Pudendal nerve entrapment
Pudendal nerve entrapment is an uncommon, chronic pelvic pain condition in which the pudendal nerve is entrapped and compressed. There are several different anatomic locations of potential entrapment. Pudendal nerve entrapment is an example of nerve compression syndrome.
Pudendal neuralgia refers to neuropathic pain along the course of the pudendal nerve and in its distribution. This term is often used interchangeably with pudendal nerve entrapment. However, it has been suggested that the presence of symptoms of pudendal neuralgia alone should not be used to diagnose pudendal nerve entrapment. That is because it is possible to have all the symptoms of pudendal nerve entrapment, as per the [|diagnostic criteria specified at Nantes in 2006], without actually having an entrapped pudendal nerve.
The pain is usually located in the perineum, and is worsened by sitting. Other potential symptoms include genital numbness, sexual dysfunction, bladder dysfunction or bowel dysfunction. Pudendal neuralgia can be caused by many factors including nerve compression or stretching of the nerve. Injuries during childbirth, sports such as cycling, chronic constipation and pelvic surgery have all been reported to cause pudendal neuralgia.
Management options include lifestyle adaptations, physical therapy, medications, long acting local anesthetic injections and others. Nerve decompression surgery is usually considered as a last resort. Pudendal neuralgia and pudendal nerve entrapment are generally not well-known by health care providers. This often results in misdiagnosis or delayed diagnosis. If the pain is chronic and poorly controlled, pudendal neuralgia can greatly affect a person's quality of life, causing depression.
Definitions
Pudendal neuropathy is any damage or disease process affecting the pudendal nerve, regardless of whether said disease process involves nerve entrapment and manifests as pain or not. It is an example of mononeuropathy.Pudendal neuralgia is chronic, neuropathic pain which is perceived along the course of and in the distribution of the pudendal nerve or its branches. Pudendal neuralgia is caused by some pathology affecting the pudendal nerve or its branches. The pain in pudendal neuralgia may or may not be of similar character to other medical conditions which are classified as neuralgia. One potential cause of pudendal neuralgia is pudendal nerve entrapment. In other words, pudendal nerve entrapment is a subtype of pudendal neuralgia. However, symptoms of pudendal neuralgia are also possible without any detectable entrapment of the pudendal nerve.
Therefore, pudendal neuralgia is the neuropathic pain component of a chronic pelvic pain syndrome that is sometimes, associated with compression and subsequent neuropathy of the pudendal nerve. In the literature however, "pudendal nerve entrapment" and its equivalent terms are often used synonymously with "pudendal neuralgia" and "pudendal neuropathy".
Symptoms
According to the Nantes diagnostic criteria, the presence of pain is essential for a diagnosis of pudendal nerve entrapment. Non pain symptoms include bladder, bowel and sexual dysfunctions. This is because the pudendal nerve is a mixed nerve and has sensory, motor and autonomic fibers.Pelvic pain
The pain is located in the sensory distribution of the pudendal nerve. In over 50% of cases, the pain is in the perineum, but may be located in the genital areas. Pain may also be perceived in the rectum. Pain may also involve the supra-pubic region and the sacrum. The pain may be only on one side, or on both sides. Another possible site of pain is the coccyx. The area where the pain is perceived may be influenced by the exact site of nerve impingement, anatomic variations of the nerve and its branches, and also central sensitization.The onset of pain symptoms is usually gradual without any single causative event, although sometimes the condition may appear suddenly after some trauma, a long distance trip, long distance cycling, or a surgical procedure in the region.
The character of the pain may be burning, aching, stabbing, knife-like, tearing, strangling, or shooting like an electric shock. This is typical of neuropathic pain.
There may be paresthesia.
Additionally, there may be referred as sciatic pain, or pain in the medial thigh which may indicate involvement of the obturator nerve. Pain may also be referred to the calf, foot and toes. Sometimes, pain is perceived in the region of the lower abdomen, posterior and inner thigh, or lower back.
Hyperesthesia may be present. There may be a sensation of a foreign body in the rectum or vagina.
The pain typically gets slowly worse over the course of the day.
The pain is positional and typically provoked or aggravated by sitting, and relieved by standing, lying down, or sitting on a toilet seat. If the perineal pain is positional, this suggests a tunnel syndrome. According to one opinion, pain while sitting which is relieved by standing or sitting on a toilet seat is the most reliable diagnostic parameter. Individuals with pudendal nerve entrapment may prefer to stand to get relief from pain. In those with pain on only one side, sitting on one buttock may be an adaptive behavior. Sitting on soft seats may be more painful than on hard seats.
The pain may be intense, chronic, and debilitating. The severity typically varies over time.
