Effects of Cochlear Implantation and Steroids on the Aging Guinea Pig Cochlea.

OBJECTIVE: The objective was to determine the effects of older age on hearing preservation after cochlear implantation (CI), and whether steroids improve hearing preservation in older animals. We hypothesized greater hearing preservation would be observed in (1) young animals compared to older animals and (2) older animals receiving steroids compared to no steroids. The secondary objective was to assess levels of fibrosis utilizing optical coherence tomography (OCT). STUDY DESIGN: Experimental Animal Study. SETTING: Laboratory. METHODS: Three groups of guinea pigs: young (YCI; 8.5 ± 0.5 weeks; n = 10), old (OCI; 19.1 ± 1.0 months; n = 9) and old + steroids (OCI+S; 19.1 ± 1.0 months; n = 9) underwent CI. The OCI+S group received a steroid taper over 7 days starting 2 days before surgery to 4 days after. Auditory brainstem response (ABR) measurements were performed preoperatively and postoperatively. OCT imaging was performed to assess cochleae for extent of fibrotic tissue growth in the scala tympani. RESULTS: The YCI group had significantly better hearing preservation as measured by smaller increases in ABR thresholds [mean shift: 2.79 ± 0.66] compared to the OCI group [mean shift = 12.44 ± 5.6]. The OCI+S group had significantly better hearing preservation [2.66 ± 1.50] compared to the OCI group. No significant differences was seen in fibrosis across groups. CONCLUSIONS: Young animals and older animals that received steroids had better hearing after CI than older animals not given steroids, but hearing preservation was not correlated with the level of fibrosis assessed using OCT. This work is the first to investigate differences in hearing preservation by age in an animal model, and supports the protective effects of steroids on hearing preservation in older individuals.

Drug-Induced Sleep Endoscopy Findings in Children With Obstructive Sleep Apnea With vs Without Obesity or Down Syndrome.

Importance: Persistent obstructive sleep apnea after adenotonsillectomy is common in children with Down syndrome or obesity. Drug-induced sleep endoscopy could help to identify anatomic differences in these patients that might affect surgical decision-making. Objective: To assess drug-induced sleep endoscopy findings in surgically naive children with obstructive sleep apnea with obesity or Down syndrome and compare these findings with children without obesity or Down syndrome. Design, Setting, and Participants: This cross-sectional analysis of data from a prospective cohort study of patients enrolled between May 1, 2015, and December 31, 2019, was conducted at an academic tertiary care children's hospital and included a consecutive sample of surgically naive children (age 2-18 years) who underwent drug-induced sleep endoscopy at the time of adenotonsillectomy for sleep-disordered breathing. Indications for sleep endoscopy included severe sleep apnea, age older than 7 years, obesity, African American race, and Down syndrome. Exposures: Drug-induced sleep endoscopy. Main Outcomes and Measures: Sleep endoscopy findings were scored according to the Sleep Endoscopy Rating Scale. Ratings at 6 anatomic levels for children with obesity and those with Down syndrome were compared with controls without obesity or Down syndrome using several measures of effect size (Cohen d, Cramer V, and η2). Results: A total of 317 children (158 girls [50%]; 219 [69%] White, 20 [6%] Black, and 103 [34%] Hispanic; mean [95% CI] age, 9.6 [9.2-10.0] years) were included, of whom 115 (36%) were controls without obesity or Down syndrome, 179 (56%) had obesity without Down syndrome, and 23 (7%) had Down syndrome. The mean apnea-hypopnea index was 16 (95% CI, 13-19), and the mean minimum O2 saturation was 83% (95% CI, 81%-85%). Compared with controls without obesity or Down syndrome, children with Down syndrome demonstrated greater overall obstruction (mean sleep endoscopy rating scale total score of 5.6 vs 4.8; Cohen d, 0.46), and greater tonsillar (percentage of complete obstruction: 65% vs 54%), tongue base (percentage of complete obstruction: 26% vs 12%), and arytenoid obstruction (percentage of at least partial obstruction, 35% vs 6%). Children with obesity had greater tonsillar (percentage of complete obstruction, 74% vs 54%) and less base of tongue obstruction (percentage of complete obstruction, 2% vs 12%) compared with controls. Conclusions and Relevance: In this cohort study, surgically naive children with obesity with obstructive sleep apnea had predominantly tonsillar obstruction, whereas children with Down syndrome demonstrated greater obstruction of the tonsils, tongue base, and arytenoids compared with controls. Routine drug-induced sleep endoscopy should be considered in surgically naive children with Down syndrome to help inform the surgical plan.