Stroke and Neurodegeneration Induce Different Connectivity Aberrations in the Insula.

GARCÍA-CORDERO I, SEDEÑO L, FRAIMAN D, CRAIEM D, DE LA FUENTE LA, SALAMONE P, SERRANO C, SPOSATO L, MANES F, IBAÑEZ A

STROKE

LIPPINCOTT WILLIAMS & WILKINS

Lugar: Philadelphia; Año: 2015

0039-2499

BACKGROUND AND PURPOSE: Stroke and neurodegeneration cause significant brain damage and cognitive impairment, especially if the insular cortex is compromised. This study explores for the first time whether these 2 causes differentially alter connectivity patterns in the insular cortex.METHODS: Resting state-functional magnetic resonance imaging data were collected from patients with insular stroke, patients with behavioral variant frontotemporal dementia, and healthy controls. Data from the 3 groups were assessed through a correlation function analysis. Specifically, we compared decreases in connectivity as a function of voxel Euclidean distance within the insular cortex.RESULTS: Relative to controls, patients with stroke showed faster connectivity decays as a function of distance (hypoconnectivity). In contrast, the behavioral variant frontotemporal dementia 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 insular cortex connectivity is affected differently by cerebral ischemia and neurodegeneration, possibly because of differences in the cause-specific pathophysiological mechanisms of each disease. These findings have important clinical and theoretical implications.