Uncommon case of complete loss of hunger following an isolated left insular stroke

The insula has long been among the least understood regions of the human brain, in part due to its restricted accessibility. Mounting evidence suggests that the insula is a prominent player in gustatory, interoceptive, and emotional processing, and likely integrates these different functions to contribute to the homeostatic control of food intake. Here we report the case of a young adult patient who lost the subjective experience of hunger following an ischemic stroke localized in the posterior left insula. The loss of hunger was not attributable to medication, substance use, or a clinical disorder, and lasted for a period of 15 months. In line with the role attributed to the insula in gustation and interoception, we suggest that the insula integrates information about taste, interoception, and the hedonic value of food in the service of homeostatic regulation.