Reflex Sympathetic Dystrophy

A. M. Siddiqui, J. B. Healy

Sligo General Hospital, Repulic of Ireland

Correspondence:
A. M. Siddiqui
Sligo General Hospital
E-Mail: abunzmah@iol.ie

Key words: reflex sympathetic dystrophy, Sudeck's atrophy, posttraumatic osteoporosis, causalgia


Introduction

Reflex Sympathetic Dystrophy (RSD) is a poorly understood condition, which if not diagnosed and treated adequately can have a devastating effect in the severely affected individuals.

RSD was first recognised by Mitchell and colleagues in 1864, who graphically reported the plight of soldiers who developed the condition as a complication of peripheral nerve injury resulting from gunshot wounds (Mitchell SW, Moorhouse GR, Kenn WW ).

Definition

The term RSD was first coined by Evans in 1946. It is now recognised that RSD is not a distinct entity but a descriptive term which does not imply aetiology( Evans JA ). At the VI th World congress on Pain the following definition of RSD was suggested:

'RSD is a descriptive term meaning a complex disorder or a group of disorders that may develop as a consequence of trauma affecting the limbs, with or without an obvious nerve lesion. RSD may also develop after visceral disease, and central nervous system lesions, or, rarely, without an antecedent event. It consists of pain and related sensory abnormalities, abnormal blood flow and sweating, abnormalities in the motor system and changes in the structure of both superficial and deep tissues (trophic changes). It is not necessary that all components are present. It is agreed that the term 'reflex sympathetic dystrophy' is used in a descriptive sense and does not imply specific underlying mechanisms'.

Terminology's for RSD

Prevalence:

Recent studies have found incidence of RSD following colles or tibial fractures in 37% of cases whereas earlier work has suggested that RSD complicated fewer than 2% of fractures (Atkins/Duckworth). Patients of any age can be affected and RSD is now increasing recognised in children (Brenstein/Singsen/Kent).

Precipitating Factors:

Much has been said about personality traits associated with RSD. Many patients with RSD have marked behavioural changes , but the question arises whether they are contributory or as a result of RSD. Two reviews suggest ( Lynch ME ; Bruhel S , Carlson CR ) that as yet there is no definite evidence that certain personality traits actually predispose to the development of RSD. Neurogenic pain can induce illness behaviour , which often results in pt. with RSD being disbelieved by doctors . This increases their distress.

Clinical features:

RSD most commonly affects the extremities : hand, wrist, knee, ankles and foot being the commonest. Occasionally a whole limb is involved there may be bilateral involvement ( Kozin F, McCarthy DJ, Sims J, Genant H ).

The clinical features are important b/c RSD is predominantly a clinical diagnosis: Variation in diagnostic criteria is a major hurdle in diagnosis and treatment, this is an area currently being addressed (Jaing W, Blumberg H, Boas RA, Cambell JN ). The process of RSD is divided into three stages (Wilson PR ):

Stage 1: Acute

Stage 2: Dystrophic

Stage 3: Atrophic

Stages 1 and 2 lasts for about 3-6 months and stage 3 can last for upto year. But these are variable.

Differential diagnosis:

It is of a swollen , tender limb:

Pathophysiology:

Both peripheral and central mechanisms are involved: Robert's hypothesis, ( Roberts WJ ) which is often quoted highlights the role of both low- threshold mechanoreceptors and a central dorsal- horn mechanism in the pathogenesis of RSD.

Central mechanism

Peripheral mechanism

As we all know now the situation is highly complex and many different mechanisms might be involved, as well as those already stated.

Investigations:

Characteristic radiographic findings are:

Bone scan (Triphasic bone scan):

Bone densitometry:

Thermography and skin blood flow measurement:

Management:

Early diagnosis is the mainstay of successful treatment of RSD. It is suggested that once it progresses to a late stage then treatment is unlikely to be successful.

Early mobilisation is a important factor in preventig RSD. It is generally accepted that physiotherapy alone or in association is a important part of management. Goal of physical therapy is to attain early active ROM. Passive exercise may make thing worse by increasing pain at point of discomfort. Lumbar sympathetic blocks were found to be an effective form of treatment for lower limb RSD compared to conservative management when 28 of 43 pt.. treated by block improved. ( Wang JK, Johnson KA, Ilstrup DM) Intravenous guanithidine block has been used successfully compared to stellate block (Bonelli S, Conoscente F, Movilia PG, Restelli L, Francucci B, Grossi E). Reserpine (Rocco AG, Kaul AF) and bretylium with lidocaine (Horod AH, Rooks MD) has also been used. Intravenous blocks can be repeated as required, the effect of first block lasts about 2 days with subsequent block lasting longer ( Hannington-Kiff JG ). Epidural blocks have benefited in minority of patients (Pountain GD, Chard MD). Drug treatment is gaining popularity , especially alpha-1 adrenoreceptor blocker, but again more randomised trials are required (Abram SE, Lightfoot RW, Ghostine SY, Azar CG, Turner DM, Kassell NF ). TENS has also been useful, especially children in an uncontrolled trial (Kesler RW, Salsbury FT, Miller LT, Rowlinson JC ). Acupuncture has also been suggested (Fialka V, Resch KL, Ritter-Dietrich D).

Future:

We still have a long way to go in understanding the mystery called RSD, but to unravel it and in order to reach the end of the road basic scientific and clinical research into RSD must continue in parallel.(Herrick AL).

Literature: