Surgery For Refractory Epilepsy Research Articles

CLINICAL AND SURGICAL APPROACH TO EPILEPSY REFRACTORY

Refractory epilepsy is characterized by the persistence of epileptic seizures even after adequate use of at least two antiepileptic drugs. This condition represents a significant challenge in the treatment of epilepsy, requiring a more assertive clinical and, in some cases, surgical approach. This study aims to review and explore the clinical and surgical approach to refractory epilepsy, highlighting the available treatment options, indications, benefits and challenges faced by patients and health professionals. This is a bibliographic review, using qualitative premises, with the PubMed, Scopus, Web of Science and Scielo databases. To better refine the research, the health descriptors “epilepsy”, “surgical treatment”, “neurostimulation” and “refractory epilepsy” were used. The clinical approach to refractory epilepsy involves careful assessment of the patient, including a detailed clinical history, complete physical examination and complementary tests such as electroencephalogram (EEG), magnetic resonance imaging (MRI) and computed tomography (CT) of the brain. The aim is to identify the origin of the epileptic seizures and determine the best therapeutic strategy. Clinical treatment usually involves optimizing drug therapy, with adjustments to the doses of existing drugs or the introduction of new drugs. However, in many cases, the response to drug treatment is unsatisfactory, leading to consideration of surgical options. Surgery for refractory epilepsy can include removing the brain tissue responsible for epileptic seizures (temporal lobectomy, focal resection, etc.), deep brain stimulation or other less invasive techniques. These procedures aim to reduce the frequency and severity of epileptic seizures, improving the patient’s quality of life. The approach to refractory epilepsy requires a multidisciplinary and individualized assessment, taking into account the clinical characteristics and specific needs of each patient. Although clinical treatment is the first line of approach, surgery can be a viable option for those who do not respond adequately to antiepileptic drugs. It is essential that patients with refractory epilepsy are referred to specialized centers for a complete and appropriate evaluation of their case.

High frequency oscillation network dynamics predict outcome in non-palliative epilepsy surgery.

High frequency oscillations are a promising biomarker of outcome in intractable epilepsy. Prior high frequency oscillation work focused on counting high frequency oscillations on individual channels, and it is still unclear how to translate those results into clinical care. We show that high frequency oscillations arise as network discharges that have valuable properties as predictive biomarkers. Here, we develop a tool to predict patient outcome before surgical resection is performed, based on only prospective information. In addition to determining high frequency oscillation rate on every channel, we performed a correlational analysis to evaluate the functional connectivity of high frequency oscillations in 28 patients with intracranial electrodes. We found that high frequency oscillations were often not solitary events on a single channel, but part of a local network discharge. Eigenvector and outcloseness centrality were used to rank channel importance within the connectivity network, then used to compare patient outcome by comparison with the seizure onset zone or a proportion within the proposed resected channels (critical resection percentage). Combining the knowledge of each patient's seizure onset zone resection plan along with our computed high frequency oscillation network centralities and high frequency oscillation rate, we develop a Naïve Bayes model that predicts outcome (positive predictive value: 100%) better than predicting based upon fully resecting the seizure onset zone (positive predictive value: 71%). Surgical margins had a large effect on outcomes: non-palliative patients in whom most of the seizure onset zone was resected ('definitive surgery', ≥ 80% resected) had predictable outcomes, whereas palliative surgeries (<80% resected) were not predictable. These results suggest that the addition of network properties of high frequency oscillations is more accurate in predicting patient outcome than seizure onset zone alone in patients with most of the seizure onset zone removed and offer great promise for informing clinical decisions in surgery for refractory epilepsy.

Memory functioning after hippocampal removal: Does side matter?

To address the memory functioning after medial temporal lobe (MTL) surgery for refractory epilepsy and relationships with the side of the hippocampal removal, 22 patients with pharmaco-resistant epilepsy who had undergone MTL resection (10 right/12 left) at the Salpêtrière Hospital were compared with 21 matched healthy controls. We designed a specific neuropsychological binding memory test that specifically addressed hippocampal cortex functioning, and left-right material-specific lateralization. Our results showed that both left and right mesial temporal lobe removal cause a severe memory impairment, for both verbal and visual material. The removal of left medial temporal lobe causes worse memory impairment than the right removal regardless of the stimuli type (verbal or visual) questioning the theory of the hippocampal material-specific lateralization. The present study provided new evidence for the role of both hippocampus and surrounding cortices in memory-binding whatever the material type and also suggested that a left MTL removal is more deleterious for both verbal and visual episodic memory in comparison with right MTL removal.

