Clinical and ultrasound characteristics of deep endometriosis affecting sacral plexus.

OBJECTIVE: To describe the sonomorphological changes and appearance of deep endometriosis (DE) affecting the nervous tissue of the sacral plexus (SP). METHODS: This was a retrospective study of symptomatic patients who underwent radical resection of histologically confirmed DE affecting the SP and who had undergone preoperative transvaginal sonography (TVS) between 2019 and 2023. Lesions were described based on the terms and definitions of the International Deep Endometriosis Analysis (IDEA), International Ovarian Tumor Analysis (IOTA) and Morphological Uterus Sonographic Assessment (MUSA) groups. A diagnosis of DE affecting the SP on TVS was made when the sonographic criteria of DE were visualized in conjunction with fibers of the SP and the presence of related symptoms corresponding to sacral radiculopathy. Clinical symptoms, ultrasound features and histological confirmation were analyzed for each patient included. RESULTS: Twenty-seven patients with DE infiltrating the SP were identified in two contributing tertiary referral centers. Median age was 37 (range, 29-45) years and all patients were symptomatic and presented one or more of the following neurological symptoms: dysesthesia in the ipsilateral lower extremity (n = 17); paresthesia in the ipsilateral lower extremity (n = 10); chronic pelvic pain radiating in the ipsilateral lower extremity (n = 9); chronic pain radiating in the pudendal region (n = 8); and motor weakness in the ipsilateral lower extremities (n = 3). All DE lesions affecting the SP were purely solid tumors in the posterior parametrium in direct contact with, or infiltrating, the S1, S2, S3 and/or S4 roots of the SP. The median of the largest diameter recorded for each of the DE nodules was 35 (range, 18-50) mm. Echogenicity was non-uniform in 23 (85%) of the DE nodules, with all but one of these nodules containing hyperechogenic areas. The shape of the lesions was irregular in 24 (89%) cases. Only one lesion exhibited a lobulated form, with all other irregular lesions showing a spiculated appearance. An acoustic shadow was produced in 20 (74%) of the nodules, all of which were internal. On color or power Doppler examination, 21 (78%) of the nodules showed no signal (color score of 1). The remaining six (22%) lesions showed a minimal color content (color score of 2). According to pattern recognition, most DE nodules were purely solid, non-uniform, hypoechogenic nodules containing hyperechogenic areas, with internal shadows and irregular spiculated contours, and were poorly vascularized on color/power Doppler examination. CONCLUSION: The ultrasound finding of a parametrial, unilateral, solid, non-uniform, hypoechogenic nodule with hyperechogenic areas and possible internal shadowing, as well as irregular spiculated contours, demonstrating poor vascularization on Doppler examination in proximity to or involving the structures of the SP, indicates DE affecting the SP. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Third-Line Therapeutic Interventions for Non-Neurogenic Bladder Dysfunction in Children.

PURPOSE OF REVIEW: The aim of this article is to review considerations and efficacy of third-line treatments for pediatric non-neurogenic bladder dysfunction, including Botulinum toxin A (BoTNA), Posterior Tibial Nerve Stimulation (PTNS), and Sacral Neuromodulation (SNM). RECENT FINDINGS: Federal Drug Administration approval for use of beta-3-agonists in overactive detrusor activity in pediatric patients may provide an additional step prior to third-line therapies. New long-term data on pediatric SNM efficacy, complications, and revision rates will provide valuable information for counseling families. BoTNA offers a safe and efficacious treatment to decrease detrusor contractility and improve bladder capacity but is limited by the half-life of BoNTA agent. Percutaneous or transcutaneous PTNS offers improved voided volumes or cure in some patients but is time-intensive. SNM can be utilized in a variety of LUTD pathology with high success rate and cure but should consider cumulative anesthetic and fluoroscopic exposures for battery replacements and re-positioning for patient growth.

Visualization of sacral nerve roots and sacral plexus on gynecological transvaginal ultrasound: feasibility study.

