Cervical spinal cord stimulation increases cerebral cortical blood flow in an experimental cerebral vasospasm model

Abstract

Cerebral microcirculatory changes during cerebral vasospasm after aneurysmal subarachnoid haemorrhage (SAH) are still controversial and uncertain. The aim of our study is to demonstrate that spinal cord stimulation (SCS) augments cerebral cortical microcirculatory blood flow in an experimental cerebral vasospasm model by using Laser Doppler Flowmetry (LDF). The experiments were carried out on 24 New Zealand rabbits. Three experimental groups were designed. In group 1, Cerebral cortical blood flow (CCoBF) was evaluated by LDF in 8 rabbits. In group 2, Intracisternal saline injection and cervical epidural electrode placement without SCS were performed in 8 animals before LDF. In group 3, LDF was performed before and after SCS on the 4th day of SAH in 8 rabbits. CCoBF parameters obtained from LDF data were compared. The occurrence of vasospasm after SAH was demonstrated with significant changes in LDF values. In all SAH animals, SCS resulted in significant increase (approximately 30%) in CCoBF. This increase was observed to continue even after the cessation of the stimulation. These results indicate that SCS improves cortical ischemia due to vasospasm after induced SAH. The cervical SCS may constitute a new therapeutic modality in treating disturbed CCoBF due to vasospasm.