The impact of transcranial direct current stimulation on cerebral vasospasm in a rat model of subarachnoid hemorrhage

Transcranial direct current stimulation (tDCS) has been shown to induce changes in cortical excitability and perfusion in a rat ischemic stroke model. Since perfusion disturbances are a common phenomenon, not only in ischemic but also in hemorrhagic stroke, tDCS might have a possible beneficial effect on cerebral perfusion in hemorrhagic stroke as well. We applied tDCS in a rat model of subarachnoid hemorrhage (SAH) and evaluated its impact on vasospasm. SAH was induced using the double-hemorrhage rat model. TDCS was applied on day 3 and 4. For vasospasm assessment magnetic resonance angiography was performed on day 1, day 2 and day 5. A total of 147 rats were operated, whereat 72 rats died before day 5 and 75 rats survived the whole experiment and could be analyzed. The cathodal group consisted of 26 rats, the anodal group included 24 rats. Thirteen rats served as controls without tDCS, and twelve rats underwent a sham operation. The cathodal group revealed the lowest incidence of new vasospasm on day 5 (p = 0.01), and the lowest mean number of vasospastic vessels per rat (p = 0.02). TDCS influences the vasospasm incidence in an SAH-model in rats, where cathodal-tDCS was associated with a lower vasospasm incidence and severity.