Sciatica of nondisc origin and piriformis syndrome: diagnosis by magnetic resonance neurography and interventional magnetic resonance imaging with outcome study of resulting treatment

MR Neurography of the Lumbosacral Plexus: Technique and Disease Patterns

The lumbosacral plexus (LSP) comprises a complex network of nerves supplying the pelvis and lower extremities and may be affected by a wide range of diseases. Lumbosacral plexopathy can be challenging to diagnose due to overlapping clinical presentations and difficulty performing electrodiagnostic testing of the deep pelvic structures. MRI-more specifically, MR neurography (MRN)-can readily depict most LSP segments. MRN techniques, preferably performed at 3.0 T, continue to evolve, with most protocols including two-dimensional and optionally three-dimensional, heavily T2-weighted fat-suppressed sequences. This article provides technical tips for optimizing LSP MRN, as well as an overview of various LSP-related pathologic conditions, with accompanying illustrative examples. ©RSNA, 2025 Supplemental material is available for this article. See the invited commentary by Chhabra in this issue.

Enhanced diagnostic value of adding 3D MR neurography sequence to routine lumbar spine MRI protocol: A retrospective study

Background

This study evaluates whether the inclusion of a 3D MR neurography sequence in the routine lumbar spine MRI protocol improves the diagnostic yield in patients presenting with low back pain, radiculopathy, or limb weakness.

Methods

A total of 277 lumbar spine MRIs with positive MR neurography findings were retrospectively reviewed. Standard MRI images (excluding neurography) were first categorized as normal, nearly normal, or abnormal. Subsequently, MR neurography findings were categorized into five groups i.e. Insignificant findings, Findings that increased diagnostic confidence in standard MRI results, Improved appreciation of disease severity, helped in better delineation of symptomatic site in multilevel disease, and those with significant findings seen only on MR neurography.Statistical analysis was conducted using a two-sample proportion z-test to compare the diagnostic value of standard MRI alone versus MRI with neurography.

Results

The addition of MR neurography increased diagnostic yield in over 87 % of cases (241/277 patients). Furthermore, in 20.5 % of cases (57/277), pathology was identified exclusively on MR neurography.

Conclusion

Adding MR neurography to routine lumbar spine MRI significantly enhances diagnostic accuracy, offering a symptom-targeted evaluation of spinal nerves. This addition holds promise for improving the workup of patients with low back pain.

Standardized measurement of the piriformis muscle and the proximal portion of the sacral nerve roots using transvaginal ultrasound

To identify the sonomorphological appearance and to measure the thickness of the piriformis muscle (PM) and the proximal portion of the sacral nerve roots S1-S3 in healthy premenopausal women.This prospective multicentric observational study included a consecutive series of women undergoing transvaginal sonography (TVS) at 2 tertiary gynecological referral centers. Standardized assessment of the pelvic organs was performed, followed by an attempt to visualize the right and left PM and sacral nerve roots S1-S3 at their origin in proximity to the sacral neuroforamen. Visualization rates, diameters of the muscle and nerve thickness, and the time needed to identify the PM were recorded.305 patients were included in the study. In 293 women (96.1%), the PM was identified bilaterally. The median diameter of the PM was 18.3mm on the right side and 18.4mm on the left side. S1 nerve roots were successfully identified bilaterally in 224 (73.4%) patients. Their right and left median diameters were 4.8mm. Both S2 nerves were successfully identified in 215 (70.5%) patients. Their median diameter were 4.3mm on both sides. S3 nerve roots were successfully identified in 203 (66.6%) patients. Their median diameter were 3.2mm on both sides.We describe methods which allow consistent and rapid identification of the PM and the S1-S3 sacral nerve roots using TVS. Visualization of the PM and the proximal portion of the sacral plexus may be useful regarding identification of pathological changes in PM thickness and could help to distinguish perineural cysts from other gynecological pathologies.

MR Imaging of Entrapment Neuropathies of the Hip

Entrapment neuropathies of the hip (ENH) can occur due to a variety of causes with clinical symptoms that may mimic musculoskeletal disorders. Etiologies include entrapment in a fibromuscular canal, tethering due to posttraumatic fibrosis and extrinsic compression from muscle hypertrophy or a mass. Magnetic resonance (MR) imaging enables detection and characterization of peripheral nerve pathology. In addition, MR imaging can impact both diagnostic judgment as well as therapeutic management (nonoperative and operative management) of patients with ENH. This review article will summarize the role of MR imaging in detection, characterization, and management of nerve entrapments around the hip joint.

