Nantes Criteria for Pudendal Neuralgia Diagnosis

The Nantes criteria are a set of five clinical requirements used to diagnose pudendal neuralgia caused by entrapment of the pudendal nerve. Published in 2008 by a multidisciplinary group of specialists who convened in Nantes, France, the criteria were developed because no imaging test or lab value can reliably confirm this condition. All five criteria must be met for the diagnosis, and a separate set of exclusion criteria helps rule out other causes of pelvic pain. For the many people who spend months or years searching for an explanation of their symptoms, the Nantes criteria remain the closest thing to a standardized diagnostic framework for pudendal nerve entrapment.

The Five Essential Criteria

Each of the five criteria targets a different clinical feature of pudendal nerve entrapment. A patient must meet all five for the diagnosis to apply.¹

Pain in the pudendal nerve territory: The pain must be felt in the areas the pudendal nerve supplies, which includes the perineum, the genitals, and the rectal region. Pain that is purely in the buttocks, tailbone, or lower abdomen does not qualify.
Worsened by sitting: Sitting compresses the nerve against bony and ligamentous structures in the pelvis, so pain that gets worse when seated is a hallmark feature. Many patients describe some relief when sitting on a toilet seat, because the open center removes pressure from the perineum.
No nighttime awakening: The pain should not wake you from sleep. Because nerve entrapment is a compression problem tied to posture and position, lying down generally relieves it. Pain that regularly wakes you at night suggests a different source, such as inflammation or a tumor.
No objective sensory loss: A clinical exam should not reveal numbness or loss of sensation in the affected area. True nerve damage from long-standing entrapment can eventually produce sensory deficits, but at the point of diagnosis the criteria expect the nerve to be irritated rather than destroyed. Detectable sensory loss points the clinician toward other neurological conditions.
Positive diagnostic nerve block: An injection of local anesthetic around the pudendal nerve should temporarily relieve the pain. This is the only criterion that involves a procedure, and it serves as both confirmation and a kind of proof of concept: if numbing the nerve takes the pain away, the nerve is the likely culprit.

What the Criteria Rule Out

Alongside the five required features, the original Nantes publication lists several exclusion criteria. Pain that is exclusively in the coccyx (tailbone), gluteal region, or lower abdomen does not fit. Purely paroxysmal pain, meaning brief shock-like jolts with no background ache, is also excluded, as is isolated itching without pain. And if imaging reveals a structural abnormality that could explain the symptoms, such as a pelvic mass or a spinal lesion, the diagnosis of pudendal nerve entrapment should not be made until that finding is addressed.²

The original paper also describes supplementary criteria that can strengthen a suspected diagnosis without being strictly required. These include burning or shooting pain quality, pain that worsens over the course of the day, pain that is predominantly on one side, and the sensation of a foreign body in the rectum or vagina. The pain is characteristically unilateral, concentrated in the pudendal nerve’s distribution on one side of the body.³

Where the Nerve Gets Trapped

The pudendal nerve travels a winding path through the pelvis, and it can become compressed at several distinct points along the way. Understanding where the entrapment occurs matters because different locations produce slightly different symptom patterns and respond to different surgical approaches.

The most common entrapment site is where the nerve passes between two ligaments deep in the pelvis: the sacrospinous and sacrotuberous ligaments, near the ischial spine. This is classified as a Type II entrapment. A second common location, Type III, is at the entrance to Alcock’s canal, a tunnel formed by the fascia of the obturator internus muscle on the inner wall of the pelvis. Spasm of that muscle can narrow the canal and squeeze the nerve.⁴

There are also anatomical differences between individuals that may affect vulnerability. Cadaver dissections have found that in some males, the pudendal nerve gives off an extra branch as it crosses behind the sacrospinous ligament. This “accessory rectal nerve” provides additional innervation to the pelvic floor muscles and was not found in female cadavers in the same study.⁵ Variations like this may partly explain why symptoms and responses to treatment differ from one person to another.

Common Causes and Risk Factors

Pudendal nerve entrapment can develop after a specific event or from repeated low-grade compression over time. Prolonged cycling is one of the most commonly cited risk factors. The narrow saddle concentrates the rider’s weight on the perineum, directly over the nerve’s path. Numbness in the perineum, penis, scrotum, or buttocks is the most recognized symptom of pudendal compression in cyclists, and pudendal nerve entrapment represents the most common cycling-associated urogenital complaint.⁶

Other reported triggers include falls onto the tailbone, vaginal childbirth, pelvic surgery, and chronic constipation with heavy straining. Repetitive squatting exercises and prolonged sitting on hard surfaces have also been implicated. In some cases, no clear precipitating event is identified, and the condition is thought to arise from gradually worsening tension in the pelvic ligaments or muscles that surround the nerve.

Why the Nerve Block Matters So Much

The fifth Nantes criterion, the diagnostic nerve block, plays an outsized role compared with the other four. A positive block does more than confirm the diagnosis. Research on surgical candidates has shown that it also predicts who is likely to benefit from surgical decompression. A study evaluating selection criteria for surgery concluded that a diagnostic anesthetic injection of the pudendal nerve is an effective predictor of surgical success and should always be part of the evaluation.⁷

A nerve block also has short-term therapeutic value. Many patients experience hours to weeks of relief after an injection, which can provide a window for physical therapy or simply a break from chronic pain. However, the relief is temporary. Nerve blocks are best understood as a diagnostic tool rather than a long-term treatment.⁸

Treatment After Diagnosis

Once the Nantes criteria confirm a diagnosis, treatment typically starts conservatively and escalates if needed. A narrative review of the condition recommends a multidisciplinary approach: avoiding activities that provoke pain (particularly prolonged sitting), physiotherapy, psychotherapy, and medications such as tricyclic antidepressants and anticonvulsants.⁹ Cushions with a cutout in the center are a common practical adaptation that removes pressure from the perineum during sitting.

