Alterations of intracerebral connectivity in epilepsy patients with secondary bilateral synchrony.

INTRODUCTION: The aim of our study was to evaluate intracerebral network changes in epilepsy patients demonstrating secondary bilateral synchrony (SBS) in EEG by applying a new Diffusion Tensor Imaging (DTI) method using an energy-based global tracking algorithm. MATERIALS AND METHODS: 10 MRI negative epilepsy patients demonstrating SBS in 10-20 surface EEG were included. EEG findings were analyzed for irritative zones characterized by focal interictal epileptiform discharges (IEDs) triggering SBS. In addition, DTI including an energy-based global tracking algorithm was applied to analyze fiber tract alterations in irritative zones. To measure the deviation of a certain cortical connection in comparison to healthy controls, normalized differences of fiber tract streamline counts (SC) and their p-values were evaluated in comparison to corresponding fibers of the control group. RESULTS: In 6 patients the irritative zone initiating SBS was located in the frontal lobe, in 3 patients in the temporal lobe and in 1 patient in the region surrounding the right central sulcus. All patients demonstrated significantly altered SC in brain lobes where the irritative zone triggering SBS was located (p ≤ 0.05). Seven out of 10 patients demonstrated SC alterations in tracts connecting brain lobes between the ipsilateral and the contralateral hemisphere (p ≤ 0.05). CONCLUSION: Our data demonstrate that alterations in fiber tracts in irritative zones triggering SBS are not necessarily associated with intracerebral lesions visible in high resolution MRI. Our study gives evidence that diffusion tensor imaging is a promising non-invasive additive tool for intracerebral network analyses even in MRI-negative epilepsy patients.

Bilateral cingulum fiber reductions in temporal lobe epilepsy with unilateral hippocampal sclerosis.

PURPOSE: To evaluate whether white matter tracts within the Papez circuit are altered in patients with unilateral hippocampal sclerosis (HS). METHODS: Twenty patients with histologically proven unilateral HS and 20 age-matched controls were studied with a 3T Epilepsy-dedicated MRI protocol including a MPRAGE sequence for hippocampus volumetry and a diffusion tensor imaging (DTI) sequence (61 diffusion-encoding directions, 2×2×2mm3 voxels) for diffusion tensor tractography (DTT). An energy-based global tracking algorithm was used to calculate streamline counts (SC) and fractional anisotropy (FA) of cingulate, fornix, and mammillo-thalamic tracts, respectively. RESULTS: Sclerotic hippocampi were significantly smaller compared to the contralateral side and to age-matched controls. Cingulum SC but not FA were reduced on the hippocampal sclerosis (258+81.0) and contralateral side (271+85.6) compared to age-matched controls (447+138). CONCLUSION: Focusing on white matter tracts of the Papez circuit we showed that in patients with intractable temporal lobe epilepsy unilateral hippocampal sclerosis is associated with a bilateral reduction of cingulum association fibers projecting from the cingulate gyrus to the parahippocampal gyrus.

The role of presurgical EEG parameters and of reoperation for seizure outcome in temporal lobe epilepsy.

PURPOSE: After surgery for intractable mesiotemporal lobe epilepsy (mTLE) seizures recur in 30-40%. One predictor for seizure recurrence is the distribution of seizure onset and interictal epileptiform discharges (IED). Our study focused on lateralization and extent of epileptiform activity regarding postoperative seizure persistence and the effect of reoperation. METHODS: This study comprises 426 consecutive patients operated for intractable mTLE. Impact of preoperative seizure onset and IED on the persistence of seizures and results of reoperation were analyzed. RESULTS: One year after surgery, 27% of patients with mTLE experienced persistent seizures (Engel II-IV). Preoperative bilateral seizure onset in EEG was predictive for postoperative seizure recurrence (Engel II-IV: 64%). Seizure foci and IED exceeding the temporal lobe in the ipsilateral hemisphere were not found to be associated with worse seizure outcome (Engel I: 72% and 75%) compared to patients with seizure foci confined to the ipsilateral temporal lobe (Engel I: 75% and 76%). Moreover, IED exceeding the affected temporal lobe in the ipsilateral hemisphere or even bilateral IED did not negatively affect seizure freedom if seizure onset was strictly limited to the affected temporal lobe (Engel I: 85% and 65%, respectively). 60% of patients reoperated in the ipsilateral temporal lobe for persistent seizures became seizure free. CONCLUSIONS: Preoperative bilateral ictal foci are a negative predictor for seizure outcome. Contrarily, IED exceeding the affected temporal lobe in the ipsilateral hemisphere or even bilateral IED had favorable seizure outcome if seizure onset is strictly limited to the affected temporal lobe. Reoperation for seizure persistence constitutes a promising therapeutic option.

