The Diagnostic Odyssey and Central Sensitization in Pudendal Neuralgia

1. The diagnostic odyssey and delays in recognition

CLINICAL FRAMEWORK MAINTAINING FACTORS

Pudendal neuralgia is primarily a clinical diagnosis. The Nantes criteria notably take into account pain located in the pudendal territory, worsened by sitting, not usually waking the patient at night, without objective sensory deficit, and relieved after a diagnostic pudendal anesthetic block (Labat et al., 2008).

None of these elements, taken in isolation, constitutes proof of anatomical compression. Likewise, imaging and additional tests can be useful for looking for certain causes or ruling out differential diagnoses, but they cannot always objectively demonstrate the mechanism responsible for the symptoms.

This situation can contribute to long diagnostic journeys: symptoms are sometimes attributed successively to the bladder, the rectum, the genitals, the muscles, or the spine before a neuropathic hypothesis is considered. Chronic pelvic pain is known to require a broad and often multidisciplinary differential evaluation (Fučík & Mašata, 2021).

A diagnostic delay does not, however, on its own constitute proof of neurophysiological worsening. It may nevertheless be accompanied by prolonged exposure to pain, activity limitation, increased stress, and a loss of confidence in the healthcare system. These factors may contribute to maintaining disability and pain.

From a functional standpoint, the time that elapses may also matter because the person sometimes continues to endure the situation that triggers their symptoms without having a coherent strategy for modulating the load. The problem is therefore not the administrative delay itself, but what persists during that delay: exposure, lack of understanding of the mechanism, contradictory trials, avoidance, or the maintenance of protective postures.

2. Distributed symptoms and differential diagnoses

The symptoms of pudendal neuralgia can be felt in different regions of the perineum, the anal margin, the urethra, the vulva, the clitoris, the penis, or the scrotum. This distribution reflects the territories of the pudendal nerve and its branches, but it does not allow clinicians to conclude automatically that the nerve is the cause of the symptom.

The logic of distribution among the branches is detailed in Referred Pain and the Pudendal Trident: Understanding Symptom Territories .

Urethral or bladder pain must be distinguished from an infection, an inflammation, bladder pain, mucosal irritation, or another urological condition. Rectal pain must be distinguished from a fissure, hemorrhoidal disease, an inflammation, functional anorectal pain, or a muscular disorder.

Similarly, genital pain may stem from a dermatological, infectious, inflammatory, vulvar, or muscular condition, or from another neuropathy. When local examinations are normal, this justifies a broader analysis, but it does not allow the conclusion that the pain is necessarily pudendal.

The review by Fučík and Mašata highlights the importance of differential diagnosis in pelvic neuropathic pain. The aim is to avoid both the multiplication of tests without a guiding hypothesis and the premature attribution of all symptoms to a single nerve structure (Fučík & Mašata, 2021).

3. Lack of understanding, stress, and the pain experience

BIOPSYCHOSOCIAL EXPERIENCE

When tests show no lesion, some people may feel that their pain is being minimized or disputed. This experience of not being understood can affect the therapeutic relationship, confidence in care, and the ability to take an active part in the care pathway.

Stress, uncertainty, lack of sleep, and the anticipation of worsening can influence perceived intensity and protective behaviors. These factors do not mean that the pain is psychological. They illustrate the biopsychosocial nature of the pain experience, in which biological, psychological, and social dimensions interact (Linton & Shaw, 2011; Darnall et al., 2017).

A person who anticipates pain may limit their movements, change their posture, or contract certain muscles. These responses may be understandable in the short term, but they can also contribute to maintaining a functional limitation when they become permanent. This relationship remains individual and does not allow the pain to be attributed to a single mechanism.

From an SBNFA™ perspective, this protection may progressively narrow the functional repertoire: fewer positions used, fewer variations in support, and more co-contractions intended to avoid the feared movement. This narrowing may limit stress redistribution and recovery. It does not mean that the pain is produced by fear; it describes a possible interaction between real pain and the bodily responses set in place to protect against it.

