Shereen M El-Abd, Abeir O Dabbous, Amira M El-Shennawy, Olfat A Khodeir
JHS 2011; 1(3): EA76-79
BACKGROUND: Balance alterations in the postoperative Cochlear Implant (CI) surgeries vary widely (Bonucci et al., 2008).
OBJECTIVE AND METHODS: This is a cross-sectional study that comprised 20 adults who underwent unilateral cochlear implantation, compared to 20 well-matched controls. The aim was to assess balance function in CI recipients using sensory organization test (SOT) of computerized dynamic posturography (CDP) and to compare the findings with vestibular evoked myogenic potential (VEMP) and to correlate findings of these 2 tests with the patients’ imbalance symptoms.
RESULTS: Vertigo was present in 5/20 cases. Eleven had post-operative dizziness. Thirteen out of 20 cases had SOT abnormalities, 10 of which had vestibular ratio abnormality. The cases had statistically significant lower scores than their controls in SOT conditions 4, 5, 6, composite score, vestibular, visual & visual preference ratios. VEMP response was preserved bilaterally in 11/20, out of which 5 had abnormal inter-aural amplitude difference, which was statistically significantly lower than the controls. The remaining 9 had lost VEMP irrespective of the tested side. Statistically significant differences in p13 latency were found comparing implanted & non- implanted ears, as well as comparing implanted ears with the controls. There was no statistically significant correlation between patients’ age, duration of sensory deprivation or implant duration with any of the posturographic or VEMP parameters. And both tests were not correlated.
CONCLUSION: Balance dysfunction is not uncommon in CI recipients post-operatively, requiring vestibular rehabilitation. We recommend adding CDP and VEMP to the routine pre-and post surgical testing.
Keywords: balance, cochlear implant, posturography, vestibular evoked myogenic potential, vestibulo-spinal reflex