Influence of age and location of ictal onset on postoperative outcome in patients with localization-related epilepsy

A Review of EEG-based Localization of Epileptic Seizure Foci: Common Points with Multimodal Fusion of Brain Data

Unexpected seizures significantly decrease the quality of life in epileptic patients. Seizure attacks are caused by hyperexcitability and anatomical lesions of special regions of the brain, and cognitive impairments and memory deficits are their most common concomitant effects. In addition to seizure reduction treatments, medical rehabilitation involving brain-computer interfaces and neurofeedback can improve cognition and quality of life in patients with focal epilepsy in most cases, in particular when resective epilepsy surgery has been considered treatment in drug-resistant epilepsy. Source estimation and precise localization of epileptic foci can improve such rehabilitation and treatment. Electroencephalography (EEG) monitoring and multimodal noninvasive neuroimaging techniques such as ictal/interictal single-photon emission computerized tomography (SPECT) imaging and structural magnetic resonance imaging are common practices for the localization of epileptic foci and have been studied in several kinds of researches. In this article, we review the most recent research on EEG-based localization of seizure foci and discuss various methods, their advantages, limitations, and challenges with a focus on model-based data processing and machine learning algorithms. In addition, we survey whether combined analysis of EEG monitoring and neuroimaging techniques, which is known as multimodal brain data fusion, can potentially increase the precision of the seizure foci localization. To this end, we further review and summarize the key parameters and challenges of processing, fusion, and analysis of multiple source data, in the framework of model-based signal processing, for the development of a multimodal brain data analyzing system. This article has the potential to be used as a valuable resource for neuroscience researchers for the development of EEG-based rehabilitation systems based on multimodal data analysis related to focal epilepsy.

Focused review: Clinico-neuropathological aspects of late onset epilepsies: Pathogenesis

The aim of the present study was to review the current knowledge on the neuropathological spectrum of late onset epilepsies. Several terms including 'neuropathology*' AND 'late onset epilepsy' (LOE) combined with distinct neuropathological diagnostic terms were used to search PubMed until November 15, 2023. We report on the relevance of definitional aspects of LOE with implications for the diagnostic spectrum of epilepsies. The neuropathological spectrum in patients with LOE is described and includes vascular lesions, low-grade neuroepithelial neoplasms and focal cortical dysplasias (FCD). Among the latter, the frequency of the FCD subtypes appears to differ between LOE patients and those with seizure onset at a younger age. Neurodegenerative neuropathological changes in the seizure foci of LOE patients require careful interdisciplinary interpretation with respect to the differential diagnosis of primary neurodegenerative changes or epilepsy-related changes. Innate and adaptive neuroinflammation represents an important cause of LOE with intriguing therapeutic options.

Role of resective surgery in patients older than 60 years with therapy-resistant epilepsy

OBJECTIVE

Epilepsy surgery for older adults is controversial owing to their longer duration of epilepsy and perceived higher surgical risk. However, because of an aging population and documented benefit of epilepsy surgery, surgery is considered more frequently for these patients. The authors' objective was to analyze the role of resective surgery in patients older than 60 years and to assess outcomes and safety.

METHODS

The authors conducted a retrospective analysis of 595 patients who underwent resective epilepsy surgery at their center from 1999 to 2018. Thirty-one patients aged 60 years or older were identified. Sixty patients younger than 60 years were randomly selected as controls. Population characteristics, results of presurgical evaluations, outcomes, and complications were analyzed.

RESULTS

No significant differences were found between the groups in terms of hemisphere dominance, side of surgery, presence of a lesion, and incidence of temporal lobe epilepsy. Epilepsy duration was greater in the older cohort (p = 0.019), and invasive EEG was more commonly employed in younger patients (p = 0.030). The rates of Engel class I outcome at 6 months, 1 year, and 2 years were 89.7%, 96.2%, and 94.7% for the older group and 75% (p = 0.159), 67.3% (p = 0.004), and 75.8% (p = 0.130) for the younger group, respectively. The proportion of seizure-free patients was greatest among those with temporal lobe epilepsy, particularly in the older group. Neurological complication rates did not differ significantly between groups, however medical and other minor complications occurred more frequently in the older group.

CONCLUSIONS

Patients older than 60 years had equal or better outcomes at 1 year after epilepsy surgery than younger patients. A trend toward a greater proportion of patients with lesional temporal lobe epilepsy was found in the older group. These results suggest that good seizure outcomes can be obtained in older patients despite longer duration of epilepsy.