OBJECTIVE: To investigate the feasibility of identifying and measuring the normal sacral plexus (SP) on gynecological transvaginal ultrasound (TVS) examination. METHODS: This was a prospective observational study conducted at a single tertiary gynecological referral center, including consecutive women undergoing TVS for various indications between November 2021 and January 2022. A standardized assessment of the pelvic organs was performed and the presence of any congenital or acquired uterine pathology or ovarian abnormality was recorded. Visualization of the right and left SP was attempted in all cases. The success rate and the time needed to identify the SP were recorded and measurements of the SP were made. RESULTS: A total of 326 patients were included in the study. In all women, the SP was identified successfully on at least one side. SP were visualized bilaterally in 317 (97.2% (95% CI, 94.4-98.5%)) women. Only the right SP was seen in 3/326 (0.9% (95% CI, 0.2-2.7%)) and only the left in 6/326 (1.8% (95% CI, 0.6-4.0%)) (P = 0.5048). There was no significant difference in the median time required to visualize the right vs left SP (9.0 (interquartile range (IQR), 8.0-10.0) s  vs 9.0 (IQR, 8.0-10.0) s; P = 0.0770). The median transverse diameter of the right SP was 15.0 (IQR, 14.2-15.6) mm and that of the left SP was 14.9 (IQR, 14.4-15.6) mm. CONCLUSIONS: We describe a novel method which allows for the consistent and rapid identification of the SP on TVS. Integrating assessment of the SP into routine pelvic TVS may be helpful particularly for women suffering from deep endometriosis. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Surgical Neuropelveology: Laparoscopic Nerve-sparing Excision of a Pelvic Schwannoma.

STUDY OBJECTIVE: To show how advanced pelvic Schwannoma can be safely managed with a laparoscopic approach. DESIGN: Demonstration of the laparoscopic technique with narrated video footage. SETTING: Schwannomas are benign tumors that arise from well-differentiated Schwann cells (glial cells) of peripheral nerve sheaths. Schwannomas are nonaggressive, slow-growing, solitary masses with a low rate of malignant transformation and a low risk of recurrence after resection. They rarely occur in the pelvis, with a reported incidence of 1% to 3%. Tumors involving spinal nerve roots commonly present with radicular pain and nerve compression syndromes (Supplemental Video 1-3). This video shows the management of pelvic Schwannoma originating from the left sacral root S1 by a minimally invasive approach. INTERVENTIONS: Laparoscopic nerve-sparing excision of a pelvic Schwannoma. CONCLUSION: Historically, pelvic schwannomas have been managed mainly by laparotomy. Here, we demonstrate the feasibility and safety of a large pelvic Schwannoma excision by a minimally invasive approach.

Nerve relationships to the sacrospinous ligament: application to suspension procedures and transgluteal approaches for nerve repair and tumor removal with three case illustrations.

BACKGROUND: Transvaginal suspension procedures often use the sacrospinous ligament (SSL), which attaches onto the ischial spine (IS). However, nerve-related sequelae (e.g., sciatic nerve injury) following such procedures have been reported. Therefore, the current anatomical study was performed to better understand these relationships. Additionally, three case illustrations of patients with injury to the sciatic nerve following sacrospinous ligament suspension procedures are included to exemplify the significance of a thorough knowledge of this anatomy. METHODS: In 20 human adult cadavers (40 sides), a gluteal dissection was performed to expose the IS and SSL and regional nerves near the greater sciatic foramen. Measurements between the IS and SSL were made between these structures and surrounding nerves. RESULTS: The average distance between the IS and sciatic nerve was 1.4 cm. From this bony part, the average distance to the S1 and S2 ventral rami was 3.1 cm and 1.9 cm, respectively. From the IS to the lumbosacral trunk, pudendal nerve, nerve to obturator internus, and superior gluteal nerve, the mean distance was 4 cm, 0.5 cm, 0.7 cm, and 4.5 cm, respectively. From the SSL to the lumbosacral trunk, S1 ventral ramus, and S2 ventral ramus, there was an average distance of 4.2 cm, 1.6 cm, and 0.8 cm, respectively. Statistically, in females, the distances from the IS and SSL to the sciatic nerve, lumbosacral trunk, superior gluteal nerve, and S1 and S2 ventral rami were shorter when compared to males. CONCLUSION: An improved understanding of the relationship between the SSL and IS and nerves near the greater sciatic foramen can lead to fewer intraoperative complications during approaches to various peripheral nerves in this region. Lastly, these relationships might help better understand the nerve injuries following pelvic suspension procedures that use the SSL.

3-T MR neurography of lumbo-sacral plexus in hereditary transthyretin-related amyloidosis with polyneuropathy.

