The largest study to date examining the relationship between cytomegalovirus ("CMV") and vestibular disorders concludes that severe cases of congenital CMV infection may impact inner-ear function, postural development, and the parts of the brain that process sensory information.

The vestibular system is responsible for processing sensory information involved with balance and eye movements. When disease or injury damages these processing areas, vestibular disorders may result.

The retrospective study was conducted in the pediatric otolaryngology department of Robert Debré University Hospital in Paris, France. Researchers examined a cohort of 52 children – 31 girls and 21 boys – born congenitally infected with CMV. Because children are often referred to Robert Debré University Hospital due to profound hearing loss requiring cochlear implantation, results from the study may be representative of only the most severe cases of CMV infection.During their evaluation, researchers performed a global vestibular assessment, which included several tests investigating ear canal and otolith function. The otolith is a structure in the inner ear that is sensitive to gravity and linear acceleration. Researchers found evidence of vestibular disorders in 48 of the 52 study participants – vestibular disorders were complete and bilateral in 30.8% of cases, partial and bilateral in 40.4% of cases, and partial and unilateral in 21.1% of cases.

Previous studies have shown that complete bilateral vestibular loss induces severe delay in posturomotor control acquisition. Posturomotor symptoms can include delayed walking, frequent falls, and loss of gravity perception, as well as cognitive dysfunctions resulting in attention deficit disorders, learning and reading difficulties, spatial disorientation, or memory-retention disorders.

Since the study results show that CMV infection can cause complete bilateral vestibular loss, the researchers concluded that congenital CMV may delay posturo-motor development in young children as well.

Early Detection May Allow for Better Care

The study suggests that congenital CMV infection may cause lesions in the cochlear and vestibular parts of the inner ear. The early identification of vestibular lesions could help reduce the incidence of long-term developmental disorders.

The researchers recommend routine screening and monitoring for vestibular lesions in order to provide better care to CMV-infected children. They recommend including vestibular lesion screening in standard assessments and follow-ups of CMV-infected children. Particularly in cases of complete bilateral vestibular loss or neurological impairment, early diagnosis may result in more timely rehabilitation, thus reducing potential developmental deficits.