Long-term outcome of nonsurgical candidates with medically refractory localization-related epilepsy

Drug-resistant epilepsy: Definition, pathophysiology, and management

There are currently >51 million people with epilepsy (PWE) in the world and every year >4.9 million people develop new-onset epilepsy. The cornerstone of treatment in PWE is drug therapy with antiseizure medications (ASMs). However, about one-third of PWE do not achieve seizure control and do not respond well to drug therapy despite the use of appropriate ASMs [drug-resistant epilepsy (DRE)]. The aims of the current narrative review are to discuss the definition of DRE, explain the biological underpinnings and clinical biomarkers of this condition, and finally to suggest practical management strategies to tackle this issue appropriately, in a concise manner.

Clinical Usefulness of Simultaneous Electroencephalography and Functional Magnetic Resonance Imaging in Children With Focal Epilepsy

Background and Purpose

The current study analyzed the interictal epileptiform discharge (IED)-related hemodynamic response and aimed to determine the clinical usefulness of simultaneous electroencephalography and functional magnetic resonance imaging (EEG-fMRI) in defining the epileptogenic zone (EZ) in children with focal epilepsy.

Methods

Patients with focal epilepsy showing IEDs on conventional EEG were evaluated using EEG-fMRI. Statistical analyses were performed using the times of spike as events modeled with multiple hemodynamic response functions. The area showing the most significant t-value for blood-oxygen-level-dependent (BOLD) changes was compared with the presumed EZ. Moreover, BOLD responses between -9 and +9 s around the spike times were analyzed to track the hemodynamic response patterns over time.

Results

Half (n=13) of 26 EEG-fMRI investigations of 19 patients were successful. Two patients showed 2 different types of spikes, resulting in 15 analyses. The maximum BOLD response was concordant with the EZ in 11 (73.3%) of the 15 analyses. In 10 (66.7%) analyses, the BOLD response localized the EZs more specifically. Focal BOLD responses in the EZs occurred before IEDs in 11 analyses and were often widespread after IEDs. Hemodynamic response patterns were consistent in the same epilepsy syndrome or when repeating the investigation in the same patients.

Conclusions

EEG-fMRI can provide additional information for localizing the EZ in children with focal epilepsy, and also reveal the pathogenesis of pediatric epilepsy by evaluating the patterns in the hemodynamic response across time windows of IEDs.

Closed-loop stimulation of the medial septum terminates epileptic seizures

Temporal lobe epilepsy with distributed hippocampal seizure foci is often intractable and its secondary generalization might lead to sudden death. Early termination through spatially extensive hippocampal intervention is not feasible directly, because of the large size and irregular shape of the hippocampus. In contrast, the medial septum is a promising target to govern hippocampal oscillations through its divergent connections to both hippocampi. Combining this 'proxy intervention' concept and precisely timed stimulation, we report here that closed-loop medial septum electrical stimulation can quickly terminate intrahippocampal seizures and suppress secondary generalization in a rat kindling model. Precise stimulus timing governed by internal seizure rhythms was essential. Cell type-specific stimulation revealed that the precisely timed activation of medial septum GABAergic neurons underlaid the effects. Our concept of time-targeted proxy stimulation for intervening pathological oscillations can be extrapolated to other neurological and psychiatric disorders, and has potential for clinical translation.

Unanticipated improvement in seizure control in drug-resistant epilepsy- real world observations

OBJECTIVES

To determine the clinical features and anti-seizure medication (ASM) strategies associated with an unanticipated substantial improvement in seizure control in patients with drug-resistant epilepsy (DRE).

METHODS

This retrospective analysis of patients attending a tertiary care epilepsy clinic between 2008 and 2017 identified all patients with active DRE (at least 1 seizure per month for 6 months, despite treatment with 2 different ASMs). All treatment interventions were recorded from when DRE was first identified to the end of the study. The primary end points were seizure freedom or meaningful reduction in seizure frequency (greater than 75 %) sustained for at least 12 months after a treatment intervention.

RESULTS

Three hundred and twenty-two patients were included in the analysis. Overall, 10 % became seizure free following ASM adjustment and an additional 10 % had a greater than 75 % improvement in seizure control (median follow-up, 4 years). An ASM introduction was ten times more likely than an ASM dose increase to improve seizure control. Combined focal and generalized epilepsy, intellectual disability and prior treatment with more than 5 ASMs were more frequently observed in those with continued pharmacoresistance. ASM responders were more likely to have primary generalized epilepsy. Rational polytherapy (combining ASMs with different mechanisms of action) was almost ubiquitous amongst ASMs responders (95 % taking at least 2 drugs with different mechanistic targets). Of the ASM additions that heralded improved seizure control, 85 % were maintained at submaximal doses.

CONCLUSIONS

This retrospective analysis of a large number of 'real-world' patients provides evidence to persist with ASM trials in DRE. Early rotation of ASMs if a clinical response is not observed at a substantial dose and rational ASM polytherapy may yield better clinical outcomes in patients with DRE, although a prospective study would need to be conducted to validate these findings.

Quality of Life and Its Determinants in Adult Drug Refractory Epilepsy Patients Who Were Not Candidates for Epilepsy Surgery: A Correlational Study

Background and Purpose

This study was performed to elucidate quality of life (QOL) and its determinants in adult drug refractory epilepsy (DRE) patients who were not candidates for epilepsy surgery.

Methods

A correlational study was performed at the center of excellence, epilepsy between July 2014 to June 2016. All consecutive DRE patients who were not candidates for epilepsy surgery were enrolled. The outcomes were QOL, assessed using the quality of life inventory in epilepsy-31 items (QOLIE-31) inventory and the correlation of QOL with epilepsy-related variables like seizure severity and frequency. We also compared current QOL with QOL during the pre-surgical evaluation to strengthen our study outcome.

Results

A total of 129 adult patients were enrolled over two years. The mean age was 26.5 ± 6.7 years and male: female ratio was 3: 1. The mean age at epilepsy onset was 9.6 ± 6.6 years and mean duration of epilepsy was 14.9 ± 7.5 years. There was lower seizure frequency than during pre-surgical evaluation in 37.2% of patients, while in 62.8% the seizure frequency remained the same or was higher. Nine (6.98%) patients became seizure free. In comparison to QOL status during the pre-surgical evaluation, there was statistically significant worsening of QOL in all domains (p < 0.01). Seizure severity significantly correlated with almost all QOL domains (p ≤ 0.01), while seizure frequency significantly correlated with only the single domain of overall QOL (p = 0.03).

Conclusions

The QOL of DRE patients who were not candidates for epilepsy surgery worsened relative to the QOL during the pre-surgical evaluation period. Seizure severity significantly correlated with QOL, but seizure frequency did not.

Efficacy and tolerability of treatment with lacosamide: Postmarketing experience from the Middle East region

PURPOSE

Lacosamide (LCM) was recently introduced in the Middle East. The aim of this study was to evaluate the safety, tolerability, and efficacy of LCM in patients with focal onset seizures and determine if our results are comparable with those derived from Western countries.

METHODS

This is a retrospective analysis from two medical centers on consecutive patients diagnosed as having focal onset seizures and treated with add-on LCM. The primary efficacy variables were the 50% responder and seizure-free rates, and the secondary outcome variables included the percentages of patients who achieved seizure remission during the last 6-month follow-up period and the percentages of discontinuation due to lack of efficacy or tolerability.

