The cold foot symptom in sciatica. A clinical and thermographic study.

A thermographic study on admission of 174 hospital patients with sciatica revealed a significant correlation between decreased temperature of the distal part of the affected limb and the probability of spinal nerve root compression. The highest order of preponderance for "coldness" was related to the group of patients whose symptoms were confirmed surgically as those of a herniated disc. The follow-up thermograms of 30 patients, on the average 29,4 months postoperatively showed correlation between normalization of the temperature and the relief of symptoms. Opinions regarding the neurophysiological mechanism of peripheral vasomotor control are controversial and the findings give rise to discussion of its complex pattern. Hypothetically derangement of anterograde axoplasmic transport of vasodilatory peptide macromolecules to the skin vessels may be involved.