A stellate ganglion block is an injection of local anesthetic in the sympathetic nerve tissue of the neck. These nerves are a part of the sympathetic nervous system. The nerves are located on either side of the voice box, in the neck. The risks of the procedure, though infrequent, may include seizure - if the medication is injected into a blood vessel - bleeding, pneumothorax (collapsed lung), brachial plexus block (temporary numb arm that lasts for a few hours), spinal or epidural block (temporary weakness or numbness from the neck down), allergic reaction to medication, nerve damage, and bruising at the injection site. There are some expected changes that result from blocking the sympathetic nerves. These changes are temporary and may last about 4 - 6 hours. Such changes include the following symptoms on the same side as the injection: drooping of the eyelid, bloodshot eye, stuffy nose and a temperature increase in the arm.
