What is a Trigger Point Injection?
A trigger point injection (TPI) involves the injection of medication such as steroids and/or anesthetic directly into the trigger point to alleviate pain. This refers to a popular option for pain management of the muscle of arms, legs, neck, and lower back 1. Neurosurgeons use this injection to treat chronic muscle pain and other issues that contain trigger points. The trigger point of muscle describes a focal area of muscle spasm that forms when muscles do not relax. This usually affects the musculoskeletal system and causes inflammation in the skeletal muscles of the patient’s back. The common sites of trigger point include the rhomboid and trapezius muscles in the upper back and shoulder areas 2.
Most of the time, patients can feel these knots under the skin. This palpable nodule looks tender, and when pushed, may radiate pain from the trigger point to the surrounding tissues. These points commonly associated with several musculoskeletal disorders such as fibromyalgia, myofascial pain syndrome, neck and back pain, tension headache, and temporomandibular pain. The medication injected into the trigger point may include anesthetics like lidocaine, bupivacaine, or a mixture of these. Rheumatologists also injected corticosteroids like cortisone alone or mixed with anesthetics like lidocaine.
Sometimes, only a needle inserted into a trigger point with no medication. This system works and known as “dry needling”. The injection helps the trigger point to become inactive and relieves pain. The development of a trigger point occurs after acute trauma or repetitive minor injury. These points usually irritate nerves around them and cause referred pain. Referred pain refers to a pain that patients feel in one part of their body, which actually caused by pain or injury in another part of the body. For example, an injured pancreas can cause pain in the back of a heart attack can cause pain in the jaw.
When Is Trigger Point Injection Used?
A trigger point injection used to ease muscle pain and helps to treat fibromyalgia, tension headaches, and myofascial pain syndrome. This syndrome refers to a chronic pain that involves the surrounding tissues of the muscle. Trigger point injection reduces localized muscle pain by relaxing the muscles. Possible causes of myofascial pain syndrome include poor posture, repetitive motion, injury, or psychological stress. Besides referred pain, a patient with myofascial pain may suffer from muscle stiffness or weakness and limited range of motion 3.
Another condition of fibromyalgia includes the symptoms of chronic pain, which affects the soft tissues of the muscle. Other symptoms of fibromyalgia include pain and stiffness throughout the body, headache, digestive problems, depression, anxiety, etc. Initially, neurologists diagnose fibromyalgia in patients who reported pain in specific trigger points throughout the body. Trigger point injection has no complications. A patient may temporarily develop soreness and numbness at the injection site 4.
How do Neurosurgeons perform a Trigger Point Injection?
Trigger point injection can be easily administered by rheumatologists, physical medicine, or rehabilitation doctors. Some intern doctors, practice doctors, and neurologists can also perform trigger point injections to the patient. This injection can easily perform in the health care professional’s office. The prevalence of myofascial trigger points among patients complaining of pain anywhere in the body ranged from 35% to 90% in the USA 5.
In the TPI procedure, a health care professional will insert a small needle into the trigger point of the patient. Before that, the patient will lie on the stomach or sitting on the examination table. The health professionals will locate the trigger point by palpation over the skin and mark the site. The injection contains some anesthetics and steroids in combination. This injection will help to alleviate the pain of the patient. Usually, this injection takes just a few minutes to administer. After the injection, neurologists will apply a small bandage over the injected area.
- Kang, J. et al. Feasibility of Ultrasound-Guided Trigger Point Injection in Patients with Myofascial Pain Syndrome. Healthcare 7, 118 (2019).
- Zhou, J. Y. & Wang, D. An update on botulinum toxin a injections of trigger points for myofascial pain. Curr. Pain Headache Rep. 18, (2014).
- Soriano, P. K., Bhattarai, M., Vogler, C. N. & Hudali, T. H. A case of trigger-point injection-induced hypokalemic paralysis. Am. J. Case Rep. 18, 454–457 (2017).
- Gandolfi, M. et al. Does myofascial and trigger point treatment reduce pain and analgesic intake in patients undergoing onabotulinumtoxinAinjection due to chronic intractable migraine? Eur. J. Phys. Rehabil. Med. 54, 1–12 (2018).
- Wong, C. S. M. & Wong, S. H. S. A new look at trigger point injections. Anesthesiol. Res. Pract. 2012, (2012).