Medical Causation

1.AUTHOR	Sacket, et al.
TITLE	Clinical epidemiology.
SOURCE	Little Brown and Company, Boston, 1991 (second edition).

2 .AUTHOR	ICD-9-CM : international classification of diseases
SOURCE	9th revision, Los Angeles, CA: PMIC, 1995.

3 .AUTHOR	Simons-D-G
TITLE	Myofascial pain syndrome due to trigger points
SOURCE	In Rehabilitation Medicine, ed. Goodgold-J, 1988, CV Mosby Co
Abstract	(Page 720) Posttraumatic hyperirritabilty syndrome. The group of myofascial pain patients with posttraumatic hyperirritability syndrome suffer greatly, are poorly understood, and are difficult to help. They respond to strong sensory stimuli much differently than most patients. Following a major impact to the body, head, or both, the muscles exhibit marked hyperirritability of trigger points and a distressing vulnerability to strong sensory stimuli. The trauma has usually been an automobile accident or fall that was sufficiently severe to have inflicted some degree of damage to the sensory pathways of the central nervous system. These patients describe constant pain that is easily augmented by any strong sensory input, including severe pain, a loud noise, vibration, prolonged physical activity, and emotional stress. It may take days or weeks to recover from a degree of trauma or noise that to most people would be inconsequential. From the date of onset, coping with pain has suddenly become the focus of life for these patients, who previously paid no particular attention to pain. Their function is impaired by a marked increase in pain and fatigue if they exceed their restricted limit of activity. b. One of the distinguishing characteristics of the posttraumatic-hyperirritability syndrome is the loss of tolerance to what are to most people inconsequential mechanical stresses such as jarring, vibration, loud noises, and mild bumps or thumps. Exposure to such a stimulus immediately produces an increase in the pain level. The stimulus also causes a markedly increased sensitivity to subsequent stimuli so they suddenly become much more vulnerable to further aggravation of their misery. This increased arousal of the sensory system subsides slowly. It may take hours, days, or weeks, depending on the intensity of the stimulus required for this increased excitability of the sensory system to subside to its previous state. A strong sensory input appears to modulate the excitability of the arousal system. This increased excitability is paralleled by a corresponding increase in irritability of all of that patient's myofascial trigger points in the involved region. c. The target area of trigger points and pain tends to concentrate in the somatic distribution of the brainstem, cervical cord, or lumbosacral cord. A few unfortunate individuals seem to have involvement of several regions. These patients are highly vulnerable to reinjury by additional trauma. It takes much less subsequent impact to exacerbate the process than in the initial accident. d. The most effective treatment has been to inactivate all identifiable trigger points and to correct perpetuating factors. On occasion it may be necesary to reset the system by suppressing central nervous system excitability. To date, barbituates have been found most effective.