OBJECTIVES: Our aim was to evaluate the ability of magnetic resonance neurography (MRN) of the lumbo-sacral plexus (LSP) to distinguish patients with hereditary transthyretin-related amyloidosis with polyneuropathy (ATTRv-PN) from asymptomatic variant carriers (AVC) and healthy controls and to assess its prognostic value. METHODS: Three-Tesla MRN was performed in 25 consecutive ATTRv-PN patients, 18 AVC, and 10 controls including T2-w DIXON and DWI MR sequences. Two blinded readers independently assessed LSP root diameter and intraneural signal on the MRN images of each subject. MRN findings were compared between groups and correlated with clinical impairment scored on the Neuropathy Impairment Score (NIS) and the modified Polyneuropathy Disability score (mPND). RESULTS: The agreement between readers on MRN images was excellent (Cohen's kappa = 0.82). LSP root enlargement was significantly more frequent in ATTRv-PN patients compared to AVC (ratio = 4.38, p = 0.038). Increased LSP root intraneural signal on T2-w images was significantly more frequent in ATTRv-PN patients compared to AVC (ratio = 3.4, p = 0.016). In contrast, there were no MRN abnormalities in controls. In ATTRv-PN patients, LSP root enlargement was associated with higher mPND scores (p = 0.03) and increased intraneural signal on T2-w images was associated with significantly higher NIS and mPND scores (p = 0.004 and 0.02, respectively). CONCLUSIONS: MRN of the LSP can help differentiate ATTRv-PN patients from AVC. LSP root enlargement and increased intraneural signal are significantly associated with clinical impairment, suggesting potential implications for patient care. KEY POINTS: • ATTRv-PN patients showed abnormal LSP changes on MRN. • MRN of the LSP can help to differentiate ATTRv-PN patients from AVC and healthy controls. • LSP root enlargement and increased intraneural signal were significantly associated with clinical impairment in ATTRv-PN patients.

Novel anatomical findings with implications on the etiology of the piriformis syndrome.

PURPOSE: The cause of the piriformis-related pelvic and extra-pelvic pain syndromes is still not well understood. Usually, the piriformis syndrome is seen as extra-pelvic sciatica caused by the entrapment of the sciatic nerve by the piriformis in its crossing through the greater sciatic foramen. However, the piriformis muscle may compress additional nerve structures in other regions and cause idiotypic pelvic pain, pelvic visceral pain, pudendal neuralgia, and pelvic organ dysfunction. There is still a lack of detailed description of the muscle origin, topography, and its possible relationships with the anterior branches of the sacral spinal nerves and with the sacral plexus. In this research, we aimed to characterize the topographic relationship of the piriformis with its surrounding anatomical structures, especially the anterior branches of the sacral spinal nerves and the sacral plexus in the pelvic cavity, as well as to estimate the possible role of anatomical piriformis variants in pelvic pain and extra-pelvic sciatica. METHODS: Human cadaveric material was used accordingly to the Swiss Academy of Medical Science Guidelines adapted in 2021 and the Federal Act on Research involving Human Beings (Human Research ACT, HRA, status as 26, May 2021). All body donors gave written consent for using their bodies for teaching and research. 14 males and 26 females were included in this study. The age range varied from 64 to 97 years (mean 84 ± 10.7 years, median 88). RESULTS: three variants of the sacral origin of the piriformis were found when referring to the relationship between the muscle and the anterior sacral foramen. Firstly, the medial muscle origin pattern and its complete covering of the anterior sacral foramen by the piriformis muscle is the most frequent anatomical variation (43% in males, 70% in females), probably with the most relevant clinical impact. This pattern may result in the compression of the anterior branches of the sacral spinal nerves when crossing the muscle. CONCLUSIONS: These new anatomical findings may provide a better understanding of the complex piriformis and pelvic pain syndromes due to compression of the sacral spinal nerves with their somatic or autonomous (parasympathetic) qualities when crossing the piriformis.

Postoperative Outcomes after Surgery for Deep Endometriosis of the Sacral Plexus and Sciatic Nerve: A 52-patient Consecutive Series.

