Urologists and gynaecologists regularly have patients presenting with symptoms of pudendal neuralgia (PN). PN is a recognised cause of chronic pelvic pain in the regions served by the pudendal nerve, typically presenting as pain in the penis, scrotum, labia, perineum, or anorectal region. Other symptoms may include dysuria (pain during voiding) urge incontinence and pain during or after ejaculation. There may be corresponding sexual and erectile dysfunction problems including impotence, impacting on relationships.
For the majority of these patients there is a definite urological or gynaecolocial diagnosis, such as prostadynia (prostatitis), orchialgia (testicular pain) or vulvodynia (vulva pain), although approximately 95% of men with chronic prostatitis do not have an infection.
However, a sub-group of these patients does not have a clear diagnosis. We have found that a range of these disorders can be related to musculoskeletal conditions of the lumbar-pelvic region, particularly mechanical dysfunction of intra-pelvic motion and pelvic muscle control that creates entrapment, irritation or tension of the pudendal nerve.
Many of these patients present with a range of signs and symptoms of PN. The symptoms are often associated with low back pain, with or without groin, buttock and leg symptoms. Further, a telling symptom is that the patients may complain that sitting will either bring on or make the symptoms worse, implicating musculo-skeletal and postural involvement.
These presentations demand a complete urological investigation. Once tests have excluded prostate, gynaecological, urinary or rectal pathology, patients are often referred for physiotherapy.
Clinically, we have observed that symptoms of PN are often associated with sacro-iliac joint (SIJ) dysfunctions. The pudendal nerve emerges from the sacral plexus (primarily S2,S3 and S4), and also gains contributions from the adjacent roots of S1 and S5. Because the course of the pudendal nerve relative to the SIJ is poorly describe in the literature, we dissected one embalmed male cadaver. We found that the pudendal nerve does not lie in close relationship to the SIJ, rather, it exits the pelvic cavity approximately 3cm below the SIJ, under the piriformis muscle, through the greater sciatic foramen and descends ventral to the sacrotuberous ligament. We found the nerve then passes under the sacrospinous ligament medial to the ischial spine and re-enters the pelvic cavity through the lesser sciatic foramen. It re-enters immediately adjacent to the inferior border of the sacrospinous ligament.
The pudendal nerve may be subject to many forms of trauma along its course. Many researchers suggest that entrapment causing adverse neural tension can occur between the sacrospinous and sacrotuberous ligaments or in the pudendal (or Alcocks) canal. [The Alcocks canal is a split of the fascia of the obturator internus]
We propose that the pudendal nerve could be compromised by dysfunction of the SIJ. Potential mechanisms could involve soft tissue damage resulting in stiffening of fibrotic scar tissue at the SIJ causing SIJ malalignment. The putative reasoning suggests that if physical stress causes the sacrum to nutate or the ilium to posteriorly rotate, tension is placed on the nerve as it moves between the sacrospinous and the sacrotuberous ligaments. The suggestion is that the sacrospinous ligament squeezes the pudendal nerve against the sacrotuberous ligament, causing sensitised and inappropriate pain patterns.
Of particular interest, one perineal branch of the nerve, the inferior pudendal (long scrotal nerve) curves below and in front of the ischial tuberosity, pierces the fascia lata and runs to the skin of the scrotum in the male and the labium majus in the female, scrotal pain (and labia pain) being one of the consistent symptoms of this condition.
As several of the lumbar nerves, in particular, the posterior femoral cutaneous nerve, inferior gluteal nerve, the tibial (medial popliteal) nerve, the common peroneal (lateral popliteal) nerve and the perforating cutaneous nerve, derive at least one slip from S2,S3 or S4, the patient may also complain of pain in the lower back, groin, buttocks, posterior thigh, calf or ankle. This may be referred either by neural convergence, by direct injury to the lumbar area, or by chronic SIJ damage impacting on L5S1, thereby interfering with local emitting lumbar nerves. Given the wide range of enervation of the SIJ and its adjacent neural structures, SIJ capsular stimulation may refer various pain patterns to the buttock, groin, thigh, calf or foot.
The first aim of rehabilitation is to mobilize the SIJ. This is attempted by exercises and manual (manipulative) techniques. Secondly, the aim is to regain motor-control of the muscles controlling the joint with exercises. Before exercises, heat is applied to patient’s lower back (SWD, very mildly thermal, 10 minutes). The final phase of treatment is to be absolutely critical of posture, particularly in sitting. The aim is to maintain the correct lumbar curve, often creating the need to prescribe the use of a lumbar roll.
An earlier pilot study on forty PN patients using this technique has shown an 85% success rate.
3. New Study
Peter has just completed a four year post graduate study at the University of Queensland with colleague Michel Coppieters to validate these findings.
A case series of 25 consecutive male patients referred from urologists were included in this study. Patients were treated over a three month period. Outcome measures at three months follow-up were compared to baseline data.
This case series provided Level 3 evidence that a program of motor control exercises and mobilization for the lumbar-pelvic region in patients with symptoms of pudendal neuralgia was successful in producing improvement in 95.5% of participants. Over a three month follow-up period, 39% had a recurrence of symptoms, but these could be managed by a home exercise program. 47.8% of the participants had also complained of sexual difficulties. Of these, after a three month follow-up period, 63.5% reported to be symptom free.
Note: This research paper has now been published on the British Journal of Urology International Website (Nov 2012). The full article with testing, exercises and manipulation can be viewed online at http://www.bjuinternational.com/case-studies/a-musculoskeletal-approach-for-patients-with-pudendal-neuralgia-a-cohort-study/
Peter’s research and clinical experience after treating 6000 patients has culminated in him writing a book Pelvic Pain – A musculoskeletal approach for treatment
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