Neuronavigation as a Tool for Pre-Surgical Planning in Refractory Epilepsy Surgery

Summary Epilepsy is one of the most frequent chronic neurological pathologies, with high incidence and prevalence worldwide. A third of these patients are resistant to treatment, which is known as refractory epilepsy. Most of these patients suffer epilepsy secondary to epileptogenic lesions, where the surgery is the only treatment that could cure epilepsy. The goal of epilepsy surgery is to remove the epileptogenic area with preservation of eloquent areas, and here the surgical experience, the neuroimaging technology and the availability of image-guided surgery systems known as a neuronavigator plays a key role. Objectives: To demonstrate the usefulness of neuronavigation in pre-surgical planning and in the surgery of refractory epilepsy. Method: A cross-sectional and analytical descriptive study was conducted based on 47 surgeries performed (12 resective, 32 palliative and 3 diagnostic) in patients with refractory epilepsy and mean age of 9.93 years (SD 4.1). In 27 patients (57.44%) the neuronavigator was used. In the group of patients operated with neuronavigation, the surgical time decreased by 47.17 minutes (p = 0.022), the amount of bleeding by 111.41 milliliters (p = 0.011) and the days of hospitalization by 6.68 days (p = 0.005), compared with the group operated without neuronavigation. Complications in the neuronavigation group were 29.63% compared to 65% in the group operated without neuronavigation (p = 0.034). Conclusions: In our series, the use of the neuronavigator in the planning and development of the surgery had a significant impact by reducing the amount of bleeding lost, the surgical time, the days of hospitalization, and the post-surgical complications.

Surgical Epilepsy Care in a Safety-Net and Private Healthcare System: A Comparative Analysis

Abstract INTRODUCTION Access to and delivery of quality surgical epilepsy care remains a challenge in both safety-net and private hospital systems. Underserved populations are more likely to utilize safety-net hospital systems, but to date there have been no published reports on epilepsy surgery outcomes in this setting. This study aimed to prospectively analyze and compare surgical epilepsy care in a safety-net versus private hospital system. METHODS We prospectively collected evaluation and treatment data in patients undergoing resective surgery for refractory epilepsy at the multi-institutional Los Angeles County Department of Health Services Comprehensive Epilepsy Program between 2010 and 2017. Seizure characteristics, pre-surgical evaluation, perioperative complications, and postsurgery seizure outcomes as measured by the Engel classification were recorded. This cohort was compared to patients treated in a private hospital system with which it collaborated during the same time period. RESULTS Data from 102 patients in the safety-net and 145 patients in the private hospital system were analyzed. There was a higher proportion of African American (P = .02) and Hispanic patients (P = .03) in the safety-net hospital system. There was no difference in mean time from epilepsy onset to surgery between groups (P = .54). The presurgical evaluation was equivalent (P &gt; .18), except for more frequent use of magnetoencephalography in the private system (P = .02). Seizure freedom outcomes were excellent, and complication rates were low with no difference between groups (P = .95 and P &gt; .22, respectively). However, patients from safety-net hospital systems were more likely to be lost to follow up (P = .04). CONCLUSION Quality surgical epilepsy care can be delivered in a safety-net hospital system and intrinsic factors of safety-net hospital do not limit quality. Partnership of safety-net hospital systems with established comprehensive epilepsy centers is essential for the delivery of quality surgical epilepsy care. The expansion of these services is vital for providing modern epilepsy care for the underserved population.

AED Strategy after Refractory Epilepsy Surgery.

Post-epilepsy surgery antiepileptic drug discontinuation (AED) practices remain unclear and little evidence about the optimum timing exists. In the present study, we reviewed the types of surgery for epilepsy and their outcome. The current concepts for discontinuation of AED after surgery are presented and all contributing factors that should be taken into consideration are discussed.

