Objective: To compare the results of auditory steady-state response (ASSR) and click auditory brainstem response (click ABR) among infants and young children tested at the Ear Unit of a Tertiary General Hospital. Methods: Design: Cross-sectional Study Setting: Tertiary General Hospital Population: Within-subject comparisons of click auditory brainstem response (click ABR) thresholds and auditory steady-state response (ASSR) thresholds among 55 infants and young children, 2 months to 35 months of age referred to the Ear Unit for electrophysiologic hearing assessment. Results: Click ABR showed strong positive correlation to all frequencies and averages of ASSR. Highest correlation was noted with the average of 1-4 kHz ASSR results with Pearson r = 0.89 (Spearman r=0.80), the average of 2-4 kHz had strong positive correlation r = 0.88 (0.79). Correlation was consistently strong through all ASSR frequencies (0.5 kHz at r=0.86 (0.74), 1 kHz at r=0.88 (0.78), 2 kHz at r=0. 87 (0.79), 4 kHz at r=0.85 (0.76)). Average differences of click ABR and ASSR thresholds were 8.2±12.9dB at 0.5 kHz, 8.6±12.6dB at 1 kHz, 5.3±11.8dB at 2 kHz and 7.8±13.4dB at 4 kHz. Among patients with no demonstrable waveforms by click ABR with maximal click stimulus, a large percentage presented with ASSR thresholds. Of these, 80.5% (33 of 41) had measurable results at 0.5 kHz with an average of 107.3±11.1dB, 85.4% (35 of 41) at 1 kHz with an average of 110.5±11.8dB, 73.2% (30 of 41) at 2 kHz with an average of 111.2±11.1dB and 63.4% (26 of 41) at 4 kHz with average of 112.2±8.21dB. Auditory steady-state response results were comparable to auditory brainstem response results in normal to severe hearing loss and provided additional information necessary for complete audiologic assessment especially among patients with severe to profound hearing loss wherein click ABR showed no responses. Up to 85.4% of patients that would have been noted to have no waveforms by click ABR still demonstrated measurable thresholds by ASSR. Conclusion: Our study suggests that ASSR may be the best available tool for assessing children with severe to profound hearing loss, and is a comparably effective tool in overall hearing assessment for patients requiring electrophysiological testing. The advantages of ASSR over click ABR include: 1) detection of frequency-specific thresholds and; 2) the detection of hearing loss thresholds beyond the limits of click ABR.

Background: Certain indigenous populations have been noted by the World Health Organization (WHO) to havethe highest prevalence ratesforchronicsuppurativeotitis media (CSOM), including the Australian Aborigines (28-43%), Greenlanders (2-10%) and Alaskan Eskimos (2-10%). Objectives: To determine the prevalence of common ear problems, particularly CSOM, among the indigenous Ati or Aeta community in Bolabog, Boracay, and to determine their hearing sensitivity using screening audiometry. Methods: Study Design - Descriptive cross-sectional study. Setting - A small Ati community in Bolabog, Boracay. Population - A total of 63 adults and children underwent medical interview and otoscopy. Additionally 24 had their hearing screened by audiometry. Results: About a quarter of the population participated in the study, including 41 children (40 percent of all children) and 22 adults (18 percent of all adults). Forty-six percent of children and 23 percent of adults who were examined had previous history of ear discharge, while 22 percent of children and 45 percent of adults who were examined had history of hearing loss. Seventeen percent of children had history of hearing loss in the family. CSOM was found in 18 (43.90 percent) children and 8 (36.36 percent) adults. Impacted cerumen was found in 17.1 percent of children. Eleven female children underwent screening audiometry. Of these, eight had normal hearing and three had abnormal findings. Thirteen adults were also tested, five of whom were male and had normal hearing bilaterally. Four of eight female adults had abnormal hearing, of which three were unilateral. Conclusions: The Ati population in Bolabog, Boracay belongs to a group with the highest prevalence rates for CSOM (27.0 percent). A bigger sample for screening audiometry is required for proper estimation of hearing loss prevalence. Both environmental and genetic factors may have increased the prevalence of CSOM in the Ati population of Boracay. (Author)
HEARING LOSS OTITIS MEDIA OTITIS MEDIA ; SUPPURATIVE

Objective: Recent advances in epigenetic studies continue to reveal novel mechanisms of gene regulation and control, however little is known on the role of epigenetics in sensorineural hearing loss (SNHL) in humans. We aimed to investigate the methylation patterns of two regions, one in RB1 and another in GJB2 in Filipino patients with SNHL compared to hearing control individuals. Methods: We investigated an RB1 promoter region that was previously identified as differentially methylated in children with SNHL and lead exposure. Additionally, we investigated a sequence in an enhancer-like region within GJB2 that contains four CpGs in close proximity. Bisulfite conversion was performed on salivary DNA samples from 15 children with SNHL and 45 unrelated ethnically-matched individuals. We then performed methylation-specific real-time PCR analysis (qMSP) using TaqMan® probes to determine percentage methylation of the two regions. Results: Using qMSP, both our cases and controls had zero methylation at the targeted GJB2 and RB1 regions. Conclusion Our study showed no changes in methylation at the selected CpG regions in RB1 and GJB2 in the two comparison groups with or without SNHL. This may be due to a lack of environmental exposures to these target regions. Other epigenetic marks may be present around these regions as well as those of other HL-associated genes.
Hearing Loss ; Methylation