Sensorineural hearing loss induced by radiation as a late effect: five cases followed by audiogram

Objective: we studied the progression of the late radiation-induced sensori neural hearing loss (SNHL) to discuss the pathological mechanism responsibl e for the progression with referring to past reports. Methods: five cases w ere selected among the SNHL cases diagnosed at the Department of Otolaryngo logy, Hokkaido University. All the cases were followed up with audiograms. Results: all of the five cases showed gradual progression of SNHL, which de veloped mostly 1-2 years after irradiation for brain tumors. Two of them sh owed rapid progression from time to time with sudden onset in their clinica l courses. All the patients were resistant to any medication such as steroi d, vitamin B12 or cerebral circulation activators. Conclusion: two patterns of progressions of radiation-induced hearing loss were observed. Both of t hem were considered to be explainable by ischemic changes of the vessels as reported earlier. Since there is no effective treatment for radiation-indu ced SNHL, it is most important to enlighten clinicians in general on this d isease. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.