RESULTS

One hundred four patients with a mean age of 30.9 years and experiencing a mean of 9.4 seizures per month during baseline were included. The 50% responder rates were 69% and 70% at 6- and 24-month follow-ups, respectively. Patients concomitantly treated with a sodium channel blocker were less likely to achieve seizure remission during the last 6-month follow-up period while the early introduction of LCM resulted in a significantly higher likelihood of achieving such a remission. Eighty-eight percent of patients were still maintained on LCM at the last follow-up, and the most common adverse events consisted of dizziness and somnolence, double vision, and nausea/vomiting.

CONCLUSIONS

Our data show similar efficacy and tolerability to those reported from Western countries. Our results also substantiate the early introduction of LCM and support the dose reduction of baseline AED especially that of sodium channel blockers to minimize adverse events.

The long-term outcomes of epilepsy surgery

Objective

Despite modern anti-epileptic drug treatment, approximately 30% of epilepsies remain medically refractory and for these patients, epilepsy surgery may be a treatment option. There have been numerous studies demonstrating good outcome of epilepsy surgery in the short to median term however, there are a limited number of studies looking at the long-term outcomes. The aim of this study was to ascertain the long-term outcome of resective epilepsy surgery in a large neurosurgery hospital in the U.K.

Methods

This a retrospective analysis of prospectively collected data. We used the 2001 International League Against Epilepsy (ILAE) classification system to classify seizure freedom and Kaplan-Meier survival analysis to estimate the probability of seizure freedom.

Results

We included 284 patients who underwent epilepsy surgery (178 anterior temporal lobe resections, 37 selective amygdalohippocampectomies, 33 temporal lesionectomies, 36 extratemporal lesionectomies), and had a prospective median follow-up of 5 years (range 1–27). Kaplan-Meier estimates showed that 47% (95% CI 40–58) remained seizure free (apart from simple partial seizures) at 5 years and 38% (95% CI 31–45) at 10 years after surgery. 74% (95% CI 69–80) had a greater than 50% seizure reduction at 5 years and 70% (95% CI 64–77) at 10 years. Patients who had an amygdalohippocampectomy were more likely to have seizure recurrence than patients who had an anterior temporal lobe resection (p = 0.006) and temporal lesionectomy (p = 0.029). There was no significant difference between extra temporal and temporal lesionectomies. Hippocampal sclerosis was associated with a good outcome but declined in relative frequency over the years.

Conclusion

The vast majority of patients who were not seizure free experienced at least a substantial and long-lasting reduction in seizure frequency. A positive long-term outcome after epilepsy surgery is possible for many patients and especially those with hippocampal sclerosis or those who had anterior temporal lobe resections.

Deep brain and cortical stimulation for epilepsy

BACKGROUND

Despite optimal medical treatment, including epilepsy surgery, many epilepsy patients have uncontrolled seizures. Since the 1970s interest has grown in invasive intracranial neurostimulation as a treatment for these patients. Intracranial stimulation includes both deep brain stimulation (DBS) (stimulation through depth electrodes) and cortical stimulation (subdural electrodes). This is an updated version of a previous Cochrane review published in 2014.

OBJECTIVES

To assess the efficacy, safety and tolerability of DBS and cortical stimulation for refractory epilepsy based on randomized controlled trials (RCTs).

SEARCH METHODS

We searched the Cochrane Epilepsy Group Specialized Register on 29 September 2015, but it was not necessary to update this search, because records in the Specialized Register are included in CENTRAL. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2016, Issue 11, 5 November 2016), PubMed (5 November 2016), ClinicalTrials.gov (5 November 2016), the WHO International Clinical Trials Registry Platform ICTRP (5 November 2016) and reference lists of retrieved articles. We also contacted device manufacturers and other researchers in the field. No language restrictions were imposed.

SELECTION CRITERIA

RCTs comparing deep brain or cortical stimulation versus sham stimulation, resective surgery, further treatment with antiepileptic drugs or other neurostimulation treatments (including vagus nerve stimulation).

DATA COLLECTION AND ANALYSIS

Four review authors independently selected trials for inclusion. Two review authors independently extracted the relevant data and assessed trial quality and overall quality of evidence. The outcomes investigated were seizure freedom, responder rate, percentage seizure frequency reduction, adverse events, neuropsychological outcome and quality of life. If additional data were needed, the study investigators were contacted. Results were analysed and reported separately for different intracranial targets for reasons of clinical heterogeneity.

MAIN RESULTS

Twelve RCTs were identified, eleven of these compared one to three months of intracranial neurostimulation with sham stimulation. One trial was on anterior thalamic DBS (n = 109; 109 treatment periods); two trials on centromedian thalamic DBS (n = 20; 40 treatment periods), but only one of the trials (n = 7; 14 treatment periods) reported sufficient information for inclusion in the quantitative meta-analysis; three trials on cerebellar stimulation (n = 22; 39 treatment periods); three trials on hippocampal DBS (n = 15; 21 treatment periods); one trial on nucleus accumbens DBS (n = 4; 8 treatment periods); and one trial on responsive ictal onset zone stimulation (n = 191; 191 treatment periods). In addition, one small RCT (n = 6) compared six months of hippocampal DBS versus sham stimulation. Evidence of selective reporting was present in four trials and the possibility of a carryover effect complicating interpretation of the results could not be excluded in five cross-over trials without any or a sufficient washout period. Moderate-quality evidence could not demonstrate statistically or clinically significant changes in the proportion of patients who were seizure-free or experienced a 50% or greater reduction in seizure frequency (primary outcome measures) after one to three months of anterior thalamic DBS in (multi)focal epilepsy, responsive ictal onset zone stimulation in (multi)focal epilepsy patients and hippocampal DBS in (medial) temporal lobe epilepsy. However, a statistically significant reduction in seizure frequency was found for anterior thalamic DBS (mean difference (MD), -17.4% compared to sham stimulation; 95% confidence interval (CI) -31.2 to -1.0; high-quality evidence), responsive ictal onset zone stimulation (MD -24.9%; 95% CI -40.1 to -6.0; high-quality evidence) and hippocampal DBS (MD -28.1%; 95% CI -34.1 to -22.2; moderate-quality evidence). Both anterior thalamic DBS and responsive ictal onset zone stimulation do not have a clinically meaningful impact on quality life after three months of stimulation (high-quality evidence). Electrode implantation resulted in postoperative asymptomatic intracranial haemorrhage in 1.6% to 3.7% of the patients included in the two largest trials and 2.0% to 4.5% had postoperative soft tissue infections (9.4% to 12.7% after five years); no patient reported permanent symptomatic sequelae. Anterior thalamic DBS was associated with fewer epilepsy-associated injuries (7.4 versus 25.5%; P = 0.01) but higher rates of self-reported depression (14.8 versus 1.8%; P = 0.02) and subjective memory impairment (13.8 versus 1.8%; P = 0.03); there were no significant differences in formal neuropsychological testing results between the groups. Responsive ictal-onset zone stimulation seemed to be well-tolerated with few side effects.The limited number of patients preclude firm statements on safety and tolerability of hippocampal DBS. With regards to centromedian thalamic DBS, nucleus accumbens DBS and cerebellar stimulation, no statistically significant effects could be demonstrated but evidence is of only low to very low quality.

