What Are Trigger Point Injections?Trigger points are localized areas of muscle spasm and inflammation. Trigger points can occur in various regions of the body. Common sites for trigger points include the rhomboid and trapezius muscles, which are located in the upper back and shoulder regions, as well as in the lower back and extremity musculature.
When the area of the trigger point is palpated, a nodule or lump is often felt. Trigger points can produce localized, as well as referred pain, when they are compressed. A localized twitch may also be visualized when the area is palpated. Trigger points are classified as being either active or latent. Active trigger points cause pain at rest. They are also tender to palpation and produce a referred pain pattern. The pain associated with active trigger points is often described as radiating or spreading. Conversely, a latent trigger point does not cause immediate pain, but may restrict movement and cause muscle weakness. Patients with trigger points commonly present with regional, persistent pain that often results in decreased range of motion of the affected muscle.
Trigger points are commonly associated with musculoskeletal disorders including neck pain, low back pain, fibromyalgia, and myofascial pain syndrome. Furthermore, trigger points may be seen in patients who suffer from headaches and temporomandibular pain. Repetitive minor injuries or acute traumatic events can lead to the development of trigger points.
A trigger point injection is a minimally invasive procedure that involves an injection of medication directly into the trigger point that helps to provide pain relief. The trigger point injection may be a single local anesthetic, a combination of local anesthetics, a corticosteroid, or a combination of an anesthetic and corticosteroid. The goal of the treatment is to inactivate the trigger point, thereby reducing pain.
How Are Trigger Point Injections Performed?Trigger point injections are performed in an outpatient setting. The patient may be lying or sitting on the exam table depending on the location of the trigger point. The trigger point is located by palpation by the physician and the site is marked. Ultrasound may also be used to identify the location of the trigger point. The skin of the site to be injected is cleaned with an antiseptic solution to help reduce the risk of infection. A local anesthetic may be applied to numb the area prior to the injection to make the procedure more comfortable for the patient. The needle is then inserted into the trigger point and the medication is injected. A bandage may be applied to the injection site after the procedure, if necessary.
After a trigger point injection, the area may be tender. Patients are advised to apply ice or heat to the tender area, and take acetaminophen or non-steroidal anti-inflammatory drugs (NSAIDs), if needed for pain control. The patient should be encouraged to remain active after the trigger point injection in an effort to put the affected muscle through its’ full range of motion in the week after the injection However, they should be advised to refrain from strenuous activity, particularly for the first three to four days after the injection.
Side effects of trigger point injections are rare, but include infection and bleeding. When cortisone is injected for a trigger point injection fat shrinkage under the skin may occur.
The anesthetic medication that is injected during a trigger point injection blocks pain receptors within the nerves that surround the muscle, which helps to reduce pain signal transmission to the brain. When a corticosteroid is also injected, it helps to reduce inflammation and swelling of the tissue surrounding the nerve, which may help to decrease a patient’s pain.
The pain relief experienced following trigger point injections varies among patients. Some physicians may recommend a series of injections for some patients that are scheduled several weeks apart in order to provide optimal relief.
Conditions Related To Trigger Point InjectionsTrigger point injections can be used to treat a variety of conditions that affect the musculoskeletal system, including:
- Fibromyalgia (when myofasical trigger points are present)
- Tension headaches
- Myofascial pain syndrome
- Neck pain
- Low back pain
Fibromyalgia is a disorder that is characterized by widespread musculoskeletal pain that is often accompanied by fatigue, memory, sleep, and mood issues. Further, patients with fibromyalgia often experience headaches, temporomandibular disorders, irritable bowel syndrome, depression, and anxiety. When patients with fibromyalgia have myofascial trigger points that are contributing to their pain symptoms, trigger point injections may help to relieve some of their pain symptoms.
Tension headaches are the most common type of headache. The pain that is associated with tension headaches may impact the whole head; however, the pain commonly begins in the back of the head or above the eyebrow. Some patients may report a band-like sensation around their head, while others report muscle tension in their neck or shoulders. While the pain associated with tension headaches is usually short-lived, some patients may experience these headaches frequently. Lidocaine trigger point injections into the myofascial trigger points located in the pericranial muscles may help to provide pain relief to patients who suffer frequent tension headaches.
Myofascial pain syndrome is a chronic pain condition. Patients with this condition have trigger points that cause radiating pain when they are compressed. Signs and symptoms of myofascial pain syndrome include a deep aching type pain in a muscle, pain that increases at night, a tender nodule in the muscle, and difficulty sleeping due to pain. Tender trigger points can be the result of injury or overuse of a muscle. Trigger point injections into the tender areas associated with this condition can help to relieve pain.
Patients may experience neck or lower back pain that is caused by trigger points in the surrounding musculature. Trigger point injections into these areas can help to provide pain relief.
ConclusionA trigger point injection is a minimally invasive treatment that can be used to treat a variety of chronic pain conditions that involve myofascial trigger points, including fibromyalgia, tension headache, myofascial pain syndrome, neck pain, and back pain.
Trigger point injections are relatively safe, with the most common side effect being injection site tenderness.
Patients suffering from chronic pain condition should speak with their physicians to determine if trigger point injections may be an effective treatment option for their condition.
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