Musculoskeletal mimics for lumbosacral radiculopathy. Part 2: Specific disorders

Lumbosacral radiculopathy is a common disorder evaluated by the electrodiagnostic medicine (EDX) consultant. Making this task difficult is the abundance of radiculopathy mimics. Peripheral neurologic mimics are common, but musculoskeletal mimics are not rare and may be less familiar to many EDX consultants. Awareness of the most common musculoskeletal mimickers-particularly key historical and physical examination features that can distinguish them from radiculopathies-can lead to an accurate diagnosis for the patient and referring provider. Part 1 of this monograph covered theoretical issues surrounding why radiculopathy mimics occur. This second part reviews the most common musculoskeletal mimics, including facet arthropathy, myofascial pain syndrome, hip pathology, greater trochanteric pain syndrome, piriformis syndrome, sacroiliac joint dysfunction, hamstring pathology, iliotibial band syndrome, and plantar fasciitis. Diagnosis of these musculoskeletal mimickers is complicated by nonspecific physical examination and imaging findings, and diagnostic injections are frequently necessary to confirm the diagnosis. Treatment for most mimickers includes physical therapy, anti-inflammatory medications, guided injections, and other conservative measures, only rarely followed by surgical intervention. EDX consultants can efficiently incorporate a few high-yield maneuvers into their physical examination based on the location of the pain to provide answers to patients presenting with a musculoskeletal mimic of a lumbosacral radiculopathy.

Assessment of the piriformis muscle and piriformis syndrome via Web of Science database: A bibliometric analysis

BACKGROUND

Piriformis syndrome, which is seen as the cause of 0.3% to 6% of low back pain, is a painful condition that occurs as a result of compression of the piriformis muscle on the sciatic nerve. Although there are many studies in the literature about piriformis syndrome, no bibliometric analysis has been found. This study aims to evaluate piriformis syndrome and conduct a bibliometric analysis of studies related to piriformis muscle and syndrome.

METHODS

This study was conducted on March 27, 2024, using data recorded in the Web of Science Core Collection Database. The search was made as "Topic = Piriformis OR Piriformis Syndrome." Accordingly, 1345 results were found, and as a result of the necessary inclusion and exclusion criteria, 961 documents remained. The data was transferred to the VOSviewer software for further analysis.

RESULTS

961 documents based on piriformis muscle or piriformis syndrome were obtained. The country with the most publications was reported to be the USA with 31.42%. Other countries are ranked at around 5% or less. While 9 of the top 10 most cited institutions are based in the USA, clinics that make significant research contributions also attract attention among these institutions. Journals that publish articles containing piriformis syndrome are prominently surgery, physical therapy, anatomy, and general medicine journals. The most repeated keywords were reported as piriformis syndrome, diagnosis, pain, muscle, sciatic nerve, and hip. In contrast, the most repeated clinical terms were reported as approach, surgery, piriformis muscle, injection, sciatica, and compression.

CONCLUSION

The findings obtained in this study are thought to be important for understanding to providing literature with new perspectives on this subject. They will also focus on the missing parts of the subject from this perspective. Also, this study would provide a novel perspective to the studies about piriformis syndrome and contribute to the researchers about the limits of the topic, and being aware of the active journals that publish papers on this issue would facilitate the work of the researchers.

Behind the Pain: Understanding and Treating Piriformis Syndrome

Piriformis syndrome (PS) is a neuromuscular condition that occurs when excessive tension or anatomical variations in the piriformis muscle compress the sciatic nerve. This compression can cause pain in the buttock that radiates down the back of the affected lower limb, often resembling sciatica. This article presents a case of a 62-year-old woman with PS, characterized by left buttock pain and paresthesia along the sciatic nerve path, unresponsive to conservative treatments. Diagnosing PS is a difficult task because its symptoms often overlap with those of other conditions, such as lumbar radiculopathy and gluteal tendinopathy. Effective management requires a combination of clinical evaluation, imaging studies, and targeted treatments. Conservative management is the mainstay of treatment, with botulinum toxin injections proving effective in cases that do not respond to standard therapies. Future research should aim to refine diagnostic criteria and investigate both surgical and non-surgical treatment options.

