Audiometric, clinical and educational outcomes in a pediatric symptomatic congenital cytomegalovirus (CMV) population with sensorineural hearing loss

Are important predictors of adverse outcome in children with symptomatic congenital cytomegalovirus infection overlooked in clinical settings?

OBJECTIVE

Congenital cytomegalovirus infection (cCMV) is a common, frequently unrecognized cause of childhood disability. The aim of the present study was to determine the symptoms that raise the suspicion of cCMV, define the neurodevelopmental outcomes, and assess their correlations.

METHODS

This longitudinal observational study comprised 78 children with symptomatic cCMV who underwent neuropediatric follow-up for 4 to 17.9 years.

RESULTS

Symptoms of central nervous system involvement, hearing/visual impairments, and hepatic involvement were mostly recognized. The average age of disease suspicion was 3.3 months. In terms of outcomes, 10.53% of the children developed complex minor neurological dysfunction and 23.68% developed cerebral palsy. Visual and hearing impairments occurred in 38.16% and 14.47% of patients, respectively. Intellectual disability was present in 30.26% of patients, and epilepsy in 21.05%. Microcephaly and hearing impairment was significantly associated with overall neurodevelopmental outcome. Microcephaly was also associated with poor motor outcomes, hearing impairment, and severe visual impairment. Furthermore, microcephaly and intrauterine growth restriction were significantly associated with poor cognitive outcomes.

CONCLUSION

Symptoms that raised the suspicion of cCMV-especially microcephaly, hearing impairment, and intrauterine growth restriction-were important parameters that were associated with outcomes; however, their recognition was often insufficient and/or late.

Risk Factors for Hearing Loss at Birth in Newborns With Congenital Cytomegalovirus Infection

Importance

With a prevalence between 0.2% and 6.1% of all live births, congenital cytomegalovirus (cCMV) infection is a major cause of congenital nonhereditary sensorineural hearing loss. Despite the large amount of research on cCMV-related hearing loss, it is still unclear which newborns are at risk of hearing loss.

Objective

To identify independent risk factors for cCMV-related congenital hearing loss and predictors of hearing loss severity at birth.

Design, Setting, and Participants

This cross-sectional study of newborns with cCMV infection used data included in the Flemish CMV registry that was collected from 6 secondary and tertiary hospitals in Flanders, Belgium, over 15 years (January 1, 2007, to February 7, 2022). Data were analyzed March 3 to October 19, 2022. Patients were included in the study after confirmed diagnosis of cCMV infection and known hearing status at birth. Patients who presented with other possible causes of sensorineural hearing loss were excluded.

Main Outcomes and Measures

Primary outcome was hearing status at birth. Clinical, neurological, and laboratory findings along with the timing of seroconversion and blood viral load were separately considered as risk factors. Binary logistic regression was performed to identify independent risk factors for congenital hearing loss in newborns with cCMV. Effect sizes were measured using Hedges g, odds ratio, or Cramer V.

Results

Of the 1033 newborns included in the study (553 of 1024 [54.0%] boys), 416 (40.3%) were diagnosed with symptomatic cCMV infection and 617 (59.7%) with asymptomatic cCMV infection. A total of 15.4% of the patients (n = 159) presented with congenital hearing loss; half of them (n = 80 [50.3%]) had isolated hearing loss. The regression model revealed 3 independent risk factors for congenital hearing loss: petechiae at birth (adjusted odds ratio [aOR], 6.7; 95% CI, 1.9-23.9), periventricular cysts on magnetic resonance imaging (MRI; aOR, 4.6; 95% CI, 1.5-14.1), and seroconversion in the first trimester (aOR, 3.1; 95% CI, 1.1-9.3). Lower viral loads were seen in patients with normal hearing compared with those with congenital hearing loss (median [IQR] viral load, 447.0 [39.3-2345.8] copies per milliliter of sample [copies/mL] vs 1349.5 [234.3-14 393.0] copies/mL; median difference, -397.0 [95% CI, -5058.0 to 174.0] copies/mL).

Conclusions and Relevance

Findings of this cross-sectional study suggest that newborns with cCMV infection and petechiae at birth, periventricular cysts on MRI, or a seroconversion in the first trimester had a higher risk of congenital hearing loss. Clinicians may use these risk factors to counsel parents in the prenatal and postnatal periods about the risk of congenital hearing loss. Moreover, linking clinical features to hearing loss may provide new insights into the pathogenesis of cCMV-related hearing loss. The importance of viral load as a risk factor for congenital hearing loss remains unclear.

