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

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

Epilepsy control following intracranial monitoring without resection in young children

Purpose: Intracranial monitoring (IM) is a key diagnostic procedure for select patients with treatment‐resistant epilepsy (TRE). Seizure focus resection may improve seizure control in both lesional and nonlesional TRE. IM itself is not considered to have therapeutic potential. We describe a cohort of patients with improved seizure control following IM without resective surgery. Methods: Over 12.5 years, 161 children underwent 496 surgeries including intracranial monitoring. We retrospectively reviewed the patients’ charts, operative reports, and radiologic scans, under an institutional review board–approved protocol. Key Findings: Seventeen patients underwent only IM, without additional resective surgery, and seven had a dramatic improvement in their epilepsy; six of the seven patients are seizure‐free (Engel class I), and one rarely has seizures (Engel class II). All seven patients had frequent seizures that led to IM: either daily (five patients) or 1–2 per week (two patients). The mean age (± standard deviation, SD) at seizure onset was 1.6 ± 1.3 years (range 0.5–4 years). Etiologies were tuberous sclerosis (3 patients), trauma (1 patient), and unknown (3 patients). Mean age at surgery (± SD) was 4.1 ± 2 years (range 1–7 years), and duration of epilepsy 2.5 ± 1.1 years (range 0.5–4 years). Duration of IM was 11.7 ± 5.6 days (5–19 days). Six patients had bilateral and one unilateral invasive electrodes. At last follow‐up, four patients required fewer antiepileptic drugs (AEDs), one had the same medication but a higher dose, and two patients were taking additional AEDs. Follow‐up was 30.6 ± 9.5 months (range 19–41 months). Significance: Although uncommon, patients with TRE may improve after IM alone. The explanation for this observation remains unclear; however, perioperative medications including steroids, direct cortical manipulation, or other factors may influence the epileptogenic network.     

Long-term outcome and predictors of resective surgery prognosis in patients with refractory extratemporal epilepsy

PurposeWe analyzed the long-term postoperative outcome and possible predictive factors of the outcome in surgically treated patients with refractory extratemporal epilepsy.MethodsWe retrospectively analyzed 73 patients who had undergone resective surgery at the Epilepsy Center Brno between 1995 and 2010 and who had reached at least 1 year outcome after the surgery. The average age at surgery was 28.3 ± 11.4 years. Magnetic resonance imaging (MRI) did not reveal any lesion in 24 patients (32.9%). Surgical outcome was assessed annually using Engel's modified classification until 5 years after surgery and at the latest follow-up visit.ResultsFollowing the surgery, Engel Class I outcome was found in 52.1% of patients after 1 year, in 55.0% after 5 years, and in 50.7% at the last follow-up visit (average 6.15 ± 3.84 years). Of the patients who reached the 5-year follow-up visit (average of the last follow-up 9.23 years), 37.5% were classified as Engel IA at each follow-up visit. Tumorous etiology and lesions seen in preoperative MRI were associated with significantly better outcome (p = 0.035; p < 0.01). Postoperatively, 9.6% patients had permanent neurological deficits.ConclusionSurgical treatment of refractory extratemporal epilepsy is an effective procedure. The presence of a visible MRI-detected lesion and tumorous etiology is associated with significantly better outcome than the absence of MRI-detected lesion or other etiology.     

Preoperative estimation of seizure control after resective surgery for the treatment of epilepsy

PurposePredicting seizure control after epilepsy surgery is difficult. The objectives of this work are: (a) to estimate the value of surgical procedure, presence of neuroimaging abnormalities, need for intracranial recordings, resection lobe, pathology, durations of epilepsy and follow-up period to predict postsurgical seizure control after epilepsy surgery and (b) to provide empirical estimates of successful outcome after different combinations of the above factors in order to aid clinicians in advising patients presurgically about the likelihood of success under their patients’ individual circumstances.MethodsWe report postsurgical seizure control from all 243 patients who underwent resective surgery for epilepsy at King's College Hospital between 1999 and 2011. Among the 243 patients, 233 had lobar or sub-lobar resections, 8 had multilobar resections and 2 had excision of a hypothalamic hamartoma. We examined the relation between postsurgical seizure control and type of surgical procedure, presence of neuroimaging abnormalities, pathology, resection lobe and the need of intra-cranial electrodes to identify seizure onset.ResultsAmong the 243 patients, 126 (52%) enjoyed outcome grade I, 40 (16%) had grade II, 51 (21%) had grade III and 26 (11%) had grade IV (mean follow-up 41.1 months). Normal neuroimaging or need for intracranial recordings was not associated with poorer outcome. Patients undergoing temporal resections showed better outcome than those with frontal resections, due to the poor outcome seen in frontal patients with normal neuroimaging. Among temporal resections, there was no difference in outcome between patients with and without neuroimaging abnormalities. Among patients with lesions on imaging, temporal and frontal resections showed similar outcomes. Likelihood of favourable outcome under the patient's individual circumstances was estimated by the tables provided. There was an 8–9% decrease in the percentage of grade I between follow-up at 12 and >36 months.ConclusionOverall, nearly 70% of patients undergoing resective surgery enjoy favourable post-surgical seizure control. Normal neuroimaging should not discourage surgery in temporal patients but is a negative prognostic sign in normal MRI frontal patients. There were no statistical differences in outcome between patients with neuroimaging lesions in frontal or temporal lobes.     

