Assessment of regional cerebral blood flow during spinal cord stimulation in humans

Increased cerebral perfusion has been reported in both animal models and humans undergoing spinal cord stimulation (SCS). However, this was an inconsistent finding and variables able to influence regional cerebral blood flow (rCBF) following SCS are poorly investigated. We report our experience on rCBF measurements by the xenon-133 inhalation technique in 20 patients receiving acute and chronic SCS for different pathologies in basal conditions. Neither acute nor chronic SCS induced significant rCBF changes in the group of patients as a whole. However females, non-atherosclerotic patients and patients with a cervical SCS lead, showed a trend (borderline statistical significance) toward a redistribution of rCBF with increased values in frontoprerolandic and decreased values in postrolandic regions. Although SCS appears to influence intracerebral distribution more than absolute changes in blood flow, the mechanisms underlying such a phenomenon remain unknown. Functional activation of frontal lobes by the ascending reticular pathways through the thalamofrontal projections could be one possible hypothesis which has to be confirmed by further studies.