Murine cytomegalovirus employs the mixed lineage kinases family to regulate the spiral ganglion neuron cell death and hearing loss

Cytomegalovirus (CMV)-induced sensorineural hearing loss (SNHL) is a worldwide epidemic. Recent studies have shown that the degree of spiral ganglion neuron (SGN) loss is correlated with hearing loss after CMV infection. We aimed to better understand the pathological mechanisms of CMV-related SGN death and to search for intervention measures. We found that both apoptosis and pyroptosis are involved in CMV-induced SGN death, which may be caused by the simultaneous activation of the p53/JNK and NLRP3/caspase-1 signaling pathways, respectively. Moreover, considering that mixed lineage kinase family (MLK1/2/3) are host restriction factors against viral infection and upstream regulators of the p53/JNK and inflammatory (including NLRP3-caspase1) signaling pathways, we further demonstrated that the MLKs inhibitor URMC-099 exhibited a protective effect against CMV-induced SGN death and hearing loss. These results indicate that MLKs signaling may be a key regulator and promising novel target for preventing apoptosis and even pyroptosis during the CMV infection of SGN cells and for treating hearing loss.

Hearing outcomes in children with Congenital Cytomegalovirus: A multi-center, single-enterprise experience

BACKGROUND

Cytomegalovirus (CMV) is the most common cause of non-genetic sensorineural hearing loss (SNHL) in the United States; yet screening for congenital CMV (cCMV) remains controversial. CMV related SNHL can be present at birth, or develop in a delayed manner, and it is a consistent feature in children with either symptomatic or asymptomatic disease. A retrospective chart review was performed to determine the characteristics of patients diagnosed with cCMV and SNHL.

METHODS

The electronic database warehouse of the Nemours Children's Health System (NCHS) was queried from 01/01/2004 to 10/05/2019. ICD 9 (771.1) and ICD 10 (B25.9, P35.1) diagnostic codes were used to identify patients throughout the system with a diagnosis of cCMV infection. Patient demographics including gender, race/ethnicity, age of diagnosis, results of newborn hearing screening (NBHS), detection and progression of hearing loss, presence of antiviral therapy, and frequency of monitoring were collected, and descriptive statistics performed.

RESULTS

Of the 170 patients confirmed to have cCMV, 153 (90%) were symptomatic and 17 (10%) were asymptomatic. CNS involvement (63.5%), radiographic evidence of disease present (69.4%), and SNHL (50.6%) were the most common manifestations of the disease. Of these 170 patients, 83 (48.8%) were determined to have SNHL eligible for evaluation. For these patients with SNHL, the average time of hearing monitoring was 50.6 months. At the time of initial reported detection 63 of 83 (76%) had bilateral hearing loss and 20 (24%) had unilateral loss. Over the study period 3 (15%) progressed from unilateral to bilateral involvement, and 32 (47%) had a deterioration in hearing, with severe to profound SNHL in at least one ear identified at the last visit in 53 (64%) patients. Newborn hearing testing results were available for 69 (83%) of those with hearing loss and 26 patients passed initial testing. However, of the 26 patients who passed, 22 (85%) eventually developed SNHL by their last visit. Within our cohort, females with cCMV were significantly more likely to have SNHL than males with cCMV (62.3% versus 37.6%; p < 0.01).

CONCLUSION

In the absence of targeted or universal cCMV screening, the majority of children identified with this condition present symptomatically. Approximately one half of children with symptomatic cCMV failed NBHS at birth while at least 25% develop SNHL later in life. Children with cCMV are at high risk of delayed onset loss and such children, particularly females, should be monitored closely.

The association between congenital cytomegalovirus infection and cerebral palsy: A systematic review and meta-analysis

Cytomegalovirus (CMV) is the most common cause of congenital infection, affecting 1% of all live births. Intrauterine infection such as CMV infection is a risk factor for developing cerebral palsy. This study aims to investigate the association between congenital CMV infection and the development of cerebral palsy. A systematic literature search was conducted in PubMed, Web of Science and Ovid SP to identify relevant studies. The quality of studies was assessed using the Newcastle-Ottawa Scale. The random-effect model was used to calculate the pooled prevalence. The generic inverse variance method was used for statistical analysis. A total of 12 studies were included in this systematic review and meta-analysis. The overall pooled prevalence of cerebral palsy among patients diagnosed with congenital CMV infection was 26% (95% confidence interval (CI), 13-40%). The overall pooled prevalence of congenital CMV infection among patients with cerebral palsy was 10.9% (95% CI, 5-16%). Congenital CMV infection was significantly associated with the development of cerebral palsy in children. Routine follow-ups should be offered to screen for cerebral palsy.