Intra-operative cortical motor mapping using subdural grid electrodes in children undergoing epilepsy surgery evaluation and comparison with the conventional extra-operative motor mapping

Objectives

The objective of this study was to review our experience with intra-operative “train of five” stimulation using subdural grid for motor mapping in children undergoing epilepsy surgery evaluation.

The role of intracranial electrode reevaluation in epilepsy patients after failed initial invasive monitoring

PURPOSE: Intracranial electrode recording often provides localization of the site of seizure onset to allow epilepsy surgery. In patients whose invasive evaluation fails to localize seizure origin, the utility of further invasive monitoring is unknown. This study was undertaken to explore the hypothesis that a second intracranial investigation is selected patients warrants consideration and can lead to successful epilepsy surgery. METHODS: A series of 110 consecutive patients with partial epilepsy who had undergone intracranial electrode evaluation (by subdural strip, subdural grid, and/or depth electrodes) between February 1992 and October 1998 was retrospectively analyzed. Of these, failed localization of seizure origin was thought to be due to sampling error in 13 patients. Nine of these 13 patients underwent a second intracranial investigation. RESULTS: Reevaluation with intracranial electrodes resulted in satisfactory seizure-onset localization in seven of nine patients, and these seven had epilepsy surgery. Three frontal, two temporal, and one occipital resection as well as one multiple subpial transection were performed. Six patients have become seizure free, and one was not significantly improved. The mean follow-up is 2.8 years. There was no permanent morbidity. CONCLUSIONS: In selected patients in whom invasive monitoring fails to identify the site of seizure origin, reinvestigation with intracranial electrodes can achieve localization of the region of seizure onset and allow successful surgical treatment.     

Levetiracetam efficacy in refractory partial-onset seizures,especially after failed epilepsy surgery

PURPOSE: We conducted a retrospective study to evaluate the efficacy of levetiracetam as adjunctive therapy in patients with localization-related epilepsy, and specifically in the subset of patients for whom epilepsy surgery failed. METHODS: Eighty-two patients with uncontrolled partial-onset seizures treated with levetiracetam were identified; epilepsy surgery had failed for 21 (25.6%; group I), and 61 (74.4%) had no prior surgery (group II). Group I and group II patients were comparable in age (mean, 40.7 vs. 41.5 years) and age at seizure onset (mean, 14.4 vs. 18.2 years). Patients who had >/=50% reduction in seizure frequency were considered responders; the remaining patients were considered nonresponders. RESULTS: In patients (group I) for whom surgery had failed, responder rate was 76.1% (16 of 21), including 10 (47.6%) patients who became seizure free. In nonsurgical patients (group II), responder rate was 34.3% (21 of 61), including nine (14.7%) patients who became seizure free. In group I, 11 (91.6%) of 12 temporal resection patients were responders, of whom eight were seizure free; of the remaining nine operated (extratemporal) patients, five (55.5%) were responders, and two were seizure free. In three responders, all in group I, a severe, delayed psychotic syndrome developed 4 to 9 months after levetiracetam introduction, leading to its discontinuation. CONCLUSIONS: These findings suggest that adjunctive levetiracetam therapy should be considered early after failed epilepsy surgery, especially after temporal resection, and may have implications for its use before surgical intervention. Patients should be under close psychiatric observation in this clinical setting.     

Treatment algorithms in refractory partial epilepsy

An algorithm is a step-by-step procedure for solving a problem or accomplishing some end....in a finite number of steps. ( Merriam-Webster, 2009 ). Medical algorithms are decision trees to help with diagnostic and therapeutic decisions. For the treatment of epilepsy there is no generally accepted treatment algorithm, as individual epilepsy centers follow different diagnostic and therapeutic guidelines. This article presents two algorithms to guide decisions in the treatment of refractory partial epilepsy. The treatment algorithm describes a stepwise diagnostic and therapeutic approach to intractable medial temporal and neocortical epilepsy. The surgical algorithm guides decisions in the surgical treatment of neocortical epilepsy.     

