Pudendal Neuralgia

 

Pudendal Neuralgia (PN) in its truest form is a tunnel entrapment neuropathy and can affect both women and men.  It is not a common condition, though patients often present with the diagnosis and no formal investigations.  It is said to affect 1 in 100000 people and around 3-5% of pelvic complaints .  The pudendal nerve is a major nerve (like the sciatic nerve) arising from the sacral plexus (S2,3,4).  It is an important nerve for differential diagnosis in cases of CPP (Chronic pelvic pain). The pudendal nerve is a mix of motor, autonomic and sensory functions and therefore affects bowel, bladder, sexual and other autonomic functions.  

Pain arising from the pudendal nerve is felt in the perinium, testicles and penis (for men), vagina (for women) and anus.  The pudendal nerve supplies the skin of the genitals and also the pelvic floor muscles. Common symptoms include: 

  • a golf ball in the perinium
  • unable to sit for long (around 50% cannot tolerate sitting)
  • burning sensation in the genitals. 
  • stabbling pain in the perinium
  • achey constant pain
  • possible sexual, bladder and bowel dysfunction
  • pain progresses through the day and better in the morning
  • pain may extend around the genetalia, rectum and even thighs

 

The nerve emerges in front of the piriformis muscle before passing between the sacrotuberous and sacrospinous ligaments.  Exiting this region the nerve enters the pudendal canal (Alcocks canal) with division giving rise to the perineal nerve, inferior rectal nerve and dorsal nerve supplying the penis and vagina.  Surgical obervations have noted differences in the structure and pathway of the nerve.  Sublte changes in ischial tuberosity and other pelvic angles have been suggested as providing opportunities for the nerve to become more susceptible to injury for some people.  A thicker obturator internus muscle has been noted which may account for nerve compression. 

Pain can develop because or tension or stretching in the saddle region like prolonged sitting or cycling, or over exertion on lifting.  More commonly ther may have been an injury to a woman through child birth.  The more robust structures in the pelvis makes this less of an issue in men.  There is emerging evidence that prolonged sitting or cycling could be a contributing factor due to the compression element.  Therefore, awareness of sitting times are a key component in the management of pain. Less common for men is the direct trauma due to surgery unless local to the rectum.  General increase in tension through the pelvis due to recurrent infection could cause muscle tightness impacting on fascia and therefore tensioning across the nerve. 

 

Examination

A sound examination of the pelvic region is essential and includes palpation, sensation testing and internal examination of the pelvic floor.  Palpation of the pudendal nerve in Alcock's Canal with a tapping pressure is almost confirmatory as it will reproduce symptoms.  However, PN is a clinical diagnosis and relies on a battery of tests in combination with a thorough history in order to determine the most likely diagnosis. MRI or CT are often unhelpful. Pudendal nerve blocks are not helpful in a high proportion of cases. 

Treatment

  • Hands on manual therapy treatment to your low back and pelvis, getting the joints moving correctly

  • Trigger point therapy: Getting the muscles working properly and rid of the overactive parts in both the low back muscles, hip muscles and pelvic floor muscles. You will also be taught how to do this yourself also.

  • Pelvic floor exercises to release your pelvic floor

  • Specific hip, spine and pelvis exercises to get you and your pelvic floor moving better, think yoga poses and squatting

  • Specialised Breathing and relaxation work

  • Re-education of the  pelvic floor, hip and abdominal musculature

  • General exercise

Medication can help with pain and include gabapentin, amytriptaline and pre-gablin.  Surgery is rarely indicated and has been shown to be helpful for some patients.  However, due to the paucity of evidence it is not a first line treatment for the majority of patient.