There was a measurable worsening but not a statistically sig
There was a measurable worsening, but not a statistically significant change in the baseline and follow-up best ear hearing scores, where the mean worsening change was 11.9 dB (95% CI: −1.11–24.86, p-value = 0.070). However, of the 16 patients, 14 (87.5%) were found to have clinically significant worsening in hearing. The change in total hearing scores for the right ear was found to have a mean change of 15.5 dB (95% CI: 1.52–29.42, p-value = 0.032). The change in total hearing scores for the left ear was found to have a mean change of 14.2 dB (95% CI: 2.25–26.19, p-value = 0.023). Mean changes for thresholds are shown in Fig. 1.
The mean elapsed time for progression of hearing loss was 2.6 ± 0.2 years. The youngest child to develop progressive hearing loss was 5 months of age, while the oldest was 4.3 years of age. Two patients eventually underwent cochlear protoporphyrin ix (CI), although ten more would be considered candidates for CI based on the patients meeting criteria for profound hearing loss. When examining the 11 cases where the better or worse ear could be compared over time, the following results were found: no change (n = 2), worsening at the same time (n = 3), better ear deteriorated first (n = 3), and worse ear deteriorated first (n = 3). Stratification based on duration of antiviral therapy revealed that 100% (6/6), 71.4% (5/7), and 100% (3/3) developed worsening hearing thresholds when treated for less than 6 weeks, between 6 weeks and 6 months, and greater than 6 months, respectively. Stratification based on age when therapy was started showed that 100% (8/8) and 75% (6/8) developed worsening hearing thresholds for those who initiated therapy when less than one month of age and for those older than one month of age, respectively. An overview of the individual hearing outcomes of each patient is demonstrated in Table 2.
Discussion The natural history of untreated severely affected cCMV children suggests that many will develop progressive loss . Dahle et al. compared the hearing outcomes of 209 symptomatic cCMV infected children to 651 asymptomatic cCMV infected children . SNHL occurred in 48 (7.4%) of asymptomatic and 85 (40.7%) of symptomatic cCMV infected children. Thirty-seven percent of the symptomatic cCMV infected children developed delayed onset and progressive SNHL. The age of presentation ranged from six months to 16.4 years, which highlights the need for continued and long-term audiologic surveillance of these children. Studies reporting efficacy of antiviral therapy for CMV induced SNHL have included only symptomatically infected infants with a relatively short follow-up period [7,11]. The National Institute of Allergy and Infectious Disease CASG presented a large, randomized controlled study of six weeks of intravenous ganciclovir compared with no treatment in infants with central nervous system involvement and less than 30 days of age . They found that infants treated with ganciclovir were more likely to have stable hearing or even hearing improvement compared to those infants who received no treatment. None of the treated infants had hearing deterioration at six months compared to 41% of the untreated infants. At the one-year follow-up, 21% infants in the treated group had some hearing deterioration in the better ear compared with 68% in the untreated group. The CASG group recently compared six-month VGC versus six-week therapy . Results showed that a longer duration of antiviral therapy does not further improve hearing function at six months, but improves hearing outcomes at 12 and 24 months as compared with a six weeks therapy (73% vs. 57%, p-value = 0.01; 77% vs. 64%, p-value = 0.04). At 24 months the six-month group also had better neurodevelopmental scores on the language composite component of the Bayley-III (p-value = 0.004). Amir et al. reported their results in 23 infants with symptomatic cCMV treated with ganciclovir for six weeks followed by oral VGCV to age 12 months . None of the 25 children with normal hearing developed worsening of their hearing at one year of age. For the 21 children presenting with hearing loss, twelve (57%) had improved hearing, eight (38%) had no change and one (5%) had worse thresholds at one-year follow-up.