by Nicole Evans M.D.

Created on: October 31, 2009

Trigger points are tender spots found in individuals with fibromyalgia and other myofascial pain syndromes. Trigger points feel like hard spots within muscles that are sore when pressed. These tense spots are often located in different muscle groups, usually near areas where muscles attach to bones.

How do trigger point injections work?

Trigger point injections are used to interrupt the pain cycle in individuals with fibromyalgia. Often, interrupting the cycle of pain can produce prolonged pain relief.

However, the actual mechanism with which trigger point injections produce symptomatic improvement is not known.

Patient's who are receiving trigger point injections should understand that the site of pain may, at times, be distant from the actual irritated trigger point that is potentially causing this pain.

Are there contraindications to trigger point injections?

There are some contraindications to trigger point injections including:

-Infection at the site of needle injection

-Current use of an anticoagulant

-A hemorrhagic (bleeding) disorder

-Severe psychiatric disturbance

-Many widespread trigger points present in the setting of an untreated endocrine imbalance such as hypothyroidism, estrogen deficiency, hypoparathyroidism, hyperparathyroidism, pituitary disorders and Cushing's disease.

How are trigger point injections done?

Trigger point injections are done with the patient sitting or lying in a comfortable position. Practitioners will prepare to inject the trigger point by pressing on the area of pain until the point of maximal tenderness is palpated. This point is often associated with a muscle spasm or nodule.

The healthcare practitioner will then mark the site with a pen, clean it, and inject the muscle spot with a local anesthetic such as lidocaine or bupivacaine. The area will be injected two or three times. Then the practitioner should massage the entire area to diffuse the anesthetic. This massaging also allows the patient to tell whether successful pain relief has been acheived.

Healthcare practitioners who inject the trigger points of fibromyalgia sufferers may be able to enhance the effectiveness of these injections by incorporating passive stretching into the treatment.

How soon does pain relief occur?

After a trigger point is injected with a local anesthetic there should be almost immediate pain relief. After the very first injection, the physician should observe for signs of an adverse reaction to the injection. This may manifest as lightheadedness, slurring of speech, drowsiness, numbness of one or more extremities and even seizure activity.

For greatest efficacy, fibromyalgia patients should also do stretching exercises, physical therapy or rest when indicated. Men and women with fibromyalgia should also be aware that the pain may recur and may actually worsen for 1 to 2 days. Followup injections may be required if the pain relief from the initial injection wears off.

*Fowler, G., Pfenninger, J. Procedures for Primary Care. 2nd Ed. Mosby Inc. 2003.

Learn more about this author, Nicole Evans M.D..
Click here to send this author comments or questions.