ALTERED LOWER-LIMB VASCULAR PERFUSION IN PATIENTS WITH SCIATICA SECONDARY TO DISC HERNIATION

Study Design. The present study attempts to document deep vascular abn ormalities of the lower extremity in cases of sciatica secondary to di scal herniation using Tc-99m methylene diphosphonate angiography. Obje ctives. Vascular abnormalities are studied compared with the contralat eral extremity and formal control subjects. An attempt is made to dete rmine the clinical usefulness of the current technique. Summary of Bac kground Data. Thermography has occasionally evidenced a decreased cuta neous temperature in patients with sciatica. There have been no studie s to date looking at the total vascular flow in this condition, mainly constituted by the muscular perfusion. Methods. Thirty patients with sciatica secondary to discal herniation. 16 patients with chronic low back pain refereed to the thigh, and 31 control subjects were examined by isotopic angiography of the posterior aspect of the thigh after in travenous injection of Tc-99m methylene diphosphonate. The affected si de was compared with the nonpainful side, and the difference was expre ssed as a percentage. Control subjects were used as reference values. Results. Abnormality in vascularization of the lower extremity was fou nd in 24 (80%) of patients with sciatica and in 11 (68.7%) of the pati ents with low back pain. The median blood flow difference was, respect ively, -12.5% and +4% in these two groups versus +2.9% in the control group. The differences between the sciatica group and the other two gr oups were statistically significant. No correlation was found with the clinical parameters studied. Conclusion. Vascular perfusion abnormali ties observed in patients with sciatica secondary to disc herniation m ay be more important than previously considered and possibly result fr om alteration in sympathetic vascular autoregulation.