International Journal of Pediatric Otorhinolaryngology
Audiometric, clinical and educational outcomes in a pediatric symptomatic congenital cytomegalovirus (CMV) population with sensorineural hearing loss
Introduction
Congenital cytomegalovirus (CMV) infection is a leading cause of neurological disease and hearing loss in children. Most of the infants with congenital CMV infection are without apparent clinical manifestations at birth (asymptomatic) and only 5–10% of the neonates exhibit findings suggestive of congenital infection (symptomatic infection). The average infection rate is 1% of all live births [1], [2], [3]. An estimated 40,000 infants in the USA are born each year with congenital CMV infection and about 7000 of these children will develop permanent central nervous system defects [1], [4], [5].
Symptomatic congenital CMV infection manifests itself as a triad of jaundice (62–76%), petechiae (58–79%) and HSM (50–88%). Microcephaly (21–53%), intra-uterine growth retardation (33–50%) and/or premature birth (25–34%) are also found [6], [7], [8], [9], [10].
The most common neurological defect (30–65% prevalence) is sensorineural hearing loss (SNHL). Other sequelae of CMV infection are mental retardation, cerebral palsy (CP), seizures and visual defects [6], [7]. The presence of specific clinical features, associated with CMV infection, has been assessed to see if they can predict hearing and neurodevelopmental outcomes. The presence of an abnormal cranial computed tomography (CT) scan, microcephaly, chorioretinitis or other neurological abnormalities at birth have been shown to forecast an adverse hearing and neurodevelopmental outcome [8], [9], [11].
CMV infection is, at this moment, the only relevant viral cause of perinatal hearing loss as rubella, measles and mumps have become rare due to vaccination. CMV is the leading cause of congenital non-hereditary sensorineural hearing loss in children [2], [12]. Peckham et al. estimated that 12% of all cases of congenital bilateral sensorineural deafness were caused by congenital CMV infection [13]. A wide variety of audiometric thresholds and outcomes have been described in this patient population.
Onset of SNHL after congenital CMV infection may be immediate (at birth) or delayed, with variability in the severity of the hearing loss in the affected children. This affects the early identification of hearing loss in this population and has implications for the implementation of newborn hearing screenings [14]. Screening for CMV infection in all neonates would improve the identification of neonatal hearing loss and identify those at risk of developing a hearing loss. Children with symptomatic infection have hearing loss at an earlier age and with greater severity than children with asymptomatic infection. Further deterioration or progression of the hearing loss will occur in a proportion of children with congenital CMV [3], [15], [16], [17], [18]. Long-term follow-up and serial audiometric testing and assessment is crucial in this population.
Based upon temporal bone studies, CMV-related SNHL is postulated to arise from a labyrinthitis induced by CMV that enters the endolymph via the stria vascularis [19]. Infected epithelial cells have been found in the walls of the inner ear and stria vascularis, with pronounced hydrops of the cochlear duct and saccule also noted [20]. CMV has also been cultured from perilymph and viral antigen production widely demonstrated in the spiral ganglion neurons and organ of corti [21], [22]. A review of published temporal bone studies demonstrated the typical inclusion cells of CMV infection in the scala media, Reissner's membrane and the stria vascularis of children who died of symptomatic congenital CMV infection [22], [23].
The purpose of this study was to examine the audiometric outcomes in a symptomatic congenital CMV population with SNHL and to compare these data with the clinical, radiological and educational findings in this population. We further sought to identify the factors associated with communication, educational and audiological outcomes in these children. We hypothesize that CMV-associated neurologic injury in newborns will positively correlate with the presence of poorer hearing, language, developmental and educational outcomes as compared to children without neurologic manifestations of CMV.
Section snippets
Patients and methods
An otologic database consisting of over 1500 children diagnosed with a permanent sensorineural hearing loss was queried for children with a proven symptomatic congenital cytomegalovirus infection. Twenty-one children in the database had a diagnosis of CMV, based on the protocol of isolating the virus from urine or saliva during the first 2 weeks of their life [24], [25]. The charts of these 21 children were then reviewed for additional clinical information including presenting history, neonatal
Study population
Twenty-one children with a documented symptomatic congenital CMV infection were identified. The hearing loss was bilateral in 16 of the 21 children (76%), while 5 children (24%) had a unilateral loss. The population was largely Caucasian (n = 16). Four were African American and 1 Hispanic. The average age of our patient population was 12 years old, ranging from 3.4 years to 17.1 years and 61% (n = 13) were male. None of the children in our study received anti-viral or immunosuppressant therapy for
Discussion
Children with sensorineural hearing loss from symptomatic congenital CMV vary widely in their clinical features, audiometric outcomes, communication mode, and need for educational support [5], [9], [10].
A progressive hearing loss was found in 43% of our patient population, similar to other reports [7], [15], [18]. As the majority of children with progressive loss began with relatively good audiometric thresholds and progressed to severe or profound hearing loss, this group warrants close
Acknowledgements
The authors would like to thank Stacy Poe, M.S., and Judy Bean, Ph.D., of the Department of Biostatistics at Children's Hospital Medical Center, Cincinnati, Ohio, for their statistical analysis of the data.
References (28)
- et al.
Congenital cytomegalovirus infection and neonatal auditory screening
J. Pediatr.
(1993) - et al.
Early clinical manifestations and intellectual outcome in children with symptomatic congenital cytomegalovirus infection
J. Pediatr.
(1987) - et al.
Newborn hearing screening: will children with hearing loss caused by congenital cytomegalovirus infection be missed?
J. Pediatr.
(1999) - et al.
Progressive and fluctuating sensorineural hearing loss in children with asymptomatic congenital cytomegalovirus infection
J. Pediatr.
(1997) Human cytomegalovirus labyrinthitis
Am. J. Otolaryngol.
(1990)- et al.
Mondini dysplasia and congenital cytomegalovirus infection
J. Pediatr.
(1994) - et al.
Early predictors of neurodevelopmental outcome in symptomatic congenital cytomegalovirus infection
J. Pediatr.
(2001) Summary of a workshop on surveillance for congenital cytomegalovirus disease
Rev. Infect. Dis.
(1991)- et al.
Congenital and perinatal cytomegalovirus infections
Semin. Perinatol.
(1993) - et al.
Maternal cytomegalovirus infection and perinatal transmission
Clin. Obtset. Gynaecol.
(1982)