Amplified musculoskeletal pain syndrome (AMPS) is an illness characterized by notable pain intensity without an identifiable physical cause. Characteristic symptoms include skin sensitivity to light touch, also known as

allodynia Allodynia is a condition in which pain is caused by a stimulus that does not normally elicit pain. For example, sunburn can cause temporary allodynia, so that usually painless stimuli, such as wearing clothing or running cold or warm water over ...

. Associated symptoms may include changes associated with disuse including changes in skin texture, color, and temperature, and changes in hair and nail growth. In up to 80% of cases, symptoms are associated with

psychological trauma Psychological trauma (also known as mental trauma, psychiatric trauma, emotional damage, or psychotrauma) is an emotional response caused by severe distressing events, such as Major trauma, bodily injury, Sexual assault, sexual violence, or ot ...

psychological stress In psychology, stress is a feeling of emotional strain and pressure. Stress is a form of psychological and mental discomfort. Small amounts of stress may be beneficial, as it can improve athletic performance, motivation and reaction to the envi ...

. AMPS may also follow physical

injury Injury is physiological damage to the living tissue of any organism, whether in humans, in other animals, or in plants. Injuries can be caused in many ways, including mechanically with penetration by sharp objects such as teeth or with ...

illness A disease is a particular abnormal condition that adversely affects the structure or function (biology), function of all or part of an organism and is not immediately due to any external injury. Diseases are often known to be medical condi ...

. Other associations with AMPS include Ehlers-danlos syndrome,

myositis Myositis is a rarely-encountered medical condition characterized by inflammation affecting the muscles. The manifestations of this condition may include skin issues, muscle weakness, and the potential involvement of other organs. Additionally ...

arthritis Arthritis is a general medical term used to describe a disorder that affects joints. Symptoms generally include joint pain and stiffness. Other symptoms may include redness, warmth, Joint effusion, swelling, and decreased range of motion of ...

, and other rheumatologic diseases. Treatment for notable pain intensity without identifiable pathophysiology can include

psychotherapy Psychotherapy (also psychological therapy, talk therapy, or talking therapy) is the use of Psychology, psychological methods, particularly when based on regular Conversation, personal interaction, to help a person change behavior, increase hap ...

to alleviate

Physical therapists Physical therapy (PT), also known as physiotherapy, is a healthcare profession, as well as the care provided by physical therapists who promote, maintain, or restore health through patient education, physical intervention, disease prevention ...

, psychologically informed physical therapists in particular, can coach people on exercises they can do everyday at home. Clinicians who use this diagnosis sometimes apply it to children and adolescents. To date, this diagnosis is used more in women.

Signs and symptoms

Amplified musculoskeletal pain is a

syndrome A syndrome is a set of medical signs and symptoms which are correlated with each other and often associated with a particular disease or disorder. The word derives from the Greek language, Greek σύνδρομον, meaning "concurrence". When a sy ...

which is a set of characteristic symptoms and signs. Essentially, the syndrome is characterized by diffuse, ongoing, daily pain associated with relatively high levels of incapability and greater care-seeking behavior. The discomfort can be in the skin (

), abdomen, throat (

dysphagia Dysphagia is difficulty in swallowing. Although classified under " symptoms and signs" in ICD-10, in some contexts it is classified as a condition in its own right. It may be a sensation that suggests difficulty in the passage of solids or l ...

headache A headache, also known as cephalalgia, is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of Depression (mood), depression in those with severe ...

, and

joints A joint or articulation (or articular surface) is the connection made between bones, ossicles, or other hard structures in the body which link an animal's skeletal system into a functional whole.Saladin, Ken. Anatomy & Physiology. 7th ed. McGraw- ...

. There can be other somatic symptoms such as, movement issues,

dizziness Dizziness is an imprecise term that can refer to a sense of disorientation in space, vertigo, or lightheadedness. It can also refer to Balance disorder, disequilibrium or a non-specific feeling, such as giddiness or foolishness. Dizziness is a ...

fatigue Fatigue is a state of tiredness (which is not sleepiness), exhaustion or loss of energy. It is a signs and symptoms, symptom of any of various diseases; it is not a disease in itself. Fatigue (in the medical sense) is sometimes associated wit ...

