Pudendal Nerve Entrapment Syndrome: Under diagnosed and inappropriately treated

Danielle R. Steilen-Matias, MMS, PA-C. Ross Hauser, MD.

Many times a patient will contact us via email or phone call and describe their long medical history of dealing with problems of pelvic area numbness and burning; they have sensations of pain or tenderness in the genitalia that would even make wearing underwear painful. Some people will describe that they have a feeling of a lump in the pelvic or groin area where there is actually no lump, just the sensation that one is there.

Both women and men may report problems of urinary problems, including frequency or urgency. Men will often report erectile dysfunction that is not responsive to traditional erectile dysfunction treatments. Women may report painful sex and other sexual dysfunctions.

The people that we see in our offices have been on a long journey to a diagnosis. One that has been elusive. Equally elusive has been any type of effective treatment.

The hunt for the cause of your pain

For many people, numerous consultations with urologists resulted in looking for a problem that a urologist treats. For many people, this is the right direction. For the people that we see in our offices, this was not the right direction as indicated by this person’s continued symptoms and a history that can suggest pudendal nerve entrapment may be occurring.

In taking a medical history, these are some of the clues that would lead us towards looking at a problem of Pudendal Nerve Entrapment Syndrome.

• Sports or work activity that aggregated the pelvic region:
  • Horseback riding
  • Cycling
  • Motorcycle riding
  • Prolonged periods of heavy-duty work where sitting is required, like landscapers on riding lawn mowers, farmers on tractors, heavy machinery operators, truck drivers, etc.
  • Note: CT or ultrasound should eliminate the possibility of compression from a tumor or cyst.
• Pain after childbirth;

Pudendal Nerve Entrapment Syndrome is mostly underdiagnosed and inappropriately treated

This is a conversation we have with many first-time patients after an examination. It goes something like this:

Based on the examination, it can be realistically determined that your symptoms of pain, dysfunction, difficulty walking, and the other things you mentioned are being caused by pelvic instability and sacral instability causing compression of your pudendal nerve, we would like to begin treatment based on pudendal nerve entrapment.

The patient will then say something to the effect of:

“What’s that?” How come my doctors never talked to me about this? I have been going to doctors for years. What is sacral instability? What is pudendal nerve entrapment?

My doctors don’t even know where the pudendal nerve is

Here is an email we received. It is unfortunately a familiar sounding circumstance that people are placed into. The email has been edited for clarity.

“I have pudendal nerve neuralgia going on 4 years. I suffer from severe, burning pudendal nerve pain in my vaginal area, anus, anterior pelvic wall. Have tried numerous medications, exercises, procedures, nerve blocks, without any relief or success. I have, not by desire but unintentionally, lost 40 pounds due to the unrelenting nerve pain and constant nausea which impairs my ability to eat properly. I am always exhausted and lack energy, due to severe pain and malnutrition. I feel the pudendal nerve is impinged/entrapped, in my S2, S3, S4 to the pelvic/anal area. Physicians I have seen aren’t experienced in diagnosing or treating pudendal neuralgia. Several of them don’t even know where the pudendal nerve is located in the body. I am so discouraged and depressed.”

“Pudendal nerve entrapment? What’s that?”

It is probably best at this point for you the reader to have this question answered from the medical research.

In March 2020, doctors from Augusta University in Georgia wrote in the medical publication StatPearls (1)

• Pudendal neuralgia (pudendal nerve pain) caused by pudendal nerve entrapment is a chronic and severely disabling neuropathic pain syndrome.
• It presents in the pudendal nerve region and affects both males and females. It is mostly underdiagnosed and inappropriately treated, and causes significant impairment of quality of life.

Perhaps you are one of the patients where pudendal nerve entrapment is mostly underdiagnosed and inappropriately treated and this is why you have continued pain.

The route of the pudendal nerve reveals the extent of the pain it can cause

One of the reasons that Pudendal neuralgia (pudendal nerve pain) is underdiagnosed and inappropriately treated is because it is easily confused with other problems. In the illustration below we can see the route of the pudendal nerve and how closely it passes by and through other structures that can be blamed for symptoms. Namely the sacrum.

In this illustration we see the influence damaged sacrotuberous and sacrospinous ligaments can have on the pudendal nerve.  Damaged sacrotuberous and sacrospinous ligaments can be responsible for groin-related pain. One possible cause of this pain is pudendal nerve compression or dysfunction. 

• The pudendal nerve emerges from the S2, S3, and S4 roots’ ventral rami of the sacral plexus.
  • (Simply, the spinal nerves exit the spinal column and split at the S2, S3, and S4 vertebra to form the sacral plexus, the nerves which provided motor and sensory nerves for the posterior or back of the thigh, most of the lower leg, and foot, and part of the pelvis. The pudendal nerve is one of these nerves.)

