Pudendal Neuralgia

Dr. Richard Marvel specializes in treating pudendal neuralgia in both men and women. On days that male PN (pudendal neuralgia) patients are treated, the appointment slots are exclusively set aside for male patients.
Please read below to learn more about pudendal neuralgia.

What is pudendal neuralgia?
What are the symptoms?
What causes pudendal neuralgia?
How is it diagnosed?
What treatment is available?

What is pudendal neuralgia?

Pudendal neuralgia (also known as Alcock’s syndrome, Pudendal Canal Syndrome) is a condition caused by an entrapment, compression or tension of the pudendal nerve resulting in pain in the distribution of the pudendal nerve.

The pudendal nerve carries both motor and sensory neurons arising from sacral segments S2, S3, and S4. These fibers join to form the nerve traveling under the piriformis muscle. The nerve then travels caudally into a small space “clamp” between the sacrospinous ligament and the sacrotuberous ligament. The nerve runs beneath the sacrospinous ligament just medial to its attachment at the ischial spine and superior to the sacrotuberous ligament. The nerve then passes ventrally, medially and caudally through the lesser sciatic foramen where it then enters the pudendal canal (also known as Alcock’s Canal) which is formed by a duplication of the aponeurosis of the obturator intemus muscle. At this level, it crosses over the falciform process of the sacrotuberous ligament. During its course, the nerve gives off several branches (levator branch, dorsal penile or clitoral branch and inferior rectal branch) before terminating as the perineal nerve which innervates the perinea, skin and superficial muscles. Keep in mind the nerve is accompanied by the pudendal artery and venous complex during its course.

The exact mechanism of nerve dysfunction and damage is dependent on its etiology. For patients with nerve entrapment and compression, an inflammatory response is engendered. This results in venous stasis increased vascular permeability and eventually demyelination. This can result in scar formation and in cases of severe injury, permanent nerve damage.

For patients with nerve tension injury, the inflammatory effect is not as severe and demyelination is not a factor. However, the neuronal function is impaired. For patients with fixation along the nerve’s course, an injury will be more common because the nerve lacks mobility and is more readily stretched. Also, pelvic floor dysfunction itself may cause pain along the pudendal nerve distribution.

What are the symptoms?

Primary symptoms of Pudendal Neuralgia include:

Pelvic pain: With pudendal neuralgia, pelvic pain typically occurs with sitting. It may be less intense in the morning and increase throughout the day. Symptoms may decrease when standing or lying down. The pain experienced can be in the clitoral or penile area, the rectum and the area in between (perineum). It can occur on both sides (bilateral) or one-sided (unilateral).

Sexual dysfunction: Women with pudendal neuralgia may experience decreased sensation in the genitals, perineum or rectum. She may experience pain with or without touch. It may be difficult or impossible for the woman to achieve orgasm. In men, sexual dysfunction presents as pain during erection, difficulty sustaining an erection or painful ejaculation.

Difficulty with urination/defecation: Patients may experience urinary hesitancy, urgency and/or frequency. Discomfort after emptying the bladder is not uncommon. Patients may feel that they have to ‘strain’ to have a bowel movement and might have pain or discomfort after a bowel movement. Constipation is also common among patients with pudendal neuralgia. In severe cases, complete or partial urinary and/or fecal incontinence may result.

The sensation of a foreign object being within the body: Some patients will feel as though there is a foreign object sitting inside the vagina or the rectum. Some describe it as “sitting on a marble” or “having something stuck inside”.

What causes pudendal neuralgia?

Pudendal neuralgia can be caused by various mechanisms. These can be separated into three basic categories:

The pudendal nerve is anatomically vulnerable to compression and entrapment along its course. Patients with anatomical predispositions (i.e. smaller canals, a narrow window between ligaments, etc.) or biomechanical abnormalities are more susceptible to compression injuries. Patients may have a silent or asymptomatic compression for an extended period of time. Then, an exacerbating and inflaming factor such as surgery, hematoma, cycling, prolonged sitting, stress and tension-holding patterns, horseback riding, etc. causes entrapment, nerve dysfunction and symptoms.

