Hearing Trajectory in Children with Congenital Cytomegalovirus Infection

Abstract

Objectives To compare hearing trajectories among children with symptomatic and asymptomatic congenital cytomegalovirus infection through age 18 years and to identify brain abnormalities associated with sensorineural hearing loss (SNHL) in asymptomatic case patients. Study Design Longitudinal prospective cohort study. Setting Tertiary medical center. Subjects and Methods The study included 96 case patients (4 symptomatic and 92 asymptomatic) identified through hospital-based newborn cytomegalovirus screening from 1982 to 1992 and 72 symptomatic case patients identified through referrals from 1993 to 2005. We used growth curve modeling to analyze hearing thresholds (0.5-8 kHz) by ear with increasing age and Cox regression to determine abnormal findings on head computed tomography scan associated with SNHL (hearing threshold ≥25 dB in any audiometric frequency) among asymptomatic case patients. Results Fifty-six (74%) symptomatic and 20 (22%) asymptomatic case patients had SNHL: congenital/early-onset SNHL was diagnosed in 78 (51%) and 10 (5%) ears, respectively, and delayed-onset SNHL in 25 (17%) and 20 (11%) ears; 49 (32%) and 154 (84%) ears had normal hearing. In affected ears, all frequency-specific hearing thresholds worsened with age. Congenital/early-onset SNHL was significantly worse (severe-profound range, >70 dB) than delayed-onset SNHL (mild-moderate range, 26-55 db). Frequency-specific hearing thresholds were significantly different between symptomatic and asymptomatic case patients at 0.5 to 1 kHz but not at higher frequencies (2-8 kHz). Among asymptomatic case patients, white matter lucency was significantly associated with SNHL by age 5 years (hazard ratio, 4.4; 95% CI, 1.3-15.6). Conclusion Congenital/early-onset SNHL frequently resulted in severe to profound loss in symptomatic and asymptomatic case patients. White matter lucency in asymptomatic case patients was significantly associated with SNHL by age 5 years.

Keywords: congenital cytomegalovirus infection; sensorineural hearing loss.

Figure 1

Congenital CMV Longitudinal Study Cohort.

Figure 2

Frequency-specific hearing trajectories by age for ears with congenital/early-onset SNHL, delayed-onset SNHL, and normal hearing, among symptomatic and asymptomatic case-patients. Caption: The “spaghetti plots” in the left-hand column fit the raw data using smoothers (i.e. splines). Individual profiles are overlaid with the average trend lines. The plots in the right-hand column show the predicted means of hearing thresholds using the corresponding fixed effects models from ordinary least squares regression.

Figure 3

Head CT scans from children with asymptomatic congenital CMV infection. Caption: A – white matter lucency (periventricular leukomalacia) not associated with prematurity. B –periventricular punctate calcification.