Fibromyalgia: A Syndrome of Disturbed Physiology

Patients with fibromyalgia experience a wide variety of symptoms related to pain, sleep deprivation, and stress. Recent research has demonstrated physiological disturbances that appear to explain many of the symptoms and clinical features of fibromyalgia.

The major feature of fibromyalgia is discomfort throughout the trunk and limbs and marked sensitivity. The physician documents the sensitivity by the demonstration of painful tender points, but the patient also recognizes sensitivity to many environment influences such as bright lights, loud noises, or various odours.

It is considered that the widespread discomfort and sensitivity relate to physiological changes in the central nervous system. Research has demonstrated changes such as high levels of substance P in the spinal fluid as well as serum, and changes in blood flow patterns in areas of the brain that process pain signals. It is still not clear how these patterns relate to patient’s symptoms.

A prominent component of pain is myofascial pain. These are localized severe muscle pains that affect trunk and limb muscles but are also frequently a cause of headaches, jaw, and chest pains. The pain source is an electrically active trigger point in the muscle or tissue. Myofascial pains are worsened by strenuous physical activities, and also by stress.

Sleep in fibromyalgia is generally superficial and non-restorative. The non-restorative sleep gives rise to symptoms of fatigue and difficulties with short-term memory and concentration. Sleep studies generally confirm significant difficulties in initiating and maintaining sleep. An alpha EEG arousal rhythm is frequently observed in sleep studies and is considered to be very characteristic of fibromyalgia.

Recent studies of the function of the stress glands of the body (hypothalamus, pituitary, and adrenals) have demonstrated some evidence of under-functioning of these glands. Studies have demonstrated low levels of corticosteroid secretion and generally a delayed or inadequate response of these glands to a stimulus such as insulin or other stimulants. It is considered that the major hypofunction may be at the level of the hypothalamus. The clinical interpretation of these findings remains to be determined.

The other area of the stress system is the autonomic nervous system comprised of sympathetic and parasympathetic divisions. The autonomic nervous system is the subconscious system that maintains the normal function of our internal organs. It responds rapidly to any form of stress, i.e. physical or emotional stimuli that threaten the balance of the body.

Several centers have demonstrated a major imbalance in this system with predominance of the sympathetic drive during the twenty-four hours of the day. This increased drive appears to be an explanation for many of the autonomic systems experienced by patients with fibromyalgia such as sensations of tingling or numbness, sensations of swelling, and frequent colour changes in the skin (e.g. blue or white patterns in the fingers when exposed to cold, and red blotchy patterns in the skin).

Other autonomic symptoms include sensations of hot and cold with or without perspiring, episodes of rapid heartbeats, and frequent dizzy spells giving rise to occasional falls. The increased sympathetic drive also explains the sleep disturbance and the sensitivity of myofascial pains to stress.

Patients with fibromyalgia generally recognize a marked sensitivity to any form of stress, and the relationship is supported by the physiological abnormalities of the stress system of the body. Thus patients with fibromyalgia have to decrease their activities to a level that allows them to better cope with their symptoms. Stress system dysfunction may be influenced by exercises and a daily modest exercise routine has been demonstrated to be helpful in the control of symptoms.