What is pudendal nerve entrapment?
Pudendal nerve entrapment syndrome is also known as the ‘cyclist syndrome’, as it is particularly prevalent in professional cyclists. It can also be suffered by people who spend many hours sitting on a hard saddle or due to traumatic causes, such as a complex childbirth, a fall on the ass in the coccyx area or deep sutures.
Although its prevalence is not well established, it is known to be more frequent in women than in men and especially from the fourth decade of life onwards, although it is increasingly appearing in younger individuals.
Entrapment of the pudendal nerve is an extremely painful condition. It is caused by the compression of a nerve located in the pelvic area. The pudendal nerve is the sensory and motor nerve that carries signals to and from the genitals, anal area and urethra. It is arranged in three branches: a branch leading to the rectum, a perineal branch and a branch leading to the genital area. Entrapment can occur anywhere along the course of the pudendal nerve or its branches.
Prognosis of pudendal nerve entrapment
Although pudendal nerve entrapment has no effect on life expectancy, it greatly affects quality of life because it causes pain.
It is not an uncommon pathology, but it is complicated to diagnose.
Symptoms of pudendal nerve entrapment
Pain is the most common symptom and can present in different forms:
- Pain only
- Pain with urinary symptoms (irritable bladder, obstructive urination).
- Pain with difficult defecation due to obstruction
- Pain with sexual dysfunction (dyspareunia, persistent arousal)
- Pain with urinary incontinence, anal incontinence or both.
- Neuropathic pain, i.e. pain due to a malfunction of the nervous system:
- Allodynia: non-painful stimulus that produces pain. For example, gentle pressure with a cotton ball.
- Formication: sensation of insects walking on the skin. They usually report feeling ants walking on the skin.
- Hyperalgesia: increased response to painful stimulus.
- Cutaneous changes: among the signs of autonomic fiber involvement we can observe changes in the skin of the gluteal region. It is possible to find “anserine”, “marbled” or “orange peel” looking skin.
Pudendal nerve entrapment syndrome is also known as ‘cyclist’s syndrome’.
Medical Tests for pudendal nerve entrapment
To determine the existence of nerve entrapment, other diseases such as hemorrhoids, fissures or tumors are first ruled out, which leads to a specific CT-guided nerve infiltration test.
Subsequently, a physical examination is performed, which includes:
- Rolling test: it consists of moving the skin and subcutaneous cell from the anus towards the pubis, on the path of the branches of the pudendal nerve, by performing this maneuver, pain will be reproduced in the affected area.
- Nerve compression at the level of the ischial spine or Alcock’s canal.
An Echo Doppler of the pelviperineal vessels and electrophysiological studies can be performed as complementary examinations; a study of the motor pathway (distal motor latency of the pudendal nerve) and a study of the somatic sensory pathway. Sacral reflex analysis is another diagnostic technique that can be used to measure the time it takes to trigger a contraction in the bulbo cavernosus muscle after electrically stimulating the dorsal nerve of the clitoris.
What are the causes of pudendal nerve entrapment?
- Profession, occupation or sports practice that involves prolonged sitting. This is the case of cyclists, in which an inadequate saddle can cause a permanent compression that eventually leads to the triggering of a SANP.
- Trauma, even long before the onset of symptoms.
- Vaginal delivery and episiotomy.
- Pelvic radiation therapy, causing morphological and structural changes in adjacent tissues, leading to compression of the pudendal nerve (PN).
- Congenital defects (bone, muscle, etc.) involving entrapment.
Can it be prevented?
In the case of cyclists, they can prevent pudendal nerve entrapment by taking into account the saddle they use. The importance of a proper saddle is essential for cyclists, in order to be very careful because of the contact that is maintained on the most sensitive and finest parts of connective tissue.
Treatments for pudendal nerve entrapment
As with any pathological condition, it can be said that treatment must be sequential and will begin with the least aggressive measures, starting with conservative treatments and moving on to surgical treatment as a last option.
Conservative treatments include:
- Symptomatic treatment of pain: as neuropathic pain is the main symptom, antidepressants and topical local anesthetics are used above all, since they reduce the excitability of the cells of the nervous system.
- Treatment with corticosteroid infiltrations: perineural infiltrations with corticosteroids and lidocaine/bupivacaine, in the interligamentous space and in Alcock’s canal, under fluoroscopy or computed axial tomography, lead to a remarkable improvement of symptoms in many cases, relax hypertonic sphincters, suppress bladder symptoms and normalize sexual dysfunction.
- Physiotherapeutic treatment: it is useful in contractures that are prolonged in time with the consequent muscle shortening that would lead to a lesion of the vascular-nerve bundle.
- Dry needling treatment or local lidocaine infiltrations: for the deactivation of trigger points of the affected pelvic floor muscles, which will allow the release of the trigger points and the decrease of the symptomatology.
Surgical treatment is aimed at achieving decompression of the pudendal nerve. The different surgical approaches can be transperineal, transgluteal and transischiorectal for men or transvaginal in women.
Which specialist treats it?
Different specialties such as the Pain Unit, Urology, Gynecology and/or Physiotherapy may be involved in the treatment of pudendal nerve entrapment syndrome.