Trigger Point Injection Defined

Trigger points are focal areas of spasm and inflammation in skeletal muscle. The rhomboid and trapezius back muscles, located in the upper back and shoulder areas, are a common site of trigger points.

In addition to the upper spine, trigger points can also occur in the low back or less commonly in the extremities.

Often there is a palpable nodule in the muscle where the trigger point is located. The area is tender, and frequently when pushed, pain radiates from the trigger point itself to an area around the trigger point.

Trigger points commonly accompany chronic musculoskeletal disorders such as fibromyalgia, myofascial pain syndrome, neck pain, and low back pain.

They may also occur with tension headache and temporomandibular pain. Acute trauma or repetitive minor injury can lead to the development of trigger points.

Trigger Point Injection Defined

How is the trigger point injection procedure performed?

The trigger point injection is performed in the health-care professional’s office, usually with the patient either lying on the exam table on the stomach or sitting on the exam table.

The exact protocol varies. The health-care professional performing the procedure locates the trigger point by manual palpation and marks the site.

Ultrasound guidance is not generally necessary. The injection site is then cleaned. Alcohol or another skin cleanser such as betadine is commonly used to clean the injection site.

Frequently, a numbing spray such as ethyl chloride is used to anesthetize the skin and make the actual injection less painful.

The needle is then inserted into the trigger point and the medication is injected. After the injection, a simple adhesive bandage may be applied.

If the area is painful after the injection, ice, heat, acetaminophen (Tylenol), or over-the-counter nonsteroidal anti-inflammatory medications such as ibuprofen (Advil) or naproxen sodium may be used.

When is a trigger point injection used?

Trigger point injection is used when a patient has a painful trigger point, especially when pain radiates from the trigger point to the surrounding area.

Trigger point injections may be used as a treatment for conditions such as fibromyalgia and myofascial pain syndrome. However, the trigger points commonly recur with chronic pain syndromes.

What are complications and side effects of trigger point injections?

A potential complication from the trigger point injection procedure is post-injection pain. This is relatively uncommon, but it can occur.

This pain usually resolves by itself after a few days. It is more common when no medication is injected into the trigger point (dry needling).

Ice, heat, or over-the-counter medications such as acetaminophen, ibuprofen, or naproxen sodium may be useful for post-injection pain.

If a steroid medication is injected into the trigger point, shrinkage of the fat under the skin can occur, leaving a dent in the skin.

This does not occur when only anesthetic is injected without any steroid medication. Other side effects are rare with trigger point injections but can occur anytime a needle punctures the skin, including infection and bleeding.

How frequently do trigger point injections need to be administered?

Optimally, a trigger point resolves after one injection. This may happen when a patient has one isolated trigger point, especially if the cause of the trigger point has been removed (such as a trigger point caused by a repetitive minor trauma or movement that will no longer be performed).

Trigger points caused by chronic conditions such as fibromyalgia and myofascial pain syndrome tend to recur due the underlying problem.

In these cases, trigger point injections may be administered on a regular or as needed basis. The frequency of trigger point injections depends on the medication being injected.

If only lidocaine or a mixture of anesthetics is injected, then the injections can be administered as ongoing therapy as frequently as monthly.

If a steroid medication is injected, TPIs should be administered much less frequently, at the discretion of the treating health-care professional, because of the risk of tissue damage or shrinkage from the steroid medication.

What do trigger points have to do with back pain and how are they treated?

Trigger points are tight-tender areas of muscle that can be very painful to touch and can cause referred, radiating pain.

Activation of trigger points in the paraspinal muscles can be caused by sudden overload during lifting objects, twisting and flexing the back, stooping or poor posture. You may also have tightness in your back that prevents you from some movements.

Trigger points can be very painful and disabling and may even cause weakness. Proper diagnosis and treatment is essential.

Treatment consists of finding ways to “de-activate” the active trigger point. This includes Myotherapy (deep pressure, counterstrain technique), Mechanical vibration, Pulsed ultrasound, Electrostimulation, Ischemic compression, Injection, Dry-needling, Spray-and-stretch, etc.

Trigger Point therapy is part of the multidisciplinary treatments we recommend and prescribe.

A thorough history and physical exam focusing on the symptoms of neck and back pain can help reveal the underlying cause of the pain.

Many patients will have trigger points that can contribute to all or most of their pain. Trigger point injection therapy is usually helpful with these patients and helps them get back on the road to recovery.

The injection is usually performed with a mixture of lidocaine and bupivicaine to ease some of the stress from injecting the muscle, followed by some dry needling which is thought to de-activate the point.

A technique called Myofascial release can be performed after the injection for further relaxation of the affected muscles. A technique called Spray-and-stretch can also be used instead of injections.

Trigger point therapy may need to be repeated for multiple sessions 1-2 weeks apart until the points are de-activated and the patient is more mobile with a decreased level of pain and tenderness.

It is one step in the road to recovery from neck and back injury and works well combined with physical/massage therapy and/or manipulative treatments.

Ciguatera Poisoning Treatment and Prevention

Ciguatera is a type of food poisoning. The ciguatera toxin may be found in large reef fish, most commonly barracuda, grouper, red snapper, eel, amberjack, sea bass, and Spanish mackerel.