Pure endoscopic management of epileptogenic hypothalamic hamartomas.

Hypothalamic hamartomas (HH) are rare congenital malformations located in the region of the tuber cinereum and third ventricle. Their usual clinical presentation is characterized by gelastic/dacrystic seizures which often become pharmaco-resistant and progress to secondary focal/generalized intractable epilepsy causing mostly in children cognitive and behavioral problems (particularly in cases of progressive epileptic encephalopathy) and precocious puberty. Whereas gelastic seizures can be surgically controlled either by resection of the lesion or disconnection (tissue-destructive) procedures, aimed at functionally prevent the spreading of the epileptic burst; generalized seizures tend to respond better to HH excision rather than isolated neocortical resections, which generally fail to control them. Prospective analysis of 14 consecutive patients harboring HH treated in an 8-year period; 12 patients had unilateral and two bilateral HH. All patients were managed by pure endoscopic excision of the HH. The mean operative time was 48 min and mean hospital stay was 2 days; perioperative blood loss was negligible in all cases. Two patients showed a transient diabetes insipidus (DI); no transient or permanent postoperative neurological deficit or memory impairment was recorded. Complete HH excision was achieved in 10/14 patients. At a mean follow-up of 48 months, no wound infection, meningitis, postoperative hydrocephalus, and/or mortality were recorded in this series of patients. Eight patients became seizure free (Engel class I), 2 other experienced worthwhile improvement of disabling seizures (Engel class II); 2 patients were cured from gelastic attacks while still experiencing focal dyscognitive seizures; and 2, having bilateral HH (both undergoing unilateral HH excision), did not experience significant improvement and required later on a temporal lobectomy coupled to amygdalohyppocampectomy. Overall, the followings resulted to be predictive factors for better outcomes in terms of seizure control: (1) cases of unilateral, Delalande class B, HH, (2) shorter history of epilepsy. Endoscopic resection of HH proved, in our series, to be effective in achieving complete control or in reducing the frequency of seizures. Furthermore, this approach has confirmed its minimally invasive nature with a very low morbidity rate: of note, it allowed to better preserve short-term memory and hypothalamic function.

Eslicarbazepine acetate: its effectiveness as adjunctive therapy in clinical trials and open studies.

Eslicarbazepine acetate (ESL) is a once-daily antiepileptic drug that is approved as adjunctive therapy in adults with focal-onset seizures. Following oral administration, ESL is rapidly metabolized to its active metabolite, eslicarbazepine, which acts primarily by enhancing slow inactivation of voltage-gated sodium channels. The efficacy and safety/tolerability of ESL in the adjunctive setting were established in a comprehensive Phase III program (n = 1702 randomized patients) and this evidence has been supported by several open studies (n = 864). ESL treatment has demonstrated improvements in health-related quality of life, in both randomized clinical trials and open studies. ESL has also been shown to be usually well tolerated and efficacious when used in the adjunctive setting in elderly patients. The effectiveness of ESL as the only add-on to antiepileptic drug monotherapy has been demonstrated in a multinational study (n = 219), subgroup analyses of which have also shown it to be efficacious and generally well tolerated in patients who had previously not responded to carbamazepine therapy. Open studies have also demonstrated improvements in tolerability in patients switched overnight from oxcarbazepine to ESL. Due to differences in pharmacokinetics, pharmacodynamics, and metabolism, there may be clinical situations in which it is appropriate to consider switching patients from oxcarbazepine or carbamazepine to ESL.

Overnight switching from oxcarbazepine to eslicarbazepine acetate: an observational study.

