The brain networks encoding visceral sensation in patients with gastrointestinal symptoms due to diabetic neuropathy.

BACKGROUND: Increasing evidence points to association between long-term diabetes mellitus and abnormal brain processing. The aim of this study was to investigate central changes due to electrical stimulation in esophagus in patients with upper gastrointestinal (GI) symptoms due to diabetic neuropathy.
METHODS: Twenty-three diabetes patients with upper GI symptoms and 27 healthy controls were included. A standard ambulatory 24-h electrocardiography was carried out. 122-channel esophageal evoked brain potentials to electrical stimulation were acquired. Brain source/network analysis was performed. Gastroparesis Cardinal Symptom Index was used to evaluate upper GI symptoms and SF-36 questionnaire was utilized to assess patients' quality of life (QOL). KEY
RESULTS: Diabetes patients with GI symptoms showed modifications in three brain networks: (i) brainstem/operculum/frontal cortex, (ii) operculum/cingulate, and (iii) mid-cingulate/anterior-cingulate/operculum/deep limbic structures. Operculum brain source in patients was localized deeper and more anterior in all three networks. The shift of operculum source was correlated with the severity of upper GI symptoms, decreased heart beat-to-beat interval, and decreased SD of the intervals. The activation of the first network was delayed in patients. Operculum source had higher activity than cingulate in the second network in patients, and this was correlated with decreased physical QOL. Deep limbic source was localized deeper in patients, which also correlated with decreased physical QOL. CONCLUSIONS & INFERENCES: This study indicates involvement of central nervous system in diabetes. Reorganization within opercular cortex was correlated with GI symptoms suggesting that operculo-cingulate cortex could contribute to development and maintenance of GI symptoms in diabetes patients.