Pudendal Nerve Injury (Pudendal Neuralgia)

The pudendal nerve

The pudendal nerve arises from the S2 to S4 sacral nerve roots, passes out of the pelvis near the ischial spine, travels through a narrow tunnel called Alcock's canal, and branches to supply:

• the skin of the perineum, anus, labia and clitoris or scrotum and penis
• the external anal sphincter and external urethral sphincter
• the pelvic floor muscles

Symptoms

• pain in the genitals, perineum or anus, on one or both sides, described as burning, stabbing, aching or electric
• pain worse when sitting, better when standing, lying down, or sitting on a toilet seat or ring cushion
• pain that may increase through the day
• a sensation of a foreign body ("golf ball") in the rectum or vagina
• numbness or pins and needles
• urinary urgency, frequency or incontinence
• constipation, pain with bowel movements or fecal incontinence
• pain during or after sex, erectile dysfunction or reduced sensation
• pain usually does not wake people from sleep

Causes

• childbirth: stretching of the nerve during prolonged pushing, forceps delivery or large babies
• prolonged cycling, horseback riding or sitting on hard surfaces
• pelvic surgery, including hysterectomy, prolapse repair with mesh and hip surgery
• trauma: falls onto the buttocks or tailbone, pelvic fractures
• chronic constipation and straining
• pelvic floor muscle tension compressing the nerve
• tumors or infections (rare)

Diagnosis

There is no single definitive test. Diagnosis is based on the pattern of symptoms using the Nantes criteria:

1. pain in the territory of the pudendal nerve
2. pain worse when sitting
3. pain does not wake the person at night
4. no numbness on clinical exam (objective numbness suggests a different problem)
5. relief from a diagnostic pudendal nerve block

Other tests help exclude other causes:

• pelvic and rectal examination
• MRI of the pelvis and lower spine
• nerve conduction studies (of limited value)
• urine tests and specialist bladder or bowel testing

Conditions to consider include vulvodynia, chronic prostatitis, interstitial cystitis, piriformis syndrome and sacral nerve root problems.

Treatment

Conservative

• avoid aggravating activities: reduce cycling and prolonged sitting; use a standing desk
• cushions: U-shaped or cut-out cushions that take pressure off the perineum
• pelvic floor physical therapy: relaxing tight muscles, internal and external manual therapy, and gentle stretching; avoid pelvic floor strengthening if muscles are overactive
• treat constipation to avoid straining

Medicines

• nerve pain medicines: gabapentin, pregabalin, amitriptyline, nortriptyline or duloxetine
• muscle relaxant suppositories in some cases
• topical anesthetic creams

Procedures

• pudendal nerve blocks with local anesthetic and steroid, guided by CT or ultrasound
• pulsed radiofrequency treatment of the nerve
• botulinum toxin injections into tight pelvic floor muscles
• neuromodulation (sacral or pudendal nerve stimulation)
• pudendal nerve decompression surgery for selected patients with confirmed entrapment who have not improved

Coping with chronic pain

Psychological support, CBT and pain management programs help, because long-lasting pelvic pain can affect sleep, mood, relationships and work.

Outlook

Many people improve with conservative treatment and nerve blocks, though recovery can take months. Nerves heal slowly, about 1 mm a day. Some have long-term pain that needs ongoing management. Early treatment and avoiding ongoing pressure on the nerve give the best results.

Frequently asked questions

What are the symptoms of pudendal nerve damage?

Typical symptoms are burning, stabbing or aching pain in the genitals, perineum or anus, worse when sitting and better when standing. Numbness, bladder or bowel problems, a feeling of something in the rectum or vagina, and sexual dysfunction may also occur.

What causes pudendal neuralgia?

Common causes are childbirth, long periods of cycling or sitting, pelvic surgery, falls onto the buttocks, chronic constipation and tight pelvic floor muscles. In some people no clear cause is found.

Can pudendal nerve damage heal?

Yes, often. Mild injuries from childbirth or cycling commonly improve over weeks to months once pressure is relieved. More severe or long-standing entrapment may need nerve blocks, physical therapy or surgery, and recovery can be slow.

How is pudendal neuralgia diagnosed?

Diagnosis is mainly clinical, based on the pattern of pain worse with sitting in the pudendal nerve area, using criteria such as the Nantes criteria. A pudendal nerve block that relieves pain supports the diagnosis. MRI helps rule out other causes.