[Blood flow changes in the legs of patients with disc herniation and spinal canal stenosis]

Blood flow changes through the leg were examined by thermography, heated thermocouple technique and straingauge plethysmography in patients with lumbar-disc herniation and spinal canal stenosis. Hypothermal areas were observed in the affected leg in disc herniation and of both legs in spinal canal stenosis. An increased blood flow through the anterior tibial muscle during sustained contraction was slightly depressed, and post-contraction hyperemia showed an increase in amount and duration in disc herniation. Levels of resting arterial inflow through the leg were almost half that of healthy individuals, and reactive hyperemia after walking revealed a marked prolongation especially in spinal canal stenosis. In postoperative cases of spinal canal stenosis the thermogram and arterial inflow of the leg returned to their normal level. These results can provide evidence of latent ischemia of the leg that may be caused by a radicular or sympathetic dysfunction in the lumbar spinal diseases.