Sudden sensorineural hearing loss (S-SNHL) is a common problem with a high
recovery rate. However, little is known of the long-term prognosis of affec
ted patients. The purpose of this follow-up study was to evaluate the long-
term hearing results of S-SNHL patients. The sample consisted of 168 patien
ts with S-SNHL treated with carbogen inhalation and/or anticoagulant therap
y during the period 1982-89. A questionnaire was sent to these patients, an
d audiological investigations were carried out in a selection of these pati
ents in 1997, Comparison of the different treatment methods showed that the
difference observed in improvement of hearing was statistically significan
t between the carbogen inhalation and anticoagulant treatment groups. The h
earing improvement achieved was stable for, on average, 8 years of follow-u
p. During the follow-up period, Meniere's disease was diagnosed in only 1 o
f the 116 patients who answered the questionnaire and no cases of acoustic
neurinoma were diagnosed, indicating that establishment of I careful patien
t history and clinical and audiological investigations are sufficient for t
he diagnosis of S-SNHL. In general, the hearing improvement achieved in S-S
NHL patients is stable during long-term follow-up.