Relative Changes in Regional Cerebral Blood Flow During Spinal Cord Stimulation in Patients with Refractory Angina Pectoris

Spinal cord stimulation applied at thoracic level 1 (T1) has a neurally mediated anti-anginal effect based on anti-ischaemic action in the myocardium. Positron emission tomography was used to study which higher brain centres are influenced by spinal cord stimulation. Nine patients with a spinal cord stimulator for angina pectoris were studied using H₂¹⁵O as a flow tracer. Relative changes in regional cerebral blood flow related to stimulation compared with non-stimulation were assessed and analysed using the method of statistical parametric mapping. Increased regional cerebral blood flow was observed in the left ventrolateral periaqueductal grey, the medial prefrontal cortex Brodmann area (BA) 9/10], the dorsomedial thalamus bilaterally, the left medial temporal gyrus (BA 21), the left pulvinar of the thalamus, bilaterally in the posterior caudate nucleus, and the posterior cingulate cortex (BA 30). Relative decreases in rCBF were noticed bilaterally in the insular cortex (BA 20/21 and BA 38), the right inferior temporal gyrus (BA 19/37), the right inferior frontal gyrus (BA 45), the left inferior parietal lobulus (BA 40), the medial temporal gyrus (BA 39) and the right anterior cingulate cortex (BA 24). It is concluded that spinal cord stimulation used as an additional treatment for angina applied at TI modulates regional cerebral blood flow in brain areas known to be associated with nociception and in areas associated with cardiovascular control.