Vestibular and balance dysfunction in children with congenital CMV: a systematic review

OBJECTIVE

This systematic review evaluates vestibular and balance dysfunction in children with congenital cytomegalovirus (cCMV), makes recommendations for clinical practice and informs future research priorities.

DESIGN

MEDLINE, Embase, EMCARE, BMJ Best Practice, Cochrane Library, DynaMed Plus and UpToDate were searched from inception to 20 March 2021 and graded according to Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) criteria.

PATIENTS

Children with cCMV diagnosed within 3 weeks of life from either blood, saliva and/or urine (using either PCR or culture).

INTERVENTION

Studies of vestibular function and/or balance assessments.

MAIN OUTCOME MEASURES

Vestibular function and balance.

RESULTS

1371 studies were identified, and subsequently 16 observational studies were eligible for analysis, leading to an overall cohort of 600 children with cCMV. All studies were of low/moderate quality. In 12/16 studies, vestibular function tests were performed. 10/12 reported vestibular dysfunction in ≥40% of children with cCMV. Three studies compared outcomes for children with symptomatic or asymptomatic cCMV at birth; vestibular dysfunction was more frequently reported in children with symptomatic (22%-60%), than asymptomatic cCMV (0%-12.5%). Two studies found that vestibular function deteriorated over time: one in children (mean age 7.2 months) over 10 months and the other (mean age 34.7 months) over 26 months.

CONCLUSIONS

Vestibular dysfunction is found in children with symptomatic and asymptomatic cCMV and in those with and without hearing loss. Audiovestibular assessments should be performed as part of neurodevelopmental follow-up in children with cCMV. Case-controlled longitudinal studies are required to more precisely characterise vestibular dysfunction and help determine the efficacy of early supportive interventions.

PROSPERO REGISTRATION

CRD42019131656.

Early Identification and Management of Congenital Cytomegalovirus

Congenital cytomegalovirus (cCMV) is the most common nongenetic cause of sensorineural hearing loss. Despite its prevalence, universal screening for cCMV is not currently performed. Hearing loss caused by cCMV is most often severe to profound, often bilateral, and may be fluctuating or progressive. Infants with hearing loss at birth and confirmed cCMV might benefit from antiviral therapy. Roughly half of hearing loss cases owing to cCMV are delayed in onset, and consequently, these children pass newborn hearing screening. Children with cCMV require close audiologic monitoring, require appropriate management with hearing aids, and should be monitored for cochlear implant candidacy.

Congenital Cytomegalovirus Infection: Epidemiology, Timely Diagnosis, and Management

Congenital cytomegalovirus (cCMV) infection is common because of the ubiquitous nature of the virus and the lack of an effective prevention strategy during pregnancy. Most infants with cCMV are asymptomatic, although a notable subset can have sequelae including, most commonly, sensorineural hearing loss and neurodevelopmental disability, which may not be present at birth. Timely screening for cytomegalovirus in the first weeks after birth is critical to appropriately diagnose congenital infection, evaluate affected infants, and determine the treatment course. Antiviral therapy with valganciclovir can optimize end hearing and neurodevelopmental outcomes in symptomatic infants. This review discusses the epidemiology and clinical manifestations of cCMV, targeted and universal screening approaches, and treatment and monitoring of infants with cCMV.

Congenital CMV-Associated Hearing Loss: Can Brain Imaging Predict Hearing Outcome?

OBJECTIVES

Congenital cytomegalovirus (cCMV) infection is the leading cause of nonhereditary sensorineural hearing loss in childhood and is also associated with CNS abnormalities. The main objective is to investigate the prognostic value of neonatal cranial ultrasound (cUS) and cranial magnetic resonance imaging (cMRI) in predicting long-term hearing outcome in a large cohort of cCMV-infected symptomatic and asymptomatic patients.

DESIGN

Data were prospectively collected from a multicentre Flemish registry of children with cCMV infection born between 2007 and 2016. Neonatal cUS and cMRI scans were examined for lesions related to cCMV infection. Audiometric results at different time points were analyzed. The imaging and audiometric results were linked and diagnostic values of cUS and cMRI were calculated for the different hearing outcomes.

RESULTS

We were able to include 411 cCMV patients, of whom 40% was considered symptomatic at birth. Cranial ultrasound abnormalities associated with cCMV infection were found in 76 children (22.2% of the cUS scans), whereas cMRI revealed abnormalities in 74 patients (26.9% of the cMRI scans). A significant relation could be found between the presence of cUS or cMRI abnormalities and hearing loss at baseline and last follow-up. Cranial ultrasound and cMRI findings were not significantly correlated with the development of delayed-onset hearing loss. Specificity and sensitivity of an abnormal cUS to predict hearing loss at final follow-up were 84% and 43%, respectively compared with 78% and 39% for cMRI. Normal cUS and cMRI findings have a negative predictive value of 91% and 92%, respectively, for the development of delayed-onset hearing loss.

