Effect of Short‐Term Theta Frequency Stimulation of the Vagus Nerve on Cognition among Patients with Refractory Epilepsy: A Pilot Study
Notice bibliographique
Résumé
Objective The purpose of this investigation is to collect preliminary data on the effect of theta frequency vagus nerve stimulation on cognitive measures, including memory retention, in patients with refractory epilepsy. Background Vagus nerve stimulation (VNS) was approved by the FDA in 1997 as an adjunctive treatment for medically refractory epilepsy. VNS provides intermittent high frequency stimulation to the left vagus nerve, resulting in retrograde stimulation to centers in the brainstem. Research interest into alternative uses of VNS has increased in popularity over the past decade, including its effect on cognition. Initial short‐term studies (3–24 hours of stimulation) have provided information on how it may be working to alter cognitive function. Two pre‐clinical studies showed that rats displayed increased memory retention after 24 hours of VNS. Clinical studies have also demonstrated a significant increase in cognitive performance when VNS is administered during the memory consolidation period of a list learning task. The nucleus of the solitary tract (NST) in the brain stem is the primary relay station for afferent vagal nerve fibers. The NST has numerous projections to various areas of the forebrain and brain stem, including the hippocampus. Stimulation of the vagus nerve has been shown to alter the electrophysiological and metabolic profiles of the hippocampus, an area that plays a critical role in learning and memory functions. The hippocampus generates and maintains high amplitude oscillations in the theta frequency range (4–8 Hz), which play an important role in memory tasks. Furthermore, there is pre‐clinical evidence that theta oscillations are depressed in rodent models with temporal lobe epilepsy, and that reduced theta activity correlates with memory deficits. We hypothesize that theta frequency VNS will have a positive effect on memory retention. Methods Patients with implanted VNS devices were identified in the medical records, consented, and screened via the Beck Depression Inventory (excluded if score > 20) and the Montreal Cognitive Assessment (excluded if score < 24). Participants then practiced cognitive tasks for 30 minutes, followed by three rounds of neurocognitive testing with different VNS settings (Figure 1). Only VNS frequency (theta: 5 Hz, beta: 25–30 Hz, and control: 0 Hz) was altered. Each round of neurocognitive testing included two tasks. The first was a memory encoding/retrieval task (California Verbal Learning Test, CVLT). The second was an executive function task administered between the encoding and retrieval portions of CVLT. Both participants and test administrators were blinded to VNS parameters. Results & Discussion Over the course of one year, data was only collected from one patient. This was due to a combination of factors, including stringent exclusion criteria, difficult patient recruitment, and an understaffed research team. However, this patient did display a 23% increase in delayed free recall performance when treated with theta frequency stimulation (Figure 2). Furthermore, accuracy and reaction time decreased by 5% and >15% for both beta and theta stimulation (as compared to the control) during the executive function task (Stroop test). While generalizable conclusions are impossible to draw from this data, the preliminary results support our hypothesis. While we are in the process of collecting more data, we hope that this study can serve as a platform for researchers to build from. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,001 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».