Occurrence of Sensorineural Hearing Loss in Viral Meningitis and Encephalitis.

Hearing loss in viral neuroinfections is poorly investigated. The present study aimed to clarify if hearing loss can develop in viral meningitis and encephalitis. An OAE (oto-acoustic emission) was measured in adult patients with viral meningitis and encephalitis on the day of admission and 30-60 days after discharge. Frequencies were categorized as Low (1, 1.5, 2 kHz), Mid (3, 4, 5 kHz), Mid-high (6, 7, 8 kHz), and High (9, 10 kHz). An OAE was measured in 41 patients with viral meningitis and 8 patients with encephalitis. Six patients with viral meningitis (15%) experienced a decrease of > 5 dB in one or more frequency categories. Twelve patients (29%) had a temporary decrease in OAE levels of more than 5 dB and 23 patients (54%) had no change in OAE levels between admission and follow-up. We found no significant differences in OAE levels from admission to follow-up between viral meningitis pathogens. In viral encephalitis, herpes simplex virus was associated with a decrease in OAE levels in all frequencies in 3 of 5 patients. Varicella zoster encephalitis was not associated with changes in OAE levels. Viral meningitis and herpes simplex encephalitis is associated with development of a sensorineural hearing loss.