Vagus Nerve Stimulation Activates Central Nervous System Structures in Epileptic Patients During PET H215O Blood Flow Imaging

Ko, David; Heck, Christi; Grafton, S. T.; Apuzzo, Michael L.J.; Couldwell, William T.; T, Chen; Day, John D.; Zelman, Vladimir; Smith, Thomas D.; DeGiorgio, Christopher M.

doi:10.1097/00006123-199608000-00061

Cited by 146 publications

(79 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Though these studies are performed on neuronal models represented by hippocampal slices, the possibility that the GABAergic inhibition in a subset of interneurons into pyramidal cells modulates gamma activity (Wendling et al, 2002) can be hypothesized also in other brain areas that share high density GABA A receptors. Given that VNS increases the metabolic rate in the thalamus (Henry et al, 1998(Henry et al, , 1999(Henry et al, , 2004Ko et al, 1996) the long-term administration of such stimulation might affect thalamocortical regulation of brain circuitry involved in the modulation of EEG rhythms. It is likely that this effect is part of the antiepileptic mechanism, and that it is induced after a medium-long delay from VNS activation, since both clinical activity and power spectrum assessed 1 month after settling the device at 1.25 mA failed to show significant differences in comparison with these calculated for the pre-implant periods (not shown).…”

Section: Discussionmentioning

confidence: 99%

“…Although the lateralized gamma power spectrum can be interpreted as a casual finding, nonetheless the peculiar pattern of gamma profiles detected in the VNS group might suggest a more direct mechanism. Indeed, it has been observed that VNS induces bilateral thalamo-cortical blood flow increase both acutely and chronically (Henry et al, 1998(Henry et al, , 1999Ko et al, 1996), and that the left position of VNS implant enhances an additional chronic increase in the right inferior postcentral gyrus (Henry et al, 2004). Though it is difficult to directly correlate minute variations in blood flow with EEG changes, the chronic blood flow asymmetry could play a role in modifying synaptic plasticity in these areas.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Increase in 20–50Hz (gamma frequencies) power spectrum and synchronization after chronic vagal nerve stimulation

Marrosu¹,

Santoni²,

Puligheddu³

et al. 2005

Clinical Neurophysiology

View full text Add to dashboard Cite

Objective: Though vagus nerve stimulation (VNS) is an important option in pharmacoresistant epilepsy, its mechanism of action remains unclear. The observation that VNS desynchronised the EEG activity in animals suggested that this mechanism could be involved in VNS antiepileptic effects in humans. Indeed VNS decreases spiking bursts, whereas its effects on the EEG background remain uncertain. The objective of the present study is to investigate how VNS affects local and inter regional syncronization in different frequencies in pharmacoresistent partial epilepsy. Methods: Digital recordings acquired in 11 epileptic subjects 1 year and 1 week before VNS surgery were compared with that obtained 1 month and 1 year after VNS activation. Power spectrum and synchronization were then analyzed and compared with an epileptic group of 10 patients treated with AEDs only and with 9 non-epileptic patients. Results: VNS decreases the synchronization of theta frequencies (P!0.01), whereas it increases gamma power spectrum and synchronization (!0.001 and 0.01, respectively). Conclusions: The reduction of theta frequencies and the increase in power spectrum and synchronization of gamma bands can be related to VNS anticonvulsant mechanism. In addition, gamma modulation could also play a seizure-independent role in improving attentional performances. Significance: These results suggest that some antiepileptic mechanisms affected by VNS can be modulated by or be the reflection of EEG changes. q

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Increase in 20–50Hz (gamma frequencies) power spectrum and synchronization after chronic vagal nerve stimulation

Marrosu¹,

Santoni²,

Puligheddu³

et al. 2005

Clinical Neurophysiology

View full text Add to dashboard Cite

show abstract

“…16 Putative targets of VNS activity have included multiple thalamic and brainstem sites proposed to desynchronize thalamocortical circuitry involved in seizure propagation. 12,16,18,20,21 Za bara 30 has demonstrated afferent projections from the vagus nerve, traveling within the nucleus tractus solitarius synapsing in the locus coeruleus and raphe magnus nuclei with effects on the release of norepinephrine and serotonin.While the mechanism of action of VNS in diminishing the frequency and intensity of seizure activity remains undetermined, multiple clinical investigations have supported its continued use in both the adult and pediatric populations. According to the most recent position statement from the American Academy of Neurology, VNS is indicated for "adults and adolescents over 12 years of age with medically intractable partial seizures who are not candidates for potentially curative surgical resections, such as lesionectomies or mesial temporal lobectomies.…”

mentioning

confidence: 99%

mentioning

confidence: 99%

Vagal nerve stimulation for the treatment of medically refractory epilepsy: a review of the current literature

Connor¹,

Nixon²,

Nanda³

et al. 2012

FOC

View full text Add to dashboard Cite

Object The authors conducted a study to evaluate the published results of vagal nerve stimulation (VNS) for medically refractory seizures according to evidence-based criteria. Methods The authors performed a review of available literature published between 1980 and 2010. Inclusion criteria for articles included more than 10 patients evaluated, average follow-up of 1 or more years, inclusion of medically refractory epilepsy, and consistent preoperative surgical evaluation. Articles were divided into 4 classes of evidence according to criteria established by the American Academy of Neurology. Results A total of 70 publications were reviewed, of which 20 were selected for review based on inclusion and exclusion criteria. There were 2 articles that provided Class I evidence, 7 that met criteria for Class II evidence, and 11 that provided Class III evidence. The majority of evidence supports VNS usage in partial epilepsy with a seizure reduction of 50% or more in the majority of cases and freedom from seizure in 6%–27% of patients who responded to stimulation. High stimulation with a gradual increase in VNS stimulation over the first 6 weeks to 3 months postoperatively is well supported by Class I and II data. Predictors of positive response included absence of bilateral interictal epileptiform activity and cortical malformations. Conclusions Vagal nerve stimulation is a safe and effective alternative for adult and pediatric populations with epilepsy refractory to medical and other surgical management.

