Intrauterine cytomegalovirus (CMV) infection may be associated with sensorineural hearing loss. The hearing loss may appear and progress during childhood and adolescence. Early diagnosis allows for early interventions that may prevent developmental problems later.
The diagnosis of congenital CMV infection may:
(1) be made on testing of a high-risk mother during the pregnancy
(2) be made on testing a symptomatic infant at birth
(3) be made by universal screening for IgM and IgG antibodies at birth
(4) go undiagnosed if none of the above are performed or detected by persistence of IgG antibodies
Sensorineural hearing loss was defined by Lanzieri et al as >= 25 dB hearing loss at any frequency (with testing performed at 4 or more frequencies)/
Hearing loss may be:
(1) congenital: present at birth
(2) early-onset: detected at first hearing test at age <= 12 months
(3) delayed-onset: detected after 1 or more assessments of normal hearing
Hearing loss may be:
(1) unilateral or bilateral.
(2) accompanied by other neurological deficits
(3) stable (same between first and last assessment) or progressive (recent worse than initial) or show fluctuations over time
(4) severe enough to justify cochlear implants
A person with unilateral hearing loss and/or progressive hearing loss may develop significant bilateral hearing loss as the patient gets older.
A child with asymptomatic congenital CMV infection and normal hearing at age 5 is not at increased risk of hearing loss compared to uninfected children. Uninfected children have a low risk of hearing loss as they grow older.
The diagnosis requires exclusion of other causes such as ototoxic drugs (gentamicin) or noise exposures.
