A case of spinal cord stimulation in Raynaud's Phenomenon: can subthreshold sensory stimulation have an effect?

Spinal cord stimulation is currently used to treat a variety of chronic intractable painful conditions. We report a case of severe Raynaud's phenomenon in the hands refractory to conservative treatment and responsive to diagnostic stellate ganglion block that was effectively treated with a spinal cord stimulator placed in the cervical epidural space. After capturing the affected areas with paresthesias, blood flow in the left hand and fingers significantly improved as evidenced by an increase in skin temperature, a change from cyanotic to pink appearance and concomitant reduction in pain. Moreover, the patient reported that limb ischemia and pain could be managed overnight with stimulation intensities that were below sensory perception thresholds. Thus it seems, at least in the overnight period, paresthesias were not required to maintain pain relief. This case presents a potential divergence between a requirement for paresthesias and pain relief in spinal cord stimulation therapy for the treatment of Raynaud's phenomenon. The possible role of the sympathetic nervous system in this relationship is also discussed.