Sympathetic Block

What is a sympathetic block?

Your sympathetic nervous system controls all of your body’s involuntary reflexes. These nerves originate in the spinal cord and branch out to influence many bodily functions like:

• Blood pressure
• Urination and defecation
• Sexual arousal

This system also controls the stress response, sending the body into high alert when it perceives danger.

A ganglion is a bundle of nerves that come together. The stellate ganglion (upper body) as well as the sympathetic chain (lower body) supply your entire body’s sympathetic nervous system. When these nerves are irritated or injured, the blood supply to your hands, feet, or other areas may be affected. This can produce pain or sensory changes. Headaches, neck pain, and facial pain can also be seen in patients who have sympathetic nerve dysfunction.

A sympathetic block is the injection of a local anesthetic into a sympathetic ganglion. This can diagnose or treat pain disorders that involve your sympathetic nervous system.

How can a sympathetic block help me?

Pain that originates from the sympathetic nervous system is not easily treated by oral pain medications. Sympathetic blocks are an effective and beneficial treatment option for many.

Sympathetic nerve blocks help relieve some of the most challenging chronic pain conditions, including:

• Complex regional pain syndrome
• Trigeminal neuralgia
• Chronic abdominal pain

Some patients with fibromyalgia may find relief from a sympathetic block, but there is limited research on this application.

Diagnosing the source of your pain

In addition to pain relief, sympathetic blocks can act as a diagnostic tool to better direct treatment, especially in the upper back and neck.

Two things may happen after receiving the sympathetic block.

First, you may experience complete pain relief. If this happens, your pain is related to your sympathetic nervous system. Continued sympathetic nerve blocks or related treatments will most likely be beneficial.

Second, the pain does not go away, but your physician determines that the sympathetic block was physiologically successful. This means that pain signals were blocked, but since pain is still present, the sympathetic nervous system is not the source of the pain.

Whether used for pain relief or as a diagnostic tool, sympathetic blocks are a minimally invasive treatment option for many people with chronic pain. For those patients, the best-case scenario with sympathetic blocks is the rapid relief of symptoms. This allows patients to experience enough relief to resume their normal daily activities and physical therapy to treat the underlying condition.

How does a sympathetic block work?

The sympathetic nerve block procedure is an outpatient procedure that uses a local topical anesthetic to ensure your comfort. For patients who are concerned about the pain of the procedure, your physician may also use intravenous sedation.

Once the skin to be injected is numbed and you are comfortable, your doctor inserts another needle near the targeted ganglion. They will use X-ray guidance to ensure proper needle placement. When the needle is in place, your doctor injects an anesthetic (e.g., lidocaine, bupivacaine) and a corticosteroid into the space where the sympathetic nerve ganglion are located.

The entire procedure takes less than 15 minutes. Your physician will monitor you after the procedure to see the effect of the block on your pain.

Risks

With few risks, sympathetic ganglion blocks are considered an appropriate and safe non-surgical treatment option for many chronic pain patients. There are complications to be aware of, though. Most complications are due to either improper needle placement or an adverse response to the injected medication.

These complications can include the following:

• Infection
• Bleeding
• Collapsed lung (pneumothorax)
• Nerve damage
• Reaction to medication

Since the procedure is blocking sympathetic nerves, you may experience some temporary side effects or changes. These changes include drooping of the eyelid and stuffy nose. They usually resolve within hours.

Recovery

Sympathetic block recovery is usually easy and rapid. You may experience some pain in the injection site that fades quickly. Apply an ice pack for comfort or utilize over-the-counter medications as directed by your doctor.

You can resume your normal activity levels as you are able. Most people can return to their normal diet and medications on the advice of their physician.

You may not experience pain relief immediately. If pain levels remain high, or you experience signs of infection at the injection site (e.g., redness, swelling, fever), call your doctor.