Abstract
The authors investigated the factors, which could decide the prognosis of sudden hearing loss (SHL), in the 124 patients treated by stellate ganglion block (SGB) concomitant with conventional medical therapy since January 1999 through December 2000. SGB was performed for all the patients six times a week (totally 13±6 times) using 7ml of 1.0% lidocaine. The effectiveness of SGB was evaluated according to the recovery criteria by the official committee of SHL, Japan, i.e.; a) cure or complete return to <20dB in all tested frequencies; b) remarkable return to average pure tone score of >30dB; c) effective return to average pure tone score of >10dB; and d) ineffective. The complete and remarkable recovery rate (a+b) was 40.3% in the patients treated by SGB, whereas it was 33.3% in the patients without SGB (n=9). As the results of the analysis, four factors were suspected to be concerned in the improvement of the prognosis of SHL. Well-recovered patients are those; 1) who were male and younger than 50 years old; 2) who had some complications relating to microcirculatory disturbances as hypertension, diabetes or hyperlipidemia, and; 3) who received the first SGB earlier after the onset of SHL. Furthermore, the patients with vertigo were also successfully treated by SGB better than in former reports. On the other hand, female patients younger than 40 years old showed poorer prognosis. The results in this study indicate that SGB would be a useful therapy for a type of SHL simply brought on by some microcirculatory disturbances, as SGB could increase the blood supply to the cochlear.