Unrepaired Trochanteric Bursae as a Risk Factor for Deep Gluteal Syndrome After Total Hip Arthroplasty: A Prospective Randomized Controlled Trial

BACKGROUND

The trochanteric bursae are often left unrepaired after total hip arthroplasty (THA) and they retract posteriorly over the muscle belly of the piriformis. Deep gluteal syndrome (DGS) is a multifactorial condition presenting as buttock pain and is attributed to nondiscogenic sciatic nerve irritation or impingement causes. The purpose of this study was to investigate the relationship between bursal repair and incidence of DGS in patients undergoing THA.

METHODS

This prospective randomized trial included patients treated with a THA between January and December 2022 for a diagnosis of primary osteoarthritis. Patients were randomized into 2 groups: group 1 underwent a routine bursal repair, while group 2 did not, leaving the bursae unrepaired. Follow-up was performed on the 15th, 30th, and 90th day postoperatively with clinical scores, physical examinations, and laboratory tests. In this cohort of 104 patients, mean age was 55 years (range, 26 to 88). Demographic variables as well as range of motion and overall clinical results showed no significant difference between the groups.

RESULTS

DGS rates were significantly more common in the patients who had an unrepaired bursa (group 2) both on the 30th and 90th postoperative days, while comparison of lateral trochanteric pain on palpation showed similar results between the groups.

CONCLUSIONS

DGS is common in individuals who have unrepaired trochanteric bursal tissue following a THA. Despite its higher frequency, these symptoms did not have a substantial impact on the overall clinical scores, which remained consistent across the study groups.

Importance of Sacrotuberous Ligament in Transgluteal Approach for Sciatic Nerve Entrapment in the Greater Sciatic Notch (Piriformis Syndrome)

OBJECTIVE

The efficacy of sciatic nerve decompression via transgluteal approach for entrapment of the sciatic nerve at the greater sciatic notch, called piriformis syndrome, and factors affecting the surgical outcome were analyzed.

METHODS

The outcome of pain reduction was analyzed in 81 patients with sciatic nerve entrapment who underwent decompression through a transgluteal approach. The patients were followed up for at least 6 months. The degree of pain reduction was analyzed using a numerical rating scale-11 (NRS-11) score and percent pain relief before and after last follow-up following surgery. Success was defined by at least 50% reduction in pain measured via NRS-11. To assess the degree of subjective satisfaction, a 10-point Likert scale was used. In addition, demographic characteristics, anatomical variations, and variations in surgical technique involving sacrotuberous ligamentectomy were analyzed as factors that affect the surgical outcome.

RESULTS

At a follow-up of 17.5±12.5 months, sciatic nerve decompression was successful in 50 of 81 patients (61.7%), and the pain relief rate was 43.9±34.17. Subjective improvement based on a 10-point Likert scale was 4.90±3.43. Among the factors that affect the surgical outcome, only additional division of the sacrotuberous ligament during piriformis muscle resection played a significant role. The success rate was higher in the scarotuberous ligementectomy group (79.4%) than in the non-resection group (42.6%), resulting in statistically significant difference based on average NRS-11 score, percent pain relief, and subjective improvement (p<0.05, independent t-test).

CONCLUSION

Sciatic nerve decompression is effective in pain relief in chronic sciatica due to sciatic nerve entrapment at the greater sciatic notch. Its effect was further enhanced by circumferential dissection of the sciatic nerve based on the compartment formed by the piriformis muscle and the sacrotuberous ligament in the greater sciatic notch.

