Altered lower limb vascular perfusion in patients with sciatica secondary to disc herniation.

STUDY

DESIGN

The present study attempts to document deep vascular abnormalities of the lower extremity in cases of sciatica secondary to discal herniation using Tc-99m methylene diphosphonate angiography.

OBJECTIVES

Vascular abnormalities are studied compared with the contralateral extremity and normal control subjects. An attempt is made to determine the clinical usefulness of the current technique. SUMMARY OF BACKGROUND DATA. Thermography has occasionally evidenced a decreased cutaneous temperature in patients with sciatica. There have been no studies 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 referred to the thigh, and 31 control subjects were examined by isotopic angiography of the posterior aspect of the thigh after intravenous injection of Tc-99m methylene diphosphonate. The affected side was compared with the nonpainful side, and the difference was expressed as a percentage. Control subjects were used as reference values.

RESULTS

Abnormality in vascularization of the lower extremity was found in 24 (80%) of patients with sciatica and in 11 (68.7%) of the patients with low back pain. The median blood flow difference was, respectively, -12.5% and +4% in these two groups versus +2.9% in the control group. The differences between the sciatica group and the other groups were statistically significant. No correlation was found with the clinical parameters studied.

CONCLUSION

Vascular perfusion abnormalities observed in patients with sciatica secondary to disc herniation may be more important than previously considered and possibly result from alteration in sympathetic vascular autoregulation.