Pelvic Prime's Anatomy Academy Series
Pudendal Neuralgia
Understanding Pudendal Neuralgia
Intrapelvic nerve entrapments can be difficult to diagnose because pain symptoms often mimic sciatica. Lack of awareness and a systematic approach to these nerve areas lead to underdiagnosis and mismanagement.
Pudendal neuralgia and Alcock's canal syndrome are often used interchangeably, but pudendal neuralgia can be caused by issues with the pudendal nerve or sacral nerve roots in the pelvis. Alcock's canal problems are just one type of pudendal neuralgia, making up only 8% of cases. Most nerve issues happen in more central parts of the nerve plexus, which are often overlooked.
Understanding these nerve areas and potential entrapments is crucial. Recently, a laparoscopic technique opened the door to safer, minimally invasive access to these nerves, leading to a new field called neuropelveology.
Intrapelvic Nerve Entrapment Syndrome
Nerve entrapment syndrome, or compression neuropathy, happens when a single nerve or nerve root is compressed. Symptoms include pain, tingling, numbness, and muscle weakness in the pelvic area. Since many intrapelvic nerves have both somatic and autonomic fibers, intrapelvic nerve entrapment can also cause visceral symptoms like urinary urgency, painful urination, rectal pain, and abdominal cramps.
Symptoms (usually causes 1 sided pain):
tingling
numbness
muscle weakness
sciatica with urinary symptoms
gluteal pain with perineal or penile pain
painful ejaculation
refractory urinary symptoms
pelvic pain
urinary urgency
painful urination
rectal pain
abdominal cramps
Treatment Rationale:
Nerve entrapment usually requires surgery to decompress the nerve. The sooner the treatment, the better the chances of success. Surgery helps about 40% of patients fully, while another 40% see significant improvement. About 20% may not see improvement or might get worse. Conservative methods can be tried depending on the entrapment cause. Multidisciplinary care is crucial for pain management and recovery.
Preoperative Care:
Medical Management: Pain management is important but complex and follows specific guidelines.
Physical Therapy: Pelvic physical therapists are essential for treating pudendal neuralgia. Pelvic floor dysfunction often accompanies intrapelvic nerve entrapment. Pelvic floor physiotherapy is the first-line treatment and can help non-emergent sciatica cases. Therapists use a whole-person approach to address biomechanical imbalances and provide integrated care, considering both physical and psychological aspects.
Postoperative Care:
Immediate Care: Techniques like electrotherapy and low-level laser help control pain. Hip mobilization exercises prevent postoperative fibrosis.
Physical Therapy: Reassessment at six weeks post-surgery is recommended. Therapists use manual therapy, cognitive behavioral approaches, and mindfulness to help reduce pain and restore function.
Common Entrapment Locations and Causes
Nerve entrapments in the pelvis can occur in various places, each causing specific symptoms. For example:
Proximal S2, S3, and S4 nerve roots: Pudendal neuralgia, gluteal and sciatic pain, and urinary issues.
Lumbosacral trunk: Caused by vein abnormalities, leading to cyclic pain.
Distal S2, S3, and S4 nerve roots: Similar symptoms to their proximal counterparts but less intense anorectal symptoms.
Proximal S1 and S2 nerve roots: Sciatica and perineal pain, often due to abnormal piriformis muscle fibers.
The Most Common Intrapelvic Nerve Entrapment Presentations:
Diagnosing IPNE involves understanding nerve distribution and correlating symptoms with potential nerve entrapments. Common sites include the proximal aspect of S2, S3, and S4 nerve roots.
Etiological Diagnosis: (identifying the underlying cause of a medical condition.)
Endometriosis: Endometriosis can cause intrapelvic nerve entrapment, with symptoms getting worse during ovulation and menstruation and improving after menstruation. Treatment includes identifying symptoms before surgery, locating the lesions, and removing them laparoscopically. Physical therapy before and after surgery can help improve sexual function and manage chronic pain. Techniques used in physical therapy include intravaginal manual techniques, digital biofeedback, electrotherapy, supervised pelvic floor exercises, visceral mobilizations, and low-intensity exercises like yoga.
Fibrosis: Fibrosis, often caused by surgery, is a common reason for intrapelvic nerve entrapment. Pelvic reconstructive procedures are high-risk, with 7% of women developing nerve pain after a vaginal hysterectomy for uterovaginal prolapse. Using therapeutic blocks with anesthetics and corticosteroids, along with osteopathic and physical therapy, can sometimes avoid the need for further surgery. Physical therapy helps manage symptoms by treating overactive pelvic floor tissues, manipulating connective tissue, mobilizing nerves, and modifying activities.
Neurovascular Conflict: Pelvic congestion syndrome can cause cyclic pelvic pain, which is often worse before menstruation and during pregnancy. Enlarged or malformed iliac blood vessels can entrap sacral plexus nerves, leading to sciatica or urinary and bowel dysfunction. Symptoms typically worsen throughout the day due to the swelling of pelvic veins. Conservative treatments include nerve blocks and pelvic physical therapy. Pelvic physical therapy for this condition involves pacing strategies, improving circulation, and ensuring the pelvic floor muscles work efficiently.
Piriformis Syndrome: Malformations of the piriformis muscle can entrap branches of the sciatic nerve. Intrapelvic fibers of this muscle can also entrap sacral nerve roots. The piriformis stretch test, performed by two examiners, helps diagnose this condition. Conservative treatments include piriformis stretching, botulinum toxin injections, and sometimes laparoscopic surgery to cut abnormal muscle bundles. Physical therapy focuses on reducing piriformis muscle overactivity, strengthening gluteal muscles, and modifying activities to manage symptoms.
Neoplasms: Tumors, such as schwannomas or metastatic tumors, can entrap nerves. Treatment is primarily surgical, with conservative treatment limited to general perioperative care.
References: Bo, K., Berghmans, B., Mørkved, S., & Van Kampen, M. (Eds.). (2023). Evidence-Based Physical Therapy for the Pelvic Floor (3rd ed.). Elsevier.