Predictive factors of postoperative outcome in the elderly after resective epilepsy surgery

OBJECTIVE

To evaluate the efficiency of resective epilepsy surgery (RES) in patients over 50 years and determine prognostic factors.

RESULTS

Over the 147 patients over 50 years (54.9±3.8 years [50-69]) coming from 8 specialized French centres for epilepsy surgery, 72.1%, patients were seizure-free and 91.2% had a good outcome 12 months after RES. Seizure freedom was not associated with the age at surgery or duration of epilepsy. In multivariate analysis, seizure freedom was associated with MRI and neuropathological hippocampal sclerosis (HS) (P=0.009 and P=0.028 respectively), PET hypometabolism (P=0.013), temporal epilepsy (P=0.01). On the contrary, the need for intracranial exploration was associated with a poorer prognosis (P=0.001). Postoperative number of antiepileptic drugs was significantly lower in the seizure-free group (P=0.001). Neurological adverse event rate after surgery was 21.1% and 11.7% of patients had neuropsychological adverse effects overall transient.

CONCLUSIONS

RES is effective procedure in the elderly. Even safe it remains at higher risk of complication and population should be carefully selected. Nevertheless, age should not be considered as a limiting factor, especially when good prognostic factors are identified.

Outcomes of epilepsy surgery in the older population: not too old, not too late

OBJECTIVE

The prevalence of epilepsy in the older adult population is increasing. While surgical intervention in younger patients is supported by level I evidence, the safety and efficacy of epilepsy surgery in older individuals is less well established. The aim of this study was to evaluate seizure freedom rates and surgical outcomes in older epilepsy patients.

METHODS

The authors' institutional electronic database was queried for patients older than 50 who had undergone epilepsy surgery during 2002-2018. Cases were grouped into 50-59, 60-69, and 70+ years old. Seizure freedom at the last follow-up constituted the primary outcome of interest. The institutional analysis was supplemented by a literature review and meta-analysis (random effects model) of all published studies on this topic as well as by an analysis of complication rates, mortality rates, and cost data from a nationwide administrative database (Vizient Inc., years 2016-2019).

RESULTS

A total of 73 patients (n = 16 for 50-59 years, n = 47 for 60-69, and n = 10 for 70+) were treated at the authors' institution. The median age was 63 years, and 66% of the patients were female. At a median follow-up of 24 months, seizure freedom was 73% for the overall cohort, 63% for the 50-59 group, 77% for the 60-69 group, and 70% for the 70+ group. The literature search identified 15 additional retrospective studies (474 cases). Temporal lobectomy was the most commonly performed procedure (73%), and mesial temporal sclerosis was the most common pathology (52%), followed by nonspecific gliosis (19%). The pooled mean follow-up was 39 months (range 6-114.8 months) with a pooled seizure freedom rate of 65% (95% CI 59%-72%). On multivariable meta-regression analysis, an older mean age at surgery (coefficient [coeff] 2.1, 95% CI 1.1-3.1, p < 0.001) and the presence of mesial temporal sclerosis (coeff 0.3, 95% CI 0.1-0.6, p = 0.015) were the most important predictors of seizure freedom. Finally, analysis of the Vizient database revealed mortality rates of 0.5%, 1.1%, and 9.6%; complication rates of 7.1%, 10.1%, and 17.3%; and mean hospital costs of $31,977, $34,586, and $40,153 for patients aged 50-59, 60-69, and 70+ years, respectively.

CONCLUSIONS

While seizure-free outcomes of epilepsy surgery are excellent, there is an expected increase in morbidity and mortality with increasing age. Findings in this study on the safety and efficacy of epilepsy surgery in the older population may serve as a useful guide during preoperative decision-making and patient counseling.

Memory outcomes of temporal lobe surgery in adults aged over 45 years

OBJECTIVE

It is assumed that temporal lobe resection in older people is associated with worse seizure outcomes and potential postsurgical memory decline. We studied postsurgical memory development and surgical efficacy in patients over 45 years of age compared with younger patients.

METHODS

We studied 88 patients (51 male and 37 female) after temporal lobe surgery, which involved hippocampal resection. The patients were evaluated before surgery and in the first (72 patients) and/or third (57 patients) postsurgical year. The Wechsler Memory Scale III test was performed to evaluate the MQ postsurgical development. Engel's classification was used to evaluate the postsurgical seizure outcome.