OBJECTIVES: There are clinical situations where it might be appropriate to switch patients from immediate-release oxcarbazepine (OXC) to eslicarbazepine acetate (ESL). We investigated the effects of transitioning patients overnight from OXC to ESL. MATERIALS AND METHODS: A retrospective, single-center study was conducted in which patients with drug-resistant focal epilepsy on a stable dose of immediate-release OXC for at least 4 weeks were switched overnight to ESL. Patients were switched because they experienced persistent seizures with OXC but were unable to tolerate increased OXC dosing due to adverse events. Tolerability was assessed using the Adverse Events Profile (AEP), quality of life was assessed using the Quality of Life in Epilepsy Inventory 10 (QOLIE-10), and alertness was assessed as reaction time using a subtest of the Test Battery for Attention Performance version 2.3. Assessments were performed immediately prior to and 5 days after switching from OXC to ESL (days 0 and 5, respectively). RESULTS: The analysis included 21 patients (12 women, 9 men; mean age 36 years). After switching from OXC to ESL, there were significant improvements in mean scores for AEP (P<.001), QOLIE-10 (P=.001), and alertness (P<.05). Adverse Events Profile total scores improved for 21/21 (100.0%) patients, QOLIE-10 total scores improved for 17/21 (81.0%) patients, and alertness scores improved for 16/21 (76.2%) patients. CONCLUSIONS: In this short-term, single-center study, an overnight switch from twice-daily OXC to once-daily ESL in patients with drug-resistant focal epilepsies resulted in improvements in side effects, quality of life, and alertness.

Long-term outcome characteristics in mesial temporal lobe epilepsy with and without associated cortical dysplasia.

OBJECT: The intention of our study was to identify predictive characteristics for long-term seizure control and running down phenomenon after surgical treatment of pharmacoresistant mesiotemporal lobe epilepsy (mTLE) with and without associated cortical dysplasia. MATERIALS AND METHODS: Our study comprises a consecutive series of 458 patients who underwent surgical treatment for intractable mTLE at the Epilepsy Center Freiburg. Data evaluated included semiology, duration and frequency of seizures, results of presurgical diagnostics including video-EEG monitoring, MRI, PET and SPECT as well as postoperative seizure outcome. Results were evaluated forming two groups: Group A consisted of isolated mesiotemporal lesions. Group B comprised patients with mTLE and additional focal cortical dysplasia (FCD). Statistical evaluation was based on the Kaplan Meier survival analysis, using log-rank-tests and a multivariate regression model. Postoperative running down phenomenon was defined as seizure freedom after a period of gradual reduction of postoperative seizure frequency. This was compared to patients with ongoing epilepsy. RESULTS: Complete seizure freedom was achieved in 65.0% of investigated patients at 1year and in 56.5% at long-term follow-up of ≥5 years after surgery. Corresponding results were 64.2% and 56.8% at 1 and ≥5 years, respectively in group A and 66.4% and 56.0%, respectively in group B. Predictive for favorable postoperative outcome in the total group were younger age at surgery, shorter duration of epilepsy, absence of secondarily generalized tonic-clonic seizures (SGTCS), presence of strictly ipsilateral temporal interictal epileptiform discharges (IEDs), complete resection of the lesion as well as absence of postoperative epileptiform activity and of early postoperative seizures. In subgroup analyses, patients of group A demonstrated longer postoperative seizure-free intervals with adolescent age at surgery, short duration of epilepsy before surgery and absence of SGTCS, whereas in patients of group B ipsilateral temporal seizure onset and strictly unilateral IEDs in EEG as well as complete resection were predictors for favorable seizure outcome. Furthermore, absence of early postoperative seizures and of spikes in EEG were predictive factors for long-term seizure-freedom in both subgroups. The running down phenomenon was found in 33 (7.2%) patients. None of the parameters evaluated demonstrated significant predictive power. Only late seizure onset and neoplastic lesions showed a trend for postoperative gradual seizure reduction in multivariate analyses. CONCLUSION: Depending on the presence or absence of focal cortical dysplasia in addition to mesiotemporal structural alterations, predictors of long-term seizure control differed regarding the relevant clinical and electrophysiological features. This is important for specific patient counseling in respective groups.

Transcutaneous Vagus Nerve Stimulation (tVNS) for Treatment of Drug-Resistant Epilepsy: A Randomized, Double-Blind Clinical Trial (cMPsE02).

