The Outcome of Cochlear Implantations in Deaf-Blind Patients: A Multicenter Observational Study.

OBJECTIVE: This multicenter study aimed to evaluate the auditory and speech outcomes of cochlear implantation (CI) in deaf-blind patients compared with deaf-only patients. STUDY DESIGN: Retrospective cohort study. SETTING: Multiple cochlear implant centers. PATIENTS: The current study was conducted on 17 prelingual deaf-blind children and 12 postlingual deaf-blind adults who underwent CI surgery. As a control group, 17 prelingual deaf children and 12 postlingual deaf adults were selected. INTERVENTION: Cochlear implantation. MAIN OUTCOME MEASURES: Auditory and linguistic performances in children were assessed using the categories of auditory performance (CAP) and Speech Intelligibility Rating (SIR) scales, respectively. The word recognition score (WRS) was also used to measure speech perception ability in adults. The mean CAP, SIR, and WRS cores were compared between the deaf-only and deaf-blind groups before CI surgery and at "12 months" and "24 months" after device activation. Cohen's d was used for effect size estimation. RESULTS: We found no significant differences in the mean CAP and SIR scores between the deaf-blind and deaf-only children before the CI surgery. For both groups, SIR and CAP scores improved with increasing time after the device activation. The mean CAP scores in the deaf-only children were either equivalent or slightly higher than those of the deaf-blind children at "12 months post-CI" (3.94 ± 0.74 vs 3.24 ± 1.25; mean difference score, 0.706) and "24 months post-CI" (6.01 ± 0.79 vs 5.47 ± 1.06; mean difference score, 0.529) time intervals, but these differences were not statistically significant. The SIR scores in deaf-only implanted children were, on average, 0.870 scores greater than the deaf-blind children at "12 months post-CI" (2.94 ± 0.55 vs 2.07 ± 1.4; p = 0.01, d = 0.97) and, on average, 1.067 scores greater than deaf-blind children at "24 months post-CI" (4.35 ± 0.49 vs 3.29 ± 1.20; p = 0.002; d = 1.15) time intervals. We also found an improvement in WRS scores from the "preimplantation" to the "12-month post-CI" and "24-month post-CI" time intervals in both groups. Pairwise comparisons indicated that the mean WRS in the deaf-only adults was, on average, 10.61% better than deaf-blind implanted adults at "12 months post-CI" (62.33 ± 9.09% vs 51.71 ± 10.73%, p = 0.034, d = 1.06) and, on average, 15.81% better than deaf-blind adults at "24-months post-CI" (72.67 ± 8.66% vs 56.8 ± 9.78%, p = 0.002, d = 1.61) follow-ups. CONCLUSION: Cochlear implantation is a beneficial method for the rehabilitation of deaf-blind patients. Both deaf-blind and deaf-only implanted children revealed similar auditory performances. However, speech perception ability in deaf-blind patients was slightly lower than the deaf-only patients in both children and adults.

Consanguinity Among Parents of Iranian Deaf Children.

BACKGROUND: It seems that there is a relationship between consanguinity and profound hearing loss but there is little data about the association of consanguinity and hearing loss in Iran. OBJECTIVES: The aim of this study is to demonstrate the causes of profound bilateral sensorineural hearing loss among Iranian samples who are candidates for cochlear implantation. METHODS: This study was retrospective, analytical, and designed to collect information about profound hearing impaired cases referred to the Baqiyatallah Cochlear implantation center using enumeration. A total of 310 children with profound hearing impairments participated in this study. They were aged from 6 months to 4 years old. The study was done between January 2007 and April 2009. Chi-square tests were used to show whether there was any statistical difference between the incidence of marital consanguinity of their parents and the normal population. RESULTS: Sixty-five percent of those 310 children had parents who had married with their relatives. Of the 203 (65%) parents that had consanguineous marriages, 132 were first cousins, which includes the children of two brothers (37 [11.8%] patrilateral parallel cousins), the children of two sisters (38 [12.2%] multi-lateral parallel cousins), or the children of a brother and a sister (57 [18.3%] cross cousins). Fifty-four (17.4%) of the parents were second cousins and 17 (5.2%) were beyond second cousins. Also, hearing loss etiology was obvious in 237 (76.3%) of the patients with profound hearing loss but was unknown in 73 (23.7%). Hereditary was identified as the most common cause in 33% of the cases. CONCLUSIONS: Our data demonstrated a 65% occurrence of consanguineous marriage among the parents of deaf children, which is statistically different from the percentage of consanguineous marriage among Iranian population (38%). This indicates an obvious relationship between severe hearing loss and consanguineous marriage.