难治性癫痫外科治疗的长期效果:一项6年随访研究结果

目的总结分析难治性癫痫外科治疗的方法及效果,为进一步的临床实践提供指导。方法综合临床症状学、神经电生理和神经影像学等方法,对66例难治性癫痫患者进行致痫灶定位和外科手术治疗,术后进行长期随访,平均随访时间为6年。结果 1例患者在随访期间因意外窒息死亡,余结果如下:谭启富标准:满意22例(33.8%),显著改善33例(50.8%),良好6例(9.2%),较差2例(3.1%),无改善2例(3.1%);Engel标准:Ⅰ级21例(32.3%),Ⅱ级13例(20.0%),Ⅲ级24例(36.9%),Ⅳ级7例(7.8%)。术后出现的并发症有偏瘫、失语、感染等,但均在短期内恢复。结论综合临床症状、神经电生理和神经影像学检查,可以精确定位癫痫患者的致痫灶,进一步选择合适的手术方法可以使难治性癫痫的外科治疗获得良好的效果。     

Depth versus subdural temporal electrodes revisited: Impact on surgical outcome after resective surgery for epilepsy

Objective

To study retrospectively the impact of electrode modality (subdural or depth electrodes) during presurgical assessment on surgical outcome after temporal lobectomy.

Consideration of epilepsy surgery in adults should be independent of age

Objectives

Epilepsy surgery is performed less frequently in persons over 45 years of age than in younger individuals, probably reflecting biases among patients, referring physicians and neurologists.

Methods

We report on a clinically heterogenous cohort of patients aged 45 years or older who underwent epilepsy surgery for medically intractable epilepsy.

Results

Over a 15-year period, 42 patients with a mean duration of epilepsy of 27.3 years underwent elective surgery. The mean follow-up period was 48 months. Thirty-two patients had an Engel class I outcome, of which 23 were totally seizure-free (Ia). Six patients had a class II outcome (rare disabling seizures), one had a class III outcome (worthwhile improvement), and three had a class IV outcome (no worthwhile improvement). The majority of patients reported an improved quality of life and satisfaction with the epilepsy surgery. A subjective improvement in cognition was reported in 7 patients while a decline was reported in 10 patients. New neuropsychiatric difficulties were reported in three patients while three patients reported improved anxiety after surgery. Only one patient became newly employed after surgery while 23 returned to driving. Permanent complications occurred in four patients (thalamic infarct during a Wada test (n = 1) and asymptomatic visual field defect (n = 3)).

Conclusions

We report a favorable outcome from epilepsy surgery in a large series of older adults and conclude that age per se is not a contraindication to epilepsy surgery. We emphasize the lack of correlation between outcome from surgery and pre-operative duration of epilepsy.     

A survey of adult and pediatric epilepsy surgery in the United Kingdom

All consultant epilepsy neurosurgeons were asked to prospectively record all epilepsy surgery procedures carried out at their center between April 2010 and March 2011. Figures were compared to a previous survey completed in 2000. Of a total of 710 procedures, temporal lobe surgery was the most common resective surgery. Although extratemporal lesional surgery was less common, vagus nerve stimulator (VNS) implantation accounted for almost half the procedures. The numbers for all surgical procedures, with the exception of VNS implantations, had decreased. This decrease may represent a global rather than a regional phenomenon. Further longitudinal multinational data on epilepsy surgery is required to confirm or refute this theory.     

Contralateral MRI abnormalities in candidates for hemispherectomy for refractory epilepsy

Purpose: To assess the impact of contralateral magnetic resonance imaging (MRI) findings on seizure outcome after hemispherectomy for refractory epilepsy. Methods: We retrospectively reviewed 110 children, 0.4–18 (median 5.9) years of age, who underwent hemispherectomy for severe refractory epilepsy at Cleveland Clinic Children’s Hospital. In children with contralateral (as well as ipsilateral) MRI findings appreciated preoperatively, the decision to proceed to surgery was based on other features concordant with the side with the most severe MRI abnormality, including ipsilateral epileptiform discharges, lateralizing seizure semiology, and side of hemiparesis. Results: We retrospectively observed contralateral MRI abnormalities (predominantly small hemisphere, white matter loss or abnormal signal, or sulcation abnormalities) in 81 patients (74%), including 31 of 43 (72%) with malformations of cortical development (MCD), 31 of 42 (73%) with perinatal injury from infarction or hypoxia, and 15 of 25 (60%) with Rasmussen’s encephalitis, Sturge‐Weber syndrome, or posttraumatic encephalomalacia. Among 84 children (76%) with lesions that were congenital or acquired pre‐ or perinatally, 67 (83%) had contralateral MRI abnormalities (p = 0.02). Contralateral findings were subjectively judged to be mild or moderate in 70 (86%). At follow‐up 12–84 (median 24) months after surgery, 79% of patients with contralateral MRI abnormalities were seizure‐free compared to 83% of patients without contralateral MRI findings, with no differences based on etiology group or type or severity of contralateral MRI abnormality. Discussion: MRI abnormalities, usually mild to moderate in severity, were seen in the contralateral hemisphere in the majority of children who underwent hemispherectomy for refractory epilepsy due to various etiologies, especially those that were congenital or early acquired. The contralateral MRI findings, always much less prominent than those in the ipsilateral hemisphere, did not correlate with seizure outcome and may not contraindicate hemispherectomy in otherwise favorable candidates.     

