Exploring asymmetry of electrical compound action potential latencies in sequential cochlear implants as a possible effect of the lateral olivocochlear bundle.
6 affiliations
- 1Former Director Audiovestibology Di Circolo Hospital, Varese, Italy.
- 2Associazione Italiana Liberi di Sentire, Varese, Italy.
- 3ENT Department, ASP Caltanissetta, Caltanissetta, Italy.
- 4S. Eugenio Otologopedic Center, Locarno, Switzerland.
- 5Section of Otolaryngology, Department of Neuroscience DNS, University of Padua, Padua, Italy.
- 6Department of Developmental and Social Psychology, University of Padua, Padua, Italy.
Abstract
Objective
Electrophysiological evaluations of the second cochlear implant (CI) in sequentially implanted patients usually consider the brainstem with electrically evoked auditory brainstem responses and the auditory cortex with slow responses. To further understand auditory electrophysiological behaviour after the second implantation, the present study investigated auditory nerve activity using electrical compound action potential (ECAP).Methods
Of 167 bilaterally implanted patients, 73 were evaluated and divided into 2 groups: patients with simultaneous (33 children and 8 adults) and sequential (21 children and 11 adults) surgeries. The sequential surgeries were further grouped into "short delay" (< 4 years) and "long delay" (> 4 years), considering the time spent between procedures. Every patient was assessed by evaluating the N1 wave of ECAP, focusing on the latencies in both ears.Results
The ECAP's interaural latencies were not statistically different in simultaneous patients and sequential progressive/acquired deaf adults. In contrast, in sequential congenital deaf children, the latencies of the second implant were temporally earlier than those of the first implant, but symmetry recovered within 2 years after surgery.Conclusions
The results revealed that late-sequential CI stimulation generates asymmetric interaural activity at the first neuron in congenitally deaf children. Such an asymmetry is due to the anticipation of the sequential N1 wave ECAP, rather than the expected delay. The hypothesis attributes it to a temporary lack of efferent system tuning, particularly the lateral olivocochlear bundle, which should still be active in implantees. These findings could enhance the benefits of sequential CI mapping by implementing a stimulation delay with a temporal duration similar to N1 anticipation until binaural processing normalises.
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BibTeX
@article{burdo2026exploring,
title = {{Exploring asymmetry of electrical compound action potential latencies in sequential cochlear implants as a possible effect of the lateral olivocochlear bundle.}},
author = {Sandro Burdo and Valentina Mannella and Lara Dalla Costa and Patrizia Trevisi and Maria Teresa Rosalia and Giuseppe Impalà and Davide Brotto},
journal = {Acta otorhinolaryngologica Italica : organo ufficiale della Societa italiana di otorinolaringologia e chirurgia cervico-facciale},
year = {2026},
month = oct,
doi = {10.14639/0392-100x-a1798},
url = {https://europepmc.org/article/MED/42969778},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Exploring asymmetry of electrical compound action potential latencies in sequential cochlear implants as a possible effect of the lateral olivocochlear bundle.
AU - Sandro Burdo
AU - Valentina Mannella
AU - Lara Dalla Costa
AU - Patrizia Trevisi
AU - Maria Teresa Rosalia
AU - Giuseppe Impalà
AU - Davide Brotto
PY - 2026
DA - 2026/10/01
JO - Acta otorhinolaryngologica Italica : organo ufficiale della Societa italiana di otorinolaringologia e chirurgia cervico-facciale
DO - 10.14639/0392-100x-a1798
UR - https://europepmc.org/article/MED/42969778
AB - Objective Electrophysiological evaluations of the second cochlear implant (CI) in sequentially implanted patients usually consider the brainstem with electrically evoked auditory brainstem responses and the auditory cortex with slow responses. To further understand auditory electrophysiological behaviour after the second implantation, the present study investigated auditory nerve activity using electrical compound action potential (ECAP).Methods Of 167 bilaterally implanted patients, 73 were evaluated and divided into 2 groups: patients with simultaneous (33 children and 8 adults) and sequential (21 children and 11 adults) surgeries. The sequential surgeries were further grouped into "short delay" (< 4 years) and "long delay" (> 4 years), considering the time spent between procedures. Every patient was assessed by evaluating the N1 wave of ECAP, focusing on the latencies in both ears.Results The ECAP's interaural latencies were not statistically different in simultaneous patients and sequential progressive/acquired deaf adults. In contrast, in sequential congenital deaf children, the latencies of the second implant were temporally earlier than those of the first implant, but symmetry recovered within 2 years after surgery.Conclusions The results revealed that late-sequential CI stimulation generates asymmetric interaural activity at the first neuron in congenitally deaf children. Such an asymmetry is due to the anticipation of the sequential N1 wave ECAP, rather than the expected delay. The hypothesis attributes it to a temporary lack of efferent system tuning, particularly the lateral olivocochlear bundle, which should still be active in implantees. These findings could enhance the benefits of sequential CI mapping by implementing a stimulation delay with a temporal duration similar to N1 anticipation until binaural processing normalises.
SN - 0392-100X
SN - 1827-675X
ER -