AUTHORS' CONCLUSIONS

Except for one very small RCT, only short-term RCTs on intracranial neurostimulation for epilepsy are available. Compared to sham stimulation, one to three months of anterior thalamic DBS ((multi)focal epilepsy), responsive ictal onset zone stimulation ((multi)focal epilepsy) and hippocampal DBS (temporal lobe epilepsy) moderately reduce seizure frequency in refractory epilepsy patients. Anterior thalamic DBS is associated with higher rates of self-reported depression and subjective memory impairment. There is insufficient evidence to make firm conclusive statements on the efficacy and safety of hippocampal DBS, centromedian thalamic DBS, nucleus accumbens DBS and cerebellar stimulation. There is a need for more, large and well-designed RCTs to validate and optimize the efficacy and safety of invasive intracranial neurostimulation treatments.

Unexpected marked seizure improvement in paediatric epilepsy surgery candidates

PURPOSE

Epilepsy surgery is performed based on the assumption that medical refractory epilepsy will continue. Rarely seizure freedom occurs before surgery is performed, while the patient is being evaluated as an epilepsy surgery candidate. The aim of this study was to describe the number of children withdrawn from an epilepsy surgery programme due to unexpected seizure improvement.

METHODS

We retrospectively studied 173 children under 18 years with medical refractory epilepsy referred for epilepsy surgery between 1996 and 2010. Medical records were reviewed in 2012 and 2015.

RESULTS

At the first evaluation point in 2012, 13 patients were withdrawn from the epilepsy surgery programme due to unexpected marked improvement. In 2015, 6 of them were still seizure free. They had unexpected seizure freedom due to change in AED treatment (n=3) or after a febrile episode (n=3). The mean number of years they had had seizures was 3.4 years (range 0.6-6.2 years) and the number of seizures at inclusion was 209 per month (range 6-750 per month). The duration of follow-up was 6.6 years after inclusion into the epilepsy surgery programme (range 4.0-13.0 years). The aetiology of the epilepsy for these patients was heterotopia (n=1), focal cortical dysplasia (n=3), infarction (n=1) and unknown, with normal MRI (n=1). They all had an IQ in the normal range. Two of the remaining 7 children were operated later.

CONCLUSION

Unexpected seizure control may occur during epilepsy surgery evaluation.

Very Long-Term Outcome of Non-Surgically Treated Patients with Temporal Lobe Epilepsy with Hippocampal Sclerosis: A Retrospective Study

Objective

Surgical intervention can result in complete seizure remission rates of up to 80% in patients with temporal lobe epilepsy with hippocampal sclerosis (TLE-HS). However, certain patients cannot be treated surgically for various reasons. We analyzed the very long-term clinical outcomes of patients with TLE-HS who could not be treated surgically.

Methods

Subjects were selected from among patients with TLE-HS who were actively followed up for >10 years and treated with medication without surgical treatment. Patient medical records were used to retrospectively study seizure frequency, various clinical factors, and social adjustment. Patients who were seizure-free or had only aura were classified into Group 1; the others were classified into Group 2. Clinical factors including both patient and disease-specific factors were compared between the two groups. Current social adjustment, including the education, work, and economic status of each patient, was also investigated.

Results

Forty-one (41) subjects met the criteria for analysis, of which 12 (29%) were classified into Group 1. The average age of patients in Group 1 was higher than that of Group 2 (p = 0.0468). Group 2 included a significantly higher rate of patients who had more than one seizure per week at the onset (p = 0.0328), as well as a greater mean number of anti-epileptic drugs taken (p = 0.0024). Regarding social adjustment, Group 2 contained significantly fewer current jobholders than Group 1 (p = 0.0288).

Conclusions

After very long-term follow-up periods, 29% of patients with TLE-HS had a good outcome through treatment with anticonvulsant medications. Older patients tended to have fewer seizures, and seizure frequency at the onset was the only factor that predicted outcome.

Drug-resistant epilepsy in adults: Outcome trajectories after failure of two medications

OBJECTIVE

To examine the seizure trajectories of adults with epilepsy developing drug-resistant epilepsy (DRE) and to identify the predictors of seizure trajectory outcome.

METHODS

Adult patients failing two antiepileptic drugs (AEDs) due to inefficacy and starting their third AED at a tertiary epilepsy center were followed for seizure trajectory outcome during medical management. Seizure trajectories were categorized into one of four patterns: (1) course with constant seizures; (2) fluctuating course; (3) delayed attainment of seizure freedom (seizure freedom delayed for >12 months after start of the study, but patient stayed in seizure freedom); and (4) early attainment of seizure freedom (within 12 months of starting study). Multiple ordinal logistic regression models were used to estimate the association between trajectory categories and clinical factors.

RESULTS

Four hundred three adult patients met the eligibility criteria. Of these, 212 (53%) never achieved a seizure-free period of a year or more. The trajectories of 63 patients (16%) had a complex fluctuating trajectory, 62 (15%) had delayed onset of seizure freedom, and 66 (16%) had an early seizure freedom. Independent predictors associated with more favorable outcome trajectories were epilepsy type and length of follow-up. Specifically, compared to patients with focal epilepsy of temporal lobe, patients with focal epilepsy of occipital lobe (OR 3.80, 95% confidence interval [CI] 1.00-14.51, p = 0.04), generalized genetic (OR 3.23, 95% CI 1.88-5.57, p < 0.0001), unclear epilepsy type (OR 3.82, 95% CI 1.53-9.52, p < 0.005), and both focal and generalized epilepsy(OR 11.73, 95% CI 1.69-81.34, p = 0.01) were significantly more likely to experience a better trajectory pattern.

SIGNIFICANCE

Examination of patterns of seizure trajectory of patients with incident DRE showed that 31% were in continuous seizure freedom at the end of the observation period.

Natural course of treated epilepsy and medico-social outcomes. Turku studies. Part II

Introduction. Population-based data on the prognosis of childhood-onset epilepsy were almost nonexistent in the 1960s. This prompted me to start an epidemiological prospective study on children with epilepsy.

Aim. To study the medical and social outcome of children with epilepsy.

Methods. The most important personal data on the natural course and outcome were reviewed and compared with the relevant data of other investigators.

Results and discussion. The natural course of treated epilepsy is remitting, uninterrupted by relapse (in 48%); a remitting-relapsing course (interrupted by relapses, in terminal remission) (19%); worsening course (early or late remission followed by drug-resistant epilepsy) (14%); and never in ≥5-year remission (drug resistance) (19%) The medical and social outcomes based on my unique, five decades followed cohort show that most subjects are in 10-year remission without medications, which is the definition of resolved epilepsy. Normal or subnormal IQ, non-symptomatic etiology, and low seizure frequency both in the first year of AED treatment and prior to medication appear to be clinical predictors of cure in childhood-onset epilepsy. Subjects with 1-year remission during the first five years form onset of treatment have more than 10-fold chance for entering 5-year terminal remission vs those who have no 1-year remission during the first five years. Even about one fourth of difficult-to-treat subjects become seizure free on medication and more than half of them enter one or more 5-year remissions. Epilepsy has a substantial impact on quality of life even in those who are seizure free off medication for many years and particularly those not in remission or in remission but still on medication.

