The scalenus anticus syndrome: Faulty diagnosis in presence of Horner's syndrome—A modified technic of infiltration

Abstract

In patients with brachial plexus pain, diagnostic infiltration of the scalenus anticus muscle with procaine must be interpreted very carefully. If, following injection, relief of pain is accompanied by a Horner's syndrome, the entire result should be ignored, and surgical approach should be postponed until a successful muscle infiltration without the sympathetic anesthesia has been obtained. Anesthesia of the cervical sympathetics will stop pain which is not scalenus anticus in origin. Also, it is an effect not duplicated by section of the muscle. In our experience, surgical failures have predominated when these facts have been ignored. We have introduced a hyponeedle technic, in which the scalenus anticus muscle may be successfully injected with little likelihood of producing a Horner's syndrome. Following these modifications of clinical interpretation and technic, our surgical efforts have been rewarded with gratifying results.