STUDY OBJECTIVE: To assess 1-year postoperative outcomes of surgery for deep endometriosis involving the sacral roots and sciatic nerve. DESIGN: Retrospective case series. SETTING: Three referral centers. PATIENTS: Fifty-two women. INTERVENTIONS: Surgery for deep endometriosis involving the sacral roots and sciatic nerve. MEASUREMENTS AND MAIN RESULTS: Deep endometriosis involved the sacral roots in 49 women (94.2%) and the sciatic nerve in 3 cases (5.8%). Sciatic pain (buttock or leg) was recorded in 43 women (82.7%), pudendal neuralgia in 11 women (21.2%), and leg motor weakness in 14 cases (27%). The surgical procedures carried out on the pelvic nerves included complete release and decompression (92.3%), excision of the epineurium by shaving (5.8%), and intraneural excision (1.9%). Additional major surgical procedures involved the digestive tract in 82.7% of the cases and the urinary tract in 46.2%. Rectovaginal fistula occurred in 13.5% of the cases. Self-catheterization was required in 14 cases (27%) at 3 weeks after surgery and in 3 women (5.8%) 12 months later. One-year follow-up showed significant improvement in quality of life measured using the Short-Form 36 questionnaire and standardized gastrointestinal scores. De novo hypoesthesia, hyperesthesia, or allodynia were recorded in 9 women (17.2%). The cumulative pregnancy rate was 77.2%% after natural conception in 47%. CONCLUSION: Laparoscopic management of deep endometriosis involving the sacral roots and sciatic nerve improves patients' symptoms and overall quality of life. Although pain reduction may be rapid after surgery, other sensory or motor complaints, including bladder dysfunction, may be recorded over months or years.

The majority of piriformis muscles are innervated by the superior gluteal nerve.

The piriformis muscle is clinically implicated in pain disorders, posterior approaches for total hip arthroplasty, and iatrogenic injury to the muscle and the surrounding nerves. The piriformis muscle has been said to receive innervation from L5 to S3 ventral rami with most sources using S1 and S2 ventral rami as the most common innervation this muscle. However, descriptions of the nerve in the literature are vague. Therefore, the aim of this study was to clarify the anatomy of the nerve supply to the piriformis muscle. Twenty sides from ten fresh-frozen cadavers were studied. Specifically, via anterior dissection of the sacral plexus, branches to the piriformis were identified. Once identified, the nerves to the piriformis muscle were traced proximally to clarify their origin. Nerves supplying the piriformis muscle existed on all sides. On 80% of sides, the piriformis was innervated by two to three nerves. The origin of these nerves was from the superior gluteal nerve on 14 sides (70%), inferior gluteal nerve on one side (5%), L5 ventral ramus on one side (5%), S1 ventral ramus on 17 sides (85%), and S2 ventral ramus on 14 sides (70%), respectively. The most common nerve branches to the piriformis are from the superior gluteal nerve, and the ventral rami of S1 and S2. Based on our study, a single "nerve to piriformis" does not exist in the majority of specimens thus this term should be abandoned. Clin. Anat. 32:282-286, 2019. © 2018 Wiley Periodicals, Inc.

[Schwannoma of the inferior gluteal nerve as a rare cause of gluteal radiating chronic low back pain]. / Schwannom des Nervus gluteus inferior als seltene Ursache von nach gluteal einstrahlenden chronischen Rückenschmerzen.

This is the first report of a schwannoma of the inferior gluteal nerve (IGN) as a cause of chronic low back pain in a 43-year-old man. The patient suffered from severe pain radiating to the gluteal region. He was treated for months without pain relief and was on long-term disability. Only a targeted sonographic exam revealed a hypoechoic intrapelvic mass along the course of the IGN. By tumor resection, a schwannoma was histologically confirmed. After tumor removal the patient is free of pain with all medication discontinued. He has been fully reintegrated into his professional life.

Laparoscopic Neuronavigation for Deep Lateral Pelvic Endometriosis: Clinical and Surgical Implications.