RESULTS

The presurgical MQ (median 88) in ≥45 years age group was significantly lower than in both younger groups (median MQ = 100 for ≤30 years age group, p = 0.002; median MQ = 107 for 31-44 years age group, p = 0.002). Three years after the surgery, the MQ decreased significantly in ≤30 years age group (p = 0.012), while only non-significant MQ decline was observed in both older groups. We found no significant impact of age on the surgical outcome.

CONCLUSION

Higher age at the time of surgery does not significantly increase the risk for postsurgical memory decline; however, older patients are more likely to have lowered presurgical MQ. We did not find significant differences in the impact of surgery on seizure outcome among the age groups. Epilepsy surgery appears to be a safe and effective method in the age over 45 years even though an earlier surgery should be preferred.

Resective epilepsy surgery in patients aged 50years and older - a retrospective study regarding seizure outcome, memory performance, and psychopathology

PURPOSE

To assess clinical and demographic characteristics in two cohorts of elderly patients with drug-resistant focal epilepsy, undergoing resective epilepsy surgery (RES). Further, to determine seizure, neuropsychological, and mental health outcomes after RES and evaluate possible influencing factors.

METHODS

Consecutive patients aged ≥50 years with temporal lobe epilepsy (TLE) who underwent curative RES in the Hamburg epilepsy surgery program (2004-2017) were identified. Data were retrospectively analyzed. Seizure outcome was classified according to ILAE and Engel outcome scales in patients with first-time surgeries and with reoperations. Previously reported predictors of the seizure outcome were evaluated using regression analyses. Changes in verbal memory were assessed for patients with complete pre- and postoperative datasets (n=30) using repeated-measures analysis of variance. For evaluation of possible predictors of psychopathologic changes after RES a regression analysis was conducted.

RESULTS

Fifty-one elderly patients underwent RES of the temporal lobe, including twelve aged ≥60 years, and five with reoperations. After one year, 65% of the patients with first-time surgeries were seizure free and 91% had a favorable outcome. At last follow-up, 49% were seizure free since surgery. Three reoperated patients had an Engel I outcome. Seizure outcome was not dependent on age at surgery, duration of epilepsy, or other evaluated variables. There was no significant decline in the memory performance after surgery. Significant improvements in mental health were found.

CONCLUSION

RES for drug-resistant TLE is safe, effective, and improves mental health also in patients aged ≥ 50 years. Thus, it should be evaluated as the treatment of choice also in this age group.

Quality of life before and after epilepsy surgery: Age is just a number

BACKGROUND

In a rapidly aging population, it is critical to analyze if the quality of life (QOL) in patients with drug-resistant epilepsy (DRE) and the change in it after epilepsy surgery is dependent on the age at operation.

METHODS

A prospective registry-based retrospective cohort study including adults with a completed pre- and post-surgery Quality of Life in Epilepsy 10 (QOLIE-10) survey. Multivariable linear regression models analyzed the baseline, postoperative, or change in QOLIE-10 score.

RESULTS

We analyzed 416 patients (51% females) with the mean age of 39.6 (SD = 12.6) years at the time of surgery, including 100 (24%) individuals 50 years or older. The younger and older adults (dichotomized as <50 vs. ≥50 and <60 vs. ≥60) had comparable pre- and post-surgery QOLIE 10 total scores. The change in total and individual QOLIE-10 items score were comparable between the groups as well. Within group improvements in total QOLIE-10 score post-surgery was in younger as well as older groups. The linear regression models showed that age, regardless of parameterization (linear or dichotomized), was not related to pre-surgery, post-surgery, and change in QOLIE-10 score, both before and after adjustment for covariates. The change in QOLIE-10 score did not show correlation with age, whether seizure freedom or relative seizure reduction was used in the model.

CONCLUSION

With QOL, before or after surgery, being independent of a patient's age, our findings suggest that well-selected older adults and the elderly should be offered epilepsy surgery without concern for an inferior improvement in QOL compared to their younger counterparts.

Epilepsy duration and seizure outcome in epilepsy surgery: A systematic review and meta-analysis

Objective

To conduct a systematic review and meta-analysis on the effect of earlier or later resective epilepsy surgery on seizure outcome.

