Neuromodulation of cerebral blood flow by spinal cord electrical stimulation: the role of the Italian school and state of art.

Hosobuchi first studied the effect of spinal cord stimulation (SCS) on cerebral blood flow (CBF) in human beings along with the demonstration that SCS can improve peripheral blood flow. Following these clinical and experimental observations Hosobuchi first used cervical SCS for the treatment of cerebral ischemia in man. Further experimental reports suggested so far that SCS 1) drastically prevents cerebral infarction progression along with a reduction in infarct volume in cats; 2) improves clinical symptoms of patients in persistent vegetative states; 3) suppress headache attacks in migraneous patients; 4) significantly reduces ischemic brain oedema in rats; 5) increase locoregional blood flow in high grade brain tumors. The authors found that SCS can produce either an increase of CBF or a reduction or no effect. In patients studied with both SPECT technique and transcranial Doppler (TCD) the sign of the induced variations, when present in both, as the same. Cervical stimulation produces more frequently an increase in CBF (61% of cervical stimulations). The authors' experimental studies confirm that SCS 1) interacts with CO2 with the mechanism of regulation of CBF in a competitive way and produce a reversible functional sympathectomy; 2) produces similar flowmetric changes in the brain as well as in the eyes; 3) can improve both clinical and haemodynamic ischemic stroke in humans; 4) prevents hemodynamic deterioration in the experimental combined ischemic and traumatic brain injury; 5) prevents experimental early vasospasm.