Sandra Dewar

Referral pattern for epilepsy surgery after evidence-based recommendations: a retrospective study.

Background: Class I evidence for surgical effectiveness in refractory temporal lobe epilepsy (TLE) in 2001 led to an American Academy of Neurology practice parameter in 2003 recommending “referral to a surgical epilepsy center on failing appropriate trials of first-line antiepileptic drugs.” We examined whether this led to a change in referral patterns to our epilepsy center. Methods: We compared referral data for patients with TLE at our center for 1995 to 1998 (group 1, n = 83) and 2005 to 2008 (group 2, n = 102) to determine whether these recommendations resulted in a change in referral patterns for surgical evaluation. Patients with brain tumors, previous epilepsy surgery evaluations, or brain surgery (including epilepsy surgery) were excluded. Results: We did not find a difference between the groups in the duration from the diagnosis of habitual seizures to referral (17.1 ± 10.0 vs 18.6 ± 12.6 years, p = 0.39) or the age at the time of evaluation (34.1 ± 10.3 vs 37.0 ± 11.8 years, p = 0.08). However, there was a difference in the distributions of age at evaluation (p = 0.03) and the duration of pharmacotherapy (p = 0.03) between the groups, with a greater proportion of patients in group 2 with drug-resistant epilepsy both earlier and later in their treatment course. Nonepileptic seizures were referred significantly earlier than TLE in either group or when combined. Conclusions: Our analysis does not identify a significantly earlier referral for epilepsy surgery evaluation as recommended in the practice parameter, but suggests a hopeful trend in this direction.

Long-term follow-up after temporal lobe resection for lesions associated with chronic seizures.

A follow-up study was conducted on 60 patients who had standard en bloc anterior temporal lobe resection, including mesiotemporal structures, as treatment for temporal lobe lesions associated with chronic, medically intractable seizures. Lesions were identified as glial tumors, hamartomas, or vascular malformations. Long-term outcome was assessed in terms of seizure frequency and certain psychosocial sequelae. Seizure onset occurred at an average age of 15 years (median = 13.5 years), and patients experienced seizures for an average of 13 years prior to surgery. The mean time of follow-up was 8.4 years postsurgery (median = 6 years). The Kaplan-Meier curve at median follow-up showed a seizure-free rate of 80%. Late seizure recurrence was documented for three patients; two had been seizure-free for 10 years and one for 15 years after surgery, before re-onset of seizures in the absence of tumor recurrence. A prolonged history of seizures prior to surgery was associated with a poorer seizure outcome (p = 0.061, suggesting that secondary epileptogenesis at sites distant to the lesion may develop with years of uncontrolled seizures. There was a low tumor recurrence rate of 3.3% (two cases). The psychosocial outcome was generally good, with 67% working or engaged in educational studies, and improvement noted in 59% of cases for one or more of the psychosocial factors investigated. This study confirms that anterior temporal lobe resection for temporal lesions associated with chronic seizures is a successful treatment with a high seizure-free rate following surgery and good psychosocial outcome.

Patient attitudes about treatments for intractable epilepsy

OBJECTIVE The goals of this study were to understand patient attitudes about the treatment of medically intractable epilepsy and to document potential barriers limiting patient access to the surgical treatment of epilepsy, highlighting the attitudes of adolescents and minorities. METHODS Focus groups of adults with intractable epilepsy (n=10), adolescents with intractable epilepsy (n=4), parents of adolescents with intractable epilepsy (n=4), and African-Americans with intractable epilepsy (n=6) were conducted at UCLA, Los Angeles, California. RESULTS Patients with intractable epilepsy communicated frustration with their continued disability despite trials of new medications. Their perceptions of the risks of the surgical treatment of epilepsy were exaggerated. Patients felt that their health care providers did not provide adequate information about epilepsy and portrayed epilepsy surgery negatively. CONCLUSIONS This study illuminated several factors that could change patient attitudes and help improve patient access to the surgical treatment of epilepsy, especially among minorities and adolescents.

A consensus-based approach to patient safety in epilepsy monitoring units: Recommendations for preferred practices

Patients in an epilepsy monitoring unit (EMU) with video-EEG telemetry have a risk for seizure emergencies, injuries and adverse events, which emphasizes the need for strategies to prevent avoidable harm. An expert consensus process was used to establish recommendations for patient safety in EMUs. Workgroups analyzed literature and expert opinion regarding seizure observation, seizure provocation, acute seizures, and activity/environment. A Delphi methodology was used to establish consensus for items submitted by these workgroups. Fifty-three items reached consensus and were organized into 30 recommendations. High levels of agreement were noted for items pertaining to orientation, training, communication, seizure precautions, individualized plans, and patient/family education. It was agreed that seizure observation should include direct observation or use of closed-circuit camera. The use of continuous observation was strongest in patients with invasive electrodes, at high risk for injury, or undergoing AED withdrawal. This process provides a first step in establishing EMU safety practices.

The evolution of epilepsy surgery between 1991 and 2011 in nine major epilepsy centers across the United States, Germany, and Australia.

Epilepsy surgery is the most effective treatment for select patients with drug‐resistant epilepsy. In this article, we aim to provide an accurate understanding of the current epidemiologic characteristics of this intervention, as this knowledge is critical for guiding educational, academic, and resource priorities.

Design considerations for a multicenter randomized controlled trial of early surgery for mesial temporal lobe epilepsy

Purpose:  To describe the trial design for the multicenter Early Randomized Surgical Epilepsy Trial (ERSET). Patients with pharmacoresistant epilepsy are generally referred for surgical treatment an average of two decades after onset of seizures, often too late to avoid irreversible disability. ERSET was designed to assess the safety and efficacy of early surgical intervention compared to continued pharmacotherapy.