, stiffness, shakiness, coordination difficulty, swelling,

fast heart rate Tachycardia, also called tachyarrhythmia, is a heart rate that exceeds the normal resting rate. In general, a resting heart rate over 100 beats per minute is accepted as tachycardia in adults. Heart rates above the resting rate may be normal ...

skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other animal coverings, such as the arthropod exoskeleton, have different ...

texture, color, or temperature changes,

paresthesia Paresthesia is a sensation of the skin that may feel like numbness (''hypoesthesia''), tingling, pricking, chilling, or burning. It can be temporary or Chronic condition, chronic and has many possible underlying causes. Paresthesia is usually p ...

, and changes in nail or hair growth. These symptoms are associated with symptoms of

anxiety Anxiety is an emotion characterised by an unpleasant state of inner wikt:turmoil, turmoil and includes feelings of dread over Anticipation, anticipated events. Anxiety is different from fear in that fear is defined as the emotional response ...

, depression,

, and

Examination

Findings on examination can include factors associated with disuse including swelling; changes in

texture, color, and temperature; changes in nail and hair growth,

muscle atrophy Muscle atrophy is the loss of skeletal muscle mass. It can be caused by immobility, aging, malnutrition, medications, or a wide range of injuries or diseases that impact the musculoskeletal or nervous system. Muscle atrophy leads to muscle weakne ...

, and radiographic

osteoporosis Osteoporosis is a systemic skeletal disorder characterized by low bone mass, micro-architectural deterioration of bone tissue leading to more porous bone, and consequent increase in Bone fracture, fracture risk. It is the most common reason f ...

Causes

It's not possible to discuss causes when there is no objectively verifiable pathophysiology. It's more accurate to describe when patients and clinicians might find this diagnosis appealing.

Psychological trauma

Psychological trauma is strongly associated with unexplained pain conceptualized as AMPS.

Physical injury

The combination of physical injury, such as a

bone fracture A bone fracture (abbreviated FRX or Fx, Fx, or #) is a medical condition in which there is a partial or complete break in the continuity of any bone in the body. In more severe cases, the bone may be broken into several fragments, known as a ''c ...

surgery Surgery is a medical specialty that uses manual and instrumental techniques to diagnose or treat pathological conditions (e.g., trauma, disease, injury, malignancy), to alter bodily functions (e.g., malabsorption created by bariatric surgery s ...

, and over protectiveness and disuse can be referred to as

complex regional pain syndrome Complex regional pain syndrome (CRPS type 1 and type 2), sometimes referred to by the hyponyms reflex sympathetic dystrophy (RSD) or reflex neurovascular dystrophy (RND), is a rare and severe form of neuroinflammatory and dysautonomic disorder ...

, a type of AMPS that is isolated to one region of the body, such as a hand or foot.

Risk factors

Asthma, autoimmune diseases, arthritis, myositis, Ehlers-Danlos syndrome, rheumatologic diseases, being female.

Rationale

AMPS is theoretical rather than experimental. The amplified pain is conceptualized as incorrect

sympathetic nervous system The sympathetic nervous system (SNS or SANS, sympathetic autonomic nervous system, to differentiate it from the somatic nervous system) is one of the three divisions of the autonomic nervous system, the others being the parasympathetic nervous sy ...

signals also known as the "fight or flight" nerves. This causes an involuntary response to pain, including

vein Veins () are blood vessels in the circulatory system of humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are those of the pulmonary and feta ...

constriction. This causes increased heart rate, increase in

muscle tone In physiology, medicine, and anatomy, muscle tone (residual muscle tension or tonus) is the continuous and passive partial contraction of the muscles, or the muscle's resistance to passive stretch during resting state.O’Sullivan, S. B. (2007) ...

, increased

respiratory rate The respiratory rate is the rate at which breathing occurs; it is set and controlled by the respiratory center of the brain. A person's respiratory rate is usually measured in breaths per minute. Measurement The respiratory rate in humans is mea ...

, and a reduce of

blood flow Hemodynamics American and British English spelling differences#ae and oe, or haemodynamics are the Fluid dynamics, dynamics of blood flow. The circulatory system is controlled by homeostasis, homeostatic mechanisms of autoregulation, just as hydrau ...

to the muscles and bone, resulting in an increase in waste products, such as

lactic acid Lactic acid is an organic acid. It has the molecular formula C3H6O3. It is white in the solid state and it is miscible with water. When in the dissolved state, it forms a colorless solution. Production includes both artificial synthesis as wel ...

. This buildup of waste products, as well as depletion of oxygen, results in the amplified pain associated with AMPS.

Classification

AMPS is classified into four different types, of which may be divided into multiple sub-types. This includes

, diffuse idiopathic pain, intermittent amplified pain, and localized amplified pain.

