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Chin Med J (Taipei) 1998;61:S23.
Director, Comprehensive Pain Program, The Toronto Hospital, Toronto, Ontario, Canada
Review of current status of knowledge
The term Reflex Sympathetic Dystrophy (RSD) has been around for many years. The 1st edition of the IASP's classification of Chronic Pain Syndromes in 1987 defines this entity as "continuous pain in a portion of an extremity after trauma which may include fracture, but does not involve a major nerve, associated with sympathetic hyperactivity". The involvement of the sympathetic nervous system (SNS) had been considered fundamental fairly early in the appearance of the condition(s), culminating in 1986 in the introduction of the term "Sympathetically Maintained Pain" by Roberts. The term Causalgia was reserved by IASP in 1987 to define "burning pain, allodynia and hyperpathia, usually in the hand or foot, after partial injury of a nerve or its major branches".
A Special Interest Group of the international Association for the Study of Pain, led to a new nomenclature, found in the 1994 Taxonomy edition of the IASP. The term Complex Regional Pain Syndromes (CRPS) was introduced (Type I near synonymous to the term Reflex Sympathetic Dystrophy and Type II synonymous to the term causalgia). The new definition for CRPS I is as follows: "A syndrome that usually develops after an initiating noxious event, not limited to the distribution of a single peripheral nerve, and disproportionate to the inciting event. It is associated at some point with evidence of edema, changes in skin blood flow, abnormal sudomotor activity in the region of pain, or allodynia or hyperalgesia". CRPS II (causalgia) is defined in 1994 in a similar manner to the definition of 1987.
Critical Appraisal
This lecture will outline the strengths and weaknesses of the new definition and critically review the utility of diagnostic and therapeutic means as currently known. A summary of the research work done at the Toronto Hospital will be presented, and principles of diagnosis and management based on this research work, will be outlined.
The position of the presenter is as follows:
1) CRPS signs and symptoms are not specific, but can be seen: a) in disease-imitators, b) as a result of limb immobility, c) arising from factitious disorders and d) in genuine neuropathic disorders affecting the peripheral and/or the central nervous system;
2) CRPS (as a neuropathic pain syndrome) may be due to multiple pathophysiologic abnormalities occuring simultaneously or sequentially at the peripheral and/or central nervous system;
3) Central sensitisation. is a very important pathophysiologic abnormality that affects prognosis and treatment outcomes;
4) Novel methods for diagnosing neuropathic pain will be presented.
Keywords. Reflex Sympathetic Dystrophy, Complex Regional Pain Syndromes, central sensitization.
[Chin Med J (Taipei) 1998;61:S23.]
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Copyright: 1998, Chinese Medical Association (Taipei)