Piriformis syndrome

Piriformis syndrome is a condition that is proposed to result from compression of the sciatic nerve, either in whole or in part, in the deep gluteal space by the piriformis muscle. The prevalence of piriformis syndrome depends upon the diagnostic criteria being used and the population studied but is estimated by some to be 5%-6% in all cases of low back, buttock, and leg pain and up to 17% of patients with chronic low back pain. While the sciatic nerve may pierce the piriformis muscle in about 16% of healthy individuals, this frequency is no different in those with the syndrome; thus, the relationship to this anatomic finding is unclear. The most common symptoms are buttock pain, external tenderness over the greater sciatic notch, and aggravation of the pain through sitting. Many clinical signs are reported for piriformis syndrome, but the sensitivity and specificity are unclear, in part because of the lack of a uniformly accepted case definition. In the majority of cases in the literature, it appears that the diagnosis is more ascribed to a myofascial condition rather than a focal neuropathy. Electrodiagnostic studies can be useful to exclude other causes of symptoms, but there is no well-accepted test to confirm the presence of piriformis syndrome. Ultrasound imaging may show thickening of the piriformis muscle, but further research is required to confirm that this is correlated with the clinical diagnosis. Magnetic resonance imaging and neurography may hold promise in the future, but there are not yet sufficient data to support adopting these methods as a standard diagnostic tool. The initial treatment of piriformis syndrome is typically conservative management with the general rehabilitation principles similar to other soft tissue musculoskeletal conditions. Local anesthetic, botulinum toxin, and/or corticosteroid injections have been reported by some to be beneficial for diagnostic or treatment purposes. Surgical interventions have also been used with variable success.

Diagnostic Approach to Lower Limb Entrapment Neuropathies: A Narrative Literature Review

Entrapment neuropathies of the lower limb are a misunderstood and underdiagnosed group of disorders, characterized by pain and dysesthesia, muscular weakness, and specific provoking movements on physical examination. The most frequent of these syndromes encountered in clinical practice are fibular nerve entrapment, proximal tibial neuropathy, sural nerve neuropathy, deep gluteal syndrome or sciatic nerve entrapment, and lateral femoral cutaneous nerve entrapment, also known as meralgia paresthetica. These are commonly mistaken for lumbar plexopathies, radiculopathies, and musculotendinous diseases, which appear even more frequently and have overlapping clinical presentations. A comprehensive anamnesis, physical examination, and electrodiagnostic studies should help clarify the diagnosis. If the diagnosis is still unclear or a secondary cause of entrapment is suspected, magnetic resonance neurography, MRI, or ultrasonography should be conducted to clarify the etiology, rule out other diseases, and confirm the diagnosis. The aim of this narrative review was to help clinicians gain familiarity with this disease, with an increase in diagnostic confidence, leading to early diagnosis of nerve damage and prevention of muscle atrophy. We reviewed the epidemiology, anatomy, pathophysiology, etiology, clinical presentation, and EDX technique and interpretation of the entrapment neuropathies of the lower limb, using articles published from 1970 to 2022 included in the Pubmed, MEDLINE, Cochrane Library, Google Scholar, EMBASE, Web of Science, and Scopus databases.

Looking beyond Piriformis Syndrome: Is It Really the Piriformis?

Piriformis syndrome is a common differential diagnosis related to sciatica. The following review provides a concise synopsis of the diagnosis, management, history, and alternatives to diagnosis of piriformis syndrome. A search of the literature for research articles related to piriformis syndrome and associated differential diagnosis of sciatica was conducted. A thorough review of the included articles found that the condition known as piriformis syndrome is over-diagnosed and that potential anatomic and biomechanical variations originating in the pelvic region might be related to the complaint of sciatica. The criteria for diagnosis are based on findings from both physical examination and radio imaging. Piriformis syndrome resembles a variety of clinical conditions; therefore, conduct of future studies should include development of a validated method for evaluation as well as clinical criteria for diagnosis of piriformis syndrome.

Variant Sciatic Nerve Anatomy in Relation to the Piriformis Muscle on Magnetic Resonance Neurography: A Potential Etiology for Extraspinal Sciatica

OBJECTIVE

To assess the prevalence and clinical implications of variant sciatic nerve anatomy in relation to the piriformis muscle on magnetic resonance neurography (MRN), in patients with lumbosacral neuropathic symptoms.

MATERIALS AND METHODS

In this retrospective single-center study, 254 sciatic nerves, from 127 patients with clinical and imaging findings compatible with extra-spinal sciatica on MRN between 2003 and 2013, were evaluated for the presence and type of variant sciatic nerves, split sciatic nerve, abnormal T2-signal hyperintensity, asymmetric piriformis size and increased nerve caliber, and summarized using descriptive statistics. Two-tailed chi-square tests were performed to compare the anatomical variant type and clinical symptoms between imaging and clinical characteristics.

