Stroke and neurodegeneration induce different connectivity aberrations in the insula

INDIRA GARCÍA-CORDERO; SEDEÑO, LUCAS; FACUNDO MANES; AGUSTÍN IBÁÑEZ

Congreso; Society for Social Neuroscience (S4SN) Annual Meeting.; 2015

Background and Purpose: Stroke and neurodegeneration cause significant brain damage and cognitive impairment, especially if the insular cortex (InsC) is compromised. This study explores for the first time whether these two etiologies differentially alter connectivity patterns in the InsC. Methods: Resting state-FMRI data were collected from insular stroke patients, behavioral variant frontotemporal dementia (bvFTD) patients, and healthy controls. Data from the three groups were assessed through a correlation function analysis. Specifically, we compared decreases in connectivity as a function of voxel Euclidean distance within the InsC. Results: Relative to controls, stroke patients showed faster connectivity decays as a function of distance (hypoconnectivity). In contrast, the bvFTD group exhibited significant hyperconnectivity between neighboring voxels. Both patient groups evinced global hypoconnectivity. No between-group differences were observed in a volumetrically and functionally comparable region without ischemia or neurodegeneration. Conclusions: Functional InsC connectivity is affected differently by cerebral ischemia and neurodegeneration, possibly due to differences in the etiology-specific pathophysiological mechanisms of each disease. These findings have important clinical and theoretical implications. [Grants from CONICYT/FONDECYT Regular (1130920/1140114); PICT (2012-0412/2012-1309), CONICET, and the INECO Foundation]