[Possibilities for residual hearing preservation with Nucleus CI532 Slim Modiolar electrode array. Case report]

Area of Science:

• Otolaryngology
• Neurosurgery
• Audiology

Background:

• Preserving residual acoustic hearing during cochlear implantation (CI) is crucial for enhancing hearing performance in hearing-impaired patients.
• Minimally invasive surgical techniques and atraumatic electrode designs are essential for minimizing implantation trauma.

Observation:

• A case study involving a patient with congenital hearing loss and residual hearing who received a Cochlear® Nucleus CI532 Slim Modiolar electrode.
• The electrode was implanted via a minimally invasive round window approach on the right ear.
• Audiological monitoring was conducted to assess postoperative acoustic residual hearing.

Findings:

• Postoperative hearing thresholds showed an initial progression of 20-25 dBHL at lower frequencies (0.25-1.0 kHz) and 5-10 dBHL at higher frequencies (2.0-4.0 kHz) compared to preoperative levels.
• Hearing thresholds at the 6-month mark indicated a slight progression above 1 kHz, but by 12 months, they improved to levels comparable to the 4th postoperative week.
• The slim modiolar electrode's proximity to the modiolus may reduce hydrodynamic load and offer neuroprotection by enabling lower stimulation intensity.

Implications:

• Preservation of acoustic residual hearing post-CI can significantly improve speech perception and sound localization abilities.
• Maintaining residual hearing is vital for future regenerative procedures and potential drug treatments for hearing loss.
• The findings support the use of slim modiolar electrodes in cochlear implantation for patients with residual hearing.