Changes in regional cerebral blood flow and three-phase bone scan after repeated somatic nerve blocks for...

The pathophysiology of complex regional pain syndrome type 1 (CRPS 1) correlates with variances in both the peripheral and central nerve system. We attempted to explore the topographic correlation between changes in regional cerebral blood flow (rCBF) and 3-phase bone scans during treatments of a series of somatic nerve blocks.

The case we present here is a 24-year-old man, who suffered CRPS 1 in his right upper extremity for 4 months, and conservative therapy proved to be ineffectual to him. As he did not respond to stellate ganglion block, the syndrome was regarded as sympathetically independent pain (SIP). However, after administering a series of brachial plexus block and local anesthetics, complete resolution of pain, and restoration of function were manifested. In addition, an increase in rCBF, evidenced by single-photon emission computed tomography (SPECT), and changes in the 3 phase bone scan before and after the nerve block appear to correlate well with the clinical improvement.

The changes in rCBF seem to support the theory that the pathogenesis of CRPS is also related to the central nervous system. Multiple somatic nerve blocks (SNB) not only improved physical function but also reversed the CRPS symptoms, for which we presume that reduced nociceptive input signals led to cortical reorganization.