Fibromyalgia

What is fibromyalgia?

Fibromyalgia is a name for widespread pain affecting the muscles but not the joints. It is a chronic condition, but it is not life-threatening or progressive and does not cause permanent damage to muscles, bones or joints. There are usually no outward signs of the condition and people with fibromyalgia often look well but feel awful. Because of this, other people may not appreciate the pain and tiredness you are suffering and this can cause additional distress. However, it is important to stress that the pain suffered by people with fibromyalgia is real and may be severe, even though it is usually not associated with visible swelling or deformities of muscles or joints.

Fibromyalgia is a common condition. A study from America found that up to 2% of people suffer from fibromyalgia, and it occurs more commonly in women than in men. The amount of pain varies from person to person and from day to day. The pain may be quite mild on many days but it is sometimes so severe that it affects your work and your personal and social life. Some people find that the pain feels worse in cold or damp weather. In fibromyalgia the tendons and ligaments, or fibrous tissues (fibro-), and the muscles (-my-) are affected by pain (-algia) and tenderness. It may feel as though the pain affects the whole body.

There are usually tender points in certain areas of the body. These tender points help the doctor to make the diagnosis. If enough pressure is applied to these points most people will find it uncomfortable, but in fibromyalgia many of these points can be extremely tender even when they are pressed quite gently. Tenderness at individual sites sometimes occurs and this can give rise to localized conditions such as tennis elbow. In fibromyalgia, however, there is tenderness at a number of points. The figure below shows the positions of the points that doctors sometimes press to check whether a person has fibromyalgia.

In the past fibromyalgia was often diagnosed as muscular rheumatism or fibrositis, or it was misdiagnosed as degenerative disease of the joints (signs of wear and tear are very common on spine x-rays as we get older, whether there is pain or not). Research in the past few years has led to a clearer picture of what we mean by fibromyalgia, and the diagnosis is being made more often by rheumatologists and general practitioners (GPs) (2). 

Figure 1. Sites of tender points in fibromyalgia

What are the symptoms of fibromyalgia?

Pain, tiredness and sleep disturbance are the main symptoms of fibromyalgia. Most people feel the pain of fibromyalgia as aching, stiffness and tiredness in the muscles around the joints. It may feel worse first thing in the morning, or as the day goes on, or with activity. It may be particularly bad in one part of the body or may be equally bad in several different areas such as the limbs, neck and back. Patients with fibromyalgia often feel that they have pain all over their bodies.

Sometimes tiredness (fatigue) can be the most severe aspect of fibromyalgia. There may be overall tiredness and lack of energy, or muscular fatigue and loss of stamina. Either way, it can be difficult to climb the stairs, do the household chores, go shopping or go to work. Becoming less fit physically makes matters worse. Waking in the morning feeling unrefreshed is common.

Less frequent but still troublesome symptoms include:

• poor circulation – tingling, numbness or swelling of the hands and feet
• headache
• irritability or feeling low or weepy
• forgetfulness or poor concentration
• feeling an urgent need to pass water
• irritable bowels (diarrhoea or constipation and abdominal pain).

Of course symptoms like these can have other causes, and your doctor can help decide whether any further tests or advice are needed. There are no blood tests, x-rays or scans that can diagnose fibromyalgia. When tests are carried out they are usually done to make sure that there is no other cause for the symptoms. In fibromyalgia, blood tests and x-rays are usually normal. The severity of the symptoms and the effects of fibromyalgia can vary considerably, and this range of severity can cause problems in diagnosing the condition and lead to varying medical opinions. Patients often find it helpful that their pattern of symptoms is taken seriously and recognized as being due to fibromyalgia – even though this may not always lead to any change in treatment (2). 

Is fibromyalgia similar to chronic or postviral fatigue (ME)?

The symptoms described in myalgic encephalomyelitis (ME) are often very similar to those in fibromyalgia except that ME sufferers can often recall a viral infection before symptoms appeared, and may have less pain. Many doctors use the term 'chronic fatigue syndrome' rather than ME. More needs to be known about these conditions before we are able to say whether they are the same thing (2).

What causes fibromyalgia?

We do not know exactly what causes fibromyalgia but there is now a clearer understanding that there is an interaction between the physical and mental aspects of this illness. Fibromyalgia is an illness involving both the mind and the body. The amount of pain felt by a person with fibromyalgia is often affected by the way they are feeling, and the reverse is also true. Feeling depressed, stressed or anxious may make the muscular pain feel worse, which may in turn add to the stress and anxiety.

Research into fibromyalgia has been stimulated by the finding of specific tender points and the discovery of sleep disturbance. Brain wave studies (electroencephalography, or EEG) during sleep have revealed that people with fibromyalgia often lose deep sleep. In an experiment, some healthy people who were woken up in each period of deep sleep suffered the typical symptoms and tender points of fibromyalgia.

Several things could cause the disturbance of deep sleep that is often found in patients with fibromyalgia. More than one cause may be affecting any particular individual. Pain or stiffness in the neck may disturb sleep. There may be the pain and stress of an injury or of another disease like arthritis. Emotional pain and the strain of anxiety or depression brought on by events or relationships at home or at work may also be important factors.

In some people with fibromyalgia there is a vicious circle of pain and sleep disturbance (see Figure 2). This can be enough to cause depression even if this was not initially a problem.

Figure 2. The cycle of pain and sleep disturbance

Research has been carried out showing that patients with fibromyalgia suffer increased sensitivity (known as sensitization) to pressure or relatively minor knocks which would not normally be painful. To some extent this may be related to chemical changes in the nervous system, but this is not fully understood (2). 

It is believed that an interruption of stage 4 (nonrapid eye movement) sleep due to intrusions of alpha rhythms is trhe underlying cause (1). 

Evaluation

The American College of Rheumatology set criteria for the diagnosis of fibromyalgia in 1990.  These included persistence of generalized musculoskeletal pain (both sides of the body, above and below the waist) for atleast 3 months.  There must also be tenderness at 11 of 18 sites (nine bilateral sites).  These include the suboccipital area, the lower cervical spine (transverse processes of C5-C7), upper trapezius, supraspinatus, second rib (costochondral junction), lateral epicondyle (2 cm distal), gluteals, greater trochanter of the femur, and the medial fat pad at the knee, (proximal to the joint line).  The sensitivity of this approach is 88%; specificity  is 81%.  Other symptoms include fatigue, sleep disturbance, persistent early morning stiffness, paresthesia, and headache (1). 

References:

1) Souza, Thomas A., Fibromyalgia.  Differential Diagnosis for the Chiropractor. 1997. p. 450-451.

2)  www.arc.org.uk, Fibromyalgia.  Arthritis Research Campaign.  October 2007.