Electrical promontory stimulation test using a portable peripheral nerve stimulator with an ear canal electrode

Michiko Kurasawa; Takeshi Nakamura; Akira Ganaha; Takahiro Nakashima; Tetsuya Tono

doi:10.1016/j.anl.2023.05.001

Electrical promontory stimulation test using a portable peripheral nerve stimulator with an ear canal electrode

Auris Nasus Larynx. 2024 Feb;51(1):76-81. doi: 10.1016/j.anl.2023.05.001. Epub 2023 May 14.

Authors

Michiko Kurasawa¹, Takeshi Nakamura¹, Akira Ganaha², Takahiro Nakashima³, Tetsuya Tono⁴

Affiliations

¹ Department of Otolaryngology and Head and Neck Surgery, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan.
² Department of Otolaryngology and Head and Neck Surgery, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan; Department of Otorhinolaryngology, Head and Neck Surgery, International University of Health and Welfare, Narita Hospital, Narita, Japan. Electronic address: ganaha.akira.t8@iuhw.ac.jp.
³ Iwayoshi Ear Nose and Throat Clinic, Miyazaki, Japan.
⁴ Department of Otolaryngology and Head and Neck Surgery, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan; Department of Otolaryngology, International University of Health and Welfare, Tochigi, Japan.

PMID: 37193621
DOI: 10.1016/j.anl.2023.05.001

Abstract

Objective: An intact cochlear nerve is necessary for successful cochlear implantation (CI). Although the promontory stimulation test (PST) using a promontory stimulator (PS) and a transtympanic needle electrode is invasive, it is still commonly used to verify cochlear nerve function. PSs are currently unavailable because they are no longer manufactured; however, considering that PST continues to be beneficial in certain situations, alternative equipment is needed. The PNS-7000® (PNS) was developed as a neurologic instrument for stimulating the peripheral nerves. This study investigated the usefulness of the ear canal stimulation test (ECST) using PNS with a silver ball ear canal electrode, which is a new noninvasive alternative technique to the PST.

Methods: ECST was performed from November 2013 to December 2018 using PS and PNS for patients with severe to profound sensorineural hearing loss. The electrical threshold, most comfortable loudness level, uncomfortable loudness level, dynamic range, and gap detection were measured in the ECST. The results of these measured PNS items were compared with PS.

Results: ECST was performed in 61 ears of 35 patients (age, 59.9 ± 20.1 years) using PS and PNS. The sound sensation was elicited in 51 (83.6%) and 52 (85.2%) ears with PS and PNS, respectively. All items excluding GAP were measured in 46 (75%) and 43 (70%) ears at 50 and 100 Hz, respectively. GAP was measured in 33 ears by the ascending and descending methods using PS and PNS. Spearman's rank-order correlation coefficient revealed a significant positive linear correlation between the PS and PNS results in all measurements. No significant difference was found between the PS and PNS thresholds in all measured items.

Conclusions: PNS is a useful instrument for performing ECST as a new alternative to PS. ECST using a silver ball electrode is a less invasive and easier test than PST.

Keywords: Ear canal stimulation test; Electrical auditory stimulation test; Peripheral nerve stimulation equipment; Promontory stimulation test.

Publication types

Clinical Study

MeSH terms

Adult
Aged
Aged, 80 and over
Cochlear Implants*
Deafness*
Ear Canal
Electric Stimulation
Hearing Loss, Sensorineural* / diagnosis
Humans
Middle Aged
Silver

Substances

Silver