These fish live in coral reef waters between latitudes of 35 degrees south to 35 degrees north, corresponding to the area located between the Tropic of Cancer and the Tropic of Capricorn.

These geographic lines ring the earth north and south of the equator and make up the tropics. These areas include the Caribbean Sea, Hawaii, and coastal Central America.

Ciguatera toxin tends to accumulate in predator fish, such as the barracuda and other carnivorous reef fish, because they eat other fish that consume toxin-producing algae (dinoflagellates) that live in coral reef waters.

Ciguatera toxin is harmless to fish but poisonous to humans. The toxin is odorless and tasteless, and it is heat-resistant, so cooking does not destroy the toxin.

Eating ciguatera-contaminated tropical or subtropical fish poisons the person who eats it.

Ciguatera Poisoning Treatment and Prevention

What are the symptoms of ciguatera poisoning?

Symptoms of ciguatera poisoning generally begins six to eight hours after eating the contaminated fish.

Symptoms include:

  • nausea,
  • vomiting,
  • diarrhea,
  • muscle pain,
  • numbness,
  • tingling,
  • abdominal pain,
  • dizziness, and
  • vertigo.
  • Hot and cold sensation may be reversed.

Severe cases of ciguatera poisoning may result in tearing of the eyes, chills, skin rash, itching, shortness of breath, drooling, and paralysis. Death due to heart or respiratory failure occurs in rare cases.


Using a household pet or even elderly relative as a simple bioasssay was and may still be practiced in many island communities.

Otherwise, only expensive ponderous bioassays in such animals as the mongoose, rat and cats were available for screening Ciguatoxin-contaminated fish until ten years ago.

The mouse bioassay, while it remains the standard diagnostic tool, does not distinguish between ciguatoxin and scaritoxin.

Over the past few years, radioimmune (RIA) or enzyme linked immunosorbent (ELISA) assays have been developed to investigate Ciguatera, including the Hokama enzyme immunoassay stick test.

Emerson et al (1983) using counter-immunoelectrophoresis disclosed precipitin lines with toxic fish extracts and effectively discriminated between samples compared with human and mouse bioassay.

However putative immune and nonimmune serum gave equally clear precipitin reactions with toxic extracts therefore the authors could not conclude that they had located a specific antibody.

Trainer et al (1990, 1991) developed an assay which can measure Ciguatoxin qualitatively and potentially quantitatively in fish and possibly human fluids.

Further work involves the application of these assays to human fluids from persons who have eaten assay-positive fish.

Management and Treatment:

Medical treatment has been to a large extent symptomatic; a variety of agents, including vitamins, antihistamines, anticholinesterases, steroids and tricyclic antidepressants, have been tried with limited results.

Gut emptying and decontamination with charcoal is recommended acutely although often the severe ongoing vomiting and diarrhea prevents this.

Atropine is indicated for bradycardia, and dopamine or calcium gluconate for shock. It is recommend that opiates and barbiturates be avoided since they may cause hypotension, and opiates may interact with maitotoxin.

With apparent considerable success, at least acutely, mannitol infusions have been used. Palafox et al (1988) administered 1 gm/kg of 20% mannitol at a rate of 500 mL/h “piggybacked” to an iv infusion of 5% dextrose in

Ringers lactate or saline solution at 30 mL/h or more depending on fluid requirements with complete reversal of symptoms in the majority of patients tested.

Subsequent reports have affirmed his success although mannitol appears to be most effective in completely relieving symptoms when given within the first 48-72 hours from ingestion.

Amitriptyline (25 to 75 mg bid) and similar medications do seem to have some success in relieving the symptoms of chronic Ciguatera, such as fatigue and paresthesias.

It is possible that nifedipine may be appropriate as a calcium channel blocker to counteract the effects of maitotoxin.

Finally, there are over 64 different local remedies including medicinal teas used in both the Indo-Pacific and West Indies regions.

None of these treatments have been evaluated in a controlled clinical trial with the exception of two controlled trials of Mannitol for treatment of acute Ciguatera, so that their true efficacy is impossible to determine.

As mentioned above, there appears to be a sensitivity to certain foods (ie. ingestion of fish (regardless of type), ethanol, caffeine, and nuts) after ciguatera poisoning and these should be avoided for 3 to 6 months after the illnesses.

In addition, there is no immunity to this illnesses and recurrences of actual ciguatera in the same individual appear to be worse than the initial illness.

As with many of the marine toxin induced diseases, the initial or index case(s) are often the tip of the iceberg.

Therefore any suspected cases of Ciguatera should be reported to the appropriate public health authorities for follow up to ascertain other cases and to prevent further spread.

And every effort should be made to obtain contaminated materials and their source.

Obviously persons who live in or travel to endemic areas should never eat barracuda or morey eel, and should be cautious with grouper and red snapper, as well as enquiring about local fish associated with Ciguatera.

Since there is no reliable way to “decontaminate” or even to distinguish contaminated fish by smell or appearance, at a minimum, people should be advised to avoid the viscera of any reef fish as well as avoiding consuming unusually large predacious reef fish especially during the reproductive season.

When should I see a doctor for ciguatera poisoning?

Severe cases of ciguatera poisoning require hospitalization for intravenous fluids.

If you think you may have ciguatera poisoning, seek immediate medical attention.

A doctor should be consulted in every case about treatment for ciguatera poisoning, including available medications.