CONCLUSIONS

Neuroimaging evidence of CNS involvement in the neonatal period is associated with the presence of hearing loss in children with a cCMV infection. Imaging abnormalities are not predictive for the development of delayed-onset hearing loss.

Audiologic Status of Children with Confirmed Cytomegalovirus Infection: a Case Series

BACKGROUND

Congenital cytomegalovirus (CMV) infection is the most common non-genetic cause of sensorineural hearing loss (SHNL) in children. Only about 10% to 15% of children with congenital CMV are symptomatic, and most are not diagnosed at birth. About 7% to 15% of clinically asymptomatic patients may develop later complications, including SNHL, which is the most common sequela in clinically asymptomatic patients. In this study, hearing status was investigated in children with confirmed CMV infection and neonatal hearing screening (NHS) histories were reviewed to explore hearing loss caused by CMV.

METHODS

The medical records of 58 children who were diagnosed with confirmed CMV infection were reviewed for clinical symptoms and signs of CMV infection. Hearing status was evaluated with age-appropriate audiological test batteries.

RESULTS

A total of 58 children (M:F = 32:26 patients; age at study: mean, 5.62 years, range, 1-10 years) were diagnosed serologically with CMV infection (14 patients, 21.1%), or diagnosed via PCR of serum (5, 7.9%) and/or PCR from urine (19, 26.8%). Hearing loss was confirmed in 11 children (19.0%), being bilateral in 6 (54.5%), and unilateral in 5 (45.5%). Note that 7 of 17 ears with hearing loss passed NHS and were diagnosed only after re-evaluation when CMV infection was identified.

CONCLUSION

Hearing loss is a serious complication of CMV infection in children. Our results highlight the importance of timely audiological evaluation in children with clinically symptomatic CMV infection even if they pass NHS.

[Common clinical causes and audiological manifestations of unilateral hearing loss in children]

Objective:To analyze the common clinical causes and audiological manifestations of unilateral hearing loss in children, and to provide a basis for early prevention and intervention. Method:A retrospective analysis of 20 cases of children diagnosed with unilateral hearing loss was conducted. The medical history was collected, followed by audiological and imaging examinations. Result:The audiological performance of 20 children with unilateral hearing loss: 1 case of conductive deafness, whose hearing curve was flat and showed moderate hearing loss. There were 19 cases of sensorineural deafness, of which 1 case was moderate deafness, 16 cases were severe deafness, and 2 cases were extremely severe deafness. The imaging results showed that there were 1 case with transverse fracture of the temporal bone, 1 case with congenital cholesteatoma, 9 cases with dysplasia of the cochlear nerve, and 4 cases with malformation of the inner ear. The history of the two children was collected and there were clear congenital cytomegalovirus infection and mumps virus infection. The causes of the remaining 3 cases were unknown. Conclusion:Unilateral hearing loss in children is a common clinical diseasewith complex and diverse causes. Carefully analysis should be made to find out the causes and symptomatic treatment to provide a basis for early prevention and intervention of children's hearing.

Genetic Testing for Congenital Bilateral Hearing Loss in the Context of Targeted Cytomegalovirus Screening

OBJECTIVES/HYPOTHESIS

To determine the prevalence of children with genetic hearing loss who are cytomegalovirus (CMV) positive at birth and the relative proportion of genetic and CMV etiology among children with congenital bilateral hearing loss.

STUDY DESIGN

Database review.

METHODS

We performed a review of clinical test results for patients undergoing comprehensive genetic testing for all known hearing loss-associated genes from January 2012 to January 2019. This population was reviewed for reported CMV status and genetic causes of congenital bilateral hearing loss.

RESULTS

In the OtoSCOPE database, 61/4,282 patients were found to have a documented CMV status, and 661/4282 had documented bilateral congenital hearing loss. Two patients were identified who had both a positive CMV result and a genetic cause for their hearing loss. Forty-eight percent of patients with bilateral congenital hearing loss (320/661) were found to have a genetic etiology. In 62% (198/320), the hearing loss was associated with pathogenic variants in GJB2, STRC, SLC26A4 or an Usher syndrome-associated gene.