Methods

We searched the electronic databases PubMed, EMBASE, and Cochrane Library for studies investigating the association of epilepsy duration and seizure freedom after resective surgery. Two reviewers independently screened citations for eligibility and assessed relevant studies for risk of bias. We combined data in meta-analyses using a random effects model. We assessed the certainty of evidence according to Grading of Recommendations Assessment, Development and Evaluation (GRADE).

Results

Twenty-five studies were included, 12 of which had data suitable for meta-analyses. Comparing seizure outcome if epilepsy surgery was performed before vs after 2, 5, 10, and 20 years of epilepsy duration, and comparing epilepsy duration <5 years to >10 years, we found significant effects favoring shorter duration with risk differences ranging from 0.15 to 0.21 and risk ratios ranging from 1.20 to 1.33 (p < 0.01 for all comparisons). According to GRADE, we found low certainty of evidence favoring shorter epilepsy duration before surgery.

Conclusion

People with shorter epilepsy duration are more likely to be seizure-free at follow-up. Furthermore, there is a positive association between shorter duration and seizure freedom also for very long epilepsy durations. Patients who might benefit from epilepsy surgery should therefore be referred for presurgical assessments without further delay, regardless of epilepsy duration. The low certainty of evidence acknowledges concerns regarding study heterogeneity and possible residual confounding.

Surgery in patients with childhood-onset epilepsy: analysis of complications and predictive risk factors for a severely complicated course

OBJECT

To compare the occurrence of surgery-related complications in patients with childhood-onset focal epilepsy operated on in the paediatric or in the adult age. To investigate risk factors for surgery-related complications in the whole cohort, with special attention to age at surgery and severe morbidity.

METHODS

A cohort of 1282 patients operated on for childhood-onset focal epilepsy was retrospectively analysed. Occurrence of surgery-related complications, including a severely complicated course (SCC: surgical complication requiring reoperation and/or permanent neurological deficit and/or death), was compared between patients operated on in the paediatric age (<16 year-old; 452 cases) and, respectively, in adulthood (≥16 year-old; 830 cases). The whole cohort of patients was also evaluated for risk factors for a SCC.

RESULTS

At last contact (median follow-up 98 months), 74.5% of patients were in Engel's class I (78.0% of children and 73.0% of adults). One hundred patients (7.8%) presented a SCC (6.4% for children and 8.6% for adult patients). Postoperative intracranial haemorrhages occurred more frequently in adult cases. At multivariate analysis, increasing age at operation, multilobar surgery, resections in the rolandic/perirolandic and in insulo-opercular regions were independent risk factors for a SCC.

CONCLUSIONS

Surgery for childhood-onset focal epilepsy provides excellent results on seizures and an acceptable safety profile at any age. Nevertheless, our results suggest that increasing age at surgery is associated with an increase in odds of developing severe surgery-related complications. These findings support the recommendation that children with drug-resistant, symptomatic (or presumed symptomatic) focal epilepsy should be referred for a surgical evaluation as early as possible after seizure onset.

Time to push the age limit: Epilepsy surgery in patients 60 years or older

Objective

To summarize the existing literature on resective epilepsy surgery (RES) in older adults (≥60 years old) and examine seizure and neuropsychological outcomes in a single‐center large cohort of older adults undergoing RES and their comparison to a consecutive, younger (25‐ to45‐year‐old) adult population who underwent RES in routine clinical practice.

Methods

First, a comprehensive literature review was performed. Then, we identified older adults who underwent RES at our center (2000–2015). Outcome analysis was performed on patients who had ≥1 year of clinical follow‐up. A younger cohort of patients who underwent RES during the same period was selected for comparison. The 2 groups were compared with respect to demographic and disease variables as well as key clinical outcomes.

Results

Seizure outcomes on 58 older patients were reported in existing literature; 72% achieved Engel class I outcome ≥1 year postoperatively. Sixty‐four older adults underwent RES at our center, accounting for 2.8% of all RES during the study period. A total of 51 older adults (M_age = 65) among them had ≥1‐year clinical follow‐up; 80% achieved Engel I outcome after a mean follow‐up of 3.2 years. This was comparable to the 68% Engel class I outcome among 50 consecutive younger adults, despite later age of onset, longer epilepsy duration, and more comorbidities (all p < 0.001) among older adults. The majority (86%) of older adults were referred to our center after years of suffering from drug‐resistant epilepsy. There were no group differences in surgical complications. However, 1 older adult passed away post‐RES. There was no difference in post‐RES neuropsychological outcomes compared to younger adults, except significantly higher number of older adults showed a decline in confrontational naming.

