Intrapelvic entrapment of sacral nerve roots by abnormal bundles of the piriformis muscle: description of an extra-spinal cause of sciatica and pudendal neuralgia

Applications of Diffusion-Weighted MRI to the Musculoskeletal System

Diffusion-weighted imaging (DWI) is an established MRI technique that can investigate tissue microstructure at the scale of a few micrometers. Musculoskeletal tissues typically have a highly ordered structure to fulfill their functions and therefore represent an optimal application of DWI. Even more since disruption of tissue organization affects its biomechanical properties and may indicate irreversible damage. The application of DWI to the musculoskeletal system faces application-specific challenges on data acquisition including susceptibility effects, the low T2 relaxation time of most musculoskeletal tissues (2-70 msec) and the need for sub-millimetric resolution. Thus, musculoskeletal applications have been an area of development of new DWI methods. In this review, we provide an overview of the technical aspects of DWI acquisition including diffusion-weighting, MRI pulse sequences and different diffusion regimes to study tissue microstructure. For each tissue type (growth plate, articular cartilage, muscle, bone marrow, intervertebral discs, ligaments, tendons, menisci, and synovium), the rationale for the use of DWI and clinical studies in support of its use as a biomarker are presented. The review describes studies showing that DTI of the growth plate has predictive value for child growth and that DTI of articular cartilage has potential to predict the radiographic progression of joint damage in early stages of osteoarthritis. DTI has been used extensively in skeletal muscle where it has shown potential to detect microstructural and functional changes in a wide range of muscle pathologies. DWI of bone marrow showed to be a valuable tool for the diagnosis of benign and malignant acute vertebral fractures and bone metastases. DTI and diffusion kurtosis have been investigated as markers of early intervertebral disc degeneration and lower back pain. Finally, promising new applications of DTI to anterior cruciate ligament grafts and synovium are presented. The review ends with an overview of the use of DWI in clinical routine. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: Stage 3.

Pain Specialist Management of Sexual Pain-II: Interventional

INTRODUCTION

Treatment of female sexual pain often requires the use of diverse modalities crossing multiple medical disciplines. Interventional procedures are important in the diagnosis and treatment of female sexual pain. Pain specialists and other medical specialties can provide these capabilities.

OBJECTIVES

To provide a current summary of the procedures used in the diagnosis and treatment of female sexual pain.

METHODS

The internet, PubMed, and the Cochrane Library were searched for relevant articles on female sexual pain within the clinical purview and scope of the practice of pain management.

RESULTS

A thorough review of the literature was conducted to include basic science studies, clinical trials, systematic reviews, consensus statements, and case reports. An effort was made to also include a sampling of information on real-world patient self-directed therapies. Descriptions of interventional procedures for the diagnosis and treatment of sexual pain were made and clinical studies reviewed. The evidence for the use of various interventional treatment strategies for sexual pain was assessed.

CONCLUSIONS

The process of care for female sexual pain employs an interdisciplinary biopsychosocial model that includes a role for interventional procedures commonly performed by pain management specialists. These specialists are a resource of knowledge, skills, and abilities that can be used to improve the care of women with chronic sexual pain.

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.

Efficacy of Respiratory Training in Relieving Postoperative Pain in Patients with Spinal Nerve Root Entrapment Syndrome

Background

Breathing exercise can help patients with dyspnea to change the wrong breathing pattern, improve the degree of freedom of respiratory muscles, increase alveolar ventilation, promote breathing, and relieve the symptoms of dyspnea patients. Therefore, this study is aimed at investigating the role of breathing training in alleviating postoperative pain in patients with spinal nerve root entrapment syndrome.

Objective

To explore the effect of respiratory training in relieving postoperative pain in patients with spinal nerve root entrapment syndrome.

Methods

Fifty-eight patients with spinal nerve root entrapment syndrome treated in our hospital from May 2020 to May 2021 were analyzed retrospectively. The patients were randomly divided into a control group (n = 29) and an observation group (n = 29). The control group was given routine postoperative pain nursing, and the observation group was given respiratory training on the basis of the control group. The scores of visual analogue scale (VAS), self-rating anxiety scale (SAS), Oswestry dysfunction index questionnaire (ODI), the dosage of postoperative analgesics, and the time of first out-of-bed activity were recorded before pain nursing intervention and 3 days and 7 days after intervention.

Results

The VAS, SAS, and ODI scores of the observation group after 3 d and 7 d of intervention were lower than those of the control group. Compared with the same group, the scores of VAS, SAS, and ODI after 3 d and 7 d of intervention were lower than those before intervention, and those after 7 d of intervention were lower than those after 3 d of intervention (P < 0.05). The dosage of postoperative analgesics and the time of first out-of-bed activity in the observation group were lower than those in the control group (P < 0.05).

Conclusion

Respiratory training can effectively relieve postoperative pain, reduce anxiety, and improve spinal function in patients with spinal nerve root entrapment syndrome, which is beneficial to the prognosis of patients and is worthy of promotion.

Transvaginal pudendal nerve blocks in patients with pudendal neuralgia: 2-year follow-up results

PURPOSE

Pudendal neuralgia (PN) is an extremely painful neuropathy of the pudendal nerve resulting in a negative impact on a patient's quality of life. The aim of this study is to evaluate the 2-year outcomes of repetitive doses of the transvaginal pudendal nerve injections (PNI), and to compare the success of the PNI concerning anatomical levels (endopelvic and extrapelvic portion) of the pudendal nerve pathology.

METHODS

This retrospective longitudinal cohort study consists of patients with PN diagnosed with the first four essential Nantes criteria. Diagnostic PNI was performed on 67 patients to fulfill the fifth criteria of Nantes. A total of 56 patients who responded to the initial diagnostic PNI underwent therapeutic repeated transvaginal PNIs twice for 3 weeks apart. Mean pain intensity scores were measured using a visual analog scale at the 1st, 3rd, 6th, 12th, and 24th months after the therapeutic blocks were completed. Effectiveness of the PNIs' was defined as ≥ 50% improvement of the initial pain, and relative improvement was defined as 30-50% improvement of the initial pain. Treatment failure was defined as the reduction of the initial pain by less than 30% or the return of the pain to its worst condition.

RESULTS

The efficacy of the PNIs significantly declined over time. Pudendal nerve blocks provided a significant decrease in pain scores; however, this decrease lost its strength significantly in the 24th month. The intervention was more effective in entrapments of the pudendal nerve between sacrospinous and sacrotuberous ligaments or below (Level-2) when compared to the injuries in the endopelvic part (Level-1). More than 50% pain reduction continued in five patients with pathology at Level-1 and 24 patients with pathology at Level-2.

CONCLUSION

Repeated PNIs could provide a significant decrease in pain scores for both short- and long-term periods. However, the efficacy of the PNIs declined over 2 years. The success of PNIs may be affected by the anatomical level of the nerve injury; therefore, interligamentous pudendal nerve entrapment cases have more benefits than the cases of pudendal nerve entrapment in the endopelvic part. However, it is recommended to perform therapeutic nerve blocks even in patients with suspected endopelvic pudendal nerve pathology before the referral to surgery.