CONCLUSIONS

We estimate that ~2% of CMV-positive newborns with hearing loss have a known genetic variant as a cause. The subcohort of CMV-positive newborns with symmetric mild-to-moderate bilateral hearing loss will have at least a 7% chance of having pathogenic gene variants associated with hearing loss. In a CMV-positive neonate who failed their newborn hearing screen bilaterally, genetic screening needs to be considered for accurate diagnosis and possible deferment of antiviral treatment.

LEVEL OF EVIDENCE

4 Laryngoscope, 130:2714-2718, 2020.

Evaluation of clinically asymptomatic high risk infants with congenital cytomegalovirus infection

OBJECTIVE

To determine the frequency of abnormal findings on evaluation of neonates with congenital CMV infection who have a normal physical examination STUDY DESIGN: Retrospective, 2-center study (1996-2017) that reviewed results of complete blood cell count and platelets, serum alanine aminotransferase (ALT) and bilirubin concentrations, eye examination, cranial ultrasonography or other neuroimaging, and brainstem evoked responses performed on neonates with congenital CMV infection and a normal physical examination RESULTS: Of 34 infants with congenital CMV infection and a normal physical examination, 56% (19/34) had ≥1 abnormality: 39%, elevated ALT concentration; 45%, abnormal neuroimaging (five, lenticulostriate vasculopathy; six, intraventricular hemorrhage; four, calcifications); 12%, anemia; 16%, thrombocytopenia; and 3%, chorioretinitis. Seven (21%) infants had sensorineural hearing loss, and 18 infants received antiviral therapy.

CONCLUSION

Some infants with congenital CMV infection and a normal physical examination had abnormalities on laboratory or neuroimaging evaluation, which in some cases prompted antiviral treatment.

The Natural History and Rehabilitative Outcomes of Hearing Loss in Congenital Cytomegalovirus: A Systematic Review

OBJECTIVE

The purpose of this study was to examine the literature regarding the natural history and rehabilitative outcomes of sensorineural hearing loss from congenital cytomegalovirus infections.

DATA SOURCES AND STUDY ELIGIBILITY CRITERIA

A systematic search was performed in PubMed, PsychINFO, CINAHL, and Web of Science to identify peer-reviewed research. Eligible studies were those containing original peer-reviewed research in English addressing either the natural history or rehabilitative outcomes of sensorineural hearing loss (SNHL) in congenital cytomegalovirus (cCMV).

STUDY APPRAISAL AND SYNTHESIS METHODS

Two investigators independently reviewed all articles and extracted data. Bias was assessed using the Cochrane Collaboration's tool and the Newcastle-Ottawa Assessment Scale.

RESULTS

Thirty-six articles were reviewed. Universal screening identifies 0.2 to 1% of newborns with cCMV infection. SNHL ranged from 8 to 32% of infants and was more prevalent in symptomatic versus asymptomatic cases. Nine to 68% of hearing loss occurs in a late or delayed fashion. In 7 to 71% of cases hearing loss is progressive. Cochlear implantation (CI) is a viable option for patients with cCMV associated hearing loss and leads to improvements in hearing and language. There is limited literature comparing rehabilitation outcomes in cCMV and non-cCMV CI recipients.

CONCLUSION

Late onset and progressive hearing loss is seen in children who develop hearing loss from cCMV. Frequent audiologic follow-up is necessary considering the natural history of cCMV hearing loss. Universal screening should be pursued due to the number of asymptomatic children, at birth, who develop late onset/delayed hearing loss. CI is an effective means of improving speech and language in this population.

Virus-induced cochlear inflammation in newborn mice alters auditory function

Although human cytomegalovirus (HCMV) is a known cause of sensorineural hearing loss in infants with congenital HCMV (cCMV) infections, mechanisms that contribute to sensorineural hearing loss (SNHL) in infants with cCMV infection are not well defined. Using a murine model of CMV infection during auditory development, we have shown that peripheral infection of newborn mice with murine CMV (MCMV) results in focal infection of the cochlea and virus-induced cochlear inflammation. Approximately 50%-60% of infected mice exhibited increased auditory brainstem response (ABR) thresholds across a range of sound frequencies. Histological analyses of the cochlea in MCMV-infected mice with elevated ABR thresholds revealed preservation of hair cell (HC) number and morphology in the organ of Corti. In contrast, the number of spiral ganglion neurons (SGN), synapses, and neurites connecting the cochlear HC and SGN nerve terminals were decreased. Decreasing cochlear inflammation by corticosteroid treatment of MCMV-infected mice resulted in preservation of SGN and improved auditory function. These findings show that virus-induced cochlear inflammation during early auditory development, rather than direct virus-mediated damage, could contribute to histopathology in the cochlea and altered auditory function without significant loss of HCs in the sensory epithelium.