RESULTS

Sixty-four variant sciatic nerves were identified with an equal number of right and left variants. Bilateral variants were noted in 15 cases. Abnormal T2-signal hyperintensity was seen significantly more often in variant compared to conventional anatomy (40/64 vs. 82/190; p = 0.01). A sciatic nerve split was seen significantly more often in variant compared to conventional anatomy (56/64 vs. 20/190; p < 0.0001). Increased nerve caliber, abnormal T2-signal hyperintensity, and asymmetric piriformis size were significantly associated with the clinically symptomatic side compared to the asymptomatic side (98:2, 98:2, and 97:3, respectively; p < 0.0001 for all). Clinical symptoms were correlated with variant compared to conventional sciatic nerve anatomy (64% vs. 46%; p = 0.01).

CONCLUSION

Variant sciatic nerve anatomy, in relation to the piriformis muscle, is frequently identified with MRN and is more likely to be associated with nerve signal changes and symptomatology.

Ischial osteochondroma as an unusual source of pregnancy-related sciatic pain: a case report

BACKGROUND

While most cases of sciatica result from degenerative conditions of the low back, some cases result from conditions of the hip and pelvic region. Sciatica developing in relation to pregnancy or labor also presents unique considerations.

CASE PRESENTATION

A 37-year-old African American woman with a history of hypertension and polycystic ovary syndrome presented to a chiropractor at a hospital-based outpatient clinic with a seven-week history of low back pain with radiation into the right lower extremity which began during labor. The chiropractor performed a brief trial of care, yet when the patient's symptoms worsened, ordered lumbar spine radiographs, followed by lumbar magnetic resonance imaging (MRI), which were both normal. The chiropractor then ordered hip radiographs, which were suggestive of ischial osteochondroma, and referred the patient to an orthopedic oncologist. MRI findings were compatible with an osteochondroma with associated adventitial bursitis and mass effect on the sciatic nerve. The patient initially chose conservative management with bursa aspiration and therapeutic injection. Despite initial relief, there was eventual return of symptoms. The patient elected to undergo surgical removal, with a positive outcome.

CONCLUSION

The key distinguishing features that led to a diagnosis of osteochondroma in this case included attention to the patient-reported symptoms and history, worsening of symptoms despite conservative care, and lack of explanatory findings on lumbar imaging. This case highlights the benefit of evaluating the hip and pelvis when the clinical features of sciatica cannot be ascribed to a lumbar etiology. This case also illustrates the role of a chiropractor working in an integrative health system to facilitate timely imaging and referrals to resolve a challenging diagnosis.

Piriformis syndrome: muscle thickness or volume does not correlate with response to CT-guided injection

OBJECTIVE

To determine whether size of the piriformis muscle, as characterized by either the coronal width or a segmented volume, correlates with outcomes after CT-guided injections.

MATERIALS AND METHODS

A consecutive series of 81 patients with piriformis syndrome received CT-guided injections of the sciatic nerve and piriformis muscle. Volume and thickness measurements of the piriformis were taken from T1W and T2W pre-injection images by two readers. A logistic regression was used to test volume and size effect on first injection response. A cox proportional hazards model was used to evaluate pain-free survival. Identical analyses were performed to test the effects of muscle mass abnormality, nerve abnormality, body mass index, and presence of a split sciatic nerve.

RESULTS

There were 15/94 negative responses, 31/94 possible positive responses, and 48/94 positive responses to CT-guided injection. The average pain-free survival time was 38.91 ± 64.43 days. There was no significant correlation of first injection responses with muscle thickness or volume. There was no significant correlation in pain-free survival for muscle thickness or volume. There was no significant correlation in first injection response or pain-free survival with body mass index, muscle abnormalities, nerve abnormalities, or split sciatic nerves. The intraclass correlation was excellent between the two readers for both muscle volume (0.95-0.98) and thickness (0.92-0.97).

CONCLUSION

Piriformis muscle volume or thickness did not significantly correlate with post-injection outcome (first injection response and pain-free survival). Thus, if the patient has clinical symptoms of piriformis syndrome, the size of muscle should not determine whether injection is advisable.