Conclusions. The prognosis is excellent for medical and social outcome. The successful outcome is confirmed by several longitudinal studies from recent decades. Good response to early drug therapy does not necessarily guarantee a favorable seizure outcome, and even a late good response may still predict a successful prognosis. Our life-cycle study is being continued and targets to answer the question whether or not childhood-onset epilepsy is a risk factor for premature and/or increased incidence of mental impairment and dementia.

The impact of receiving a diagnosis of Non-Epileptic Attack Disorder (NEAD): A systematic review

BACKGROUND

Clinicians have reported observations of the immediate cessation of non-epileptic attacks after the diagnosis of NEAD is presented.

OBJECTIVE

The purpose of this systematic review was to examine the impact of receiving a diagnosis of NEAD.

SEARCH STRATEGY

A literature search across the databases Medline, PsycINFO, EMBASE, and CINAHL, and additional hand searching, identified six original studies meeting criteria for the review.

SELECTION CRITERIA

Included studies were original peer-reviewed articles investigating the impact of receiving a diagnosis of NEAD on adult populations with at least one outcome measured pre- and post-diagnosis.

ANALYSIS

The studies were assessed for methodological quality, including biases. This assessment was developed to include criteria specific to research regarding NEAD and diagnosis.

RESULTS

Six identified studies, with a total of 153 NEAD participants, examined the impact of receiving a diagnosis on seizure frequency. Two of the six also examined the impact on health-related quality of life. The findings were inconsistent, with approximately half the participants experiencing seizure reduction or cessation post-diagnosis. Diagnosis appeared to have no significant impact on health-related quality of life. The overall evidence lacked quality, particularly in study design and statistical rigour.

CONCLUSIONS

Mixed results and a lack of high quality evidence were found. Concerns are considered regarding the appropriateness of seizure frequency as the primary outcome measure and the use of epilepsy control groups. Indications for future research include: measuring more meaningful outcomes, using larger samples and power calculations, and ensuring consistent and standard methods for communicating the diagnosis and recording outcomes.

Predictors of spontaneous transient seizure remission in patients of medically refractory epilepsy due to mesial temporal sclerosis (MTS)

PURPOSE

To analyze the predictors of spontaneous transient seizure remission for ≥1 year in patients with drug-resistant epilepsy (DRE) due to mesial temporal sclerosis (MTS).

METHODS

This analysis included 38 patients with DRE (M:F = 20:18, age: 31.7 ± 10.9 years) diagnosed with unilateral MTS (right:left = 16:22). Group I ('remission' group) comprised of patients with seizure remission (M:F = 10:8, age: 32.8 ± 12.3 years, mean seizure free period: 2.2 ± 1.1 years; median: 2.1 years). Group II ('non-remission' group) comprised of age and gender matched 20 patients (M:F = 10:10, age: 30.7 ± 9.7 years) with unilateral MTS who never had seizure remission and subsequently underwent epilepsy surgery. Groups I and II were compared to find the predictors associated with transient seizure remission.

RESULTS

The age at onset of seizures in group I was 13.2 ± 11.8 years and in group II was 12.0 ± 7.6 years. The duration of seizure was: group I - 19.7 ± 12.5 years and group II - 19.3 ± 7.7 years. Past history of seizure remissions (p < 0.001), frequent periods of remissions (p < 0.001), first remission within a year of onset of seizures (p = 0.04) and normal EEG (p = 0.04) were the important clinical predictors associated with seizure remission in this cohort. Fifteen patients in group I (83.3%) experienced remission following either change in AED (p ≤ 0.001) or increase in AED dosages (p < 0.001). There was no difference between the two groups regarding the type of semiology (partial vs. secondarily generalized) (p = 0.50), family history of seizures (p = 1.0), side of the lesion (p = 0.34), history of febrile seizures (p = 1.0) and the number of AEDs used (p = 0.53).

CONCLUSION

The present study unfolds, some of the clinically relevant predictors associated with transient seizure remission in patients with DRE and MTS. Future molecular and network studies are required to understand its mechanism.

The prognosis of refractory epilepsy patients rejected from epilepsy surgery

OBJECTIVE

Up to one-third of individuals diagnosed as having epilepsy continue to have seizures despite appropriate anti-epileptic drug treatment. These patients are often referred for presurgical evaluation, and many are rejected from focal resective surgery due to medical reasons or, alternatively, they choose not to undergo it. We compared the outcomes and characteristics of the non-operated patients who continued on medical therapy alone with those who underwent vagus nerve stimulator (VNS) implantation in addition to medical therapy.

METHODS

The medical records of consecutive adult patients referred for presurgical evaluation for suitability for epilepsy surgery in the Tel-Aviv Sourasky Medical Center between 2007 and 2011 and were rejected from or decided against surgery were reviewed. Updated information on seizure frequency was supplemented by telephone interviews between April and July, 2013.

RESULTS

Fifty-two patients who continued solely on medical therapy and 35 patients who additionally underwent VNS implantation were included in the study. Forty-seven of the former and 33 of the latter agreed to be interviewed. There was a significant improvement in the seizure frequency between the time of the presurgical evaluation and the time of the interview in both groups. Eight medically treated patients (17%) and 2 patients who also underwent VNS implantation (6%) reported being seizure-free during the preceding 3 months.

CONCLUSIONS

A considerable minority of patients with refractory epilepsy who were rejected or chose not to undergo epilepsy surgery may improve over time and even become seizure-free following adjustment of anti-epileptic drugs with or without concomitant VNS.

Long-term outcomes in patients after epilepsy surgery failure

PURPOSE

The primary aim of this study was to analyze the long-term outcomes of patients who were classified as Engel IV one year after resective epilepsy surgery. The secondary objectives were to evaluate the effectiveness of different treatment options and to examine the reasons that the patients did not undergo resective reoperation.

METHODS

Our study was designed as a retrospective open-label investigation of the long-term outcomes of 34 patients (12% of all surgically treated patients) who were classified as Engel IV one year after epilepsy surgery.

RESULTS

At the last follow-up visit (average of 7.6 ± 4.2 years after surgery), 12 of the 34 examined patients (35.3%) were still classified as Engel IV; 22 of the 34 patients (64.7%) were improved (Engel I-III). Of the 34 patients, 8 (23.5%) achieved an excellent outcome, classified as Engel I, 3 patients (8.8%) were classified as Engel II, and 11 patients (32.4%) as Engel III. The seizure outcome in the patients classified as Engel I was achieved by resective reoperation in 4; by a change in antiepileptic medication in 3 patients; and by vagus nerve stimulation (VNS) in 1 patient. The seizure outcome of Engel II was achieved by a change in antiepileptic medication in all 3 patients. Of the 34 patients, a total of 6 (17.6%) underwent resective reoperation only. The major reasons for this were the absence of a plausible hypothesis for invasive re-evaluation, the risk of postoperative deficit, and multifocal epilepsy in the rest of patients.

CONCLUSION

Although the reoperation rate was relatively low in our series, we can achieve better or even excellent seizure outcomes using other procedures in patients for whom resective surgery initially failed.

Deep brain and cortical stimulation for epilepsy

BACKGROUND

Despite optimal medical treatment, including epilepsy surgery, many epilepsy patients have uncontrolled seizures. In the last decades, interest has grown in invasive intracranial neurostimulation as a treatment for these patients. Intracranial stimulation includes both deep brain stimulation (DBS) (stimulation through depth electrodes) and cortical stimulation (subdural electrodes).