The pudendal nerve travels between two muscles, the piriformis and coccygeus muscles. It can get trapped there.

• The pudendal nerve travels between two muscles, the piriformis and coccygeus muscles.
  • Please see our article Piriformis Syndrome and Sciatica Pain. Typically pudendal neuralgia and pudendal nerve entrapment is a symptom of pelvic and lower back instability which can include concurrent symptoms of sciatica.
  • A study in the journal Current Bladder Dysfunction Reports (2) noted that “in the athlete, flexion and abduction of the thigh are common motions, and they may lead to hypertrophy of the piriformis muscle. If the sciatic notch (where the piriformis muscle and the pudendal nerve pass) is narrowed because of the posterior orientation (a distorted orientation from pelvic/spinal instability) of the ischial spine, the cross-sectional area of the greater sciatic notch is reduced. Concomitant hypertrophy of the piriformis muscle may cause compression of the pudendal nerve against the posterior edge of the sacrospinous ligament.”

Getting trapped between the sacrotuberous and sacrospinous ligaments

• The pudendal nerve leaves the pelvic cavity through the greater sciatic foramen ventral to the sacrotuberous ligament.
  • The greater sciatic foramen (opening) is at the rear of the pelvis. The opening is formed by the sacrotuberous and sacrospinous ligaments. The piriformis muscle passes through the foramen as well. As you can see we have piriformis muscle again interacting with the pudendal nerve in a confined space.
  • Let’s also note that the sacrotuberous and sacrospinous ligaments and pudendal nerve are having an interaction. Damaged sacrotuberous and sacrospinous ligaments can be responsible for groin-related pain. Again here is a situation where pudendal nerve compression or dysfunction is not a problem in isolation. The supporting ligaments of the pelvis, when damaged can cause pudendal nerve compression as well as symptoms more closely related to Sacroiliac Joint Dysfunction. Please see our article: Sacroiliac Joint Dysfunction Treatment Options where we introduce research on pelvic and spinal ligaments being identified as a point of interest in treating groin pain related to sacroiliac joint dysfunction.
• At the ischial spine level, (a small bony projection towards the rear pelvis at the vaginal or scrotum level) the pudendal nerve passes to and under the sacrospinous ligament to re-enter the pelvic cavity through a lesser sciatic foramen.
  • Again, an interaction is occurring between the pudendal nerve and a ligament that attaches the pelvis to the spine to the ischial spine level to the tailbone. If this ligament is damaged, weakened, or loose, the pudendal nerve can be stretched or compressed and pudendal nerve function impaired, meaning symptoms begin.
• The pudendal nerve then courses in the pudendal or Alcock canal (an area in the pelvis that the internal pudendal artery, internal pudendal veins, and the pudendal nerve pass. It is easy to see why pelvic instability could cause significant dysfunction in blood flow to an out of the area).

Finally, it divides into three branches: anal/rectal, perineal, and clitoral/penile.

Constipation, inability to eliminate

I can’t poop

This is a common problem in situations of Pelvic Floor Dysfunction and in pudendal nerve entrapment. When a patient reports that chronic constipation and discomfort with bowel movement has joined the list of symptoms, another set of diagnostic tests are brought into play.

• The three last branches of the pudendal nerve terminate in the ischioanal fossa.
  • One branch that terminates at the ischioanal fossa or ischiorectal fossa as it is sometimes referred to is the anal/rectal branch. The ischioanal fossa is an area that controls the muscles of the anal canal (which is why some patients have complaints of constipation or inability to eliminate) including the external sphincter muscle.

Sensitivity or pain problems in the penis or clitoris

• The clitoral/penile branch or dorsal sensory nerve of the penis or clitoris is another of the last branches of the pudendal nerve. Patients with problems of this branch may report pain during and not during sex, inability to orgasm, problems with a constantly erect penis, or over-stimulated clitoris without sexual stimulus.

The pudendal nerve entrapment syndromes subdivide into four types based on the level of compression.

• Type I – Entrapment below the piriformis muscle as the pudendal nerve exits the greater sciatic notch.
• Type II – Entrapment between sacrospinous and sacrotuberous ligaments – this is the most common cause of nerve entrapment.
• Type III – Entrapment in the Alcock canal.
• Type IV – Entrapment of terminal branches.

In this illustration we the areas of the groin and vaginal area impacted by the genitofemoral nerve, the pudendal nerve, and the inferior cluneal nerve. The pudendal nerve encompasses the area of the vagina and anus.

A doctor in 1915 said there is a big problem with missing the diagnosis of chronic pudendal nerve compression in bladder pain syndrome sufferers who had a triad of perineal pain, urinary urgency, and frequency despite sterile urine cultures excluding urinary infections. Doctors in 2020 agree it is still a problem 105 years later.