STUDY OBJECTIVE: To evaluate the clinical presentation and surgical outcome in patients with deep lateral pelvic endometriosis (dLPE). DESIGN: A retrospective multicentric study (Canadian Task Force classification II-2). SETTING: University tertiary referral centers. PATIENTS: One hundred forty-eight women with deep infiltrating endometriosis (DIE). INTERVENTIONS: Laparoscopic excision of DIE. Disease distribution was classified as follows: central pelvic endometriosis (CPE) when DIE involved 1 of the following anatomic sites: cervix, vagina, uterosacral ligaments, rectum, bladder, or pelvic peritoneum; superficial lateral pelvic endometriosis when parametria, ureters, or hypogastric plexus were involved; and dLPE in the presence of sacral plexus and/or sciatic nerve infiltration. MEASUREMENTS AND MAIN RESULTS: All patients showed CPE. LPE was detected in 116 cases (78.4%); among these, we observed dLPE in 41 patients (35.3%). dLPE occurred in 40% of women with CPE and in 72.7% of patients with hypogastric plexus involvement. Thirty women with dLPE (73.2%) received gastrointestinal or urologic resection in addition to gynecologic procedures compared with 40 patients (57.1%) without dLPE (p = .001). No differences were observed in terms of perioperative complications according to the presence of dLPE. According to univariate/multivariate analysis, chronic pelvic pain was the only predictor of dLPE (odds ratio = 3.041, p = .003). The median preoperative visual analog scale for dysmenorrhea (median = 8, range, 0-10) and dyspareunia (median = 5; range, 0-10) dropped to 0 after surgery. The median follow-up was 36 months (range, 6-66 months) with a recurrence rate of 8.8%. CONCLUSIONS: dLPE is not a rare event in women with DIE. Complete laparoscopic removal of endometriosis seems to ensure benefit in terms of recurrence rate without increased surgical morbidities.

Lymphangiomatosis: a rare entity presenting with involvement of the sacral plexus.

Lymphangiomatosis is an uncommon disease process characterized by multisystem lymphatic malformations that can involve numerous body systems, including organs, muscles, soft tissues, and bones. Involvement of the nervous system is rare and has even been previously described as a site of sparing. We present a case of a 24-year-old female with known lymphangiomatosis, presenting with acute onset of lower extremity paresthesias, weakness, and new urinary retention. MRI of the pelvis revealed lymphangiomatosis of the sacral plexus, which has not been previously reported. We will review the clinical and imaging manifestations of lymphangiomatosis and provide a differential diagnosis for masses of the lumbosacral plexus. Although lower extremity pain and weakness encountered in the emergency department or outpatient setting is most frequently caused by lumbar spine pathology, occasionally, abnormalities of the lumbosacral plexus may prove to be the cause. While peripheral nerve sheath tumors lead the differential diagnosis of tumor or tumor-like entities involving the lumbosacral plexus, lymphangiomatosis is a rare differential consideration.

Surgical anesthesia with a combination of T12 paravertebral block and lumbar plexus, sacral plexus block for hip replacement in ankylosing spondylitis: CARE-compliant 4 case reports.

BACKGROUND: Anesthesia management for patients with severe ankylosing spondylitis scheduled for total hip arthroplasty is challenging due to a potential difficult airway and difficult neuraxial block. We report 4 cases with ankylosing spondylitis successfully managed with a combination of lumbar plexus, sacral plexus and T12 paravertebral block. CASE PRESENTATION: Four patients were scheduled for total hip arthroplasty. All of them were diagnosed as severe ankylosing spondylitis with rigidity and immobilization of cervical and lumbar spine and hip joints. A combination of T12 paravertebral block, lumbar plexus and sacral plexus block was successfully used for the surgery without any additional intravenous anesthetic or local anesthetics infiltration to the incision, and none of the patients complained of discomfort during the operations. CONCLUSIONS: The combination of T12 paravertebral block, lumbar plexus and sacral plexus block, which may block all nerves innervating the articular capsule, surrounding muscles and the skin involved in total hip arthroplasty, might be a promising alternative for total hip arthroplasty in ankylosing spondylitis.

Sacral malformations: use of imaging to optimise sacral nerve stimulation.

INTRODUCTION: The success of sacral nerve stimulation, a common treatment for pelvic floor disorders, depends on correct placement of the electrodes through the sacral foramina. When the bony anatomy and topography of the sacrum and sacral spinal nerves are intact, this is easily achieved; where sacral anomalies exist, it can be challenging. A better understanding of common sacral malformations can improve the success of sacral nerve stimulation (SNS) electrode placement. MATERIAL AND METHODS: We reviewed 998 consecutive MRI scans performed to investigate low back pain in patients who had undergone CT and/or X-ray. RESULTS: Congenital sacral malformations were found in 24.1%, the most common being sacral meningeal cysts (16%) and spina bifida occulta (9.9%). Others were lumbosacral transitional vertebrae (2.5%), anterior occult meningocele (0.5%), partial sacral agenesis (0.2%) and vertebral dysplasia of S1 (0.2%). CONCLUSION: This radiologic review uncovered a high incidence of sacral malformations, and most were asymptomatic. All surgeons who perform SNS should have a basic understanding of sacral malformations, their incidence and effect on foraminal anatomy. Imaging will aid procedural planning.