Prevalence and predictors of subclinical seizures during scalp video-EEG monitoring in patients with epilepsy

Objective: This study first aimed to establish the prevalence and predictors of subclinical seizures in patients with epilepsy undergoing video electroencephalographic monitoring, then to evaluate the relationship of sleep/wake and circadian pattern with subclinical seizures. Methods: We retrospectively reviewed the charts of 742 consecutive patients admitted to our epilepsy center between July 2012 and October 2014. Demographic, electro-clinical data and neuroimage were collected. Results: A total of 148 subclinical seizures were detected in 39 patients (5.3%) during video electroencephalographic monitoring. The mean duration of subclinical seizures was 47.18 s (range, 5–311). Pharmacoresistant epilepsy, abnormal MRI and the presence of interictal epileptiform discharges were independently associated with subclinical seizures in multivariate logistic regression analysis. Subclinical seizures helped localizing the presumed epileptogenic zone in 24 (61.5%) patients, and suggested multifocal epilepsy in five (12.8%). In addition, subclinical seizures occurred more frequently in sleep and night than wakefulness and daytime, respectively, and they were more likely seen between 21:00–03:00 h, and less likely seen between 09:00–12:00 h. Thirty patients (76.9%) had their first subclinical seizures within the first 24 h of monitoring while only 7.7% of patients had their first subclinical seizures detected within 20 min. Conclusion: Subclinical seizures are not uncommon in patients with epilepsy, particularly in those with pharmacoresistant epilepsy, abnormal MRI or interictal epileptiform discharges. Subclinical seizures occur in specific circadian patterns and in specific sleep/wake distributions. A 20-min VEEG monitoring might not be long enough to allow for their detection.     

Psychotic disorders in Argentine patients with refractory temporal lobe epilepsy: A case–control study

The issue of psychotic disorders in epilepsy has given rise to great controversy among professionals; however, there are not many studies in this area and the physiopathological mechanisms remain unknown. The aim of this study was to describe the spectrum of psychotic disorders in an Argentine population with refractory temporal lobe epilepsy (RTLE) and to determine the risk factors associated with psychotic disorders. Clinical variables of the epileptic syndrome were compared among a selected population with RTLE with and without psychotic disorders (DSM-IV/Ictal Classification of psychoses). Logistic regression was performed. Sixty-three patients with psychotic disorders (Psychotic Group, PG) and 60 controls (Control Group, CG) were included. The most frequent psychotic disorders were brief psychotic episodes (35%) (DSM-IV) and interictal psychosis (50%) (Ictal Classification). Risk factors for psychotic disorders were bilateral hippocampal sclerosis, history of status epilepticus, and duration of epilepsy greater than 20 years.     

Long-term seizure outcome and its predictors in patients with recurrent seizures during the first year aftertemporal lobe resective epilepsy surgery

Purpose: The existing data on the implications of the characteristics of seizures that recur during the first year following epilepsy surgery on subsequent seizure outcome are conflicting. We investigated the impact of recurrent seizures in the first postoperative year and their attributes on long‐term seizure outcome. Methods: We studied the postoperative courses of 492 patients who had completed two or more years of follow‐up after temporal lobe resective epilepsy surgery. We used Kaplan‐Meier survival curves to define long‐term seizure outcome and assessed the predictive value of recurrent seizure characteristics on the outcome by univariate and multivariate proportional hazards regression models. Key Findings: In our patients, seizure recurrences during the first postoperative year, irrespective of the attributes of recurrent seizures (such as provoked vs. unprovoked, and timing and number of recurrences), imparted fourfold to sevenfold increased hazards for continued seizures beyond the first postoperative year. Although patients with complex partial seizures with or without secondary generalized tonic–clonic seizures (CPS/GTCS) had a sixfold increased risk, those with auras alone had only a borderline risk for seizures beyond the first postoperative year. In the multivariate model, CPS/GTCS as the predominant seizure type and three or more seizure recurrences during the first postoperative year independently predicted unfavorable long‐term seizure outcome. Significance: Our study provides valuable information that is helpful in prognosticating and counseling patients, and in making rational decisions on the withdrawal of antiepileptic drugs following surgery. Our findings enhance the general understanding of the etiopathogenesis of surgical failure.