Complex Regional Pain Syndrome Caused by Lumbar Herniated Intervertebral Disc Disease

Most cases of complex regional pain syndrome (CRPS) occur after some inciting injury. There are a few cases of CRPS after an operation for disc disease. CRPS from a mild herniated intervertebral disc (HIVD) without surgical intervention is even rarer than CRPS after an operation for disc disease. A 22-year-old man was transferred to a pain clinic. He had continuously complained about back and right leg pain. He presented with a skin color change in the right lower leg, intermittent resting tremor, stiffness, and swelling in the right leg. He complained of a pulling sensation and numbness in his right buttock, posterior thigh, lateral calf, and ankle. This symptom was in accordance with L4/5 radiculopathy. Magnetic resonance imaging (MRI) also showed L4/5 HIVD that was central to the bilateral subarticular protrusion. He was diagnosed as having CRPS, which fits the revised International Association for the Study of Pain (IASP) criteria. He fulfilled 4 symptom categories (allodynia, temperature asymmetry and skin color change, sweating changes, decreased range of motion and motor dysfunction) and 3 of 4 sign categories (allodynia, temperature asymmetry and skin color changes, decreased range of motion and motor dysfunction). The bone scan and thermography also revealed CRPS. For the past 2 months, we have performed intensive treatments. But, he never became pain-free and walking for 5 minutes led to persistent leg pain. We decided to perform percutaneous nucleoplasty, which can directly decompress a HIVD. On the next day, he achieved dramatic symptom relief. The visual analog scale (VAS) score improved to 3, compared to the VAS score of 9 at the first visit. The skin color change, allodynia, and tremor in the right leg disappeared, and the temperature asymmetry normalized. Motor weakness of the right leg also recovered. We report an unusual case of CRPS that was caused by L4/5 HIVD without a history of trauma or surgery. It has a clear causal relationship between HIVD and CRPS and definitively fits in the newly revised IASP criteria. In conclusion, mild HIVD can cause CRPS without any trauma. And percutaneous nucleoplasty can be considered as a treatment option.