Risk Factors Analyses for Seizure Recurrence in Different Periods After Refractory Epilepsy Surgery: A Prospective Single-Center Study.

To evaluate the potential risk factors associated with seizure recurrence in different periods after epilepsy surgery. A total of 303 patients with refractory epilepsy after epilepsy surgery were included. The Kaplan-Meier method with log-rank test and univariate and multivariate Cox proportional hazards model were performed to calculate the comparison of survival curves between groups and identify the risk factors associated with seizure recurrence in different periods after surgery. The significant predictors of seizure recurrence were determined, including duration of epilepsy (P= 0.018), seizure types (P= 0.009), magnetic resonance imaging findings (P= 0.007), intracranial electroencephalographic recordings (P= 0.002), sides of epileptogenic zone (P= 0.025), and types of surgery (P= 0.002). Moreover, the significant predictors of seizure recurrence within 12 months after surgery were also included, such as gender (P= 0.007), duration of epilepsy (P= 0.013), intracranial electroencephalographic recordings (P= 0.003), and types of surgery (P < 0.001). Our results indicated that the variables of magnetic resonance imaging findings (P= 0.015), sides of epileptogenic zone (P= 0.004), and seizure relapse within 12 months after surgery (P < 0.001) were significantly associated with seizure recurrence in 12-36 months after surgery. Seizure relapse within 12 months after surgery (P < 0.001) was also associated with seizure recurrence >36 months after surgery. We reconfirmed the well-known risk factors associated with seizure recurrence and also identified the controversial variables. In addition, we found that the risk factors associated with seizure recurrence were different in different periods after epilepsy surgery.

Surgical Approaches to Treating Epilepsy in Children

Surgery for refractory epilepsy in appropriately selected children is effective. The key factors influencing a good outcome are careful selection of candidates, early referral to pediatric epilepsy surgical unit, underlying neuropathology and the completeness of surgical resection of the seizure focus. Although the primary aim of a surgery is seizure freedom, benefits are also seen in cognitive development. Early prompt referral is therefore desired to optimise outcome. Focal resections involving the temporal and frontal lobes are the common resective procedures in children, with cortical malformations the most common underlying pathology. Hemispherectomy or multilobar procedures are more commonly performed in children younger than four years. Seizure free rates reach 60-80%. The availability of newer techniques for presurgical evaluation, along with invasive intracranial electroencephalographic (EEG) recording, has facilitated surgical consideration. Resective surgery may also be beneficial for children who may appear to have bilateral or generalised clinical or EEG features associated with focal lesions on MRI. Vagal Nerve Stimulation (VNS) and corpus callosotomy are employed for selected candidates not suitable for resective surgery with good results.

Surgery for refractory epilepsy caused by non -posttraumatic encephalomalacia

Objective To analyze the strategy and outcome of complete lesion resection (CLR) and multiple subpial transaction (MST) for epilepsy caused by non - posttraumatic encephalomalacia.Methods 28 cases were treated with CLR and MST according to preoperative magnetic resonance image (MRI), positive (PET) and 128 - led long - term video EEG. They were followed up for more than 1 year,and their outcome was graded by Engel scales for analysis. Results Grade Ⅰ was observed in 6 cases and Grade Ⅱ in 11 cases, Grade Ⅲ in 9 cases and Grade Ⅳ in 2 cases. Satisfactory seizure control was found in patients with localized encephalomalacia, or far away from eloquent area, or without brain atrophy, more than 80%. Conclusion CLR combined with MST is effective and safe for epilepsy caused by nonposttraumatic encephalomalacia. And the cases with localized encephalomalacia, or far away from eloquent area, or without brain atrophy are likely to have a better outcome. Key words: Encephalomalacia; Epilepsy; Surgical procedures,operative

Nosocomially AcquiredPseudomonas stutzeriBrain Abscess in a Child: Case Report and Review

Pseudomonas stutzeri is a rare cause of nosocomial infection. We report a pediatric case of nosocomially acquired P. stutzeri brain abscess after subdural grid implantation before surgery for refractory epilepsy and review the literature.