The vagus nerve somatosensory evoked potential in the intact brain: state-of-evidence and some representative vignettes.
Somatosens Mot Res
; 38(1): 41-47, 2021 03.
Article
en En
| MEDLINE
| ID: mdl-33200653
OBJECTIVE: Scalp-recorded evoked potentials elicited by applying afferent electrical stimulation at the tragus region of the human external ear have shown inconsistent results. We aim to disentangle discrepant findings and interpretations, and put forward novel physiological explanations on the origin of the vagus nerve somatosensory evoked potentials (VSEP). METHODS: We systematically search and critically appraise in PubMed, Web of Science, and Scielo databases the scientific reports publishing VSEP findings elicited by afferent electrical stimulation at the tragus region from individuals without brain disorders. Eligible studies published from January 2000 to April 2020 were extracted. The following information was identified from each article: number of participants; age; gender; stimulating/recording and grounding electrodes as well as stimulus side, intensity, duration, frequency, and polarity. Information about physiological parameters and neurobiological variables was also extracted. Representative vignettes with novel scalp responses induced by stimulating the tragus were also included to add support to our conclusions. RESULTS: 140 healthy participants were identified from six selected reports. Mean age ranged from 24.3 to 61.5 years. Stimulating and recording aspects were miscellaneous among studies. Scalp responses marked as the VSEP were recorded in 76% of participants, and showed high variability, low validity and poor reproducibility. Age correlated with response latencies. There were not gender differences in scalp response parameters. Cardiovascular function was unaltered by tragus stimulation. Vignettes showed that the VSEP was scalp muscle responses. CONCLUSION: VSEP did not fulfil evoked potential guidelines. VSEP corresponded to volume conduction propagating from muscles surrounding scalp recording sites.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Nervio Vago
/
Potenciales Evocados Somatosensoriales
Tipo de estudio:
Prognostic_studies
Límite:
Adult
/
Humans
/
Middle aged
Idioma:
En
Revista:
Somatosens Mot Res
Asunto de la revista:
NEUROLOGIA
/
PSICOFISIOLOGIA
Año:
2021
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Reino Unido