Significance

RES in well‐selected older adults is a safe and effective therapy, and advanced age should not preclude consideration of surgical therapy in older adults with pharmacoresistant epilepsy.

Memory Rehabilitation in Patients with Epilepsy: a Systematic Review

Memory failure is a common clinical concern of patients with epilepsy and is associated with significant functional impairments. Thus, memory rehabilitation is of critical clinical importance. In this article, we aimed to systematically evaluate the efficacy of memory rehabilitation in patients with epilepsy. The Preferred Items for Systematic Reviews and Meta-Analyses (PRISMA) was used to guide searches, extraction and reporting of data in this review. PsycINFO, Medline and PsychBITE searches yielded 95 studies. Twelve papers met inclusion criteria, reporting outcomes of cognitive or behavioural interventions that specifically targeted the rehabilitation of memory in patients with epilepsy. Methodological rigour was rated using the Single-Case Experimental Design (SCED) scale for single-case studies and a modified version of the Downs and Black checklist for group studies. Twelve prospective studies, nine group (six pre-post design, one waitlist crossover, two randomised controlled trials) and three single-case studies were identified. Eleven of the studies included adults, eight of which involved adults with temporal lobe epilepsy (TLE). One paediatric study was identified. The quality of group studies ranged from 36% (poor) to 72% (good), using the modified Downs and Black checklist. Single-case studies were assessed using the SCED scale and assessed to range in quality from four to seven out to 11. Overall, memory rehabilitation was associated with improved memory function in all studies. Verbal memory outcomes were most commonly examined and associated with improvements. This review found that the level of evidence available to support rehabilitation of memory in patients with epilepsy was generally weak and inconsistent. Nevertheless, studies conducted to date, albeit of limited methodological quality, offer preliminary evidence that memory rehabilitation is associated with improvements in verbal memory in patients with temporal lobe epilepsy. Little is known about the efficacy of memory rehabilitation in patients with non-TLE, children, and other aspects of memory difficulties. Guidelines for future research are proposed.

Somatic complications of epilepsy surgery over 25 years at a single center

INTRODUCTION

Epilepsy surgery is an effective treatment for refractory focal epilepsy. Risks of surgery need to be considered when advising individuals of treatment options. We describe the frequency and nature of physical adverse events associated with epilepsy surgery in a single center.

MATERIAL AND METHODS

We reviewed the prospectively maintained records of adults who underwent epilepsy surgery at our center between 1990 and 2014 to identify peri/postsurgical adverse events. These were categorized into neurological deficits and those related to surgery (e.g. wound infections). Neurological deficits were categorized as expected or unexpected and into transient (≤3 months) or persistent (>3 months), RESULTS: There were 911 procedures with no peri-operative deaths. Persistent neurological adverse events were seen following 157 (17.2%) procedures. The most common persistent expected complication was quadrantanopia after temporal lobe resections (72/764, 9.4%). Unexpected persistent neurological complications occurred in 20 procedures (2.2%) and included: quadrantanopia (6, 0.7%); hemianopia (2, 0.2%); hemi/mono-paresis/sensory loss (9, 1%); dysphasia (10, 1%); frontalis muscle weakness (2, 0.2%); and oculomotor weakness (1, 0.1%). 106 surgery related adverse events occurred in 83 procedures, with severe infections requiring bone-flap removal in 24 (2.6%) procedures and intracranial infections in 8 (0.9%). The risk of post-resective severe infection increased by 4 fold (OR 4.32, 95% CI 2.1-8.9, p<0.001) with use of subdural EEG monitoring prior to resection. In consequence, in August 2011 we introduced antibiotic coverage in all individuals undergoing intracranial monitoring. Also, after August 2011 there was greater use of Stereo-EEG (SEEG) than subdural (OR 9.0 CI 0.36-224.2, p=0.18ns). One complicated by severe infection. Other surgical complications included haematoma (0.3%), hydrocephalus (0.3%) and CSF leak (1.2%). None had permanent complications.

