title: Comparing neurostimulation technologies in refractory focal-onset epilepsy.
abstract: For patients with pharmacoresistant focal epilepsy in whom surgical resection of the epileptogenic focus fails or was not feasible in the first place, there were few therapeutic options. Increasingly, neurostimulation provides an alternative treatment strategy for these patients. Vagal nerve stimulation (VNS) is well established. Deep brain stimulation (DBS) and cortical responsive stimulation (CRS) are newer neurostimulation therapies with recently published long-term efficacy and safety data. In this literature review, we introduce these therapies to a non-specialist audience. Furthermore, we compare and contrast long-term (5-year) outcomes of newer neurostimulation techniques with the more established VNS. A search to identify all studies reporting long-term efficacy (>5 years) of VNS, CRS and DBS in patients with refractory focal/partial epilepsy was conducted using PubMed and Cochrane databases. The outcomes compared were responder rate, percentage seizure frequency reduction, seizure freedom, adverse events, neuropsychological outcome and quality of life. We identified 1 study for DBS, 1 study for CRS and 4 studies for VNS. All neurostimulation technologies showed long-term efficacy, with progressively better seizure control over time. Sustained improvement in quality of life measures was demonstrated in all modalities. Intracranial neurostimulation had a greater side effect profile compared with extracranial stimulation, though all forms of stimulation are safe. Methodological differences between the studies mean that direct comparisons are not straightforward. We have synthesised the findings of this review into a pragmatic decision tree, to guide the further management of the individual patient with pharmacoresistant focal-onset epilepsy.
authors: Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK Oxford Epilepsy Research Group, NIHR Biomedical Research Centre, John Radcliffe Hospital, Oxford, UK.
authors: Inuka Kishara
authors: IK
authors: Gooneratne
authors: Nuffield Department of Surgery, University of Oxford, Oxford, UK Department of Neurosurgery, John Radcliffe Hospital, Oxford, UK.
authors: Alexander L
authors: AL
authors: Green
authors: NYU Langone Medical Center, Comprehensive Epilepsy Center, New York, New York, USA.
authors: Patricia
authors: P
authors: Dugan
authors: Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK Oxford Epilepsy Research Group, NIHR Biomedical Research Centre, John Radcliffe Hospital, Oxford, UK.
authors: Arjune
authors: A
authors: Sen
authors: Carlo Besta Neurological Institute, Milan, Italy.
authors: Angelo
authors: A
authors: Franzini
authors: Nuffield Department of Surgery, University of Oxford, Oxford, UK Department of Neurosurgery, John Radcliffe Hospital, Oxford, UK.
authors: Tipu
authors: T
authors: Aziz
authors: Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK Oxford Epilepsy Research Group, NIHR Biomedical Research Centre, John Radcliffe Hospital, Oxford, UK.
authors: Binith
authors: B
authors: Cheeran
mesh_terms: D002540:Cerebral Cortex / Q000503:physiopathology; D046690:Deep Brain Stimulation / Q000379:methods; D000069279:Drug Resistant Epilepsy / Q000175:diagnosis / Q000523:psychology / Q000628:therapy*; D004828:Epilepsies, Partial / Q000523:psychology / Q000628:therapy*; D006801:Humans; D008134:Long-Term Care; D009483:Neuropsychological Tests; D011788:Quality of Life; D065908:Transcranial Direct Current Stimulation / Q000379:methods*; D016896:Treatment Outcome; D055536:Vagus Nerve Stimulation / Q000379:methods*
keywords: ELECTRICAL STIMULATION; EPILEPSY; EPILEPSY, SURGERY