Clear clinical communication must therefore acknowledge two things at once: the absence of a visible lesion does not negate the reality of the pain, and the presence of pain does not allow a pudendal lesion to be inferred automatically.

4. Central sensitization and hypersensitivity

NEUROPHYSIOLOGY POSSIBLE MECHANISM

Central sensitization refers to an increase in the responsiveness of nociceptive neurons in the central nervous system to signals that are normally painful or to stimuli that are usually only mildly so. It may contribute to pain hypersensitivity, but its presence should not be inferred solely from the duration of symptoms (Woolf, 2011).

In other words, it concerns the gain of nociceptive processing rather than whether the signal is real or unreal. A peripheral input may continue to exist, while the response it produces becomes more intense, longer-lasting, or more widespread. Recognizing this amplification therefore amounts neither to denying a local cause nor to psychologizing the pain.

Possible manifestations include dynamic allodynia, pressure hyperalgesia, increased temporal summation, and a spread of pain sensitivity. These signs can guide clinical reasoning, but they do not on their own constitute specific proof of central sensitization.

Allodynia is pain provoked by a stimulus that is not normally painful, such as light touch or rubbing. In the pelvic region, hypersensitivity to touch may also have a local, peripheral, dermatological, or neuropathic cause. Interpretation must therefore remain clinical and differential (Woolf, 2011; Clauw, 2015).

Chronic pain may combine nociceptive, neuropathic, and nociplastic mechanisms to varying degrees. Central sensitization therefore does not replace the search for a peripheral cause and does not necessarily mean that no local structure is involved in the symptoms (Clauw, 2015; Nijs et al., 2014).

In the specific case of pudendal neuralgia, it is preferable to speak of possible central sensitization or associated hypersensitivity when the clinical findings suggest it, rather than to assert that the condition is systematically “centralized.”

The most coherent model is often bidirectional: persistent peripheral inputs may keep the alarm system active, while heightened sensitivity may lower the threshold at which posture, contact, or sitting duration become painful. The relative contribution of these two components cannot be determined from a single symptom.

5. Implications for comprehensive care

INTEGRATED APPROACH SBNFA™ HYPOTHESIS

Recognizing possible central sensitization changes the way pain is interpreted, but it does not lead to abandoning the search for peripheral factors. A comprehensive approach can simultaneously take into account mechanical loads, neuromuscular factors, sleep, activity, stress, pain-related beliefs, and coping strategies.

Interventions should be individualized and determined with qualified professionals. Depending on the clinical picture, they may include clear information about pain, a reduction in aggravating factors, a gradual return to activity, attention to the pelvic floor, and an appropriate approach to sensitization.

The literature on central sensitization generally recommends combining education, attention to peripheral factors, and strategies aimed at modulating the nervous system, rather than seeking an exclusively local solution (Nijs et al., 2011; Nijs et al., 2014).

Therapeutic communication is also an important element. Explaining that pain can be real without a visible lesion helps avoid invalidation. Care should be taken, however, not to replace diagnostic uncertainty with a single, definitive explanation.

The SBNFA™ framework can use this reading to describe an interaction between mechanical loads, pain, muscle guarding, stress, and nerve sensitivity. This framework remains an internal conceptual model and does not constitute a validated medical classification.

The distinction between structural contribution, functional mechanisms, and adaptive reserve is developed in SBNFA™ Triage: Distinguishing Structural Factors from Functional Mechanisms .

This interaction can be organized into a functional loop: pain or perceived threat → muscle guarding and reduced movement → narrower postural repertoire → less variable loading and more difficult recovery → lowered tolerance threshold → earlier onset of pain. Stress, lack of sleep, and uncertainty may reinforce the loop, without necessarily being its origin.

The conceptual aim is therefore neither to “treat only the nerve” nor to “desensitize only the brain.” It consists in identifying the contributions that are still active: peripheral factors, sitting loads, protective hypertonia, reduced variability, recovery, and neurophysiological amplification.

Scientific References