CONCLUSIONS

Adverse event rates are similar to other series. Epilepsy surgery carries well defined surgical and neurological risks. The risks of somatic adverse events, in addition to neuropsychiatric and neuropsychological complications need to be made clear to individuals considering this treatment option.

Cognitive outcomes of temporal lobe epilepsy surgery in older patients

PURPOSE

To examine the cognitive risks of temporal lobe surgery in patients aged 50 years and older.

METHODS

We analysed data from 55 patients who underwent temporal lobe surgery (26 left-sided:29 right sided) from 1988 to 2012 at our centre. Pre-surgical and one year post-operative memory and naming capacity were compared to data obtained from two younger cohorts; 185 aged 18-30 and 220 aged 31-49.

RESULTS

Pre-operative memory impairments were most marked for the oldest cohort and were associated with a longer duration of epilepsy. Naming capacity improved with age and better performance was associated with a later age at epilepsy onset. Post-operative declines were largest in older patients, achieving statistical significance for verbal memory, naming and subjective ratings. Left temporal lobe resections carried the greatest risk of memory and naming decline. Cognitive outcomes were unrelated to seizure outcome, VIQ or mood.

CONCLUSION

Our findings indicate the cognitive risks of TLE surgery are greater for older patients. Cognitive outcomes need to be considered when assessing the efficacy of epilepsy surgery in older cohorts and pre-operative performance levels need to be taken into account.

Complications of epilepsy surgery in Sweden 1996–2010: a prospective, population-based study

OBJECT

Detailed risk information is essential for presurgical patient counseling and surgical quality assessments in epilepsy surgery. This study was conducted to investigate major and minor complications related to epilepsy surgery in a large, prospective series.

METHODS

The Swedish National Epilepsy Surgery Register provides extensive population-based data on all patients who were surgically treated in Sweden since 1990. The authors have analyzed complication data for therapeutic epilepsy surgery procedures performed between 1996 and 2010. Complications are classified as major (affecting daily life and lasting longer than 3 months) or minor (resolving within 3 months).

RESULTS

A total of 865 therapeutic epilepsy surgery procedures were performed between 1996 and 2010, of which 158 were reoperations. There were no postoperative deaths. Major complications occurred in 26 procedures (3%), and minor complications in 65 (7.5%). In temporal lobe resections (n = 523), there were 15 major (2.9%) and 41 minor complications (7.8%); in extratemporal resections (n = 275) there were 9 major (3.3%) and 22 minor complications (8%); and in nonresective procedures (n = 67) there were 2 major (3%) and 2 minor complications (3%). The risk for any complication increased significantly with age (OR 1.26 per 10-year interval, 95% CI 1.09–1.45). Compared with previously published results from the same register, there is a trend toward lower complication rates, especially in patients older than 50 years.

CONCLUSIONS

This is the largest reported prospective series of complication data in epilepsy surgery. The complication rates comply well with published results from larger single centers, confirming that epilepsy surgery performed in the 6 Swedish centers is safe. Patient age should be taken into account when counseling patients before surgery.

Long-term seizure and psychosocial outcomes after resective surgery for intractable epilepsy

Resective surgery is considered an effective treatment for refractory localization-related epilepsy. Most studies have reported seizure and psychosocial outcomes of 2-5 years postsurgery and a few up to 10 years. Our study aimed to assess long-term (up to 15 years) postsurgical seizure and psychosocial outcomes at our epilepsy center. The Henry Ford Health System Corporate Data Store was accessed to identify patients who had undergone surgical resection for localization-related epilepsy from 1993 to 2011. Demographics including age at epilepsy onset and surgery, seizure frequency before surgery, and pathology were gathered from electronic medical records. Phone surveys were conducted from May 2012 to January 2013 to determine patients' current seizure frequency and psychosocial metrics including driving and employment status and use of antidepressants. Surgical outcomes were based on Engel's classification (classes I and II=favorable outcomes). McNemar's tests, chi-square tests, two sample t-tests, and Wilcoxon two sample tests were used to analyze the relationships of psychosocial and surgical outcomes with demographic and surgical characteristics. A total of 470 patients had resective epilepsy surgery, and of those, 50 (11%) had died since surgery. Of the remaining, 253 (60%) were contacted with mean follow-up of 10.6±5.0years (27% of patients had follow-up of 15 years or longer). Of the patients surveyed, 32% were seizure-free and 75% had a favorable outcome (classes I and II). Favorable outcomes had significant associations with temporal resection (78% temporal vs 58% extratemporal, p=0.01) and when surgery was performed after scalp EEG only (85% vs 65%, p<0.001). Most importantly, favorable and seizure-free outcome rates remained stable after surgery over long-term follow-up [i.e., <5 years (77%, 41%), 5-10 years (67%, 29%), 10-15 years (78%, 38%), and >15 years (78%, 26%)]. Compared to before surgery, patients at the time of the survey were more likely to be driving (51% vs 35%, p<0.001) and using antidepressants (30% vs 22%, p=0.013) but less likely to be working full-time (23% vs 42%, p<0.001). A large majority of patients (92%) considered epilepsy surgery worthwhile regardless of the resection site, and this was associated with favorable outcomes (favorable=98% vs unfavorable=74%, p<0.001). The findings suggest that resective epilepsy surgery yields favorable long-term postoperative seizure and psychosocial outcomes.