Hearing Loss Progression and Contralateral Involvement in Children with Unilateral Sensorineural Hearing Loss

Objectives

We undertook this study to determine the rate of hearing loss progression in the affected ear of children with unilateral sensorineural hearing loss and without an enlarged vestibular aqueduct, and the rate of new-onset hearing loss in the contralateral ear.

Methods

We searched the database at our pediatric tertiary care center to identify patients who met the inclusion criteria, examining demographic variables, audiometric data, and presumptive causes.

Results

We identified 198 patients. At presentation, they showed slight left-sided and male predominances. Of 142 patients who had sufficient audiometric follow-up for us to evaluate progression, 21% showed ipsilateral progression and 10.6% developed new-onset hearing loss in the contralateral ear. Isolated high-frequency loss was identified in 11 patients (5.6%), 8 of whom had sufficient follow-up for us to identify progression. Two showed progression; 4 others with progression in the ipsilateral ear developed new-onset high-frequency loss in the contralateral ear. Temporal bone anomalies were identified in 26 children (13%), and these children were more likely to have profound hearing loss than were those without temporal bone anomalies (46% versus 23%).

Conclusions

The findings suggest that unilateral sensorineural hearing loss may not always be a unilateral process, but that it may be the initial manifestation of bilateral auditory dysfunction.

Hearing loss and congenital CMV infection: a systematic review

BACKGROUND AND OBJECTIVE

Hearing loss caused by congenital cytomegalovirus (cCMV) infection was first observed in 1964. Today cCMV is the most common cause of nonhereditary sensorineural hearing loss in childhood. Our objective was to provide an overview of the prevalence of cCMV-related hearing loss, to better define the nature of cCMV-associated hearing loss, and to investigate the importance of cCMV infection in hearing-impaired children.

METHODS

Two reviewers independently used Medline and manual searches of references from eligible studies and review articles to select cohort studies on children with cCMV infection with audiological follow-up and extracted data on population characteristics and hearing outcomes.

RESULTS

Thirty-seven studies were included: 10 population-based natural history studies, 14 longitudinal cohort studies, and 13 retrospective studies. The prevalence of cCMV in developed countries is 0.58% (95% confidence interval, 0.41-0.79). Among these newborns 12.6% (95% confidence interval, 10.2-16.5) will experience hearing loss: 1 out of 3 symptomatic children and 1 out of 10 asymptomatic children. Among symptomatic children, the majority have bilateral loss; among asymptomatic children, unilateral loss predominates. In both groups the hearing loss is mainly severe to profound. Hearing loss can have a delayed onset, and it is unstable, with fluctuations and progression. Among hearing-impaired children, cCMV is the causative agent in 10% to 20%. Despite strict selection criteria, some heterogeneity was found between selected studies.

CONCLUSIONS

This systematic review underscores the importance of cCMV as a cause of sensorineural hearing loss in childhood.

Viral causes of hearing loss: a review for hearing health professionals

A number of viral infections can cause hearing loss. Hearing loss induced by these viruses can be congenital or acquired, unilateral or bilateral. Certain viral infections can directly damage inner ear structures, others can induce inflammatory responses which then cause this damage, and still others can increase susceptibility or bacterial or fungal infection, leading to hearing loss. Typically, virus-induced hearing loss is sensorineural, although conductive and mixed hearing losses can be seen following infection with certain viruses. Occasionally, recovery of hearing after these infections can occur spontaneously. Most importantly, some of these viral infections can be prevented or treated. For many of these viruses, guidelines for their treatment or prevention have recently been revised. In this review, we outline many of the viruses that cause hearing loss, their epidemiology, course, prevention, and treatment.

Aetiology of congenital hearing loss: a cohort review of 569 subjects

OBJECTIVE

Newborn hearing screening was implemented in Flanders about fifteen years ago. The aim of this study was to determine the aetiology of hearing loss detected by the Flemish screening programme.

METHODS

From 1997 to 2011, 569 neonates were referred to our tertiary referral centre after failed neonatal screening with Auditory Brainstem Responses. In case hearing loss (HL) was confirmed, further diagnostic testing was launched. A retrospective chart review was performed analysing the degree of HL, risk factor and aetiology.

RESULTS

Metabolic disorders (0.5%), infectious diseases (35.8%), congenital malformations (6.1%) and genetic abnormalities (19.8%), whether or not syndromic, were retained. In 35% of the subjects no obvious aetiology could be determined in the current study.

CONCLUSION

In contrast to the literature findings, this series shows a genetic syndromic cause in 80% of the genetic bilateral HL cases. On the other hand connexin positive diagnoses were mostly underrepresented in this study, showing the need for better screening.