Here is a paper from March 2020 in the Journal of Brachial Plexus and Peripheral Nerve Injury (3). Let’s see if you find something familiar in what these doctors from University Hospital in Basel, Switzerland, and Johns Hopkins University are saying about the misdiagnosis of your problems.

Interstitial cystitis or bladder pain syndrome (a diagnosis some of you may have received to describe your symptoms of bladder and pelvic pain and frequent urge to urinate that has finally been determined not to come from urinary tract problems) is a highly painful and disabling and probably the most misdiagnosed urologic condition.

What makes this article fascinating is that the researchers are documenting that what you have has been misdiagnosed since at least 1915, when one doctor figured out that for many, this is a problem of chronic pudendal nerve compression. How? Let’s go back to the study:

. . .classic symptoms of perineal pain (the area between the anus and scrotum or anus and vagina), urinary urgency, and frequency despite sterile urine cultures (not a urinary tract infection) were already described more than a century ago in a report on soldiers during World War  I due to chronic pudendal nerve compression. Dr. Georg Zülzer over 100 years ago noted in his paper “Irritation of the Pudendal Nerve (Neuralgia). A Frequent Clinical Picture during War Feigning Bladder Catarrh (discharge. mucus),” the correct clinical observations of modern diagnosis and therapy of pudendal nerve compression.

Dr. Zülzer observed these symptoms in 1915:

• sufferers had a triad of perineal pain, urinary urgency, and frequency despite sterile urine cultures excluding urinary infections.

That lump sensation explained:

• sufferers had characteristic skin hypersensibility of the perineum in a rhomboid shape (a tilted rectangle) which corresponds to the innervation area of the pudendal nerve with its two branches deriving from the “pudendal plexus.” (That is that lump sensation.)
• In 1915 Dr. Georg Zülzer probably gave the first exact clinical description of symptoms due to pudendal nerve compression. Pudendal nerve compression should always be taken into account when examining and treating patients with symptoms of IC/BPS.

Treatment for Pudendal Nerve Entrapment Syndrome

Most of the patients we see have already had a long history of testing and diagnosis elimination scans. This includes for women a vaginal examination, for men a rectal examination. The goal of these examinations is to palpitate or apply pressure to the branches of the pudendal nerve to reproduce a pain response of nerve sensation. Many will have already had an MRI or CT scan to document nerve compression. Some would have had nerve conduction studies to assess damage or compression of the pudendal nerve.

Many also had nerve blocks. A painkiller not only improves pain but isolates the cause of the problem on the pudendal nerve. If pain relief is achieved, even in the very short term, then there is confidence the problem is the pudendal nerve.

Because a nerve block does not work, for some, this should not rule out the pudendal nerve. In a May 2020 study in the journal Pain Medicine (3), researchers noted that two common methods of nerve blocks using ultrasound guidance, one injection is given at the ischial spine or the other option the injection is given at the Alcock’s or Pudendal canal were on average 80% accurate for hitting their mark.

Treatments for pudendal neuralgia that you may have already tried that did not help

For some people, any one of these treatments may be enough to provide pain relief and an improvement in quality of life. Unfortunately, the people who have success with these treatments are not the people that we see in our offices. We see the people who continue to have problems.

Many doctors tell their patients that the most important aspect of treating pudendal nerve pain is to figure out what is causing it. This of course is something we all agree on. But what if you are looking in the wrong places? Likely if you look in the wrong places you will get the wrong treatment. Many doctors focus on treating the injured pudendal nerve. This may not be the best treatment plan if you do not treat the problems of pelvic instability and sacrum instability we discussed above. Else wise the pudendal nerve will remain or repeatedly become entrapped. This could be why you are not getting long-term results and have bounced from specialist to specialist.

The first options were conservative care, simply avoidance of those things that cause pain.

• Don’t sit for too long
• Avoid activities such as cycling, horseback riding, motorcycling, riding tractors, or lawnmowers where obvious aggravation of your symptoms could occur.
• Nerve pain medications
• Physical therapy and exercise programs for pelvic floor muscles
• Pudendal nerve blocks and injections
  • For many patients, a steroid or painkiller injection can have good temporary results. We see many of these patients as these results wear off and typically their doctors have been recommending more doses. If you are reading this article, you may be one of these people where treatments provided less and less pain relief.
• Electrical nerve stimulation
  • Electrical nerve stimulation is considered an option especially in situations of stress urinary incontinence. Many women get this treatment following childbirth when the pudendal nerve and urinary sphincter.
• Decompression surgery

So is this you?