BACKGROUND: Various brain stimulation techniques are in use to treat epilepsy. These methods usually require surgical implantation procedures. Transcutaneous vagus nerve stimulation (tVNS) is a non-invasive technique to stimulate the left auricular branch of the vagus nerve at the ear conch. OBJECTIVE: We performed a randomized, double-blind controlled trial (cMPsE02) to assess efficacy and safety of tVNS vs. control stimulation in patients with drug-resistant epilepsy. METHODS: Primary objective was to demonstrate superiority of add-on therapy with tVNS (stimulation frequency 25 Hz, n = 39) versus active control (1 Hz, n = 37) in reducing seizure frequency over 20 weeks. Secondary objectives comprised reduction in seizure frequency from baseline to end of treatment, subgroup analyses and safety evaluation. RESULTS: Treatment adherence was 84% in the 1 Hz group and 88% in the 25 Hz group, respectively. Stimulation intensity significantly differed between the 1 Hz group (1.02 ± 0.83 mA) and the 25 Hz group (0.50 ± 0.47 mA; p = 0.006). Mean seizure reduction per 28 days at end of treatment was -2.9% in the 1 Hz group and 23.4% in the 25 Hz group (p = 0.146). In contrast to controls, we found a significant reduction in seizure frequency in patients of the 25 Hz group who completed the full treatment period (20 weeks; n = 26, 34.2%, p = 0.034). Responder rates (25%, 50%) were similar in both groups. Subgroup analyses for seizure type and baseline seizure frequency revealed no significant differences. Adverse events were usually mild or moderate and comprised headache, ear pain, application site erythema, vertigo, fatigue, and nausea. Four serious adverse events were reported including one sudden unexplained death in epilepsy patients (SUDEP) in the 1 Hz group which was assessed as not treatment-related. CONCLUSIONS: tVNS had a high treatment adherence and was well tolerated. Superiority of 25 Hz tVNS over 1 Hz tVNS could not be proven in this relatively small study, which might be attributed to the higher stimulation intensity in the control group. Efficacy data revealed results that justify further trials with larger patient numbers and longer observation periods.

Adjunctive retigabine in refractory focal epilepsy: Postmarketing experience at four tertiary epilepsy care centers in Germany.

PURPOSE: Retigabine (RTG, ezogabine) is the first potassium channel-opening anticonvulsant drug approved for adjunctive treatment of focal epilepsies. We report on the postmarketing clinical efficacy, adverse events, and retention rates of RTG in adult patients with refractory focal epilepsy. METHODS: Clinical features before and during RTG treatment were retrospectively collected from patients treated at four German epilepsy centers in 2011 and 2012. RESULTS: A total of 195 patients were included. Daily RTG doses ranged from 100 to 1500 mg. Retigabine reduced seizure frequency or severity for 24.6% and led to seizure-freedom in 2.1% of the patients but had no apparent effect in 43.1% of the patients. Seizure aggravation occurred in 14.9%. The one-, two-, and three-year retention rates amounted to 32.6%, 7.2%, and 5.7%, respectively. Adverse events were reported by 76% of the patients and were mostly CNS-related. Blue discolorations were noted in three long-term responders. Three possible SUDEP cases occurred during the observation period, equalling an incidence rate of about 20 per 1000 patient years. CONCLUSIONS: Our results are similar to other pivotal trials with respect to the long-term, open-label extensions and recent postmarketing studies. Despite the limitations of the retrospective design, our observational study suggests that RTG leads to good seizure control in a small number of patients with treatment-refractory seizures. However, because of the rather high percentage of patients who experienced significant adverse events, we consider RTG as a drug of reserve.

Perampanel for focal epilepsy: insights from early clinical experience.

Perampanel is approved for adjunctive therapy of focal epilepsy with or without secondarily generalized seizures in patients aged >12 years. This narrative review uses real-world and clinical trial data to elucidate perampanel's role in the clinic. Audit data show good tolerability with perampanel and higher freedom-from-seizure rates in elderly vs younger patients. When using perampanel in elderly patients, special attention should be given to comorbidities and co-medication to avoid potential interactions or adverse events. Slower titration is generally recommended, and seizure control should be reassessed at a dose of 4 mg before further dose increases. Perampanel efficacy is similar in adolescents and adults; however, somnolence, nasopharyngitis, and aggression are more frequent in adolescents vs the overall population. Individualized and slow-dose titration can minimize adverse events. Low serum concentrations of perampanel may occur in patients also receiving some enzyme-inducing anti-epileptic drugs; a perampanel dose increase may be required. Adverse events of importance with perampanel include dizziness; anger, aggression, and hostile behavior (particularly in adolescents); and falls (particularly in patients >65 years). An individualized approach to dosing, including slower up-titration and bedtime dosing, reduces dizziness risk. Other drugs may cause or aggravate dizziness; reducing concomitant drugs may be necessary when up-titrating perampanel. It would seem clinically appropriate to give due consideration to avoiding use in patients with a history of anger or hostile/aggressive behavior. The possibility of such behaviors should be discussed with patients before starting perampanel, with monitoring during up-titration. Slower up-titration of perampanel in older patients helps reduce fall risk.