Pelvic floor physical therapy is widely recommended, but patients report mixed results. A cross-sectional study of people with pudendal neuralgia found that the average self-reported improvement after pelvic floor physical therapy indicated no to minimal change. About two thirds of participants reported no meaningful improvement, and roughly one in eight said their symptoms actually worsened. Only about one in five reported much or very much improvement.¹⁰ Participants who received only pelvic floor physical therapy, without other concurrent treatments, reported slightly lower satisfaction. This does not mean physical therapy is useless for everyone, but it does suggest that expectations should be realistic and that therapy works best as one piece of a broader approach rather than a standalone solution.

Surgical Decompression

When conservative measures fail to control the pain, surgery to physically free the nerve from the tissue compressing it becomes an option. A systematic review and meta-analysis pooling data from nineteen studies and over 800 patients found that the overall rate of significant pain relief across all surgical techniques was about two thirds.¹¹

Outcomes varied considerably depending on the surgical approach. The laparoscopic (camera-guided, minimally invasive) technique had the highest success rate at roughly nine in ten patients, though it also carried a complication rate of about 16 percent. The perineal approach, performed through a small incision between the genitals and anus, showed a success rate closer to seven in ten. The transgluteal approach, through the buttock, had the lowest success rate at about half. Patient age and length of follow-up also significantly influenced outcomes, with younger patients and shorter follow-up periods tending to show better numbers.¹²

These numbers come with a large caveat: the studies were highly heterogeneous, meaning they differed substantially in how they selected patients, defined success, and followed up. And surgery for pudendal nerve entrapment is not a quick fix. Recovery is often measured in months, and some patients experience a temporary increase in pain before improvement begins.

Pulsed Radiofrequency as an Alternative

For patients who do not respond adequately to nerve blocks or conservative care but are not surgical candidates, pulsed radiofrequency offers a middle-ground option. The technique delivers short bursts of electrical energy to the nerve, aiming to disrupt pain signaling without causing permanent nerve damage.

A case series from a Dutch university hospital followed twenty women with pudendal neuralgia who had not improved with standard treatments, including nerve blocks. At three months after pulsed radiofrequency, about four in five described their condition as much or very much better. At a median follow-up of four years, that proportion rose to roughly nine in ten, with no serious side effects observed.¹³ These are encouraging results, though they come from a small, uncontrolled series at a single center. Larger comparative studies are still needed before pulsed radiofrequency can be considered a well-established treatment.

The Psychological Dimension of Chronic Pelvic Pain

Pudendal neuralgia is rarely encountered in primary care, and many patients see multiple specialists over years before receiving a diagnosis. That prolonged uncertainty takes a toll. Pain in the genitals and perineum is difficult to discuss, carries stigma, and can disrupt sexual function, relationships, and the ability to work at a desk job. Case reports in the literature emphasize that psychological factors can perpetuate and amplify pain in patients with pudendal neuralgia, making a psychosocial approach just as important as the medical one.¹⁴

This is not a suggestion that the pain is “in your head.” Nerve entrapment is a physical, mechanical problem. But chronic pain of any kind changes how the nervous system processes signals, and emotional distress, anxiety about the condition, and feelings of isolation can lower a person’s pain threshold. Addressing those factors through cognitive behavioral therapy, pain psychology, or peer support groups does not replace physical treatment, but it can meaningfully improve a patient’s quality of life while other interventions are tried.

Limitations and Ongoing Debate

The Nantes criteria were developed by expert consensus, not by testing them against a gold standard and measuring their diagnostic accuracy. No such gold standard exists for pudendal nerve entrapment: there is no blood test, and imaging studies like MRI neurography are still evolving and not yet reliable enough to confirm or exclude the diagnosis on their own. The criteria have never been formally validated in a large, prospective diagnostic accuracy study comparing them against a definitive reference test.

Some clinicians point out that the criteria may be too restrictive. The requirement that pain should not wake you at night, for instance, was originally included because entrapment pain is postural, but patients with severe, long-standing entrapment sometimes do report nighttime symptoms as the nerve becomes increasingly irritated. Similarly, the absence of sensory loss on exam can be difficult to interpret, especially in patients who have had the condition for many years and may be developing early nerve damage.

Others argue the criteria are too broad in a different way: because each criterion is assessed clinically rather than measured objectively, the results can vary depending on the examiner’s experience. The nerve block, the most “objective” of the five criteria, depends on accurate needle placement and can produce false negatives if the anesthetic misses the nerve or false positives if it spreads to adjacent structures.

Despite these limitations, the Nantes criteria remain widely referenced because no better alternative has emerged. They give clinicians a structured checklist in a field where the diagnosis has historically been made haphazardly or not at all, and they provide a common language for communication between pelvic pain specialists, surgeons, and researchers. For patients, simply knowing the criteria exist can be validating: the five items map closely onto the experience many have been struggling to describe to doctors for years.