Cochlear implants in children deafened bij congenital cytomegalovirus

Introduction: Congenital cytomegalovirus (cCMV) is the most common intra-uterine viral infection in most developed countries. Moreover, cCMV has been identified as the leading cause of non-genetic congenital sensorineural hearing loss (SNHL) in infants. The vast majority of infected newborns are asymptomatic at birth (90%), although 7%-21% of patients are at risk for developing SNHL, neurologic deficits and behavioural problems later on in life. Approximately 10% of the infected infants (symptomatic cCMV children) are born with clinically apparent sequelae, including SNHL, mental retardation, microcephaly and severe neurologic deficits. Cochlear implantation is of value in the setting of cCMV-associated severe SNHL although the outcome is less predictive.Methods: A retrospective study of the pediatric patient database of the Ghent University Hospital was performed. Since 1992, 84 children have been implanted uni- or bilaterally. From this population, eight children were identified as being deaf caused by congenital CMV infection. A control group of eight cochlear implanted children deafened by Connexin 26 (Cx26) was drawn from our database and matched for age of implantation, experience with their CI and chronological age. Outcome of cochlear implantation was measured by means of the childU+2019s speech perception and production skills. These abilities were assessed with the Categories of Auditory Performance (CAP) and the Speech Intelligibility Rating (SIR) respectively. Results: Of the 8 children, 3 were symptomatic cCMV children, while the remaining 5 had an asymptomatic cCMV infection. Two of the asymptomatic children passed the newborn hearing screening (by means of AABR at the age of 1 month). These children developed a delayed-onset SNHL. None of the asymptomatic children had extra-auditory manifestations of the cCMV infection. All symptomatic children had additional problems, such as microcephaly, epilepsy and hypotonia.The overall perceptive (CAP) and productive (SIR) outcome of the cCMV and Cx26 group were compaired. No statistical significant differences were found between both groups for CAP (U+0445²(7) = 5.67, p>0.05), nor SIR (U+0445²(4) = 6.48, p>0.05) scores. When comparing CAP scores within each matched pair, it can be seen that 6 of the 8 (75%) cCMV children perform worse and 2 (25%) perform better. With respect to SIR scores, it was found that 3 out of 8 (37.5%) cCMV children perform worse, 3 children perform the same (37.5%) and 2 children (25%) perform better.Conclusion: In this study we have shown that asymptomatic cCMV children can achieve substantial auditory perceptive and productive skills following cochlear implantation, comparable with their CI Cx26 peers. Also sympomatic cCMV children perform sometimes better than initially expected. Thus early hearing rehabilitation of children with cCMV-related deafness can successfully increase access to oral language, even in the presence of CNS abnormalities. Secondly, seen the difficulties to predict which cCMV infected children will develop hearing loss and, among those who develop hearing loss, whether or not the loss will continue to deteriorate, all cCMV infected children need to be identified and long-term audiological follow-up assessment after universal newborn hearing screening should be taken care of.