CT-guided nerve block for pudendal neuralgia: diagnostic and therapeutic implications

The objective of our study was to help clarify the role of CT-guided pudendal nerve blocks in the problematic and poorly understood entity of pudendal neuralgia (PN).

Over a 1-year period, 52 CT-guided pudendal nerve blocks were performed in 31 patients (28 women, three men; age range, 22-80 years) who suffered from chronic pelvic pain with a presumed diagnosis of PN. A combination of anesthetic and steroid was injected into the pudendal (Alcock) canal. Pre- and postprocedural pain scores (0-10) were tallied and assessed by Student t tests. A p value < 0.05 was indicative of a significant difference.

All procedures were successful technically, which was defined as contrast material filling the pudendal canal on CT and subsequent infusion of anesthetic and steroid. Pre- and postprocedural pain scores ranged from 2 to 10 (mean score, 6.13) and 0-10 (mean score, 2.14), respectively; the difference was statistically significant for each nerve block session (first session, p < 0.001; second session, p < 0.001; third session, p = 0.049). Of the 31 patients, two had long-term relief with pudendal nerve blocks alone. Fourteen had subsequent surgery based on initial improvement with block(s), and all 14 patients improved with surgical nerve release. Two patients had no diagnostic response and the diagnosis of PN was excluded. The gynecologic service followed the remaining 13 patients clinically.

CT-guided pudendal nerve blocks appear to be valuable diagnostically for PN and uncommonly therapeutically. On the basis of these preliminary results, we have developed an algorithm for the role of the procedure for PN.