• You had repeated MRIs.
• To confirm pudendal nerve damage you had nerve blocks.
• Once confirmed you were given a lifestyle and activity modification list.
• A list of prescription medications was then prescribed:
  • Women may get tricyclic antidepressants, because of complaints of Vulvodynia (vulval pain), or Vestibulodynia a very painful burning or sensation of “being rubbed raw,” by sitting or sexual intercourse or generalized vulvar dysesthesia (VDY), vaginal pain.
  • Gabapentinoids, a non-opioid medication may be offered as an alternative painkiller. New updates in December 2019 warned of possible significant respiratory side-effects of these drugs so alternatives to these alternatives may have been offered.
  • Depression and anxiety medications such as Serotonin and norepinephrine reuptake inhibitors may be offered.
  • Finally physical therapy.

If you are reading this article it is likely that you have already been through a myriad of treatments and they have failed and your next step is to burn out the nerve with radio-frequency nerve ablation or pudendal nerve neurolysis, freeze out the nerve with cryotherapy, or get pudendal nerve neuromodulation to help with pain and urinary problems.

Pudendal Nerve Entrapment Syndrome Treatment means treating the problems of pelvic instability causing the entrapment

In this video, Dr. Hauser explains how pelvic instability can lead to symptoms related to pudendal neuralgia. The summary transcript and explanatory notes are below.

A common condition that we see is pelvic floor dysfunction which causes pudendal neuralgia or compression of the pudendal nerve. The most common treatment for pelvic floor dysfunction are the different types of physical therapy and they are often helpful but very seldom do I find that it cures people.

If somebody has really severe pudendal neuralgia they may undergo surgical decompression. In this procedure, the surgeon is trying to release the nerve surgically from being compressed along the nerve path.

What most people do not realize is that the pudendal nerve gets stretched and compressed and irritated because of pelvic instability.

At 1:25 Dr. Hauser traces the path of the nerves through the sacrum. One of these nerves is the pudendal nerve.

What would cause compression of the pudendal nerve and irritation? Rotation of the sacrum

• At 3:00 of the video, Dr. Hauser discusses when there is sacrum instability there can be pudendal neuralgia or compression of the pudendal nerve.
• What would cause the sacrum to rotate? To sublux? Weakened and damaged pelvic and sacral ligaments. If the ligaments are not holding the bones in place, they float and have too much movement.
• This is when we look at either sacroiliac ligament laxity or pubic symphysis laxity.
  • Sacroiliac laxity, in other words, the sacrum and the iliac crest move too much So for example, say a person had right side pudendal neuralgia and what that would cause is unbelievable pain in the perineum and it often can be on one side. The pudendal nerve travels between the sacrotuberous ligament and the sacrospinous ligament. So if someone has instability from ligament laxity on one side that would mean that that the bones are goes to move and move and pinch and trap the pudendal nerve.

Prolotherapy treatments

Clinical observations over the course of decades have shown Prolotherapy treatment to injured ligaments induces a mild “healing” inflammatory reaction, which stimulates the repair of injured or lax ligaments. Prolotherapy injections can strengthen the sacrotuberous ligament and the sacrospinous ligament and bring the pelvis and sacrum back into their natural alignment and alleviate pressure on the pudendal nerve.

Prolotherapy to the pelvis involves a dextrose injection treatment to any of the numerous ligaments that may be weak and causing pelvic instability. This treatment initiates a mild inflammatory response in the treated pelvic area. D-glucose (also called dextrose) is the normal sugar in the body, and when injected activates the immune system.  The body’s normal healing inflammatory reaction boosts the blood flow to the area and attracts immune cells to the weakened or injured ligaments being treated. These cells will cause regeneration and strengthening of the injured areas. Once the ligaments are strengthened, the pelvis becomes stabilized. Referral pain will stop, contracted muscles will relax, and chronic pelvic pain will abate.

If you have a question about Pudendal Nerve Entrapment Syndrome, get help and information from our Caring Medical staff

1 Kaur J, Singh P. Pudendal Nerve Entrapment Syndrome. In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2020. [Google Scholar]
2 Possover M, Forman A. Voiding Dysfunction Associated with Pudendal Nerve Entrapment. Current Bladder Dysfunction Reports. 2012 Dec;7(4):281. [Google Scholar]
3 Gohritz A, Dellon AL. Bladder Pain Syndrome/Interstitial Cystitis due to Pudendal Nerve Compression: Described in 1915-A Reminder for Treating Pelvic Pain a Century Later. J Brachial Plex Peripher Nerve Inj. 2020;15(1):e5-e8. Published 2020 Mar 6. doi:10.1055/s-0039-1700538 [Google Scholar]
4 Soucy B, Luong DH, Michaud J, Boudier-Revéret M, Sobczak S. Accuracy of Ultrasound-Guided Pudendal Nerve Block in the Ischial Spine and Alcock’s Canal Levels: A Cadaveric Study. Pain Medicine. 2020 May 25. [Google Scholar]

3348

• Surgery
• NSAIDs
• Cortisone Shots
• R.I.C.E.