Complex regional pain syndrome Complex regional pain syndrome (CRPS type 1 and type 2), sometimes referred to by the hyponyms reflex sympathetic dystrophy (RSD) or reflex neurovascular dystrophy (RND), is a rare and severe form of neuroinflammatory and dysautonomic disorder ...

Complex regional pain syndrome is a term for any amount of spontaneous regional pain lasting longer than the expected recovery time of an observed

physical trauma Injury is physiology, physiological damage to the living tissue of any organism, whether Injury in humans, in humans, Injury in animals, in other animals, or Injury in plants, in plants. Injuries can be caused in many ways, including mechanic ...

, or other

. This includes two separate types: type I and type II. Type I CRPS, formerly known as reflex sympathetic dystrophy (RSD) or "Sudeck's atrophy", refers to CRPS ''without'' any observed nerve damage. Type II, formerly known as causalgia, refers to CRPS ''with'' observed nerve damage. This form, similarly to other forms of AMPS, is known to be able to spread from one limb to a new limb. 35% of people effected with CRPS report full-body impacts from the condition. Common symptoms of CRPS include

musculoskeletal pain Musculoskeletal disorders (MSDs) are injuries or pain in the human musculoskeletal system, including the joints, ligaments, muscles, nerves, tendons, and structures that support limbs, neck and back. MSDs can arise from a sudden exertion (e.g., l ...

; swelling; changes to the skin texture, color, or temperature; and limited

range of motion Range of motion (or ROM) is the linear or angular distance that a moving object may normally travel while properly attached to another. In biomechanics and strength training, ROM refers to the angular distance and direction a joint can move be ...

Diffuse idiopathic pain

This type of AMPS includes full-body pain. It is also known as juvenile

fibromyalgia Fibromyalgia (FM) is a functional somatic syndrome with symptoms of widespread chronic pain, accompanied by fatigue, sleep disturbance including awakening unrefreshed, and Cognitive deficit, cognitive symptoms. Other symptoms can include he ...

Intermittent amplified pain

This type of AMPS refers to amplified pain that varies in intensity over time.

Localized amplified pain

This refers to localized amplified pain ''without'' other symptoms. This type ''cannot'' include symptoms such as swelling;

texture, color, or temperature changes; or

perspiration Perspiration, also known as sweat, is the fluid secreted by sweat glands in the skin of mammals. Two types of sweat glands can be found in humans: eccrine glands and Apocrine sweat gland, apocrine glands. The eccrine sweat glands are distribu ...

. Observation of these symptoms implies the diagnosis of

Diagnosis

Because of the little awareness on AMPS, the condition is frequently not diagnosed when symptoms first present, often with multiple diagnoses of physical conditions before the diagnosis of AMPS. The condition is diagnosed through observation of various patient traits. A full overview of the patients medical history, as well as out rule of any potention physical causes, such as a

. If no physical causes are observed, a diagnosis of AMPS is likely possible. Other common steps that are taken may include bone scans to detect possible signs of reduced blood flow;

magnetic resonance imaging Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to generate pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and ...

(MRI) to detect possible

edema Edema (American English), also spelled oedema (British English), and also known as fluid retention, swelling, dropsy and hydropsy, is the build-up of fluid in the body's tissue (biology), tissue. Most commonly, the legs or arms are affected. S ...

, or

; Nerve testing can be used to look for

pain Pain is a distressing feeling often caused by intense or damaging Stimulus (physiology), stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sense, sensory and emotional experience associated with, or res ...

or sensitivity issues; and

X-ray An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...

s can detect osteoporosis as the result of AMPS. While all of these tests can detect possible signs of AMPS, better outcomes are usually made with less tests, and immediate treatment of AMPS without looking for possible differential diagnoses.

Management

As AMPS is not a disease, there is no one specific

cure A cure is a substance or procedure that resolves a medical condition. This may include a medication, a surgery, surgical operation, a lifestyle change, or even a philosophical shift that alleviates a person's suffering or achieves a state of heali ...

for it. Management of the condition is a process of patients learning to manage the abnormal amplified pain. This can include a combination of treating the cause(s) of the condition, as well as managing the symptoms of the condition.

Medication

As psychological stress accounts for up to 80% of cases of AMPS, medication often involves typical antidepressants. These are also often prescribed for chronic pain due to the impact they have on serotonin and its impact on muscular pain and control. Many providers also use an injectable medication for treatment of AMPS.