Prelingual sensorineural hearing loss and infants at risk: Western Sicily report

OBJECTIVE

To evaluate independent etiologic factor associated with sensorineural hearing loss (SNHL) in newborn at risk; to study the role of their interaction especially in NICU infants who present often multiple risk factors for SNHL.

METHODS

The main risk factors for SNHL reported by JCIH 2007 were evaluated on 508 infant at risk ranging from 4 to 20 weeks of life, transferred to the Audiology Department of Palermo from the main births centers of Western Sicily. After a global audiological assessment, performed with TEOAE, tympanometry and ABR, the prevalence and the effect of risk factors was statistically studied through univariate and multivariate analysis on the total population (normal and deaf subjects).

RESULTS

Fifty-one infants (10.03%) were diagnosed with SNHL (45 bilateral and 6 monolateral) with a mean hearing threshold of 87.39 ± 28.25 dB HL; from logistic regression analysis family history of hearing impairment (HI) and TORCH infections resulted independent significant risk factors (P<0.00001 and P=0.024 respectively). High SNHL percentages were evidenced also in NICU babies, due to the various pathologies and risk factors presented by these infants, and among newborns who suffered from hyperbilirubinemia requiring exchange transfusion (11.97% and 9.52% respectively). Craniofacial abnormalities (CFA) and syndromes associated to HI showed an important relationship (P<0.00001) with conductive hearing loss (CHL). Multiple regression analysis of the variation in SNHL among NICU infants evidenced an increased risk for SNHL of 21.24% and of 19.33% respectively in preterm infants and in case of hyperbilirubinemia if respiratory distress is concomitant with these risk factors. It was also observed an higher risk of SNHL (99.66%) in case of coexistence of prematurity and hyperbilirubinemia. Finally among infants with very low birth weight (VLBW) it was evidenced a statistically difference between the mean weight of SNHL infants respect to NHL newborns (P=0.048).

CONCLUSION

The high SNHL prevalence (10.03%) in our cohort underlines how infants at risk are more susceptible to suffer from SNHL; in particular NICU newborns have a 33% greater chance of developing SNHL, because of the presence of multiple risk factors (or=1.33) and their interaction. As the number of coexisting risk factors increases, the prevalence of SNHL also increases (r(2)=0.93).

Congenital cytomegalovirus infection: update on management strategies

Congenital cytomegalovirus (CMV) infections are underrecognized as a cause of serious morbidity in newborn infants. The era of therapeutic nihilism regarding these infections has come to an end, however, as useful therapies are now available that may modify the outcome. The infected fetus can be treated in utero, or the newborn infant can be treated when CMV is recognized in the neonatal period. Expanded screening of newborns for congenital CMV infection will make it even more important for clinicians to be aware of current therapeutic options. The most effective option for the treatment of life-threatening or sight-threatening CMV disease at any age is the nucleoside analog ganciclovir. For the newborn with congenital CMV infection, the value of ganciclovir appears to relate to its ability to preserve hearing; other improvements in overall neurodevelopmental status are inferred but remain to be proven. In the pregnant woman with primary CMV infection, the use of CMV-specific immune globulin, though still investigational, is garnering attention and may prove to be a valuable therapy.

Hearing thresholds in children with a congenital CMV infection: a prospective study

OBJECTIVE

Hearing thresholds in children with a congenital cytomegalovirus (cCMV) infection are not always stable. Children can develop late onset hearing loss, fluctuations, progression (worsening) and improvement of hearing loss. Knowledge about these characteristics is important to understand why long term follow up in these children is mandatory.

METHODS

We prospectively follow a cohort of 154 children with cCMV infection, 68 of which met the inclusion criteria of at least 3 hearing evaluations over a period of at least 18 months in the absence of other risk factors for hearing loss. In those 68 children we evaluated the occurrence of unstable hearing thresholds: late onset hearing loss, fluctuations, progression and improvement of hearing loss.

RESULTS

Unstable hearing thresholds were observed in 29.4% of children with cCMV infection of which 19.2% were found in the group of children with ultimately normal hearing and in 62.5% of children with sensorineural hearing loss (SNHL) (p=0.0027). Fluctuations occurred in 16.2%. Late onset hearing loss occurred in 4.3% of children with a normal hearing at birth. In children with SNHL, progression or worsening of hearing thresholds occurred in 27.3% and improvement of thresholds in 40.9%. Important changes in thresholds only occurred in 13.2% of all children and predominantly in children who finally develop SNHL.

