain in 500 adult patients with focal epilepsies examined the efficacy and tolerability of add-on lacosamide. Factors associated with better efficacy/tolerability were analyzed. After 12months, the responder rate (≥50% reduction in seizure frequency) was 57.1%, and the seizure-free rate was 14.9%. Efficacy was better when lacosamide was the first or second add-on AED, although there was a small chance to be seizure-free even for patients who had received ≤10 prior AEDs. The mechanism of action of concomitant AEDs is important in all the stages, but differences are smaller in the early stages. Lacosamide was generally well tolerated. A slower dosage-titration schedule was associated with a lower adverse event rate. Further investigation of the timing of initiation of lacosamide add-on therapy and ideal combinations of AEDs is required.