Opioid Opioids are a class of Drug, drugs that derive from, or mimic, natural substances found in the Papaver somniferum, opium poppy plant. Opioids work on opioid receptors in the brain and other organs to produce a variety of morphine-like effects, ...

use is not recommended for most AMPS cases, as it can worsen recovery, and in rare cases, make the condition worse.

Physical therapy

Physical treatment of AMPS is very common and is shown to have long term benefit. This includes

physical therapy Physical therapy (PT), also known as physiotherapy, is a healthcare profession, as well as the care provided by physical therapists who promote, maintain, or restore health through patient education, physical intervention, disease preventio ...

massage therapy Massage is the rubbing or kneading of the body's soft tissues. Massage techniques are commonly applied with hands, fingers, elbows, knees, forearms, feet, or a device. The purpose of massage is generally for the treatment of body stress or pa ...

, and

aerobic exercise Aerobic exercise, also known as cardio, is physical exercise of low to high intensity that depends primarily on the aerobic energy-generating process. "Aerobic" is defined as "relating to, involving, or requiring oxygen", and refers to the use of ...

. Physical therapy involves training the use of the affected limb or training the use of the body. This is for the purpose of retraining muscles after

, and retraining how to use the affected muscles with less amplified pain. Massage therapy is used to desensitize the affected area or body so it can build a tolerance to pain. This can help with symptoms such as

and

hyperalgesia Hyperalgesia ( or ; ''hyper'' from Greek ὑπέρ (''huper'') 'over' + ''-algesia'' from Greek ἄλγος (algos) 'pain') is an abnormally increased sensitivity to pain, which may be caused by damage to nociceptors or peripheral nerves and ...

in AMPS, as well as indirectly help with other common symptoms by relieving the patient of pain which could have been the cause of

, depression,

, as well as a number of physiological conditions, including

Psychotherapy

References

{{reflist, refs= {{cite web , url=https://my.clevelandclinic.org/health/diseases/17933-amplified-musculoskeletal-pain-syndrome-amps-in-children , title=Amplified Musculoskeletal Pain Syndrome in Children , publisher=Cleveland Clinic {{cite web , url=https://www.hopkinsallchildrens.org/Services/Anesthesiology/Pain-Management/Chronic-Pain-Management/Amplified-Musculoskeletal-Pain-Syndrome-in-Childre , title=Amplified Musculoskeletal Pain Syndrome in Children , publisher=Johns Hopkins All Children's Hospital {{cite web , url=https://www.childrens.com/specialties-services/conditions/amplified-musculoskeletal-pain-syndrome-amps , title=Amplified Musculoskeletal Pain Syndrome (AMPS) , publisher=Children's Health {{cite web , url=https://www.congress.gov/bill/116th-congress/house-resolution/588/text , title=Expressing support for the designation of "National Amplified Musculoskeletal Pain Syndrome Awareness Day" , publisher=

United States Congress The United States Congress is the legislature, legislative branch of the federal government of the United States. It is a Bicameralism, bicameral legislature, including a Lower house, lower body, the United States House of Representatives, ...

{{cite web , url=https://www.hss.edu/condition-list_amplified-musculoskeletal-pain-syndrome.asp#symptoms , title=Amplified Musculoskeletal Pain Syndrome , publisher=Hospital for Special Surgery {{cite web , url=https://care.choc.org/causes-and-treatment-for-pain-amplification-syndrome , title=Causes and Treatment for Pain Amplification Syndrome , publisher=

Children's Hospital of Orange County Children's Hospital of Orange County or CHOC is a pediatric healthcare system based in Orange County, California. Its flagship hospital, CHOC Hospital Main Campus – Orange, is a pediatric acute care hospital located in Orange, California. The ...

, author1=Andrew Shulman MD PhD, date=July 2019 Nerve, nerve root and plexus disorders Syndromes of unknown causes Chronic pain syndromes Osteopathies

Signs and symptoms

Examination

Causes

Psychological trauma

Physical injury

Risk factors

Rationale

Classification

Complex regional pain syndrome Complex regional pain syndrome (CRPS type 1 and type 2), sometimes referred to by the hyponyms reflex sympathetic dystrophy (RSD) or reflex neurovascular dystrophy (RND), is a rare and severe form of neuroinflammatory and dysautonomic disorder ...

Diffuse idiopathic pain

Intermittent amplified pain

Localized amplified pain

Diagnosis

Management

Medication

Physical therapy

Psychotherapy

See also

References