CONCLUSIONS

Unstable hearing thresholds are frequently found in children with cCMV infection and occur not only in children who develop hearing losses but also in children who have a normal hearing at the last visit. Important changes in hearing thresholds of > 30 dB are more frequently seen in children who ultimately will develop SNHL.

Hearing status in children with congenital cytomegalovirus: up-to-6-years audiological follow-up

OBJECTIVE

To evaluate the audiological outcome of children with congenital cytomegalovirus infection.

METHODS

In a prospective study, the hearing of ninety seven congenitally cytomegalovirus-infected children, born between January 2003 and July 2009, was systematically evaluated until the age of six, applying the Flemish CMV protocol. Depending on the age of the child, the protocol provides hearing evaluation by objective-, play- or conventional audiometry. Symptomatic children with hearing loss at birth were treated with ganciclovir, if parents consented.

RESULTS

Seventy children had a pass on initial screening, 27 had unilateral or bilateral hearing loss. Within the normal hearing group, one asymptomatic and two symptomatic children developed late-onset hearing loss. Within the group with hearing loss, 8 children received ganciclovir, while 8 symptomatic and 11 asymptomatic children did not receive ganciclovir. As for the treated group, 37.5% of the children had stable hearing loss, one child had progressive and one child had fluctuating hearing loss. Improvement of hearing threshold occurred in 37.5% of the children. Among the untreated symptomatic children, hearing loss remained stable in 50%, while progression occurred in 37.5%. In the group of asymptomatic children with hearing loss, hearing loss was most commonly stable (72.7%). Within the group of normal hearing ears at birth (n=156), there is a significant better progression in pure tone average for ears of asymptomatic subjects in comparison to ears of symptomatic subjects (p≤0.0001). As for the group of ears with hearing loss at birth (n=38), analysis shows no evidence for a difference in pure tone average progression between the different groups (p=0.38).

CONCLUSIONS

Cytomegalovirus infection may cause hearing loss, in both symptomatic and asymptomatic children. Our data show a significant difference, between both groups, in the progression of pure tone average of normal hearing ears at birth, in favor of the asymptomatic children. This is not the case for ears with hearing loss at birth. However, this may be due to the small number of ears in this group. Our data show the tendency that treatment with ganciclovir increases the likelihood of improvement and reduces the likelihood of deterioration of the hearing.

Universal newborn hearing screening in 2010

PURPOSE OF REVIEW

The objectives of this review are to provide the reader with a current and concise review of the data and trends in universal newborn hearing screening. Within a relatively short period of time, the concept of screening all infants for hearing loss at the time of birth has evolved from a nascent process to a truly universal system in most developed countries. As a result, the focus and challenges of universal newborn hearing screening have shifted to topics of developing even more efficient and cost-effective approaches, and potentially melding physiologic hearing screenings with ancillary screening techniques.

RECENT FINDINGS

Enhancement of the universal newborn hearing screening process is likely to be accomplished by implementation of novel tools such as wideband reflectance technologies and intelligent incorporation of screening for common genetic and viral causes of congenital hearing loss.

SUMMARY

With such a rapidly evolving process, it will be critical for clinicians to understand the benefits and limitations of various newborn hearing screening methodologies in order to determine the most appropriate management of children referred from their universal newborn hearing screening. This will entail a working knowledge of emerging audiologic tools as well as infectious and genetic causes of pediatric hearing loss.

Rehabilitation and outcome of severe profound deafness in a group of 16 infants affected by congenital cytomegalovirus infection

The aim of the study was to characterize the audiological consequences of congenital cytomegalovirus infection (CMV) and to evaluate the outcome of rehabilitation with hearing aids and/or cochlear implant (CI), associated with an adequate speech-language therapy. A retrospective review of data was made from a total of 16 infants, affected by severe to profound hearing loss from congenital CMV infection, referred to a tertiary audiological center for rehabilitation. Audiological evaluation was performed using behavioral audiometry, auditory brainstem responses (ABR) and/or electrocochleography (ECochG). Of the 16 children (median age at diagnosis of hearing loss: 21.33 +/- 0.7 months) with CMV hearing loss, 14 were affected by profound bilateral hearing loss and received a CI, while 2 were affected by bilateral severe hearing loss and received hearing aids. Cochlear implants can provide useful speech comprehension to patients with CMV-related deafness, even if language development is lower when compared to a group of Connexin (Cx) 26+ cochlear-implanted children (eight subjects), matched for age. Congenital CMV infection still represents a serious clinical condition, as well as an important cause of hearing loss in children. More studies have claimed to identify the pathophysiological mechanisms of damage and thus to ensure a better therapeutic approach. Nonetheless, in cases of CMV-deafened babies, the overall outcome of cochlear implantation is good.