Normalization of network connectivity in hemispatial neglect recovery

In this study, we test the hypothesis that recovery of hemispatial neglect correlates with a return of network connectivity toward a normal pattern, herein defined as “network normalization.”
MethodsWe measured attention deficits with a neuropsychological battery and FC in a large cohort of stroke patients at, on average, 2 weeks (n = 99), 3 months (n = 77), and 12 months (n = 64) postonset. The relationship between behavioral improvement and changes in FC was analyzed both in terms of a priori regions and networks known to be abnormal subacutely and in a data‐driven manner.
ResultsAttention deficit recovery was mostly complete by 3 months and was significantly correlated with a normalization of abnormal FC across many networks. Improvement of attention deficits, independent of initial severity, was correlated with improvements of previously depressed interhemispheric FC across attention, sensory, and motor networks, and a restoration of the normal anticorrelation between dorsal attention/motor regions and default‐mode/frontoparietal regions, particularly in the damaged hemisphere.
InterpretationThese results demonstrate that abnormal network connectivity in hemispatial neglect is behaviorally relevant. A return toward normal network interactions, and presumably optimal information processing, is therefore a systems‐level mechanism that is associated with improvements of attention over time after focal injury. Ann Neurol 2016

Source: Annals of Neurology - June 8, 2016 Category: Neurology Authors: Lenny E. Ramsey, Joshua S. Siegel, Antonello Baldassarre, Nicholas V. Metcalf, Kristina Zinn, Gordon L. Shulman, Maurizio Corbetta Tags: Research Article Source Type: research