Here are some of the differences between complex regional pain syndrome I (RSD) and complex regional pain syndrome II (causalgia):
- Sympathetic hyperactivity due to trauma to an extremity, such as a fracture, that doesn’t include direct trauma to a peripheral nerve.
- Usually involves the distal part of the extremity and occurs all around the limb.
- Involves probably the peripheral nervous center and possibly the central nervous syndrome.
- Onset is usually a few weeks after the injury.
- The pain is described as a burning pain made worse by movement or touching the skin.
- Increased temperature of the skin and increased sweating. There is decreased sympathetic variability and increased swelling.
- Later, skin constricts and there is vasoconstriction with a cold extremity.
- Later, there is atrophy of the skin, soft tissue and bone. Hair fails to grow and nails grow slowly.
- X-ray shows atrophy and osteoporosis of bone.
- Persists indefinitely if not treated.
- Sympathetic block and physical therapy seem to help.
- Complications include disuse atrophy, suicide and drug abuse.
- Patients can suffer from depression and social fears.
- Burning pain, hyperpathia or allodynia of an extremity following a direct nerve injury.
- Can simply be symptomatic near the injury but not the extremity all around
- Usually involves the median nerve, the tibial nerve, the ulnar nerve and the sciatic nerve.
- Can occur immediately following the injury or months later.
- Constant burning pain made worse by light touch, movement, change in exercise and stress.
- Atrophy of the appendages, atrophy of bones, joints and muscles.
- Cool, clammy skin that is red in color and sweaty; there is lack of sensation and motor skills in the area innervated by the damaged nerve.
- Sounds or bright lights can trigger burning pain.
- Signs of hyperactivity of the sympathetic nervous system as found by galvanic skin testing and plethysmography.
- Usually, there is no spontaneous remission if not treated but spontaneous remission is possible.
- Sympathetic block done several times along with physical therapy can lead to permanent relief.
- Risk of suicide and drug abuse if left untreated.
- Peripheral and central nervous system involved in an unknown way.
- The nerve damage is usually just partial.
Differential Diagnosis of CRPS-I vs. CRPS-II
Etiology – Any trauma
Localization – Distal extremities
Spread of Symptoms – Obligatory
Spontaneous pain – Common, usually deep
Mechanical Allodynia – Most patients
Autonomic symptoms – Seen distally and spreading
Motor symptoms – Distally and generalized
Sensory symptoms – Distally and generalized
Etiology – Partial nerve lesion
Localization – Along the route of a nerve
Spread of Symptoms – Rare
Spontaneous pain – Obligatory, usually superficial
Mechanical Allodynia – All patients along nerve distribution
Autonomic symptoms – In nerve distribution
Motor symptoms – In nerve distribution
Sensory symptoms – In nerve distribution