OBJECTIVES

To assess the efficacy, safety and tolerability of deep brain and cortical stimulation for refractory epilepsy based on randomized controlled trials.

SEARCH METHODS

We searched PubMed (6 August 2013), the Cochrane Epilepsy Group Specialized Register (31 August 2013), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 7 of 12) and reference lists of retrieved articles. We also contacted device manufacturers and other researchers in the field. No language restrictions were imposed.

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing deep brain or cortical stimulation to sham stimulation, resective surgery or further treatment with antiepileptic drugs.

DATA COLLECTION AND ANALYSIS

Four review authors independently selected trials for inclusion. Two review authors independently extracted the relevant data and assessed trial quality and overall quality of evidence. The outcomes investigated were seizure freedom, responder rate, percentage seizure frequency reduction, adverse events, neuropsychological outcome and quality of life. If additional data were needed, the study investigators were contacted. Results were analysed and reported separately for different intracranial targets for reasons of clinical heterogeneity.

MAIN RESULTS

Ten RCTs comparing one to three months of intracranial neurostimulation to sham stimulation were identified. One trial was on anterior thalamic DBS (n = 109; 109 treatment periods); two trials on centromedian thalamic DBS (n = 20; 40 treatment periods), but only one of the trials (n = 7; 14 treatment periods) reported sufficient information for inclusion in the quantitative meta-analysis; three trials on cerebellar stimulation (n = 22; 39 treatment periods); three trials on hippocampal DBS (n = 15; 21 treatment periods); and one trial on responsive ictal onset zone stimulation (n = 191; 191 treatment periods). Evidence of selective reporting was present in four trials and the possibility of a carryover effect complicating interpretation of the results could not be excluded in 4 cross-over trials without any washout period. Moderate-quality evidence could not demonstrate statistically or clinically significant changes in the proportion of patients who were seizure-free or experienced a 50% or greater reduction in seizure frequency (primary outcome measures) after 1 to 3 months of anterior thalamic DBS in (multi)focal epilepsy, responsive ictal onset zone stimulation in (multi)focal epilepsy patients and hippocampal DBS in (medial) temporal lobe epilepsy. However, a statistically significant reduction in seizure frequency was found for anterior thalamic DBS (-17.4% compared to sham stimulation; 95% confidence interval (CI) -32.1 to -1.0; high-quality evidence), responsive ictal onset zone stimulation (-24.9%; 95% CI -40.1 to 6.0; high-quality evidence) ) and hippocampal DBS (-28.1%; 95% CI -34.1 to -22.2; moderate-quality evidence). Both anterior thalamic DBS and responsive ictal onset zone stimulation do not have a clinically meaningful impact on quality life after three months of stimulation (high-quality evidence). Electrode implantation resulted in asymptomatic intracranial haemorrhage in 3% to 4% of the patients included in the two largest trials and 5% to 13% had soft tissue infections; no patient reported permanent symptomatic sequelae. Anterior thalamic DBS was associated with fewer epilepsy-associated injuries (7.4 versus 25.5%; P = 0.01) but higher rates of self-reported depression (14.8 versus 1.8%; P = 0.02) and subjective memory impairment (13.8 versus 1.8%; P = 0.03); there were no significant differences in formal neuropsychological testing results between the groups. Responsive ictal-onset zone stimulation was well tolerated with few side effects but SUDEP rate should be closely monitored in the future (4 per 340 [= 11.8 per 1000] patient-years; literature: 2.2-10 per 1000 patient-years). The limited number of patients preclude firm statements on safety and tolerability of hippocampal DBS. With regards to centromedian thalamic DBS and cerebellar stimulation, no statistically significant effects could be demonstrated but evidence is of only low to very low quality.

AUTHORS' CONCLUSIONS

Only short term RCTs on intracranial neurostimulation for epilepsy are available. Compared to sham stimulation, one to three months of anterior thalamic DBS ((multi)focal epilepsy), responsive ictal onset zone stimulation ((multi)focal epilepsy) and hippocampal DBS (temporal lobe epilepsy) moderately reduce seizure frequency in refractory epilepsy patients. Anterior thalamic DBS is associated with higher rates of self-reported depression and subjective memory impairment. SUDEP rates require careful monitoring in patients undergoing responsive ictal onset zone stimulation. There is insufficient evidence to make firm conclusive statements on the efficacy and safety of hippocampal DBS, centromedian thalamic DBS and cerebellar stimulation. There is a need for more, large and well-designed RCTs to validate and optimize the efficacy and safety of invasive intracranial neurostimulation treatments.

Advancing the management of childhood epilepsies

Childhood epilepsies comprise a heterogeneous group of disorders and syndromes that vary in terms of severity, prognosis and treatment requirements. Effective management requires early, accurate recognition and diagnosis, and a holistic approach that addresses each individual's medical and psychosocial needs within the context of their overall health status and quality of life. With increasing understanding of underlying aetiologies, new approaches to management and treatment are emerging. For example, genetic testing is beginning to provide a tool to aid differential diagnosis and a means of predicting predisposition to particular types of epilepsy. Despite the availability of an increasing number of antiepileptic drugs (AEDs)--due not only to the development of new AEDs, but also to changes in regulatory requirements that have facilitated clinical development--seizure control and tolerability continue to be suboptimal in many patients, and there is therefore a continuing need for new treatment strategies. Surgery and other non-pharmacological treatments (e.g. vagus nerve stimulation, ketogenic diet) are already relatively well established in paediatric epilepsy. New pharmacological treatments include generational advances on existing AEDs and AEDs with novel modes of action, and non-AED pharmacological interventions, such as immunomodulation. Emerging technologies include novel approaches allowing the delivery of medicinal agents to specific areas of the brain, and 'closed-loop' experimental devices employing algorithms that allow treatment (e.g., electrical stimulation) to be targeted both spatially and temporally. Although in early stages of development, cell-based approaches (e.g., focal targeting of adenosine augmentation) and gene therapy may also provide new treatment choices in the future.

Diagnostic evaluation in patients with intractable epilepsy and normal findings on MRI: a decision analysis and cost-effectiveness study

BACKGROUND AND PURPOSE

Patients with focal intractable epilepsy and normal MR imaging findings frequently undergo further diagnostic tests to localize the epileptogenic zone. The aim of this study was to determine the cost-effective diagnostic strategy that will identify the epileptogenic zone in patients with suspected focal intractable epilepsy and normal MR imaging findings by using decision analysis.

MATERIALS AND METHODS

A Markov decision model was constructed by using sensitivities and specificities of test strategies, seizure outcomes following surgical and medical treatment, cost, utilities, probabilities, and standardized mortality ratios. We compared 6 diagnostic test strategies: PET, ictal SPECT, and MEG individually; and combinations of PET+SPECT, PET+MEG, and SPECT+MEG. The outcomes measured were health care costs, QALY, and ICER. One-way and probabilistic sensitivity analyses were conducted to adjust for uncertainties in model parameters.

RESULTS

The preferred strategies were PET+MEG and SPECT. The health care cost of the baseline strategy (PET+MEG) was $95,612 with 16.30 QALY gained. SPECT cost $97,479 with 16.45 QALY gained and an ICER of $12,934/QALY gained compared with those in PET+MEG. One-way sensitivity analyses showed that the decisions of the model were sensitive to variations in sensitivity and specificity of the test strategies. Probabilistic sensitivity analysis showed that when the willingness to pay was <$10,000, PET+MEG was the favored strategy, but the favored strategy changed to SPECT when the willingness to pay was >$10,000.

