Vagus Nerve Stimulation in Medically- Resistant Epilepsy: Efficacy and Tolerance

Background: Epilepsy is a common neurological disease that affects 1% of the population. One third of patients with epilepsy will not respond to antiseizure medications. The most effective treatment when a patient has medically resistant epilepsy is epilepsy surgery. Unfortunately, in many cases surgery is not possible. Neuromodulation is a therapy used in those patients and Vagus Nerve Stimulation (VNS) is the most common type. There are many studies focusing on seizure reduction using VNS, it is still unclear which patients will obtain the greatest benefits. Objective: To define the seizure response post-VNS implantation, to determine predictive factors associated with good outcomes after VNS implantation and to evaluate complications and side effects. Analysis will be completed in the total sample of VNS cases, in the paediatric subgroup, in medically resistant generalized epilepsy and pregnant women implanted with VNS. Patients & Methods: Patients with medically resistant epilepsy implanted with VNS at the London Health Science Centre-Western University, from 1997 to July 2018. Results: 1) VNS in epilepsy: 114 patients were included. Median seizure rate reduction was - 67.8% and 55.6% (n=41) had a ≥50% seizure reduction. There was a reduction of hospitalization after VNS implantation from 89.5% (n=102) to 45.6% (n=52). 5.3% (n=6) developed side effects associated with the implantation; and side effects were reported in 63.2% (n=72). 2) Paediatric Group: 22 patients were included. The median age when the VNS was implanted was 13. A ≥50% seizure reduction was achieved in 50% (n=11) and the median seizure reduction was -75%. Side effects were detected in 54.5% (n=12). 3) 46 patients were included in this study with a history of medically resistant generalized epilepsy. The mean age at implantation was 24 years-old. Of the LGS group 41.7% (n=12) of patients had an overall seizure reduction of ≥50%, and in the GGE group 64.7% (n=11) had a seizure reduction of ≥50%. There was a significant reduction of seizure-related hospital admissions. 4) Four patients and seven pregnancies were included. The median duration since implantation was 3.17 years. Three required c-sections, one related to failure to progress, the second due to pre-eclampsia and the third due to breach presentation. All babies were healthy, except one with developmental delay of unclear severity. Conclusion: 1) VNS can reduce the number of seizures by 50% in more than half of the patients implanted. VNS has shown a reduction in hospitalization. It is a safe therapy with frequent mild side effects. 2) The paediatric population obtained similar results compared to the total sample. 3) VNS should be considered as a treatment in patients with therapy resistant generalized epilepsy, especially in cases with GGE. 4) Our small sample suggests VNS is a relatively safe therapy during pregnancy, however, larger sample series should be collected

Cefalea postarteriografía y/o stenting carotídeo

Objetivos: La arteriografía cerebral y colocación de stent carotídeo se ha descrito que pueden ocasionar la aparición de cefalea, sin saber quiénes la desarrollan ni que características presenta. Material y método: Mediante estudio prospectivo observacional, se recogieron los datos de pacientes que fueron sometidos a arteriografía y/o stenting carotídeo ingresados en Hospital Clínico Lozano Blesa. Se estudiaron variables sociodemográficas, factores de riesgo cardiovascular, afectación carotídea y antecedentes de cefalea primaria. Se realizó una entrevista estructurada antes, después del procedimiento, tras 24 horas y al cabo de un mes, para registrar la aparición de cefalea. Resultados: se incluyeron un total de 25 pacientes con una media de edad de 67 años; un 92% (N=23) fueron varones y un 8 %(N=2) mujeres. El 21% (N=5) tenían antecedentes de cefalea, en el 60% (N=12) migraña con aura y 40% (N=8) cefalea tensional. La cefalea apareció en 4 pacientes (16%), siendo en el 75% (N=3) durante el procedimiento y en un caso en las primeras 6 horas. En un caso la duración fue menor de 10 minutos, y en otro entre 10-120 minutos. Las principales localizaciones fueron en igual porcentaje la región fronto-temporal y la facial. Descrita como opresiva en un 75% (N=3), con intensidad leve-moderada (50%) y el 50% precisaron analgesia. Se vió una relación estadísticamente significativa entre la aparición de la cefalea y afectación de la arteria carótida interna izquierda (p=0.059). Conclusiones: La cefalea poststent precisa de más estudios para poder determinar sus características

Long Term outcomes after NORSE: Treatment with Vagus Nerve Stimulation

New-onset refractory status epilepticus (NORSE) is associated with high mortality, therapy resistant epilepsy (TRE) and poor cognitive and functional outcomes. Some patients develop multifocal TRE, for whom surgery with a curative intention, is not an option. In these patients, Vagus Nerve Stimulation (VNS) is performed as a palliative treatment. We report the long-term outcomes regarding seizure frequency, functional and cognitive outcome, and effectiveness of VNS in two patients with TRE as a consequence of NORSE. In the first patient with cryptogenic NORSE, VNS implantation occurred during the acute stage, probably contributing to the cessation of her status epilepticus. However, in the long-term follow-up, the patient persisted with daily multifocal seizures. In the second patient, VNS implantation was delayed to manage his epilepsy when the NORSE, ultimately due to autoimmune encephalitis, had resolved. During long-term follow-up, no reduction in seizure frequency was achieved. The current evidence supporting the use of VNS in patients with TRE after NORSE warrants further investigation