Intracranial electrode monitoring for seizure localization: indications, methods and the prevention of complications.

&NA; Surgery is a successful method of treatment for certain epilepsies. Patient evaluation is directed towards seizure classification and localization. In most cases patients are able to progress from a noninvasive evaluation utilizing extracranial electrodes directly to resective surgery. In a few complex situations patient evaluation requires the placement of intracranial electrodes for accurate localization of the epileptogenic focus. The placement of intracranial electrodes is a surgical procedure which carries significant risk. Meticulous multidisciplinary care is required to achieve a safe and successful surgical outcome. Astute nursing care is pivotal to the success of intracranial monitoring and essential to the prevention of complications.

Epileptogenic temporal cavernous malformations: Operative strategies and postoperative seizure outcomes

Operative treatment of epileptogenic cavernous malformations (CM) continues under debate. Most studies focus on surgery for supratentorial CM in general. For temporal lobe CM, surgical decision-making concerns in particular whether to perform lesionectomy alone or the additional excision of mesial temporal structures. The purpose of this case series was to evaluate operative strategies used to treat epileptogenic temporal CM and to report resultant postoperative seizure outcomes. Twelve consecutive cases of patients with medically intractable epilepsy who underwent operation for temporal CM between 1996 and 2006 were retrospectively reviewed. When the temporal CM directly invaded the hippocampus or amygdala, the affected structures were resected in addition to the lesion; when the CM was located in the superficial temporal cortex, and there was no radiographic evidence of hippocampal sclerosis, lesionectomy alone was done; with CM located between the superficial temporal cortex and the mesial temporal region, other factors were considered in decision-making, such as lesion proximity to the deep mesiotemporal structures and preoperative epilepsy duration. For six of the twelve patients, extended lesionectomy (EL) alone was done; for the other six, tailored anteromedial temporal resection with hippocampectomy and/or amygdalectomy was performed in addition to EL. Postoperatively, 11 patients - all with preoperative VEM demonstrating electroclinical seizure patterns concordant with lesion location - were seizure-free. We conclude that epileptogenic temporal CM are surgically remediable, when approached with the above operative strategies and presurgical VEM. On the basis of these postoperative seizure control results, we recommend consideration of concurrent resection of mesial temporal structures with EL for certain temporal CM.

Perceptions of epilepsy surgery: a systematic review and an explanatory model of decision-making.

BACKGROUND Clear evidence supports the benefits of surgery over medical therapy for patients with refractory focal epilepsy. Surgical procedures meet the needs of fewer than 2% of those eligible. Referral to a tertiary epilepsy center early in the course of disease is recommended; however, patients live with disabling and life-threatening seizures for an average of 22years before considering surgical treatment. Reasons for this treatment gap are unclear. PURPOSE A critical analysis of the literature addressing perceptions of surgical treatment for epilepsy is placed in the context of a brief history and current treatment guidelines. Common conceptual themes shaping perceptions of epilepsy surgery are identified. DATA SOURCES Data sources used for this study were PubMed-MEDLINE and PsycINFO from 2003 to December 2013; hand searches of reference lists. DATA SYNTHESIS Nine papers that addressed patient perceptions of surgery for epilepsy and three papers addressing physician attitudes were reviewed. Treatment misperceptions held by both patients and physicians lead to undertreatment and serious health consequences. Fear of surgery, ignorance of treatment options, and tolerance of symptoms emerge as a triad of responses central to weighing treatment risks and benefits and, ultimately, to influencing treatment decision-making. Our novel explanatory framework serves to illustrate and explain relationships among contributory factors. LIMITATION Comparisons across studies are limited by the heterogeneity of study populations and by the fact that no instrument has been developed to consistently measure disability in refractory focal epilepsy. CONCLUSION Exploring the components of decision-making for the management of refractory focal epilepsy from the patients perspective presents a new angle on a serious contemporary challenge in epilepsy care and may lead to explanation as to why there is reluctance to embrace a safe and effective treatment.

Multimodal data and machine learning for surgery outcome prediction in complicated cases of mesial temporal lobe epilepsy

BACKGROUND This study sought to predict postsurgical seizure freedom from pre-operative diagnostic test results and clinical information using a rapid automated approach, based on supervised learning methods in patients with drug-resistant focal seizures suspected to begin in temporal lobe. METHOD We applied machine learning, specifically a combination of mutual information-based feature selection and supervised learning classifiers on multimodal data, to predict surgery outcome retrospectively in 20 presurgical patients (13 female; mean age±SD, in years 33±9.7 for females, and 35.3±9.4 for males) who were diagnosed with mesial temporal lobe epilepsy (MTLE) and subsequently underwent standard anteromesial temporal lobectomy. The main advantage of the present work over previous studies is the inclusion of the extent of ipsilateral neocortical gray matter atrophy and spatiotemporal properties of depth electrode-recorded seizures as training features for individual patient surgery planning. RESULTS A maximum relevance minimum redundancy (mRMR) feature selector identified the following features as the most informative predictors of postsurgical seizure freedom in this studys sample of patients: family history of epilepsy, ictal EEG onset pattern (positive correlation with seizure freedom), MRI-based gray matter thickness reduction in the hemisphere ipsilateral to seizure onset, proportion of seizures that first appeared in ipsilateral amygdala to total seizures, age, epilepsy duration, delay in the spread of ipsilateral ictal discharges from site of onset, gender, and number of electrode contacts at seizure onset (negative correlation with seizure freedom). Using these features in combination with a least square support vector machine (LS-SVM) classifier compared to other commonly used classifiers resulted in very high surgical outcome prediction accuracy (95%). CONCLUSIONS Supervised machine learning using multimodal compared to unimodal data accurately predicted postsurgical outcome in patients with atypical MTLE.