Progression of hearing loss in Meniere's disease
1978 Volume 37 Issue 1 Pages 27-33
Details
1978 Volume 37 Issue 1 Pages 27-33
Fluctuating hearing loss is a characteristic feature of Meniere's disease, but in some cases, hearing deteriorates gradually and progresses to an irreversible state after repeated fluctuation. In other cases, hearing loss develops rapidly and to a moderate degree.
Ninety-two cases of unilateral Meniere's disease according to the criteria of the Research Committee of Meniere's Disease of the Japanese Welfare Ministry were studied. Among them the progression of hearing loss of twenty-nine cases was evaluated, and three or more audiograms were obtained during the observation period of at least six months.
Hearing loss was classified into four categories-progression, fluctuation, progression with fluctuation and unchanged. Progression was said to occur if the hearing level changed over two frequencies between 250Hz-4000Hz by 15dB increase and remained at this state for at least six months. Fluctuation in hearing was said to occur if the hearing level changed over two frequencies by at least 15dB and again returned to the original level. Progression with fluctuation. was said to occur if the hearing showed the conditions of both progression and fluctuation as mentioned above. Unchanged : No change during the observation period.
The results were as follows :
1) Hearing fluctuation was seen in most cases within three months.
2) Progression of hearing loss was observed in 34% of twenty-nine cases, while fluctuation of hearing was seen in 41%.
3) Hearing loss within one year after an initial vertiginous attack varied in degree, while the hearing loss was progressive with time.
4) Progression with or without fluctuation can be judged within three years, according to the criteria mentioned above.
5) Electrocochleographic studies using a trans-tympanic recording demonstrated positive summating potential (+SP) at 8000Hz in most cases. No changes of +SP were, however, observed after either endolymphatic sac operation or furosemide injection (20mg). Based on these findings mechanisms of hearing progression, the relationship of +SP to Meniere's disease and therapeutic effects of endolymphatic sac surgery as a preventive method for hearing deterioration or progression were discussed.
