Pudendal Nerve Entrapment: Symptoms, Diagnosis and Treatment in the UK

Pudendal nerve entrapment (PNE) is a type of pudendal neuralgia where the pudendal nerve is compressed or 'trapped' as it travels through the pelvic region. This nerve is the main nerve of the perineum—the area between the tailbone and the pubic bone. It is responsible for sensation in the genitals, anus, and perineum, as well as controlling the muscles involved in urination and bowel movements.

When this nerve becomes compressed, it results in chronic, often debilitating pain. In the UK, this condition is increasingly recognised as a significant cause of chronic pelvic pain (CPP). Unlike some other forms of pelvic discomfort, the pain associated with PNE is typically 'positional', meaning it changes significantly based on whether you are sitting, standing, or lying down. According to NICE (National Institute for Health and Care Excellence), chronic pain management involves a move away from simple analgesics towards specialized neuropathic pain relief and physical therapy.

The hallmarks of pudendal nerve entrapment are sensory. British patients often describe the sensation as having a 'red hot poker' or a 'foreign object' lodged in the rectum or vagina. Common symptoms include:

• Sitting Pain: The pain is usually worse while sitting and improves or disappears entirely when standing or lying down.
• Neuropathic Pain: A burning, tingling, or electric-shock sensation in the pelvic floor, clitoris, or labia.
• Numbness: A loss of sensation in the saddle area, which can lead to sexual dysfunction.
• Urinary Urgency: A constant feeling of needing to empty the bladder, sometimes accompanied by pain during urination.
• Bowels: Pain during or after bowel movements or a feeling of rectal fullness.

Crucially, the pain of PNE rarely wakes a person up at night; most patients find relief once they are horizontal and the pressure on the nerve is removed.

In the UK, certain lifestyle factors and medical events are frequently linked to the development of PNE. The nerve can be compressed by ligaments (such as the sacrospinous or sacrotuberous ligaments) or within Alcock’s canal. Common triggers include:

1. Prolonged Sitting and Cycling

Professional or heavy recreational cyclists are at higher risk due to the sustained pressure of the saddle on the pudendal nerve. This is sometimes referred to as 'Cyclist’s Syndrome'. High-intensity spinning classes or long office hours without ergonomic support also contribute.

2. Pelvic Trauma and Surgery

Trauma to the pelvis, such as a fall onto the buttocks or a car accident, can shift structures that then compress the nerve. Additionally, surgical procedures—particularly those involving vaginal mesh or pelvic reconstructive surgery—can inadvertently lead to nerve entrapment.

3. Pregnancy and Childbirth

The physical strain of labour, particularly a prolonged second stage or an instrumental delivery (using forceps or ventouse), can stretch or compress the pudendal nerve, leading to postnatal pelvic pain that may persist if not addressed.

Pudendal nerve entrapment can be difficult to diagnose because its symptoms overlap with other conditions like interstitial cystitis or endometriosis. UK clinicians often use the 'Nantes Criteria' to help identify the condition. Diagnostic steps usually include:

• Clinical History: Your GP will ask about the positional nature of your pain.
• Internal Examination: A specialist pelvic physiotherapist or doctor may perform an internal exam to check for specific 'trigger points' along the course of the pudendal nerve.
• Diagnostic Nerve Block: A local anaesthetic is injected near the nerve. If the pain is immediately relieved, it strongly suggests the pudendal nerve is the source of the trouble.
• MRI Proctogram or Neurography: While standard MRIs often look normal, specialised imaging can sometimes show nerve thickening or entrapment points.

Treatment for PNE in the UK follows a 'stepped care' approach, starting with the least invasive methods as per NHS guidance.

Pelvic Floor Physiotherapy

This is often the first line of defence. Specialist physiotherapists can use internal release techniques to relax the muscles (such as the obturator internus) that may be compressing the nerve. They also provide 'nerve gliding' exercises.

Lifestyle Modifications

Using a 'pudendal cushion' (a U-shaped or doughnut-shaped cushion with a cut-out in the centre) can allow you to sit without putting pressure on the perineum. Avoiding heavy lifting and high-impact exercise is also recommended during the recovery phase.

Neuropathic Medication

Standard paracetamol or ibuprofen are rarely effective for nerve pain. Instead, doctors may prescribe amitriptyline, gabapentin, or pregabalin, which work by altering the way the brain processes pain signals.

Surgery

If conservative measures fail after 6-12 months, pudendal nerve decompression surgery may be considered to physically free the 'trapped' nerve. This is a specialist procedure performed at a few tertiary centres in the UK.

Navigating chronic pelvic pain can be frustrating and isolating. If you are experiencing pain when sitting that is affecting your quality of life, you can speak to a GP online today. An online GP can provide a calm, evidence-based assessment of your symptoms from the comfort of your home.

During a GP consultation, your doctor can:

• Review your symptoms against the Nantes Criteria.
• Discuss initial pain management strategies and prescribe neuropathic medications if appropriate.
• Advise on lifestyle changes, such as the best types of seating or activity modifications.
• Provide a referral letter to a UK-based specialist pelvic physiotherapist or a gynaecology consultant for further investigation.

Early intervention is key to preventing the nerve pain from becoming a chronic, 'centralised' pain syndrome.