A study concerning the features and onset mechanism of spontaneous dysgeusia

Abstract

We herein report 13 suggestive cases of spontaneous dysgeusia (SD), including an examination of the features of SD. Our study revealed that SD resembles glossodynia regarding the symptoms and background characteristics, to the extent that it is often difficult to distinguish between the two. The oral sensation is affected by the surrounding atmosphere. SD is one of the known oral sensations. In our study, 62.7% of SD patients reported having some degree of stress in their family life. The number of SD patients has shown an increasing trend in recent years; for example, while 14 SD patients visited our clinic from 2007 to 2009, this number increased to 65 from 2019 to 2021. We suspect this increase is due to aging or caring for a family member. The second taste area is known to be activated when people see an angry expression. Indeed, a few patients reported noticing SD when they witnessed a family member do an angry expression. Unpleasant tastes and disgust are memorialized in the amygdala. Unpleasant information stimulates the amygdala, and unpleasant tastes are generated in the brain, which patients realize on the tongue. We conclude that this is the mechanism underlying the development of SD.