[Differential Diagnosis of Epileptic and Psychogenic Non-Epileptic Seizures and Treatment Consequences]. / Differenzialdiagnose epileptischer und psychogener nicht-epileptischer Anfälle und sich hieraus ergebende Behandlungskonsequenzen.

Psychogenic non-epileptic seizures (PNES) are one of the most important differential diagnoses of epileptic seizures and represent a challenging pathology for clinicians. The aim of this article is to impart clinical criteria for an accurate diagnosis of psychogenic non-epileptic seizures since an early and appropriate treatment may considerably improve the prognosis.

[Slow release versus immediate release oxcarbazepine in difficult-to-treat focal epilepsy: a multicenter, randomized, open, controlled, parallel group phase III study]. / Retardiertes vs. schnell freisetzendes Oxcarbazepin bei therapierefraktärer fokaler Epilepsie : Eine offene multizentrische, randomisierte kontrollierte Studie.

BACKGROUND: The aim of the study was an assessment of the tolerability and efficacy of slow release oxcarbazepine (OXC-MR) versus immediate release OXC (OXC-IR) after forced titration in patients with focal epileptic seizures with and without secondary generalization who had previously not become seizure-free under OXC-IR with or without concomitant antiepileptic drugs. The primary study variable was to assess the maximum tolerated dosage with OXC-MR and OXC-IR. PATIENTS AND METHODS: This was designed as a multicenter, randomized, open, controlled, parallel group phase III study. After randomization patients received OXC-MR or OXC-IR for a study period of 26 days. The initial dosage of 900 mg, 1,200 mg or 1,500 mg OXC was increased every 5 days by 300 mg up to a maximum daily dosage of 2,700 mg. In cases of intolerable adverse events dosage could be reduced by 150 mg 2 days after an increase. Adverse events and executive abilities were assessed with the questionnaire "Adverse Event Profile plus" and with the Epitrack® test protocol. Serum concentrations of OXC and its active metabolite were measured in a part of the patient group. RESULTS: The 71 patients (54% male, age: 19-70 years) enrolled in the study were randomized. The maximum mean daily OXC dosage at the end of the study period was 1,950 mg with OXC-MR and thus statistically significantly higher than in OXC-IR group (1,650 mg, p = 0.022). The number of causally related adverse events was lower in the OXC-MR group (n = 104 versus n = 138 with OXC-IR) and CNS-related adverse events such as dizziness, tremor, somnolence and headache occurred significantly less often with OXC-MR (OXC-MR 65.7%, OXC-IR 88.9%, p = 0.01). Fluctuations of serum concentrations of the active metabolite were less pronounced under the OXC-MR regimen. CONCLUSIONS: Due to better tolerability OXC-MR allowed higher maintenance dosages to be reached than OXC-IR. In spite of a higher mean daily dosage adverse events and especially CNS-related adverse events occurred less often than with OXC-IR.

[Abrupt switch from extended-release oxcarbazepine to eslicarbazepine acetate]. / Abrupter Austausch von retardiertem Oxcarbazepin gegen Eslicarbazepinacetat.

BACKGROUND: Eslicarbazepine acetate (ESL) was labelled for add-on treatment of adults with focal epilepsies in 2009. ESL is a derivative of carbamazepine and oxcarbazepine (OXC) that promises potentially better effectiveness. It has not yet been investigated how to switch from OXC to ESL and if this switch causes any clinical changes. MATERIAL AND METHODS: We replaced extended-release OXC by ESL abruptly according to a 1:1 ratio in 12 patients. Standardized tests and questionnaires addressing side effects, quality of life and alertness were performed immediately prior and 5 days after the switch. We also measured the serum levels of sodium and the common metabolite monohydroxy derivative. RESULTS: No problems occurred. Concerning the parameters investigated no significant differences were found. In 9 of 12 cases serum sodium levels fell without clinical consequences. CONCLUSION: The exchange of extended-release OXC by ESL is easy to perform. Clinically relevant alterations were not apparent immediately after the switch. Sodium serum level controls are recommended also with the use of ESL.