Pudendal neuralgia (PN) is a result of pudendal nerve entrapment or injury, also called “Alcock
syndrome.” Pain that develops is often chronic, and at times debilitating. If conservative measures
fail, invasive treatment modalities can be considered. The goal of this case report is to add to
a small body of literature that a pulsed radiofrequency (PRF) ablation can be effectively used
to treat PN and to show that high resolution MR neurography imaging can be used to detect
pudendal neuropathy.
Case Presentation: We present a case of a 51-year-old woman with 5 years of worsening
right groin and vulva pain. Various medication trials only lead to limited improvement in pain.
The first diagnostic right pudendal nerve block was done using 3 mL of 0.25% bupivacaine
with 6mg of betamethasone using a transgluteal technique and a target of the right ischial
spine; this procedure resulted in ~8 hours of > 50% pain relief. The patient was then referred
for MR neurography of the lumbosacral plexus. This study revealed increased signal of the right
pudendal nerve at the ischial spine and in the pudendal canal, findings consistent with the clinical
picture of PN. Six weeks after the initial block, the patient underwent a second right transgluteal
pudendal nerve block, utilizing 3 mL of 0.25% bupivacaine with 40 mg of triamcinolone
acetonide; this procedure resulted in ~8 hours of 100% pain relief. Satisfied with these results
the patient decided to undergo pudendal nerve PRF ablation for possible long-term relief. For
this therapeutic procedure, a right transgluteal approach was again utilized. PRF ablation was
performed for 240 seconds at 42° Celsius. Following this ablation the patient reported at least 6
weeks of significant (> 50%) pain relief.
Discussion and Conclusion: In this paper we presented a case of successful treatment of
PN with PRF ablation and detection of pudendal neuropathy on MR neurography. We believe
that transgluteal PRF ablation for PN might be an effective, minimally invasive option for those
patients that have failed conservative management. MR neurography employed in this case is
not only helpful in confirming the diagnosis of PN but could also be useful in ruling out other
causes of pelvic pain, such as genitofemoral neuropathy, endometriosis, adenomyosis, or pelvic
mass lesion. To conclude, transgluteal PRF ablation can serve as a viable treatment option for
mitigating symptoms of pudendal neuropathy and MR neurography is useful in confirming a
clinically suspected diagnosis of PN.
Key words: Pelvic pain, pudendal neuralgia, MR neurography, pulsed radiofrequency ablation,
transgluteal technique, Alcock canal syndrome
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