Multicentre cohort study of cochlear implantation outcomes in Thailand.

OBJECTIVES: To report the status and outcomes of cochlear implantation in Thailand. DESIGN: Cohort study. SETTING: Tertiary care and university hospitals. PARTICIPANTS: Patients who underwent cochlear implant surgery in Thailand. INTERVENTIONS: This project collected data from all government and university hospitals in Thailand where cochlear implant surgery was performed between 2016 and 2020. PRIMARY AND SECONDARY OUTCOME MEASURES: Baseline characteristics, operation data, complications, audiological outcomes and quality of life were reported. RESULTS: This study included 458 patients, and nearly half of the patients were children and adolescents (46.94%). The mean age of the patients was 2.96±5.83 years. At 1 year postoperatively, the mean pure tone average of the hearing threshold in the implanted ear significantly improved from unaided preoperative baseline (mean difference (MD) 64.23 dB HL; 95% CI 59.81 to 68.65; p<0.001). The mean speech recognition threshold also improved (MD 55.96 dB HL; 95% CI 49.50 to 62.42, p<0.001). The quality-of-life scores of the EQ-5D-5L, PedsQL and HUI3 questionnaires at 1 year showed improved mobility (range, 0-5; MD 0.65; 95% CI 0.05 to 1.25; p=0.037), hearing (range, 0-6; MD 0.96; 95% CI 0.30 to 1.61; p=0.006) and speech (range, 0-5; MD 0.44; 95% CI 0.04 to 0.84; p=0.031). Common complications included electrode dislodgement (2.18%), vertigo (1.23%) and meningitis (1.93%). CONCLUSIONS: Excellent audiological outcomes and improvement in the quality of life in the mobility, hearing and speech domains were observed in patients who underwent cochlear implantation in Thailand.

Middle Ear Extramedullary Hematopoiesis: A Case Report.

Background: Extramedullary hematopoiesis (EMH) in the middle ear is exceedingly rare, with fewer than five cases reported. The authors report the first Thai case of middle ear EMH Case Report: A 32-year-old Thai thalassemic man presented with complaint of right-sided hearing loss from a middle ear mass. The CT/MRI was done and the diagnosis of EMH was confirmed by a pathological examination after a surgical removal. Conclusion: A differential diagnosis of EMH should also be done in thalassemic patients presented with a middle ear mass.

Distribution of type IV collagen in the cochlea in Alport syndrome.

OBJECTIVE: To determine the distribution of alpha1, alpha3, and alpha5 chains of type IV collagen in the cochlea in Alport syndrome. DESIGN: Case-control study. PATIENTS: Two patients with sensorineural hearing loss due to Alport syndrome. Both patients had known mutations in the COL4A5 gene. MAIN OUTCOME MEASURES: Immunostaining was used to study the distribution of type IV collagen (alpha1, alpha3, and alpha5 chains) within the cochlea. Immunostaining was also performed in the cochlear tissues of an unaffected individual used as a control. RESULTS: In the control ear, alpha1 staining was observed in the basement membrane overlying the basilar membrane, in the basement membrane of cochlear blood vessels and Schwann cells, and within the spiral limbus. In the control ear, we also observed strong staining for alpha3 and alpha5 chains in the basement membrane overlying the basilar membrane and within the spiral ligament. In both cases with Alport syndrome, no immunostaining was observed for alpha3 or alpha5 chains within the cochlea, whereas alpha1 staining was present in locations similar to that seen in the control ear. CONCLUSIONS: The results indicate that isotype switching does not occur within the cochlea in Alport syndrome. The results are also consistent with the hypothesis that the sensorineural hearing loss in Alport syndrome may be due to alterations in cochlear micromechanics and/or dysfunction of the spiral ligament.

Quantification of angiogenesis in otosclerosis.

OBJECTIVES/HYPOTHESIS: The determinants of clinical versus histologic otosclerosis are unknown, but angiogenesis is associated with active disease. We hypothesized that quantification of angiogenesis in otosclerotic human temporal bones could reveal significant differences between clinical and histologic cases. STUDY DESIGN: We reviewed all otosclerosis specimens meeting criteria from the temporal bone collection of the Massachusetts Eye and Ear Infirmary and 10 normal controls. METHODS: Digital images were taken at predilection sites, followed by computer-assisted analysis. Canalicular area (CA), the aggregate of vascular spaces within bone, microvessel density (MVD), area, and depth were the main measures. Evidence of a direct connection between local vessels and the vasculature of the otosclerotic focus was also recorded for each specimen. RESULTS: The average area (mm) and depth (number of sections containing otosclerosis) of clinical lesions was significantly greater than histologic lesions. Total microvessel counts were significantly greater in clinical versus histologic lesions, and both clinical and histologic lesions contained significantly greater numbers of microvessels than the normal otic capsule. CA was also significantly higher in clinical lesions. MVD was slightly but not significantly higher in clinical lesions. Importantly, a direct connection between named vessels and the otosclerotic vasculature was significantly more frequent in clinical lesions. CONCLUSIONS: Computer-assisted quantification revealed significantly greater measures of angiogenesis in clinical versus histologic otosclerosis. Direct connection to adjacent vessels may support angiogenesis in this disease. Sustained angiogenesis may be an important determinant of clinical otosclerosis.