Complex regional pain syndrome involving the lower extremity: a report of 2 cases of sphenopalatine block as a treatment option.

We report 2 cases of complex regional pain syndrome (CRPS) involving the lower extremity; in both, a sphenopalatine ganglion (SPG) block was performed as part of a pain management program. In the first case, a woman in her late twenties presented with CRPS in the left lower extremity that was inadequately controlled with typical oral medications. Sympathetic block of the extremity did not provide significant pain relief. However, a noninvasive sphenopalatine block with 4% tetracaine resulted in a 50% reduction in pain level. The patient was shown how to self-administer the sphenopalatine block and was provided with exercises and therapy to help improve her functional status. The second case involved a woman in her mid forties with CRPS in the right lower extremity that was partially controlled with oral medications. The patient experienced a 50% reduction in pain level when SPG block with 4% tetracaine was given. Further study is needed to determine the effects of SPG blocks on symptoms related to chronic regional pain syndrome.