Canadian epilepsy priority-setting partnership: Toward a new national research agenda

Background: Health research agendas are often set by researchers or by industry and may not reflect the needs and priorities of end users. This priority-setting partnership (PSP) for epilepsy was undertaken to identify the most pressing unanswered questions about epilepsy and seizures from the perspective of people with epilepsy (PWE) and their care providers. Methods: Using the methodology developed by the James Lind Alliance (JLA), evidence uncertainties were gathered via online surveys from stakeholders across Canada. Submissions were formed into summary questions and checked against existing evidence to determine if they were true uncertainties. Verified uncertainties were then ranked by patients, caregivers, and healthcare providers and a final workshop was held to reach a consensus on the top 10 priorities. Results: The final top 10 list reflects the priority areas of focus for research as identified by the Canadian epilepsy community, including genetic markers for diagnosis and treatment, concerns about living with the long-term effects of epilepsy, and addressing knowledge gaps in etiology and treatment approaches. Conclusion: This project represents the first systematic evidence of patient- and clinician-centered research priorities for epilepsy. The results of this priority-setting exercise provide an opportunity for researchers and funding agencies to align their agendas with the values and needs of the epilepsy community in order to improve clinical outcomes and quality of life (QOL) for PWE

Waveform detection by deep learning reveals multi-area spindles that are selectively modulated by memory load

Sleep is generally considered to be a state of large-scale synchrony across thalamus and neocortex; however, recent work has challenged this idea by reporting isolated sleep rhythms such as slow oscillations and spindles. What is the spatial scale of sleep rhythms? To answer this question, we adapted deep learning algorithms initially developed for detecting earthquakes and gravitational waves in high-noise settings for analysis of neural recordings in sleep. We then studied sleep spindles in non-human primate electrocorticography (ECoG), human electroencephalogram (EEG), and clinical intracranial electroencephalogram (iEEG) recordings in the human. Within each recording type, we find widespread spindles occur much more frequently than previously reported. We then analyzed the spatiotemporal patterns of these large-scale, multi-area spindles and, in the EEG recordings, how spindle patterns change following a visual memory task. Our results reveal a potential role for widespread, multi-area spindles in consolidation of memories in networks widely distributed across primate cortex

Evaluación y manejo de primera crisis epiléptica

Epileptic seizures are a common cause of medical consultation in the emergency room and in outpatient settings. The evaluation of the first epileptic seizure is of upmost importance as not all patients presenting with seizures have epilepsy (two or more unprovoked crises separated more than 24 hours; one single crisis with a high risk of recurrence (>60%); or evidence of an epileptic syndrome needing treatment based on the definition by the International League against Epilepsy). On the other hand, not every patient with a first episode should be just observed not offering proper treatment. This decision is based on the risk of recurrence. For that purpose, the American Academy of Neurology (AAN) recommends classifying the first seizures into five groups depending on the risk of recurrence, these groups are: patients with provoked seizures; patients with acute symptomatic seizures; patients with remote symptomatic seizures; first seizure associated with an epileptic syndrome, and first seizure of unknown origin. The AAN guidelines for the management of the first seizure published in 2015 suggests that patients with symptomatic remote seizures (non-evolutive and old cerebral lesions), patients with interictal epileptiform abnormalities, patients with abnormal findings on MRI or CT scan, and patients with nocturnal seizures had a high risk for recurrence (>60%) and should be treated. Current evidence suggests that there is no difference in early or delay treatment for controlling seizures at the long-term.Las crisis epilépticas son una causa frecuente de consulta en la emergencia y en la atención ambulatoria. La evaluación de una primera crisis epiléptica reviste gran trascendencia en este contexto, ya que la ocurrencia de ésta no implica necesariamente el diagnóstico de epilepsia (dos o más crisis no provocadas separadas por más de 24 horas; una crisis única con alto riesgo de recurrencia (>60%); o la evidencia de un síndrome epiléptico – definición de la Liga Internacional para la Lucha Contra la Epilepsia, ILAE) y el tratamiento subsecuente. Por otro lado, no todo paciente con primera crisis debe ser dejado en observación sin recibir el manejo apropiado. Esta decisión está en función del riesgo de recurrencia de crisis. Para ello, la Academia Americana de Neurología (AAN de sus siglas en inglés) recomienda la clasificación de la primera crisis epiléptica en cinco grupos y dependiendo del riesgo de recurrencia de crisis establecido para cada uno de ellos, se tendrá una guía para proceder o no con el tratamiento antiepiléptico. Los grupos son: pacientes con crisis epiléptica provocadas; pacientes con crisis sintomáticas agudas; pacientes con crisis sintomática remotas; primera crisis asociada a síndromes epilépticos; primera crisis de causa desconocida. La guía publicada por AAN en el 2015 para el manejo de primera crisis, sugiere que los pacientes con crisis sintomáticas remotas (lesiones cerebrales pasadas no evolutivas), pacientes con anormalidades epileptiformes interictales; pacientes con estudios de imagen anormales (RMN y TC); y pacientes con crisis nocturnas, tienen un riesgo elevado para recurrencia de crisis (>60%) por lo que deben ser tratadas. La evidencia disponible a la fecha sugiere también que no hay diferencia significativa en el inicio precoz o diferido del tratamiento antiepiléptico para el control de las crisis a largo plazo