Blakley B, Ashiri M, Moussavi Z, Lithgow B. Verification EVestG recordings are vestibuloacoustic signals.
Laryngoscope Investig Otolaryngol 2022;
7:1171-1177. [PMID:
36000057 PMCID:
PMC9392376 DOI:
10.1002/lio2.862]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 05/24/2022] [Accepted: 06/21/2022] [Indexed: 11/30/2022] Open
Abstract
Introduction
Neural dysfunction is associated with aberrant nerve firing; thus, electrodiagnosis has the potential for objective diagnosis and quantification of neural dysfunction. Electrical stimulation alters nerve firing and may also have treatment potential. This article outlines some findings related to electrodiagnosis and electrical stimulation of the ear. The quasi‐synchronous firing of many vestibuloacoustic nerve fibers can produce an extracellular potential defined as a field potential (FP). Electrovestibulography (EVestG) is a method to record vestibuloacoustic signals and detect the associated FPs. A clear picture of the muscle‐, EEG‐, saccade‐related, or other artefactual origins, and the physiologic basis of FPs recorded with EVestG, is evolving. EVestG was applied to demonstrate the effect of electrical stimulation on spontaneous FPs in the ear canal.
Methods
Bilateral EVestG recordings were conducted on 14 guinea pigs before and after stimulation with 3–0.5 mA ipsilateral anodal electrical pulses before and after ablation via unilateral Scarpa's ganglionectomy to elucidate the origin of the EVestG recorded spontaneous FPs.
Results
Anodal electrical stimulation suppresses the recorded activity. There was a significant reduction of the level of recorded signal observed following anodal stimulation on the ablated but not the intact side.
Conclusion
Electrical stimulation of the external auditory canal reduces spontaneous electrical activity in the ear canal, some of which is due to central nervous system activity. The EVestG recorded FPs have a major vestibuloacoustic component.
Collapse