Lower reward sensitivity in frontostriatal stroke: Influence of depression and resting-state functional connectivity.

Stroke patients have shown low reward sensitivity, which is a transdiagnostic dimension that defines the extent to which a person actively pursues rewarding stimuli. Low reward sensitivity has been related to depression and dysregulation of the frontostriatal network. To date, studies have addressed this dimension in heterogenic stroke lesions and the underlying mechanisms of frontostriatal stroke patients are still unknown. This study included 54 participants (32 chronic frontostriatal stroke patients and 22 healthy controls). Reward sensitivity was assessed using the probabilistic reversal learning task. Depressive symptoms were measured with the Adult Self-Report, and resting-state functional connectivity (rsFC) was examined using functional near-infrared spectroscopy (fNIRS) in prefrontal, motor, and parietal cortices. Group differences and predictors of reward sensitivity were analyzed using Bayesian ANCOVA and multiple regression models. Stroke patients displayed lower reward sensitivity, higher depressive problems, and lower resting-state functional connectivity between the right orbitrofrontal cortex and the left dorsolateral prefrontal cortex, the right orbitrofrontal cortex and the right dorsolateral prefrontal, and the right dorsolateral prefrontal cortex and right premotor cortex and supplementary motor area. In stroke patients, lower reward sensitivity was predicted by higher depressive problems and lower resting-state functional connectivity between the right dorsolateral prefrontal cortex and the right premotor cortex and the right supplementary motor area. This work showed the relevance of reward sensitivity in frontostriatal post-stroke patients and its relationship with depression, and supports the resting-state functional connectivity measurement for characterizing abnormalities in connectivity in stroke patients.