Vestibular function prior to cochlear implantation in patients with non-syndromic hearing loss caused by CDH23...

Vestibular involvement in CDH23-related nonsyndromic hearing loss remains incompletely understood, particularly prior to cochlear implantation.

To evaluate vestibular function prior to cochlear implantation in patients with severe to profound non-syndromic hearing loss caused by CDH23 mutations.

We retrospectively evaluated vestibular function in seven patients with severe to profound non-syndromic hearing loss caused by CDH23 mutations who were scheduled for cochlear implantation. Vestibular assessment included caloric testing, ACS-cVEMP, BCV-oVEMP, and damped rotation testing, depending on age.

Six patients had homozygous missense mutations, and one had compound heterozygous mutations in CDH23. Caloric testing revealed unilateral reduced responses in two patients (28.6%). Damped rotation testing, performed in four pediatric patients, showed a unilateral reduced response in one patient (25%). ACS-cVEMP demonstrated a unilateral reduced response in one patient (14.3%) and an absent response in another (14.3%). BCV-oVEMP, conducted in three patients, revealed a unilateral absent response in one patient (33.3%). Overall, unilateral vestibular dysfunction was identified in four of seven patients (57.1%).

More than half of patients with CDH23-related non-syndromic deafness exhibited unilateral vestibular dysfunction prior to cochlear implantation, suggesting that preoperative vestibular assessment may be clinically relevant in this population.