Sudden
sensorineural hearing loss (SSNHL) is frequently classified as 'idiopathic' since the causative factor is not identified in most cases. In the present study we determined whether SSNHL is associated with common
viral infections, namely enterovirus, cytomegalovirus (CMV) and Epstein-Barr virus (EBV). Between April 2004 and March 2005, we conducted a prospective cohort study on 48 unselected patients with unilateral idiopathic SSNHL. Plasma samples obtained at presentation were analyzed for the presence of enterovirus
RNA by reverse-transcription polymerase chain reaction (RT-PCR). Recent occurrence of CMV and
EBV infection was determined by serological tests. Among 23 men and 25 women aged 18-84 years (mean age 51.67 years), none presented with clinical symptoms of a
viral infection compatible with preceding or concurrent
viral infection. One patient (2.08%) had evidence of
enterovirus infection by RT-PCR, 3 patients (6.25%) had EBV
IgM, and none were positive for CMV
IgM. The majority of SSNHL patients (91.67%) did not have evidence of any of the three common
viral infections upon presentation. The present study failed to identify recent or concurrent systemic
viral infections among SSNHL patients, except for a small proportion who demonstrated recent
viral infection. Therefore the theory that
viral infection is
a factor in SSNHL pathogenesis is not supported by this study. Further studies in larger patient populations and different epidemiological settings are required in order to verify the true role of
viral infections in SSNHL.