Sacral or radicular type factors causing nerve compression or inflammation at the sacral or nerve root level. Possible examples being benign or malignant tumors and trauma to the area.

The pudendal nerve is also vulnerable to tension injuries. A variety of factors can put undo tension on the nerve causing it to lengthen beyond its normal limits and result in neural inflammation. Possible factors include vaginal childbirth, constipation with repetitive straining to defecate and squatting with heavy weights. Pelvic floor dysfunction, genital prolapse, and so-called descending perineum syndrome can also contribute to nerve tension injury. Fixation along the nerve pathway will result in the nerve becoming more likely to be injured with-any of the above factors.

How is it diagnosed?

As with our other pelvic pain conditions that we manage, much of the diagnosis is made in a thorough history. Often patients will state that sitting increases symptoms and standing decreases symptoms somewhat. On exam, altered skin sensitivity may be noted. Pressure on the pudendal trunk (transrectally palpated) may produce pain.

A pudendal nerve block can be both therapeutic and diagnostic. It may produce significant pain relief for several hours to several weeks. If the block results in pain relief, it suggests that at least some of the pain is originating from the pudendal nerve.
Electrophysiologic evaluation can help confirm the site of entrapment and the type of nerve damage. The studies consist of EMG testing of the eternal anal sphincter, sacral reflex, pudendal nerve terminal motor latency (PNTML) and somatosensory evoked potential studies.

What treatment is available?

Medical
– Analgesic (including narcotic) medications are often limited in how well they can address neuropathic pain (pain arising from a nerve.) Pain modulators such as tricyclic antidepressants and neuroleptics (i.e. Neurontin, Zonegran, etc.) have varied efficacy. Nerve infiltration (“blocks”) with a combination of local anesthetic (Lidocaine or Marcaine) combined with a steroid (Triamcinolone or Solu-Medrol). Sometimes it takes several injections to gain the full effect. Success rates also vary widely where between 15-60% are cured or improved with this approach alone.

Lifestyle Modifications
– Avoiding activities which worsen the condition is crucial (cycling, sitting, etc.). Sitting pads, especially those designed with cutouts to transmit pressure away from the perineum, can be very helpful.

Physical Therapy
– Musculoskeletal dysfunctions can cause pudendal neuralgia as well as other painful pelvic syndromes. Physical therapy is an effective method of minimizing or eliminating the other factors that can worsen pudendal neuralgia (tightened pelvic floor muscles, trigger points, etc). It is important to acknowledge this interaction between musculoskeletal and neural dysfunction as it is unusual that one exists without the other. Physical therapists require special training to treat pudendal neuralgia. Typically, the shortened pelvic floor/pudendal neuralgia will become symptomatically exacerbated with Kegel exercises and these should be avoided until otherwise instructed by a professional. The program should also include connective tissue mobilization, neural mobilization, and a home exercise program.

– The above mentioned musculoskeletal dysfunctions can be responsible for the pain that persists after a decompression procedure. It is recommended that external physical therapy begins one-month post-operatively and that pelvic floor rehabilitation gets initiated at 3 months.

Sacro-iliac joint dysfunction commonly co-exists with pelvic pain. When the sacrotuberous ligament is severed during decompression, SIJD is a common post-operative complication. Patients typically will have persistent (or ‘new’) pain and pelvic dysfunction. It is recommended that post-operative physical therapy begins one-month post-operatively and that pelvic floor rehabilitation is initiated at three months.

Surgical
– There are three main surgical techniques are currently available worldwide for nerve decompression (the transperineal approach, the trans gluteal approach, and the trans-ischio rectal approach). The theory is similar to other nerve decompression procedures performed for nerve entrapments in other regions of the body (i.e. carpal tunnel release). The procedures differ in their approach to the area of entrapment.

The three main surgical techniques all have advantages and disadvantages. There has never been a head to head randomized trial to determine which is best. Comparing the currently published trials is also difficult because of different modes of evaluation of efficacy, preoperative evaluation, definitions, and degree of long-term follow-up.