CONCLUSIONS

PET+MEG and SPECT were the preferred strategies in the base case. The choice of test was dependent on the sensitivity and specificity of test strategies and willingness to pay. Further study with a larger sample size is needed to obtain better estimates of sensitivity and specificity of diagnostic tests.

Determinants of quality of life in patients with refractory focal epilepsy who were not eligible for surgery or who rejected surgery

The aim of the study was to assess the determinants of quality of life (QOL) in adult patients with refractory focal epilepsy who were not eligible for surgery or who rejected surgery after presurgical evaluation. The QOLIE-31, the Hospital Anxiety and Depression Scale and PESOS questionnaire were mailed in 2009 to all adult patients who had been evaluated for suitability for epilepsy surgery between 2001 and 2007 in the Bethel Epilepsy Center and had been deemed not eligible for surgery or had decided against surgery. Questionnaires were sent by post to 359 patients: 172 (47.9%) replied, and of these, 125 patients were eligible for this study. The remaining 47 patients were excluded mainly because they did not fulfill the criteria of refractory epilepsy. Out of the included 125 patients, 106 were considered to be poor surgical candidates for medical reasons, and 19 had decided against surgery. The mean follow-up was 4.1±2.1 years. In the past 6 months, 13.9% of the patients were seizure free, 12 of them (9.6%) were seizure free for one year, 10.7% had 1-2 seizures, 11.5% had 3-5 seizures, 27.0% had one or more seizures a month, 23.0% had one or more seizures a week, and 13.9% had one or more seizures a day. Patient-perceived changes in their seizures since presurgical evaluation were rated by 15.6% of the patients as 'improved significantly', by 28.7% as 'improved', by 46.7% as 'no change', by 6.6% as 'deteriorated' and by 2.5% as 'significantly deteriorated'. Quality of life in patients with refractory epilepsy was much lower compared to operated patients from our center. Multivariate analysis of QOL showed that depression and anxiety are strong predictors but not exclusively. Furthermore, tolerability and efficacy of AEDs are significant predictors of most QOLIE-31 subscales. Employment, seizure frequency, patient-perceived change in their seizures, number of AEDs and the degree of comorbidity appeared as predictors for some aspects of QOL as well. When excluding anxiety and depression, the most important predictors of QOL were tolerability of AEDs and employment. For other aspects of QOL, efficacy of AEDs, gender, number of AEDs, degree of comorbidity and a certificate of disability were additional predictors. The results of the multivariate analysis did not essentially change when seizure-free patients were excluded.

CONCLUSION

Quality of life in non-operated patients with refractory epilepsy is significantly lower than in operated patients from the same center. Besides depression and anxiety, patient-rated tolerability and efficacy of AEDs, seizure frequency and employment are the main determinants of QOL.

Long-term outcome in children with intractable epilepsy showing bilateral diffuse cortical glucose hypometabolism pattern on positron emission tomography

The objective of this study is to determine the long-term outcome of children with intractable epilepsy who have diffuse cortical hypometabolism on 2-deoxy-2-((18)F)fluoro-D-glucose positron emission tomography (FDG-PET) scans. Seventeen children with intractable epilepsy showing bilateral, diffuse cortical hypometabolism on FDG-PET were followed up through telephone interview from 1 year 4 months to 11 years 4 months (mean: 5 years 7 months ± 2 years 1 month) after their PET scans. One child succumbed to Sanfilippo disease at age 20 years. Only 2 children were seizure free. Fifty percent had walking difficulties, 56.25% were not toilet trained, all had speech difficulties, 43.75% had behavioral problems, 37.5% had poor eye contact, 75% had socialization difficulties, and 87.5% attended special schools. Three children were found to have genetic causes, including a 4-MB deletion of the mitochondrial genome, MECP2 duplication, and Lafora disease. In conclusion, the long-term outcome in this patient population is poor, and they tend to suffer from genetic/neurodegenerative diseases.

Seizure frequency and social outcome in drug resistant epilepsy patients who do not undergo epilepsy surgery

Little is known about the long term prognosis of refractory epilepsy patients who do not undergo epilepsy surgery. We performed a telephone survey and chart review of patients who underwent presurgical evaluation in our Unit but did not have surgery, from 1998 until 2004. We contacted 84 patients; mean follow-up was 6.7 years. Four patients (4.7%) had died, presumably of SUDEP. Ten patients (13.1%) were seizure free. In most patients with seizures, frequency remained stable (24/80, 30%) or had decreased by ≥50% (26 patients, 30.9%). Most patients (69, 86.2%) believed their health was similar or better respect to the moment they underwent presurgical evaluation. Employment situation was stable in 64/80 patients (80%), but 11 had received new disability wages. Family situation was also generally unchanged (69/80 patients, 86.2%). Most patients were not taking antidepressants. Seizure free patients scored higher in satisfaction with life. This information can be used to counsel refractory patients.

Surgery for extratemporal nonlesional epilepsy in adults: an outcome meta-analysis

PURPOSE

To better evaluate surgery for extratemporal lobe epilepsy (ETLE) in adults, we conducted a meta-analysis of previous studies that analyzed postoperative seizure outcomes for ETLE.

METHODS

After searching PubMed for appropriate studies, patient data were reviewed, and data on patients who fit the authors' criteria were extracted. Statistical analysis compared each variable with surgical outcome to determine if an association existed.

RESULTS

For the 131 patients who were included in the analysis, the age at surgery, age of seizure onset, and duration of epilepsy were not found to be statistically and significantly related to seizure outcome. Similarly, seizure semiology, abnormality on magnetic resonance imaging, lateralization of the seizures, the need for intracranial monitoring, pathological findings, and the type and location of surgery did not appear to be associated with outcome.

CONCLUSIONS

This meta-analysis confirms the findings of other centers: ETLE surgical outcomes are less desirable than those for temporal lobe epilepsy. None of the factors studied in adults showed significant association with outcome. Contrary to some reports, shortening the duration of epilepsy by pursuing surgery as early as possible also does not appear to improve outcomes. The creation of standard protocols among epilepsy centers is needed to allow for a detailed evaluation of outcomes across different centers and, ultimately, to better assess the factors associated with improved outcomes.

Surgery for extratemporal nonlesional epilepsy in children: a meta-analysis

PURPOSE

Previous small studies have demonstrated that seizure outcomes following surgery for extratemporal lobe epilepsy (ETLE) in children are worse than those for temporal lobe epilepsy. We have conducted a meta-analysis of the available literature to better understand ETLE surgical outcomes in children.

METHODS

We searched PubMed (1990-2009) for appropriate studies using the following terms: ETLE, ETLE surgery, ETLE surgery outcome, frontal lobe epilepsy, occipital lobe epilepsy, and parietal lobe epilepsy. Our collected data included patient age at seizure onset and surgery, the cerebral lobe involved with epileptogenesis, MRI findings, predominant seizure semiology, intracranial monitoring use (electrode implantation), epileptic region histopathology, and postoperative seizure outcome. Statistical analysis was performed to determine associations among these variables and postoperative outcome.

