ostructureAssessedby Diffusion Tensor Imaging in Patients With Diabetes Mellitus and Gastrointestinal Symptoms

OBJECTIVEdIn patients with long-standing diabetes mellitus (DM), there is increasing ev-idence for abnormal processing of gastrointestinal sensations in the central nervous system.Using magnetic resonance diffusion tensor imaging, we characterized brain microstructure inareasinvolvedinvisceralsensoryprocessingandcorrelatedthesefindingstoclinicalparameters.RESEARCH DESIGNANDMETHODSdTwenty-sixpatientswith DM and gastrointes-tinal symptoms and 23 healthy control subjects were studied in a 3T scanner. The apparentdiffusioncoefficient(i.e.,diffusivityofwater)andfractionalanisotropy(FA)(i.e.,organizationoffibers) were assessed in the“sensory matrix” (cingulate cortex, insula, prefrontal and secondarysensory cortex, amygdala, and corona radiata) and in corpus callosum.RESULTSdPatientshaddecreasedFAvaluescomparedwithcontrolsubjects:1)allareas(P=0.025);2)anterior(P,0.001),mid-(P=0.001),andposterior(P,0.001)cingulatecortex;3)prefrontal cortex gray matter (P , 0.001); 4) corona radiata (P , 0.001); 5) secondary sensorycortex(P=0.008);6)anteriorwhitematter(P=0.045);andanteriorgraymatter(P=0.002)andposteriorgraymatter(P=0.002)insula.Nodifferencewasfoundincorpuscallosum(P.0.05).Themicrostructuralchangeswere forsomeareascorrelatedtoclinicalparameterssuchasbloat-ing (anterior insula), mental well-being (anterior insula, prefrontal cortex, and mid-cingulatedand corona radiata), autonomic function based on electrocardiographic results (posterior insulaand anterior cingulate), and presence of gastroparesis (anterior insula).CONCLUSIONSdThe findings of this explorative study indicate that microstructuralchanges of brain areas involved in visceral sensory processing are associated with autonomicdysfunction and therefore may be involved in the pathogenesis of gastrointestinal symptoms inDM patients.