show abstract

“…Los resultados objetivados con estas técnicas no son homogéneos. Estudios mediante PET con agua indicaron un aumento en el flujo sanguíneo cerebral durante las fases de estimulación del nervio vago izquierdo, siendo especialmente significativo en el tálamo derecho, corteza temporal posterior bilateral, putamen izquierdo y zona de hemisferio cerebeloso inferior izquierdo 33,38 Henry et al 26 encontraron un aumento de flujo en el hipotálamo, tálamo, corteza insular, giro poscentral, área inferior del cerebelo y cara rostral del bulbo, y una disminución de forma bilateral en hipocampo, amígdala y área posterior del giro singular. En un estudio posterior, estos mismos autores encontraron un aumento del flujo en ambos tálamos asociado a una reducción significativa del número de crisis, lo que sugeriría que el efecto antiepiléptico podría relacionarse con un aumento de actividad sinóptica en el tálamo 27 .…”

Section: Figura 5 Instantánea Quirúrgica Del Electrodo Tunelizado Y unclassified

Estimulación eléctrica vagal en el tratamiento de la epilepsia rebelde: Situación actual

2008

View full text Add to dashboard Cite

ResumenLa estimulación intermitente vagal es una técnica de neuroestimulación de reciente incorporación en el tratamiento de pacientes con epilepsia refractaria al tratamiento farmacológico convencional. Hasta el momento presente y, a pesar de algunos resultados dispares, se ha mostrado como una alternativa eficaz y segura en el tratamiento de estos pacientes. El presente trabajo de revisión pretende acercar la técnica quirúrgica de implantación, comentar las indicaciones y resultados obtenidos hasta la actualidad, y profundizar en los posibles mecanismos de acción de este tipo de estimulación, para finalmente realizar una aproximación crítica a la misma, intentando puntualizar cúales han sido los problemas e inconvenientes que han impedido la utilización generalizada de esta alternativa quirúrgica antiepilép-tica.PALABRAS CLAVE: Epilepsia. Estimulación eléctrica vagal. Seguridad y eficacia. Mecanismos de acción. Vagus nerve stimulation for the treatment of refractory epilepsy. State of the art SummaryThe vagus nerve stimulation (VNS) therapy is a new neurostimulation technique used for treating pharmacoresistant epilepsy. It can be considered an effective and safe alternative for the treatment of refractory epilepsy patients. In the present review, we describe the surgical implantation technique, its indications and results achieved until now. We will also summarize the possible mechanisms of action of VNS therapy. Finally, we will comment on the difficulties and inconvenients that did not allow this antiepileptic surgical technique to become more widely used.KEY WORDS: Epilepsy. Vagus nerve stimulation. Save and efficacy. Action mechanisms. IntroducciónLa epilepsia es una patología que afecta al 1% de la población general y que podría ser considerada en términos globales como el segundo trastorno neurológico en cuanto a incidencia y prevalencia 60 . Esta enfermedad tiene importantes repercusiones psicológicas y económicas tanto en el paciente que la sufre como en la sociedad que tiene que sufragar los gastos que la misma supone. Además, estos factores se ven aumentados por los efectos secundarios en la esfera cognitiva, caracterológica y emocional, que con frecuencia complican los tratamientos con fármacos antiepilépticos a largo plazo. Es por ello que se hace imperiosa la necesidad de buscar e investigar nuevas modalidades de tratamiento efectivo no farmacológico.El final del siglo XX ha supuesto un avance importante en el tratamiento de las epilepsias. Sin embargo, a pesar de la proliferación actual de estudios que han aumentado el conocimiento sobre las causas de la epilepsia y que han posibilitado la introducción de nuevos fármacos antiepilépticos, se puede afirmar que todavía un 30-40% de los pacientes no tienen un control satisfactorio de sus crisis 11.13.71 . En función de ello se calcula que en Estados Unidos, los pacientes tratados correctamente sin un control adecuado de las crisis podrían estar entre 150.000 y 300.000. Extrapolando estos datos, en España serían unos 20.000-40.000 pacientes. Alreded...

show abstract

Vagus Nerve Stimulation Activates Central Nervous System Structures in Epileptic Patients During PET H215O Blood Flow Imaging

Abstract: VNS causes activation of several central areas including contralateral thalamus. Localization to the thalamus suggests a possible mechanism to explain the therapeutic benefit, consistent with the role of the thalamus as a generator and modulator of cerebral activity.

Cited by 146 publications

References 17 publications

Increase in 20–50Hz (gamma frequencies) power spectrum and synchronization after chronic vagal nerve stimulation

Increase in 20–50Hz (gamma frequencies) power spectrum and synchronization after chronic vagal nerve stimulation

Vagal nerve stimulation for the treatment of medically refractory epilepsy: a review of the current literature

Estimulación eléctrica vagal en el tratamiento de la epilepsia rebelde: Situación actual

Contact Info

Product

Resources

About