To evaluate the utility of cochlear implantation in patients with sensorineural hearing loss (SNHL) associated with Kelch like protein 11 (KLHL11) IgG paraneoplastic neurologic syndrome (PNS).

SNHL is a frequent manifestation of KLHL11 IgG associated PNS and leads to significant morbidity. The role of cochlear implantation, in addition to immune therapy, in this population remains unknown.

We performed a retrospective chart review (January 2000 - January 2026) to identify patients with KLHL11 IgG associated SNHL who underwent cochlear implantation.

Among 65 patients with KLHL11 IgG, 29 (44%) had SNHL. Of these, five (17%; all male; median age 37 years (range 21-64)) underwent cochlear implantation (3 unilateral, 2 bilateral ears). SNHL was the initial manifestation in 3 of 5 patients (60%), and all had rhombencephalitis. Testicular seminoma was identified in one patient, anterior mediastinal mass in one and three had regressed testicular germ cell tumor or testicular microcalcification. All patients received corticosteroids, and three (60%) received second-line immunotherapy. The median interval from hearing loss to cochlear implantation was 30.5 months (range 10-48). The median mRS score remained 4 (range: 3-4) from the time of cochlear implantation through the last follow up. All patients had profound hearing loss (median pure tone average of the three most affected frequencies: 110 dB (range 80-120). Following cochlear implantation, two patients achieved open-set speech perception (including one with preserved pre-implantation speech perception). Sound awareness improved in all.

Data from this case series suggest that cochlear implantation improves sound awareness. It may restore open-set speech perception in patients with preserved pre-implantation speech perception, thus supporting auditory pathway dysfunction beyond cochlea.