Topography and landmarks for the nerve supply to the levator ani and its relevance to pelvic floor pathologies.

The aim of this study was to explore the anatomical variations of the nerve to the levator ani (LA) and to relate these findings to LA dysfunction. One hundred fixed human female cadavers were dissected using transabdominal, gluteal, and perineal approaches, resulting in two hundred dissections of the sacral plexus. The pudendal nerve and the sacral nerve roots were traced from their origin at the sacral foramina to their termination. All nerves contributing to the innervation of the LA were considered to be the nerve to the LA. Based on the spinal nerve components, the nerve to the LA was classified into the following categories: 50% (n = 100) originated from S4 and S5 (type I); 19% (n = 38) originated from S5 (type II); 16% (n = 32) originated from S4 (type III); 11% (n = 22) originated from S3 and S4 (type IV); 4% (n = 8) originated from S3, S4, and S5 (type V). Two patterns of nerve termination were observed. In 42% of specimens, the nerve to the LA penetrated the coccygeus muscle and assumed an external position along the inferior surface of the LA muscle. In the remaining 58% of specimens, the nerve crossed the superior surface of the coccygeus muscle and continued along the superior surface of the iliococcygeus muscle. Damage to the nerve to LA has been associated with various pathologies. In order to minimize injuries during surgical procedures, a thorough understanding of the course and variations of the nerve to the LA is extremely important.

Lower limb orthopedic surgery in geriatric patients under paravertebral blocks: A prospective feasibility study.

BACKGROUND: Aging causes progressive deterioration of all the organ systems. Physiological changes of aging and co-morbidities make regional anesthesia a preferred technique for this age group. Regional anesthesia with risk of hypotension and its consequences is fraught with dangers. Peripheral nerve blocks (PNBs) are much safer and give much superior post-op analgesia. The present study was undertaken to perform major lower limb orthopedic surgeries PNBs in geriatric settings. METHODS: A feasibility study was undertaken in patients above age of 60 years admitted for lower limb surgeries to undertake these surgeries under para-vertebral blocks for a period of one year from Mar 2011 to Feb 2012. RESULTS: The responses and results of 203 eligible patients averaging 69.5 years. Mean duration of surgical procedure was 174.6 min and surgical analgesia was 334.5 min. Mean time of analgesic supplementation postoperative 398.3 min. The incidence of adverse effects (hypotension) requiring intervention was 5 out of 203, failure rate 2 out of 203. CONCLUSION: All major lower limb surgeries can be done under combined lumbar and sacral plexus block with additional supplementation for the skin at the line of incision especially in case the surgery involving hip with intercostal block at 11th ICS. The study strongly recommends it as a technique of choice in geriatric cases rather than reserving it for only moribund cases.

Spinal cord stimulation of the conus medullaris for refractory pudendal neuralgia: a prospective study of 27 consecutive cases.

AIMS: Thirty percent of patients with pudendal neuralgia due to pudendal nerve entrapment obtain little or no relief from nerve decompression surgery. The objective was to describe the efficacy of spinal cord stimulation of the conus medullaris in patients with refractory pudendal neuralgia. METHODS: This prospective study, conducted by two centers in the same university city, described the results obtained on perineal pain and functional disability in all patients with an implanted conus medullaris stimulation electrode for the treatment of refractory pudendal neuralgia. Twenty-seven consecutive patients were included by a multidisciplinary pelvis and perineal pain clinic between May 2011 and July 2012. Mean follow-up was 15 months. The intervention was an insertion of a stimulation electrode was followed by a test period (lasting an average of 13 days) before deciding on permanent electrode implantation. Maximum and average perineal pain scores and the pain-free sitting time were initially compared during the test and in the long-term (paired t-test). The estimated percent improvement (EPI) was evaluated in the long-term. RESULTS: Twenty of the 27 patients were considered to be responders to spinal cord stimulation and 100% of implanted patients remained long-term responders (mean tripling of sitting time, and mean EPI of 55.5%). CONCLUSIONS: Spinal cord stimulation of the conus medullaris is a safe and effective technique for long-term treatment of refractory pudendal neuralgia. Routine use of this technique, which has never been previously reported in the literature in this type of patient, must now be validated by a larger scale study.