Nerve Entrapments in the Pelvis and Hip

Clinical symptoms of pelvic entrapment neuropathies are widely variable and frequently nonspecific, thus rendering it difficult to localize and diagnose. Magnetic resonance imaging (MRI), and in particular MR neurography, has become increasingly important in the work-up of entrapment neuropathies involving the pelvic and hip nerves of the lumbosacral plexus. The major sensory and motor peripheral nerves of the pelvis and hip include the sciatic nerve, superior and inferior gluteal nerves, femoral nerve, lateral femoral cutaneous nerve, obturator nerve, and pudendal nerve. Familiarity with the anatomy and imaging appearance of normal and pathologic nerves in combination with clinical presentation is crucial in the diagnosis of entrapment neuropathies.

Trigger Point Injections

Myofascial pain and myofascial pain syndromes are among some of the most common acute and chronic pain conditions. Many interventional procedures can be performed in both an acute and chronic pain setting to address myofascial pain syndromes. Trigger point injections can be performed with or without imaging guidance such as fluoroscopy and ultrasound; however, the use of imaging in years past has been recommended to improve patient outcome and safety. Injections can be performed using no injectate (dry needling), or can involve the administration of local anesthetics, botulinum toxin, or corticosteroids.

Endoscopic Sciatic Neurolysis for Deep Gluteal Syndrome: A Systematic Review

Deep gluteal syndrome (DGS) is an underdiagnosed condition caused by an extra-spinal entrapment of the sciatic nerve in the deep gluteal space. Symptomatic patients who fail conservative treatment require surgical decompression of the nerve either by an open or endoscopic approach. In recent times, there has been an increasing trend towards minimally invasive surgery performed with endoscopic techniques. This systematic review aimed to assess the effectiveness of endoscopic sciatic nerve decompression in the management of DGS. A comprehensive search of the PubMed, Web of Science, Cumulated Index to Nursing and Allied Health Literature (CINAHL), and SPORTDiscus databases were performed on January 3, 2022. All English-language clinical studies on DGS treated with endoscopic surgical decompression were included. The initial search criteria identified 145 articles, of which four studies were available for the final review. There was one level III evidence, while the remaining three were level IV, comprising 144 patients with a mean age of 46 years. The Coleman methodology score (CMS) was utilized to assess the quality of the studies and the mean score was 62 (range, 52 to 71). The presence of fibrovascular bands and bursal tissue was the most common cause of DGS, followed by musculotendinous structures. The average follow-up of the included studies was 26.3 months (range, 12 to 32 months). Less favorable outcomes were seen in patients with major traumatic sciatic neuropathies after fractures or open reconstructive hip surgeries. Conversion to formal open surgery was recorded in one case of DGS caused by sciatic nerve schwannoma due to poor endoscopic access. One patient developed postoperative recurrent sciatic nerve entrapment due to a foreign body reaction requiring an open decompression. Overall, the available studies reported a high degree of clinical success with a low rate of complications, albeit no high-quality studies could be identified.

Sciatic foramen anatomy and common pathologies: a pictorial review

This article reviews the relevant anatomy, imaging features on computed tomography, magnetic resonance imaging, and management of common processes involving the sciatic foramen. The anatomy of the sciatic foramen is complex and provides an important conduit between the pelvis, gluteus, and lower extremity. This paper reviewed the anatomy, common pathologies, and imaging features of this region including trauma, infection, nerve entrapment, tumor spread, hernia, and vascular anomaly.

Deep Gluteal Pain in Orthopaedics: A Challenging Diagnosis

Identifying the specific source of gluteal pain can elude the most seasoned orthopaedic diagnosticians. Patients will often present with a protracted course of symptoms, and failure to successfully identify and treat the underlying etiology leads to frustration for both patient and clinician. Pain deep in the buttocks can arise from compression, inflammation, or injury of one or more of the structures in this anatomically dense area. Although sacroiliitis, hip arthritis, and trochanteric bursitis may also masquerade as gluteal pain, sciatic nerve irritation in its various presentations causes a substantial percentage of cases. Deep gluteal syndrome, hamstring syndrome, and ischiofemoral impingement can have overlapping presentations but can be differentiated by clinical examination and judiciously placed diagnostic corticosteroid injections. Although nonsurgical management, including physical therapy, relative rest, and injections represent the mainstay of treatment, open and endoscopic surgical approaches have yielded encouraging success rates in refractory cases.