Urinary
There may be bladder dysfunction such as urinary incontinence, urinary frequency, dysuria, urinary urgency, or dyspareunia. There may be symptoms which are similar to interstitial cystitis.Rectal
may be present such as fecal incontinence There may be numbness of the anal region. There can be pain after defecation; typically minutes or hours later.Sexual
A systematic review found that the pudendal nerve may be implicated in various sexual dysfunctions such as persistent genital arousal disorder, erectile dysfunction / impotence, premature ejaculation, and vestibulodynia. There may be pain after ejaculation and pain after sex. Additionally, another review that looked at cycling-related sexual dysfunction suggested that cycling may indirectly cause sexual dysfunction by disturbing the testosterone signaling aspect of the hypothalamic-pituitary-gonadal axis of the body. There may be numbness of the genital area. Numbness of the penis and erectile dysfunction without neuropathic pain may be caused by pudendal nerve compression, especially in cyclists. Compression of both the pudendal nerve and the pudendal artery may be occur and cause erectile dysfunction and premature ejaculation. Persistent genital arousal disorder has been linked to minimal but chronic compression of the dorsal branch of the pudendal nerve.In cyclists
In male competitive cyclists, it is often called "cyclist syndrome". This is a rare condition in which recurrent numbness of the penis and scrotum develops after prolonged cycling. There may be altered sensation of ejaculation, disturbance of micturition, and reduced awareness of defecation. Nerve entrapment syndromes, presenting as genital numbness, are amongst the most common bicycling associated urogenital problems.Epidemiology
The exact prevalence is unknown, but pudendal nerve entrapment and pudendal neuralgia are thought to be uncommon or rare. The incidence of pudendal neuralgia was estimated as 1 in 100000 in the general population by the International Pudendal Neuropathy Association. The true number could be higher due to some cases not being correctly diagnosed. Others state that pudendal neuralgia may be over-diagnosed. According to one source, pudendal nerve entrapment is the most common cause of chronic pelvic pain. Pudendal neuropathy may occur in males and females, but is more common in females. It has been reported at any age from toddlers to 90-year-olds. 160 male cyclists who trained for a 540 km bicycle race responded to a questionnaire regarding pudendal nerve entrapment symptoms. 22% said they had symptoms of impotence. 30% reported hand numbness, which may represent entrapment of the median nerve or the ulnar nerve.Anatomy
Normal anatomy
Each person has 2 pudendal nerves; one on either side. The pudendal nerve is a mixed nerve which contains motor, sensory and sympathetic autonomic axons. It stems from the ventral rami of the sacral spinal nerves S2, S3, and S4 of the sacral plexus.The path of the pudendal nerve is very complicated. It passes through the pelvis, buttocks, and perineum. As part of the sacral plexus, the nerve fibers from S2, S3, and S4 unite together to form the pudendal nerve just above the superior border of the sacrotuberous ligament and the upper fibers of the ischiococcygeus muscle. The nerve progresses between the piriformis and coccygeus muscles and exits the pelvis by passing through the greater sciatic foramen and enters the gluteal region. In this region it passes over the back surface of sacrospinous ligament, close to its attachment to the ischial spine, where it lies medially to the internal pudendal artery and the internal pudendal vein. The pudendal nerve then re-enters the pelvic cavity through the lesser sciatic foramen into the pudendal canal. The pudendal canal is a fascial compartment located in the inferior border of the obturator internus fascia lining the lateral wall of the ischiorectal fossa. The canal runs from the ischieal spine to the posterior edge of the ischiopubic ramus. According to one report, the pudendal nerve is fixed to the dorsal surface of the sacrospinous ligament in all cases.
In the posterior part of the pudendal canal, the pudendal nerve gives off 2 branches: the inferior rectal nerve, the perineal nerve. The remaining portion of the pudendal nerve continues anteriorly and is named the dorsal sensory nerve of the penis in males or clitoris in females. The inferior rectal branch of the pudendal nerve supplies efferent motor innervation to the external anal sphincter. This branch also supplies sensation to the anal canal, where it plays a role in maintaining continence and allows discrimination of the contents of the rectum. The perineal branch and the inferior rectal nerve of the pudendal nerve supply pubococcygeus and puborectalis of the levator ani muscle. The dorsal nerve of the penis supplies sensation to the penis in males, and the dorsal nerve of the clitoris supplies sensation to the clitoris in females. By providing sensation to the penis and the clitoris, the pudendal nerve is responsible for the afferent component of penile erection and clitoral erection. The posterior scrotal nerves supply sensation to the posterior scrotum in males, and the posterior labial nerves supply sensation to the labia majora in females.