Outcomes after resective epilepsy surgery in patients over 50 years of age in Sweden 1990-2009--a prospective longitudinal study

PURPOSE

Most epilepsy surgery candidates are young adults. Outcome reports after epilepsy surgery in patients ≥50 years are few and varying. The aim of this study was to describe patient characteristics of older compared to younger adults and analyse seizure, complication and vocational outcomes in a large population-based series.

METHODS

We analysed data from the Swedish National Epilepsy Surgery Register for 1990-2009 for patients ≥19 years at resective surgery who had completed two-year follow-up. Variables studied were seizure outcome, histo-pathological diagnoses, complications and vocational outcome. Data from patients ≥50 years and 19-49 years at surgery were compared.

RESULTS

558 Adults underwent resective epilepsy surgery 1990-2009 and had two-year follow-up. 12% of the adults (67 patients) were ≥50 years at surgery. Patients ≥50 had longer epilepsy duration, more often had mesial sclerosis and less often had neurodevelopmental tumours and cortical malformations. The proportion of seizure-free patients at two-year follow-up did not differ between those ≥50 and 19-49 years (61% versus 61% seizure-free last year, 48% versus 43% completely seizure-free since surgery), neither did the occurrence of major complications (3% in both groups). The vocational situation was mainly stable between baseline and two-year follow-up in both groups, although older patients were less often employed than younger.

CONCLUSION

12% of adults in the Swedish series were ≥50 years at epilepsy surgery. Seizure outcome was as good for older as for younger adults, and there was no difference in the occurrence of major complications. This constitutes important information in the presurgical counselling process.

Clinical predictors of 2-year outcome of resective epilepsy surgery in adults with refractory epilepsy: a cohort study

OBJECTIVES

Resective epilepsy surgery is currently a standard treatment for intractable epilepsy. Seizure freedom and discontinuation of antiepileptic drugs are the ultimate goals of epilepsy treatment. This study was carried out to delineate (1) possible differences in the success rate of epilepsy surgery 6 and 24 months after surgery; and (2) the clinical predictors of a good response to surgery.

SETTING

This is a cohort study performed at a tertiary care unit of a university hospital.

PARTICIPANTS

In this cohort study, 189 adults with intractable epilepsy who underwent epilepsy surgery were included. We collected clinical data at three time points, that is, preoperative and 6 and 24 months after surgery.

PRIMARY AND SECONDARY OUTCOME MEASURES

Engel class I-IV classification was the primary outcome measure of epilepsy surgery. The authors statistically adjusted Engel class I-IV classification for postoperative changes in antiepileptic drugs and used this new classification as a secondary outcome variable.

RESULTS

The success rate was 78.8% 6 months after surgery and increased to 88.3% 24 months after surgery. This success rate was reflected not only by the reduced number of seizures postsurgery, but also by a reduced dosage and use of antiepileptic drugs. Logistic regression analysis showed that a successful outcome of surgery is predicted by having temporal rather than extratemporal lobe epilepsy and less than nine presurgery seizures per month, while a positive familial history of epilepsy, younger age and dysphoric symptoms, the first 3 months after surgery, significantly worsened the outcome of surgery. Duration of illness, age at onset, epilepsy location, type of lesions and the presence of psychosis were not significant in predicting treatment outcome.

CONCLUSIONS

These findings have clinical relevance in that a better selection of patients based on the significant clinical predictors will increase the success rate of epilepsy surgery and treatment.