聴神経腫瘍患者における前庭機能評価の個別化に向けて

Background: Age-related vestibular decline frequently accompanies presbycusis, and older adults undergoing cochlear implantation (CI) may be particularly vulnerable to postoperative dizziness due to a reduced compensatory capacity and a higher burden of comorbidities. Although CI is an effective treatment for severe-to-profound sensorineural hearing loss in the elderly, its impact on vestibular function remains a critical concern. This study aimed to compare pre and postoperative vestibular performance in older patients (≥65 years) versus younger adults undergoing CI in order to identify the risk factors for postoperative vestibular deterioration and critical issues that characterize this category and carry out personalized preoperative counseling. Methods: In this monocentric observational study, adults undergoing CI were divided into two groups: older patients (OPS, ≥65 years) and younger patients (YPS, <65 years). Vestibular function was assessed preoperatively and one month postoperatively through a Dizziness Handicap Inventory (DHI), history of recurrent falls, clinical examination, video head impulse test (VHIT), bithermal caloric testing, and computerized dynamic posturography (Sensory Organization Test, SOT). Risk factors for postoperative vestibular worsening were analyzed using ANOVA test and chi-square statistics, with significance set at p < 0.05. Results: A total of 63 patients were included, with 18 surgeries involving OPS and 45 involving YPS. Preoperatively, OPS showed significantly higher rates of vestibular abnormalities on caloric testing (55.5% vs. 17.7% bilateral hyporeflexia, p < 0.05) and a higher prevalence of recurrent falls (33.3% vs. 4.4%, p < 0.05). Early postoperative dizziness (DHI¹) increased significantly in both groups, but age ≥ 65 was a risk factor for ≥10% worsening (OR 2.2, p < 0.05). At one month, YPS returned to baseline DHI values, whereas OPS showed persistent dizziness with significantly higher DHI² scores (29.2 vs. 12.9, p < 0.05). Vestibular worsening was identified in 33.3% of VHIT assessments and 44.4% of caloric tests in OPS, with caloric testing proving more sensitive than VHIT. Implantation on the better-functioning vestibular side and the presence of ≥3 comorbidities increased the likelihood of persistent postoperative dizziness. Conclusions: Older age is a significant risk factor for persistent dizziness and vestibular impairment one month after CI. Given the reduced compensatory capacity typical of older adults, vestibular assessment should play a central role in preoperative decision-making, particularly for side selection. Bithermal caloric stimulation is recommended as the most sensitive tool for detecting clinically relevant vestibular changes. Preoperative counseling for older CI candidates should include a detailed discussion of vestibular risks and the possible need for postoperative rehabilitation.