Interoception after frontal brain injury: A systematic review

Abstract Objective: Interoception is crucial for emotional processing. It relies on the bidirectional connections between the insula, a crucial structure in interoception, and the frontal lobe, which is implicated in emotional experiences. Acquired frontal brain injury often leads to emotional disorders. Our goal was to explore the interoceptive profiles of patients with frontal lesions with or without insular involvement. Method: Given the neuroanatomical links between interoception and emotions, we conducted a systematic Preferred Reporting Items for Systematic Reviews and Meta-analyses guided review of studies assessing at least one dimension of interoception in adults with acquired frontal injuries, with or without associated insular lesions. Results: Seven articles were included. The review indicated that interoceptive accuracy declines after frontal injuries. The two studies that investigated interoceptive sensitivity found lower scores in patient groups. Finally, inconsistent results were found for interoceptive metacognition after frontal damage. Conclusions: This review is the first to explore interoceptive disorders after acquired frontal brain injury. The findings reveal deficits in cardiac interoceptive accuracy and interoceptive sensitivity following frontal damage. Inconsistent results were observed for interoceptive metacognition. Further research is needed to confirm the presence of interoceptive deficits following a frontal lesion. Additionally, the relationship between interoceptive deficits and emotional disorders, often reported after frontal brain injury, should be investigated.