RESULTS

Ninety-five patients from 17 studies satisfied the inclusion criteria. Pathological findings (p = 0.039) and seizure type (p = 0.025) were significantly associated with outcome: A larger proportion of patients with cortical dysplasia and complex partial seizures experienced better outcomes. Age at surgery (p = 0.073) and the cerebral resection site (p = 0.059) were marginally associated with seizure outcome.

CONCLUSIONS

This study confirms previous reports: Surgical outcomes for ETLE epilepsy are significantly worse than those for temporal lobe epilepsy. The reasons for this difference may include the diffuse nature of the pathology involved in ETLE, difficulty in localizing the seizure focus in young children, and involvement of "eloquent" nonresectable cortex in epileptogenesis. Because of the reporting variability among different epilepsy centers, more uniform protocols are necessary for fair evaluation and comparison of outcomes among the different centers.

New developments in antiepileptic drug resistance: an integrative view

Current theories on drug resistance in epilepsy include the drug transporter hypothesis, the drug target hypothesis, and a novel approach called the inherent severity model of epilepsy, which posits that the severity of the disease determines its relative response to medication. Valuable as each of these hypotheses is, none is currently a stand-alone theory that is able to convincingly explain drug resistance in human epilepsy. As a consequence, it may be of interest to update and integrate the various hypotheses of drug resistance and to explore possible links to the severity of epilepsy. The observation that a high frequency of seizures prior to onset of treatment is a prognostic signal of increased severity and future drug failure suggests that common neurobiological factors may underlie both disease severity and pharmacoresistance. Such a link has been proposed for depression; however, the evidence for a direct mechanistic link, genetic or otherwise, between drug response and disease severity of human epilepsy is still elusive. Although emerging data from experimental studies suggest that alterations in GABA(A) receptors may present one example of a mechanistic link, clearly more work is needed to explore whether common neurobiological factors may underlie both epilepsy severity and drug failure.

Placebo-corrected efficacy of modern antiepileptic drugs for refractory epilepsy: systematic review and meta-analysis

Although adjunctive treatment with modern antiepileptic drugs (AEDs) is standard care in refractory epilepsy, it is unclear how much of the effect can be attributed directly to the AEDs and how much to the beneficial changes seen with placebo. Therefore, we performed a systematic review and meta-analysis of the evidence to determine the placebo-corrected net efficacy of adjunctive treatment with modern AEDs on the market for refractory epilepsy. Of 317 potentially eligible articles reviewed in full text, 124 (39%) fulfilled eligibility criteria. After excluding 69 publications, 55 publications of 54 studies in 11,106 adults and children with refractory epilepsy form the basis of evidence. The overall weighted pooled-risk difference in favor of AEDs over placebo for seizure-freedom in the total sample of adults and children was 6% [95% confidence interval (CI) 4-8, z = 6.47, p < 0.001] and 21% (95% CI 19-24, z = 17.13, p < 0.001) for 50% seizure reduction. Although the presence of moderate heterogeneity may reduce the validity of the results and limit generalizations from the findings, we conclude that the placebo-corrected efficacy of adjunctive treatment with modern AEDs is disappointingly small and suggest that better strategies of finding drugs are needed for refractory epilepsy, which is a major public health problem.

Comparison of outcomes of video/EEG monitoring between patients with epileptic seizures and those with psychogenic nonepileptic seizures

We followed 103 patients for 6-16 months after discharge from elective long-term video/EEG monitoring to compare clinical outcomes and quality of life between patients diagnosed with epileptic (ES) and those diagnosed with psychogenic nonepileptic (PNES) seizures. Outcome measures determined at telephone or mail follow-up included seizure frequency, antiepileptic drug use, and self-reported quality of life using the Quality of Life in Epilepsy inventory. Of the 62 responders, 41 were diagnosed with ES and 11 with PNES, using strictly applied criteria. Those with ES reported significant improvement in Seizure Worry (P=0.003), Medication Side Effects (P<0.001), and Social Function (P<0.001). In addition, both groups showed a decrease in seizure frequency. Furthermore, both groups showed a significant decrease in antiepileptic drug use at follow-up, with a greater, and sustained, decrease for the PNES group. Approximately half the patients in each group reported an improvement in overall condition.

Prognosis of patients with mesial temporal lobe epilepsy due to hippocampal sclerosis

PURPOSE

Hippocampal sclerosis (HS) is the most common pathology in mesial temporal lobe epilepsy (MTLE). There are a few reports concerning prognosis in patients with MTLE-HS treated medically. The study was carried out to determine the clinical risk factors affecting prognosis.

METHODS

We enrolled 287 patients with MTLE-HS treated medically. Gender, age at onset of epilepsy, history of trauma, infection, febrile convulsion, status epilepticus, mental retardation, handedness, consanguinity, side of hippocampal sclerosis, additional extrahippocampal temporal lesion, aura, seizures types, antiepileptic drugs, psychiatric disturbances and seizure frequency were noted. All patients were divided into three groups. Group I: patients seizure-free during follow up, Group II: patients with improved seizure control whose seizure frequency had decreased >50% after the treatment, and Group III: patients with poor seizure control whose seizure frequency had no change or increased. Each clinical feature was also compared among three subgroups statistically.

RESULTS

Early age of seizure onset [Group II-III (p=0.000) and Group I-III (p=0.0004)], age of head trauma [Group II-III (p=0.04)], the presence of mental retardation (p=0.04) and female sex (p=0.03) were risk factors for poor prognosis. However, the other parameters did not affect prognosis.

CONCLUSION

Recognizing bad prognostic features such as the presence of mental retardation, early age of seizure onset, age of head trauma and female gender may help physicians to identify risk groups with MTLE-HS and drug resistance seizures for epilepsy surgery.

Levetiracetam in the treatment of epilepsy

Epilepsy is a common chronic disorder that requires long-term antiepileptic drug therapy. Approximately one half of patients fail the initial antiepileptic drug and about 35% are refractory to medical therapy, highlighting the continued need for more effective and better tolerated drugs. Levetiracetam is an antiepileptic drug marketed since 2000. Its novel mechanism of action is modulation of synaptic neurotransmitter release through binding to the synaptic vesicle protein SV2A in the brain. Its pharmacokinetic advantages include rapid and almost complete absorption, minimal insignificant binding to plasma protein, absence of enzyme induction, absence of interactions with other drugs, and partial metabolism outside the liver. The availability of an intravenous preparation is yet another advantage. It has been demonstrated effective as adjunctive therapy for refractory partial-onset seizures, primary generalized tonic-clonic seizures, and myoclonic seizures of juvenile myoclonic epilepsy. In addition, it was found equivalent to controlled release carbamazepine as first-line therapy for partial-onset seizures, both in efficacy and tolerability. Its main adverse effects in randomized adjunctive trials in adults have been somnolence, asthenia, infection, and dizziness. In children, the behavioral adverse effects of hostility and nervousness were also noted. Levetiracetam is an important addition to the treatment of epilepsy.

Seizure remission and relapse in adults with intractable epilepsy: a cohort study

PURPOSE

To investigate the cumulative probabilities of >or=12 month seizure remission and seizure relapse following remission, and to test the associations of clinical characteristics with these two study end points in a prevalence cohort of intractable adult epilepsy patients during medical management.

