Pharmacoresistance and the role of surgery in difficult to treat epilepsy.

Departments of Clinical Neurosciences and Community Health Sciences and the Hotchkiss Brain Institute, University of Calgary, Division of Neurology, Foothills Medical Centre, 1403 29th Street NW, Calgary, AB T2N 2T9, Canada.
Nature Reviews Neurology (Impact Factor: 15.52). 09/2012; DOI: 10.1038/nrneurol.2012.181
Source: PubMed

ABSTRACT Pharmacoresistance occurs in up to 30% of patients with epilepsy, and is most commonly associated with epilepsy of structural or metabolic origin, abnormal findings on brain imaging or examination, and failure to respond to the first two antiepileptic drugs. However, in patients presumed to have difficult to treat epilepsy, factors that might result in apparent treatment resistance (misdiagnosis of epilepsy, incorrect drug and/or dose, and lifestyle issues) must first be excluded and the diagnosis re-examined. Epilepsy is commonly misdiagnosed, especially in patients with syncope and psychogenic events. The initial steps in confirming the diagnoses of both epilepsy and pharmacoresistance are to obtain a detailed, reliable history and to conduct a careful review of all prior trials of antiepileptic drug therapy. Once the diagnoses of epilepsy and pharmacoresistance are confirmed, the seizure type, epilepsy syndrome, and expected course of the disorder dictate its medical and surgical management. Epilepsy surgery should be considered promptly in these patients, since few interventions are as effective as brain surgery in this setting, particularly in patients with focal pharmacoresistant epilepsy. This Review discusses the concept of pharmacoresistance and describes the approach to management of the patient with difficult to treat epilepsy, focusing on the important role of epilepsy surgery.

1 Bookmark
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective F-18 Fluorodeoxyglucose positron emission tomography (FDG-PET) and ictally subtracted single photon emission tomography (iSPECT) are important for localizing the epileptogenic focus. The following study analyzes the role of inter-concordance between FDG-PET and iSPECT in predicting long-term outcomes after epilepsy surgery. Methods We prospectively evaluated (January 2003-January 2008) patients undergoing surgery for temporal or extratemporal drug refractory epilepsy (DRE) who had at least a 5 years follow up. Patients with MRI and video EEG (vEEG) concordance for the seizure focus underwent iSPECT and FDG-PET. Concordance of the iSPECT and FDG-PET with each other and with the substrate (defined by MRI and vEEG) for temporal and extra-temporal epilepsies was evaluated and correlated with outcomes. Results One hundred twenty-three patients (74 males) were included in the study (mean age at time of surgery: 18.9 ± 10.41 years). The mean age of onset of seizures was 9.87 ± 8.37 years. The most common semiology was complex partial (45%). When both FDG-PET and iSPECT were concordant with each other, this translated into a (Class I Engel at 5 years) outcome of 62% for extra-temporal epilepsies (provided they were also concordant with the lesion, as defined by MRI and vEEG). This percentage was significant (p < 0.01) compared with all other situations (both FDG-PET/iSPECT not concordant to MRI/vEEG, only PET or iSPECT concordant with MRI/vEEG). This correlation was not found for the temporal epilepsies, where the MRI and vEEG were the most important prognostic parameters. In both temporal and extratemporal epilepsies the concordance of the iSPECT/FDG-PET with the MRI/vEEG correlated with a better 5-year outcome (Temporal: 70% vs 25%; Extra-temporal: 62% vs 33%; p < 0.05). Significance: Concordance between non-invasive investigation iSPECT and FDG-PET is an important predictive factor for surgical outcomes in extra-temporal epilepsy.
    Epilepsy Research 09/2014; · 2.19 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To describe the impact of epilepsy surgery on quality of life through the application of the quality of life in epilepsy (QOLIE-10) scale in a low income population. We conducted an observational, descriptive, and cross-sectional study. The data for all patients who underwent epilepsy surgery from the aforementioned period were registered retrospectively through a review of their clinical history. Clinical variables of interest for this study were obtained through phone contact, and the QOLIE-10 scale was applied. This study included a total of 89 patients with whom phone contact was established and who met the inclusion criteria. Of these patients, 30.3% were without anti-seizure medication at the time of the survey's application, and only 19.1% were still under polytherapy. A total of 47.1% of the patients had returned to some work activity that they would have not been able to perform before because of their disease. All of the components of the QOLIE-10 scale improved significantly (p<0.05) after the surgical procedure, except the variable of "fear of the sudden occurrence of seizures". The variables with greatest impact after the surgical procedure were depression, work activity, and quality of life in general. Epilepsy surgery has a positive impact on the quality of life of patients with low resources and in vulnerable social conditions. It is still to be determined if, in this population, work and social reintegration have a greater impact on the quality of life than other clinical and/or paraclinical variables. Copyright © 2014 Elsevier B.V. All rights reserved.
    Epilepsy research. 02/2015; 110C:183-188.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Arch Neurocien (Mex) INNN, 2014 Tiempo estimado entre el inicio de las crisis y el tratamiento quirúrgico en pacientes con epilepsia refractaria Artículo original RESUMEN La epilepsia afecta al 2 % de la población mundial. El 30% de estos pacientes son refractarios al tratamiento médico y por tanto son candidatos a cirugía. La epilepsia no controlada, tiene graves consecuencias físicas, emocionales, cognitivas y sociales. De ahí la necesidad de efectuar una evaluación temprana para considerar los beneficios de la cirugía. Desgraciadamente, la experiencia en muchos centros, muestra que la cirugía se retrasa por varios años. Objetivo: evaluar el tiempo que tarda un paciente que es refractario al tratamiento médico desde el inicio de sus crisis hasta la cirugía en la Clínica de Epilepsia del Hospital General de México. Material y métodos: se realizó un estudio observacional, documental, retrospectivo de los pacientes con epilepsia refractaria sometidos a cirugía en la Clínica de Epilepsia del Hospital General de México. Resultados: se incluyeron un total de 272 pacientes sometidos a diferentes procedimientos quirúrgicos para control de la epilepsia en el periodo comprendido de Enero 1992 a Junio epilepsia, lobectomía temporal anterior, neuromodulación, transección subpial. Tiempo estimado entre el inicio de las crisis y el tratamiento quirúrgico en pacientes con epilepsia refractaria ABSTRACT Arch Neurocien
    Arch Neurocienc (Mex). 07/2014; 19(3):151-154.