Transcranial Direct Current Stimulation Reverses Stroke-Induced Network Alterations in Mice

BACKGROUND:Beyond focal effects, stroke lesions impact the function of distributed networks. We here investigated (1) whether transcranial direct current stimulation (tDCS) alters the network changes induced by cerebral ischemia and (2) whether functional network parameters predict the therapeutic efficacy of tDCS in a mouse model of focal photothrombotic stroke. METHODS:Starting 3 days after stroke, cathodal tDCS (charge density=39.6 kC/m(2)) was applied over 10 days in male C57Bl/6J mice under light anesthesia over the lesioned sensory-motor cortex. Functional connectivity (resting-state functional magnetic resonance imaging) was evaluated for up to 28-day poststroke, with global graph parameters of network integration computed. RESULTS:Ischemia induced a subacute increase in connectivity accompanied by a significant reduction in characteristic path length, reversed by 10 days of tDCS. Early measures of functional network alterations and the network configuration at prestroke baseline predicted spontaneous and tDCS-augmented motor recovery. DISCUSSION:Stroke induces characteristic network changes throughout the brain that can be detected by resting-state functional magnetic resonance imaging. These network changes were, at least in part, reversed by tDCS. Moreover, early markers of a network impairment and the network configuration before the insult improve the prediction of motor recovery.

Automated summary

In this study, the researchers investigated whether transcranial direct current stimulation (tDCS) can alter the network changes caused by cerebral ischemia and whether functional network parameters can predict the therapeutic efficacy of tDCS. The results showed that tDCS reversed the increased connectivity and reduced characteristic path length caused by ischemia. Additionally, early network changes and the network configuration prior to stroke predicted motor recovery.