Gustatory Change after Sympathetic Ganglion Block in Complex Regional Pain Syndrome Type I Patient: A case report

ABSTRACT

Some reports provide conclusive evidence of close interactive regulation between the taste receptor and sympathetic nervous system. We report a middle-aged male patient with gustatory change after cervical sympathetic ganglion block (CSGB) who had been suffering from hypersensitivity to sour taste since developing complex regional pain syndrome (CRPS) type 1, diagnosed according to the revised CRPS criteria. Despite receiving two high doses of prednisolone therapy, he experienced the recurrence of CRPS symptoms. We attempted other therapy treatments, including pamidronate intravenous infusion, non-steroidal anti-inflammatory drugs, opioids, tricyclic antidepressants, and CSGB. Following each CSGB administration, the patient reported decreased hypersensitivity to sour-tasting foods, such as kimchi and oranges, with decreased pain and reduction of dysautonomic symptoms. This case demonstrates that overactivation of the sympathetic nervous system may influence sensitivity and regulation of gustatory receptors; therefore, a patient demonstrating CRPS symptoms, including taste alterations, may respond positively to CSGB therapy.