METHODS

A retrospective cohort study of intractable epilepsy patients seen in 2001 at a single center was conducted. Kaplan-Meier analysis was used to estimate the cumulative probabilities of seizure remission and subsequent seizure relapse. Cox proportional hazards models were used to estimate the association (1) between clinical factors and >or=12 month seizure remission and (2) between clinical factors and seizure relapse following remission.

RESULTS

One hundred eighty-seven subjects met the eligibility criteria for intractable epilepsy. The estimate of probability of remission was about 4% per year. Seizure remission was temporary for some individuals, as 5 out of 20 subjects with remission ultimately relapsed. No clinical factors predicted the likelihood of achieving >or=12 month seizure remission or subsequent seizure relapse.

DISCUSSION

Some people with intractable epilepsy achieve >or=12 month seizure remission during medical treatment. Remission, however, is only temporary for some individuals. We were unable to identify clear predictors for remission.

Assessment of the Long-term Effects of Epilepsy Surgery with Three Different Reference Groups

PURPOSE

It is difficult to validly assess the long-term effect of epilepsy surgery. Here, this is attempted by comparing the outcome of surgically treated pharmacoresistant epilepsy patients to three different nonoperated comparison groups regarding seizure control, antiepilepsy drug (AED) usage, and health related quality of life (QOL).

METHODS

One hundred thirty-one operated patients (group 1, mean follow-up since presurgical assessment 6.9 years), 105 patients awaiting presurgical assessment (group 2, mean follow-up after assignment to waiting list 0.8 years), 99 patients considered to be presurgical candidates who chose to withdraw from waiting for presurgical assessment (group 3, mean follow-up after assignment to waiting list 5.5 years), and 49 patients who were not deemed to be eligible for surgery after comprehensive assessment (group 4, mean follow-up since presurgical assessment 6.5 years) were studied. The patients completed a questionnaire on seizures, AED usage, and QOL (ESI-55).

RESULTS

The surgical patients had a better outcome than all three comparison groups regarding seizure frequency, seizure freedom rate, and number of AEDs used. They scored higher than groups 2, 3, and 4 on 7/11, 6/11, and 3/11 ESI-55 domains, respectively.

CONCLUSIONS

The superior long-term outcome of the operated patients was most marked if compared to the patients awaiting surgery. This is compatible with the assumption that patients present for presurgical candidacy selection and assessment at a "nadir" of their disease course. After several years, a regression to the mean occurs which reduces (but does not abolish) the differences between nonoperated and operated patients.

Results of epilepsy surgery: still so much to learn

Predicting Long-Term Seizure Outcome after Resective Epilepsy Surgery: The Multicenter Study

Spencer SS, Berg AT, Vickrey BG, Sperling MR, Bazil CW, Shinnar S, Langfitt JT, Walczak TS, Pacia SV

Neurology 2005;65(6):912–918

Background

In a seven-center prospective observational study of resective epilepsy surgery, the authors examined probability and predictors of entering 2-year remission and the risk of subsequent relapse.

Methods

Patients aged 12 years and over were enrolled at time of referral for epilepsy surgery, and underwent standardized evaluation, treatment, and follow-up procedures. The authors defined seizure remission as 2 years completely seizure-free after hospital discharge with or without auras, and relapse as any seizures after 2-year remission. The authors examined type of surgery, seizure, clinical and demographic variables, and localization study results with respect to prediction of seizure remission or relapse, using χ2 and proportional hazards analysis.

Results

Of 396 operated patients, 339 were followed over 2 years, and 223 (66%) experienced 2-year remission, not significantly different between medial temporal (68%) and neocortical (50%) resections. In multivariable models, only absence of generalized tonic–clonic seizures and presence of hippocampal atrophy were significantly and independently associated with remission, and only in the medial temporal resection group. Fifty-five patients relapsed after 2-year remission, again not significantly different between medial temporal (25%) and neocortical (19%) resections. Only delay to remission predicted relapse, and only in medial temporal patients.

Conclusion

Hippocampal atrophy and a history of absence of generalized tonic clonic seizures were the sole predictors of 2-year remission, and only for medial temporal resections. Antiepileptic Drug Withdrawal after Successful Surgery for Intractable Temporal Lobe Epilepsy Kim YD, Heo K, Park SC, Huh K, Chang JW, Choi JU, Chung SS, Lee BI Epilepsia 2005;46(2):251–257

Purpose

To investigate the prognosis related to antiepileptic drug (AED) discontinuation after successful surgery for intractable temporal lobe epilepsy.

Methods

The clinical courses after temporal lobectomies (TLs) were retrospectively analyzed in 88 consecutive patients. All the patients had TLs as the only surgical procedure, and they had been followed up for longer than 3 years. AED discontinuation was attempted if the patient had been seizure free without aura for ≥1 year during the follow-up period.

Results

Sixty-six (75%) patients achieved complete seizure freedom for ≥1 year; 28 patients were seizure free immediately after surgery (immediate success); and 38 patients became seizure free after some period of recurrent seizures (delayed success). AED discontinuation was attempted in 60 (91%) of 66 patients with a successful outcome. In 13 (22%) patients, seizure relapse developed during AED reduction ( n = 60), and in 7 (12%) patients after discontinuation of AEDs ( n = 38). The seizure recurrence rate was not different between the immediate- and delayed-success groups. Among 20 patients with seizure relapse related to AED tapering, 9 (45%) of them regained seizure freedom after reinstitution of AED treatment, and AEDs were eventually discontinued in 6 of them. Seizures that recurred after complete AED discontinuation had a better prognosis than did the seizures that recurred during AED reduction (seizure freedom in 86% vs 23%). At the final assessment, 54 (61%) patients had been seizure free ≥1 year; 37 without AEDs and 17 with AEDs. The successful discontinuation of AEDs was more frequent for patients with a younger age at the time of surgery and for those patients with shorter disease duration.

Conclusions

Our results suggest that seizure freedom without aura at ≥1 year is a reasonable indication for the attempt at AED discontinuation. The subsequent control of recurrent seizures was excellent, especially if seizures relapsed after the complete discontinuation of AEDs. Younger age at the time of surgery and a shorter disease duration seem to affect successful AED discontinuation for a long-term period.

Comparison of short-term outcome between surgical and clinical treatment in temporal lobe epilepsy: A prospective study

OBJECTIVE

To compare the efficacy of medical and surgical treatment for refractory mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE).

METHODS

A prospective controlled non-randomized study of 26 patients with MTLE who underwent surgical treatment and 75 patients with MTLE who underwent medical treatment between August 2002 and October 2004. All patients failed to achieve seizure control with at least two first line antiepileptic drugs (AED) for partial seizures before entering the study. We used Kaplan-Meier survival analyses as a function of time of seizure recurrence to obtain estimates of 95% confident interval of seizure freedom and log-rank test to compare the status of seizure control between the two groups.

RESULTS

The cumulative proportion of patients free of all seizures (Engel's class IA) was higher in the surgical group (73%) compared to the clinical group (12%) (p<0.0001). In the surgical group, 2 of 26 patients (7.7%) had transient adverse effects and 2 of 26 patients (7.7%) had a permanent deficit related to the surgical procedure. In the clinical group 7 patients (9.3%) major adverse events during follow-up, including burns and status epilepticus.

CONCLUSIONS

Surgical treatment for patients with MTLE who failed to achieve seizure control with two previous AED regimens was more efficient than medical treatment with further trials of AED.