Interscalene brachial plexus block for scapular and upper chest pain due to cervical radiculopathy: a randomized controlled clinical trial.

BACKGROUND: Animal experiments have shown that one of the pathways for pain originating from the cervical spine is the sympathetic trunk. However, there have been few reports regarding the cervical pain pathway and efficacy of interscalene brachial plexus block for upper limb, scapular and chest pain originating in the cervical spine in clinical cases. The purpose of the present study was to clarify the efficacy of interscalene brachial plexus block for upper limb, scapular and chest pain.

METHODS: Patients (137 men and 223 women) who had cervical radicular pain were studied. The intensity of upper limb, scapular and chest pain was measured by using a VAS before injection and at 5 min and 7 days after injection. To evaluate the efficacy of interscalene brachial plexus block, patients with cervical radicular pain who had received NSAIDs for at least 2 weeks were randomized to interscalene brachial plexus block or control block groups. VAS scores were compared to assess the effects of injection and the pain pathway.

RESULTS: The average VAS score for upper limb pain with or without scapular and chest pain was significantly reduced by interscalene brachial plexus block compared with control block at 5 min and 7 days after injection. After interscalene brachial plexus block, 89 patients reported symptoms of stellate ganglion block versus no patients after control block. Scapular and chest pain was significantly reduced in the patients with stellate ganglion block compared to those without stellate ganglion block.

CONCLUSIONS: Interscalene brachial plexus block is useful for upper limb, scapular and chest pain due to disorders of the cervical spine. The scapular and chest pain pathway is more likely to be interrupted by an interscalene brachial plexus block that causes a stellate ganglion block compared to an interscalene brachial plexus block without stellate ganglion block.