Background: Neurophysiologic studies on human and nonhuman primates implicate an orbitofrontal-insular-striatal circuit in high-level regulation of feeding. However, the role of these areas in determining feeding disturbances in neurologic patients remains uncertain.
Objective and methods: To determine brain structures critical for control of eating behavior, we performed a prospective, laboratory-based, free-feeding study of 18 healthy control subjects and 32 patients with neurodegenerative disease. MR voxel-based morphometry (VBM) was used to identify regions of significant atrophy in patients who overate compared with those who did not.
Results: Despite normal taste recognition, 6 of 32 patients compulsively binged, consuming large quantities of food after reporting appropriate satiety. All six patients who overate were clinically diagnosed with frontotemporal dementia (FTD), a disorder previously associated with disordered eating, while the nonovereaters were diagnosed with FTD, semantic dementia, progressive aphasia, progressive supranuclear palsy, and Alzheimer disease. VBM revealed that binge-eating patients had significantly greater atrophy in the right ventral insula, striatum, and orbitofrontal cortex.
Conclusion: Binge eating can occur despite reported satiety and is associated with damage to a right-sided orbitofrontal-insular-striatal circuit in humans. These findings support a model in which ventral insular and orbitofrontal cortices serve as higher-order gustatory regions and cooperate with the striatum to guide appropriate feeding responses.