Manifestation of Congenital CMV-Related Hearing Loss in Cohort Followed at Ear, Nose, and Throat Clinic

<b>Background/Objectives:</b> Cytomegalovirus (CMV)-associated hearing loss is common in non-genetic congenital hearing loss. Despite this high prevalence, a wide range of clinical characteristics exists, and the pattern of hearing loss remains unknown. This study aims to describe the clinical manifestations in children with CMV-associated hearing loss and to clarify the timing of hearing level change and the degree of hearing level fluctuation. <b>Methods:</b> A total of 54 patients with hearing loss due to congenital CMV infection were included. Hearing loss type (congenital or later onset), hearing loss laterality (unilateral or bilateral), severity at first and last visit, hearing progression and timing, and the difference between patients with intellectual disability and without intellectual disability were assessed. <b>Results:</b> The number of patients with congenital hearing loss and later onset hearing loss were 19 patients and 13 patients, respectively. Seventy-four percent (14/19) of the congenital hearing loss patients and 62% (8/13) of the later onset hearing loss patients eventually progressed to severe to profound hearing loss bilaterally. Progression occurred in less than 1 year (9 cases), between 1 and 3 years (7 cases), between 3 and 7 years (4 cases), or more than 8 years (1 case). Multiple progression events occurred in 11 cases. <b>Conclusions:</b> Sixty-one percent of patients had progression of hearing loss. Several cases experienced progression over more than one year and showed multiple progression events. CMV patients without intellectual disability tended to suffer later onset hearing loss. Sixty-nine percent of the patients eventually progressed to bilateral severe to profound hearing loss, which means that continuous long-term follow-up is required.