Complex Regional Pain Syndrome

Complex regional pain syndrome can be a debilitating, painful condition in a limb, associated with sensory, motor, autonomic, skin and bone abnormalities ⁽¹⁾. Complex regional pain syndrome commonly arises after an injury to the affected limb, with many people noticing the onset of symptoms within one month. However, there has been no relationship shown between the onset of complex regional pain syndrome and the severity of the initial trauma ⁽²⁾. In some cases, there is no initial trauma at all (9%). Complex regional pain syndrome usually affects one limb, however, in 7% of cases, the condition has been shown to later spread and involve additional limbs ⁽⁵⁾.

Complex regional pain syndrome can be divided into two types:

• Type 1: this is the most common type and is defined by the absence of a lesion (damage) to a major nerve.
• Type 2: less common and defined by damage to a major nerve.

At present, the diagnosis of either type of complex regional pain syndrome has no bearing on the management strategies ⁽²⁾. This means that regardless of the type of complex regional pain syndrome you have, the treatment will be the same. Complex regional pain syndrome is still a relatively poorly understood condition so research and clinical studies into the causes, management and treatment are ongoing.

The cause of complex regional pain syndrome is not yet fully understood however, it is thought that it usually begins after sustaining an injury or trauma. One avenue explored by research into the cause of complex regional pain syndrome is thought to be related to either an injury or abnormality to the peripheral nervous system (nervous system outside the brain and spinal cord) and central nervous system (brain and spinal cord) of the body.

The two types of complex regional pain syndrome, although similar in terms of signs, symptoms and treatment, are thought to have different causes. It is believed that type 1 complex regional pain syndrome occurs after an illness or injury that did not directly damage the nerves in the affected limb. Type 2 is thought to only occur after a distinct nerve injury. Overall, 5% of people who develop symptoms do so following a traumatic injury and 91% of all complex regional pain syndrome cases occur following surgery ⁽²⁾.

This is a very rare condition that normally begins after another condition or injury, overall it only affects 0.00026% of the population. It is more common in people that have had paralysis to one side of the body, nerve injury or in conditions such as multiple sclerosis.

A diagnosis of complex regional pain syndrome is usually made by a GP or consultant. Confirmation of the diagnosis is based on clinical examination and presenting signs and symptoms in accordance with the Budapest diagnostic criteria.

An answer of yes to all questions A-D on the Budapest diagnostic criteria will generate a diagnosis of complex regional pain syndrome. However, for those who fulfil the criteria but do not have any limb signs (i.e. swelling, colour or temperature changes) a diagnosis of ‘complex regional pain syndrome – not otherwise specified’ is given ⁽²⁾. This means patients who did not fulfil the Budapest criteria, but whose signs and symptoms could not be better explained by any other diagnosis.

As well as this, other diagnostic tools can be used:

• Sweat testing: this involves taking a sweat sample from both sides of the body at the same time and using a Q-sweat instrument to measure the amount of sweat production. In complex regional pain syndrome, the affected limb may sweat excessively or not at all.

Your physiotherapist should be able to help you understand the condition and what needs to be implemented to effectively reduce the impact on your day-to-day life. This will include activity modification strategies as well as other useful treatments aimed at reducing discomfort. Regular adherence to a condition-specific rehabilitation programme is important in the management of this condition. It should be noted that rehabilitation exercises are not always a quick fix, but if adhered to on a consistent basis (weeks to months), over time they have been shown to yield positive outcomes.

The approaches that have been shown to have a positive effect are:

• Gentle limb movements.
• Frequently giving attention to the affected limb.
• Desensitisation (touching and stroking the limb).
• Remaining as active as possible.
• Pacing, prioritising and planning activities ⁽²⁾.

For patients wanting to achieve a high level of function or return to sport, we would encourage a consultation with a physiotherapist as you will likely require further progression beyond the advanced rehabilitation stage.

As part of a comprehensive treatment approach, your musculoskeletal physiotherapist may also use a variety of other pain-relieving treatments to support symptom relief and recovery. Whilst recovering you might benefit from a further assessment to ensure you are making progress and establish the appropriate progression of treatment.  Ongoing support and advice will allow you to self-manage and prevent future re-occurrence.

• Research has also shown that techniques such as relaxation, cognitive behaviour therapy, deep breathing exercises and biofeedback (a type of therapy that uses sensors attached to your body to measure key body functions, e.g. heart rate monitor) can also aid recovery/management.
• Occupational therapy to help with adaptations and aids for functional tasks, educating around pacing and helping with engagement with community groups.
• Dermatology to help with skin changes including dryness, glossy texture, swelling/oedema.
• Psychological support, with studies showing 1:1 input, can be more beneficial when compared to group settings, using cognitive behavioural therapy, behavioural treatment, and relaxation methods such as tai chi, yoga. ⁽⁴⁾