Pediatric Amplified Musculoskeletal Pain Syndrome

Introduction

Amplified musculoskeletal pain syndrome (AMPS) is a term for non-inflammatory musculoskeletal pain. Several studies have noted amplified musculoskeletal pain syndrome, usually in children ranging in age from 11.5 to 15 years, and often in girls. Children below four years of age have never been reported with the syndrome.

What Is Pediatric Amplified Musculoskeletal Pain Syndrome?

Amplified musculoskeletal pain syndrome is a condition in which excruciating pain is experienced anywhere in the body in children. The pain can be sudden in onset or persistent, localized to a particular area of the body or affect the whole body.

What Is the Cause of Amplified Musculoskeletal Pain Syndrome in Children?

Amplified musculoskeletal pain in children could be caused by:

• Injuries - Such as burns, deep cuts, fractures of the bone, or excessive strain on the muscle can cause a tear.

• Diseases - Such as juvenile idiopathic arthritis, tendonitis, and influenza.

• Psychological Stress - Due to an unfortunate event or childhood trauma.

Normally, for an individual, the sensation of pain is due to the signal from the nerve endings that are sent to the brain from the site of the affected, through the spinal cord to the brain. In the case of an abnormal reflex, when this pathway is interrupted due to any of the causes, the pain signals go to the brain and autonomic nerves (neurovascular nerves). Autonomic nerves control blood flow through the blood vessels.

When the pain signal reaches the autonomic nerves, it causes the blood vessels to constrict. The constriction causes a decrease in blood flow to the organs and tissues, which causes waste to build up in the body. The decrease in oxygen and increase in waste products are responsible for the amplified pain the child experiences. This amplified pain further decreases the oxygen supply by going through the abnormal reflex pathway, and the cycle continues, causing excruciating pain throughout the body.

What Are the Types of Amplified Pain?

Amplified pain can be continuously experienced or have the following characteristics:

• Localized Amplified Pain Without Autonomic Changes - One or two affected body regions.

• Diffuse Amplified Pain - Three or more affected body regions. It is also called total body pain or juvenile fibromyalgia.

• Intermittent Amplified Pain - The episodes of pain come and go away on its own.

• Complex Regional Pain Syndrome (CRPS) With Autonomic Changes - Autonomic changes include color and temperature changes, for example, cold and blue or swelling and sweating.

What Are the Symptoms of Amplified Musculoskeletal Pain in Children?

The symptoms of amplified musculoskeletal pain may be sudden in onset or develop over weeks. Some of the common symptoms of amplified musculoskeletal pain are:

• Pain - localized or generalized which may be constant or intermittent.

• Change in Skin Color or Temperature - Localized or all over the body.

• Allodynia - Increased sensitivity, with a normal touch of the skin feeling especially painful.

• Headache, abdominal pain.

• Trouble Sleeping and Concentrating - due to pain.

• Difficult in Mobility - due to stiffness and swelling in joints.

• Anxiety and depression due to the excruciating episodes of pain.

• Tremors, paralysis, blindness, or non-epileptic seizures without the presence of any underlying explainable conditions.

How to Diagnose Amplified Musculoskeletal Pain in Children?

The diagnosis of amplified musculoskeletal pain is confirmed after all the other possibilities of pain are ruled out and by the child's presentation of episodes of pain.

• A physical examination to assess the joints, mobility, and strength of muscles and bones is conducted.

• X-rays and scans may help find the cause (a sign of injury) for amplified musculoskeletal pain. Blood tests are usually normal for amplified musculoskeletal pain unless an underlying disease condition is present (for example: juvenile idiopathic arthritis).

• Any possibility of psychological stress for the child is carefully assessed; this could be a stressor for amplified musculoskeletal pain syndrome or a consequence of the condition.

How to Treat Amplified Musculoskeletal Pain Syndrome in Children?

The treatment focuses mainly on the physical functioning and emotional well-being of the child.

1. Regular Exercise:

• Regular exercise (physical therapy) is important for the child to improve blood flow and physical function including strength, balance, and flexibility. A trainer or a therapist can curate an exercise plan suited best for the child based on the symptoms experienced.

• Highly intense aerobic exercises for up to six hours a day may also be done to improve circulation and mobility for the child.

• Desensitizing techniques are exercises that are done to reduce sensitivity (allodynia) so that normal contact with the skin feels less painful. Texture rubbing (soap, lotion, towel, ice), constant touch, or pressure are some of the commonly used desensitizing techniques that can help children. The average duration of the training is two weeks. As the exercises progress, the location of pain may change for some children, and that is quite normal. The aim is to exercise through the pain and train the brain to respond normally to stimuli. Once the child cooperates and is motivated to get back to normal, the exercises can be done at home. Following the instructions and duration for the exercises is necessary to avoid a relapse of the condition.

2. Psychological Therapy: On the evaluation of the child, if any possibility of a psychological factor being a stressor is uncovered, relevant counseling therapies are initiated. Psychological therapy helps the child express feelings and thoughts and to control the anxiety episodes and depression if present as a consequence of amplified musculoskeletal therapy.

Psychological therapy assists the child to relax and calm the body’s stress response. Meditation, imagination, or progressive muscle relaxation are some of the techniques that are practiced. Children also learn coping skills and stress management through journaling, creative writing, art, music, etc. These practices also help reduce the fear of pain in children. Sometimes, these sessions may include parents or other family members to ensure an understanding of the health condition from the child’s perspective.

Most children return to normalcy within a few weeks or a month of exercise. Some may occasionally continue to have episodes of mild pain, and recover over time. Some of the children experience relapses after six months of physical therapy and exercises, which are successfully managed with physical therapy itself. Recurrent relapse episodes must not be ignored, and exercises must begin early to prevent the development of any significant disabilities in the child.

Conclusion

It takes a team approach to treat the child’s condition and break the pain cycle. Once children with amplified musculoskeletal pain syndrome understand that the body is not actually in pain, it helps the child cope better and work through the pain. With regular exercise following the diagnosis, the child can restore function, resolve the pain eventually, and lead a quality life.