6793 Paradoxical vestibular presentations in congenital cytomegalovirus infection

Objectives To highlight the heterogenous vestibular presentations in a cohort of children diagnosed with congenital Cytomegalovirus (cCMV) that underwent auditory and vestibular function tests. Methods This is a retrospective case note review of children with cCMV that was seen in a tertiary Audiovestibular Medicine Service who were seen in the last 6 months and had positive vestibular quantification diagnostic test results during their total patient journey. Inclusion criteria were confirmed cCMV status and presence of abnormal vestibular function tests. This was part of a wider ongoing audit of auditory and vestibular function in children referred to our Department with confirmed cCMV, registered with the Clinical Audit Department within our NHS Trust. Results 3 patients presented due to initial concerns around hearing and 1 patient presented with systemic manifestations of cCMV. Infection with CMV was confirmed by positive Guthrie newborn blood spot test. One patient continued to have bilateral normal hearing into the teenage years. However, this child had bilateral compensated partial vestibulopathy. The other 3 had unilateral sensorineural hearing loss (SNHL) at birth. One of them continued to have stable unilateral SNHL into teenage years but had paradoxical contra-lateral partial vestibulopathy. The other 2 with congenital unilateral SNHL developed progressive bilateral SNHL by age 3 years, with one child receiving bilateral cochlear implantation by age 6 years. Both children who had progressive deafness had bilateral vestibulopathy. The child with normal hearing and the 2 children with progressive SNHL had positive neuro-radiological features on Magnetic Resonance Imaging. One patient required patient-specific vestibular rehabilitation for compensation and improvement of overall balance function. The other 3 children improved their balance function with age. Conclusion Vestibular dysfunction is well known in those with cCMV.¹ This highlights the importance of assessing and quantifying the vestibular function in those with cCMV, with or without hearing loss. Vestibulopathy indicates an effect into the inner ear labyrinth. This may have subsequent prognostic importance for future hearing and vestibular function. Additionally, it will guide patient-specific treatment that includes amplification options and vestibular rehabilitation. Audio-vestibular phenotype will guide the clinicians to counsel the parents of children with cCMV regarding the variable long-term outcomes for hearing, balance, oculomotor function and gross motor development. Reference Shears A, Yan G, Mortimer H, et al. Vestibular and balance dysfunction in children with congenital CMV: a systematic review. Archives of Disease of Childhood Fetal & Neonatal Edition. May 2022;107:F630–F636. doi:10.1136/archdischild-2021-323380.