Cortical reorganization following auditory deprivation predicts cochlear implant performance in postlingually deaf adults.

Long-term hearing loss in postlingually deaf (PD) adults may lead to brain structural changes that affect the outcomes of cochlear implantation. We studied 94 PD patients who underwent cochlear implantation and 37 patients who were MRI-scanned within 2 weeks after the onset of sudden hearing loss and expected with minimal brain structural changes in relation to deafness. Compared with those with sudden hearing loss, we found lower gray matter (GM) probabilities in bilateral thalami, superior, middle, inferior temporal cortices as well as the central cortical regions corresponding to the movement and sensation of the lips, tongue, and larynx in the PD group. Among these brain areas, the GM in the middle temporal cortex showed negative correlation with disease duration, whereas the other areas displayed positive correlations. Left superior, middle temporal cortical, and bilateral thalamic GMs were the most accurate predictors of post-cochlear implantation word recognition scores (mean absolute error [MAE] = 10.1, r = .82), which was superior to clinical variables used (MAE: 12.1, p < .05). Using the combined brain morphological and clinical features, we achieved the best prediction of the outcome (MAE: 8.51, r = .90). Our findings suggest that the cross-modal plasticity allowing the superior temporal cortex and thalamus to process other modal sensory inputs reverses the initially lower volume when deafness becomes persistent. The middle temporal cortex processing higher-level language comprehension shows persistent negative correlations with disease duration, suggesting this area's association with degraded speech comprehensions due to long-term deafness. Morphological features combined with clinical variables might play a key role in predicting outcomes of cochlear implantation.

Long-term Change in the Speech Perception Ability in Pediatric Cochlear Implants and the Effect of the Age at Implantation.

OBJECTIVE: We analyzed the long-term changes in speech perception ability of pediatric cochlear implants (CIs) to evaluate the effect of the age at the time of surgery. STUDY DESIGN: Retrospective. SETTING: Tertiary care academic center. PATIENTS: One hundred fourteen prelingually deaf children with CI use duration >10 years. MAIN OUTCOME MEASURES: Categories of auditory performance (CAP) scores and monosyllabic word recognition scores using the Asan-Samsung Korean word list (ASK-WRS) and a conventional word list (KS-WRS) were the main outcomes. Outcomes were compared according to the age at surgery (group I, 1-2 yr; II, 2.1-3 yr; III, 3.1-7 yr; IV, 7.1-13 yr). RESULTS: CAP scores reached plateaus at 2.6 to 3.3 years post-CI; groups I to III showed better scores than group IV. The maximum CAP score was obtained in all children of groups I to III and in 65% of group IV. ASK-WRSs reached plateaus at 3.2 to 4.8 years post-CI. Younger patients at CI operation showed better ASK-WRSs (97, 93, 90, and 54% in groups I-IV, respectively), but the differences were not significant (I versus II and II versus III). Ceiling effect (perfect score) was observed in early groups (67, 44, 30, and 0% in groups I-IV). KS-WRSs, which is a challenging test, reached plateaus at 7.2 to 8.4 years postsurgery with no ceiling effect. Early implantees showed significantly better scores (88, 82, 73, and 46% in groups I-IV). CONCLUSIONS: Speech perception ability after CI showed audiological age-specific improvement evaluated by various test methods. The most challenging test demonstrated long-term performance differences by the age at CI operation.

Speech Perception Growth Patterns in Prelingual Deaf Children With Bilateral Sequential Cochlear Implantation.

OBJECTIVE: To evaluate speech perception following the first (CI-1) and second (CI-2) cochlear implantation (CI) in children with sequential bilateral CI. STUDY DESIGN: Retrospective. PATIENTS: Seventy children with follow-up for 60 months post CI-1 and 36 months post CI-2. MAIN OUTCOME MEASURES: Word recognition score (WRS) was the main outcome. WRSs were compared by age at CI operation (group A ≤ 3.5 yr, B 3.6-8.6, for CI-1; group I ≤ 3.5 yr, II 3.6-7.0, III 7.1-13, IV > 13, for CI-2). RESULTS: For CI-1, the WRS of group A exceeded 80% at 24 months post procedure, earlier than group B (54 mo). Group A also had a shorter period of CI-1 use up to the WRS plateau than group B. CI-2 showed an initial burst of WRS growth much earlier than CI-1. This initial burst was most robust within 3 months in group II, but modest in group IV. The periods of CI-2 use (11-17 mo) up to the WRS plateau were much shorter than CI-1 (40-64 mo). Group I did not show the best WRS at 1 month post CI but later exceeded the other groups. CONCLUSION: Children received an immediate benefit by a burst of WRS growth from CI-2 earlier than CI-1, even within 3 months, suggesting that CI-1 gets the auditory cortex ready to foster speech processing from CI-2. The CI-2 performance depends on age at CI-2 implantation and on CI-1 performance. Our current findings will be relevant for clinicians who are counselling parents on CI-2 surgery.

Prognostic roles of preoperative CT findings and air-bone gaps in type 1 tympanoplasty.

BACKGROUND: Although CT has been used widely, the role of preoperative CT findings including other factors in tympanoplasty has not been elucidated comprehensively. AIMS/OBJECTIVES: To evaluate relationship of CT findings with other factors and audiological results in type 1 tympanoplasty. MATERIAL AND METHODS: A cohort of consecutive 175 patients with type 1 tympanoplasty was enrolled. Addition of mastoidectomy was based on the presence of soft tissue in antrum on CT. Postoperative air-bone gap (ABG) and reperforation rate were analyzed. RESULTS: Positive soft tissue in antrum on CT was found in 52 (29.7%) patients and showed larger preoperative ABG than the negative group. Successful ABG closure (≤20 dB) was obtained in 97% when preoperative ABG ≤20 dB, but it decreased as the preoperative ABG increased (83% with preoperative ABG of 21-30 dB, and 0% with preoperative ABG >30 dB). Postoperative reperforation rate was positively related to the preoperative ABG, but not the presence of soft tissue in the antrum, the size, or locations of preoperative perforations. CONCLUSIONS AND SIGNIFICANCE: Our findings showed that temporal bone CT was helpful in determining addition of mastoidectomy and the presence of soft tissue in the antrum was associated with large ABG.