A wrist fracture heals. The cast comes off. And the hand underneath is burning, swollen, and too sensitive to bear the weight of a shirtsleeve. Complex regional pain syndrome is defined by that disproportion — pain far greater and far more persistent than the injury that started it can account for. At Remix Medical in Houston, our board-certified pain physicians treat CRPS as the nervous system disorder it is, and treat it early, because timing changes the outcome more than any single intervention.
What is Complex Regional Pain Syndrome?
CRPS is chronic pain in a limb — most often a hand or foot — that develops after an injury, surgery, stroke, or heart attack. Alongside the pain come changes you can see and measure: differences in skin color, temperature, sweating, and swelling between the affected limb and the other side.
There are two types. Type I, formerly called reflex sympathetic dystrophy, develops without a confirmed nerve injury and accounts for the large majority of cases. Type II, formerly causalgia, follows an identifiable nerve injury. The distinction does not substantially change how CRPS is treated.
How CRPS Is Diagnosed
There is no single confirmatory test. Diagnosis rests on clinical criteria — most often the Budapest Criteria, which require continuing pain disproportionate to the inciting event, together with reported symptoms and observed signs across four categories:
- Sensory — heightened sensitivity, or pain provoked by light touch that should not hurt
- Vasomotor — asymmetry in skin temperature or color between the limbs
- Sudomotor and edema — swelling, or changes in sweating
- Motor and trophic — reduced range of motion, weakness, tremor, or changes in hair, nail, and skin growth
A diagnosis also requires that no other condition better explains the findings. Imaging and nerve conduction studies are used mainly to exclude alternatives rather than to confirm CRPS.
What Triggers CRPS
1. Limb Injury
Fracture is the single most common trigger, followed by sprains, crush injuries, and burns.
2. Surgery
Including minor procedures, and including operations that went entirely as planned.
3. Prolonged Immobilization
Extended casting or splinting of a limb.
4. Nerve Injury
A confirmed nerve injury is what defines type II.
5. Stroke or Heart Attack
Less common, but recognized inciting events.
The mechanism involves the sympathetic nervous system, peripheral nerves, and changes in how the spinal cord and brain process signals from the limb — which is why CRPS behaves so differently from ordinary pain after an injury.
How Remix Medical Can Help
Two things drive outcomes: starting early, and keeping the limb moving. CRPS responds best when treatment begins within the first months, and delay makes it considerably harder to reverse. Resting an exquisitely painful limb is the instinctive response, and it is usually the wrong one — immobilization tends to make CRPS worse.
Care is multidisciplinary, and interventional procedures earn their place by making active therapy possible rather than by replacing it.
| Approach | What it involves |
|---|---|
| Physical and occupational therapy | The cornerstone — graded motor imagery, mirror therapy, desensitization, and progressive use of the limb |
| Neuropathic pain medication | Agents targeting nerve pain mechanisms, used to enable therapy rather than as a standalone treatment |
| Sympathetic nerve blocks | Stellate ganglion block for the upper limb, lumbar sympathetic block for the lower — both diagnostic and therapeutic where a sympathetically maintained component exists |
| Behavioral pain management | Addresses the sleep, mood, and fear-of-movement components that entrench chronic pain |
| Spinal cord or dorsal root ganglion stimulation | Evaluated for pain that persists despite therapy and blocks, and increasingly considered earlier rather than as a last resort |