Hemodynamic changes from spinal cord stimulation for vascular pain

The hemodynamic changes induced by spinal cord stimulation (SCS) have been studied in a group of 20 patients with peripheral vascular pain. The surgical technique consisted of the introduction of 1 or 2 electrodes in the subarachnoid space up to the level of the painful area, for mono or bipolar SCS. Several techniques have been used for evaluation of hemodynamic changes induced by SCS. Peripheral blood flow speed was measured by means of ultrasound Doppler, showing a raised maximum speed during stimulation, and a tendency of the pulse wave to return to normal. Thermography showed a marked increase of temperature in the painful area. Preoperatively, plethysmography showed an absence of the typical flow waveform, whilst postoperative recordings showed a small wave of progressively increasing amplitude. Scintigraphy with 201TI showed an increase in muscular blood flow in previously hypovascularized areas. The mechanism of action of SCS on peripheral blood flow and vascular pain is discussed.