Piriformis Syndrome Masquerading as an Ischiofemoral Impingement

Hip pain can have a number of different etiologies. Ischiofemoral impingement (IFI), an etiology causing extra-articular hip pain, shares many of the same symptoms as other causes of gluteal or inguinal pain, making its diagnosis difficult. We present a case of a young female with persistent deep gluteal pain who was diagnosed with IFI based on radiographic findings; however, a diagnostic injection into the quadratus femoris did not confirm IFI as the primary pain generator. The patient subsequently failed several trials of physical therapy designed to address this diagnosis. The diagnosis was expanded to include piriformis syndrome and the modified treatment approach resulted in complete resolution of her pain. The similarities of these pathologies resulted in a delay of definitive treatment and would have potentially required unnecessary surgery. This case study highlights the diagnostic conundrum clinicians face in the evaluation of gluteal hip pain and provides an algorithm for considering alternate diagnoses when conservative management fails to achieve expected results.

The diagnostic pitfalls of lumbar disc herniation---- malignant sciatic nerve tumour: two case reports and literature review

Background

Sciatica pain is a typical symptom of lumbar disc herniation (LDH), but some neurogenic and malignant tumours surrounding the sciatic nerve can also cause similar symptoms. These tumours are often misdiagnosed or even mistreated as LDH in clinical practice.

Case presentation

In our clinical practice, we found two patients with malignant tumours who were misdiagnosed with LDH. One patient complained of pain and numbness in the right lower limb. The primary diagnosis was LDH, and the patient underwent posterior lumbar interbody fusion surgery. After the operation, the symptoms were not alleviated. Then, diffuse large B-cell lymphoma involving the soft tissue and the sciatic nerve was identified. Another patient who manifested with radiating pain in the right lower limb was diagnosed with LDH at Chengde Central Hospital. He received regular conservative treatment for approximately 6 months, but his symptoms were not relieved, and then he was referred to our hospital. A malignant peripheral nerve sheath tumour (MPNST) of the sciatic nerve was diagnosed, and he received cisplatin (DDP) chemohyperthermia.

Conclusions

Descriptions of tumour lesions involving the sciatic nerve and misdiagnosed as LDH in the literature are rare. In the reported literature, 7 patients were misdiagnosed with LDH, and all patients presented with sciatica. Among them, 4 patients only received surgical treatment, 1 patient only underwent neurolysis, and 2 patients received both surgical and chemotherapy treatment. Their low incidence and similar clinical manifestations to LDH make malignant tumours involving the sciatic nerve easy to misdiagnose. When the clinical symptoms and signs are inconsistent with the imaging findings, we need to be aware of non-discogenic sciatica, including tumours involving the sciatic nerve. Furthermore, tumours that grow near the exit of the sciatic notch may be misdiagnosed because of their deeper location and because they are covered with gluteal muscles. Sometimes sciatica caused by sciatic nerve tumours is only distal, without any radicular distribution. This pain is more severe than that caused by LDH, and this pain is not related to the position of the lumbar spine. Thus, it is beneficial to perform a detailed physical examination of the sciatic nerve to avoid this kind of misdiagnosis.

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

Piriformis syndrome is a well-known extra-spinal cause of sciatica characterized by the entrapment of the sciatic nerve by variant bundles of the piriformis muscles in the deep gluteal space. In this case series, we describe the entrapment of intrapelvic portions of the sacral nerve roots by a variant bundle of the piriformis muscle originating medially to the sacral foramina, the surgical technique for the laparoscopic treatment of this condition, and the outcomes of the first eight cases treated with this technique. Five female and three male patients presenting with sciatica, pudendal pain and lower urinary tract symptoms underwent a laparoscopic exploration of the intrapelvic portion of the sacral nerve roots and transection of the abnormal piriformis bundle. Surgical technique is demonstrated in the Supplementary Video. Clinical success was achieved in seven of the eight patients, with a reduction of pain numeric rating scale from 8.5 (±1.2; 7-10) pre-operatively to 2.1 (±2.6; 0-7), 1-year following surgery. In conclusion, entrapment of intrapelvic portions of the sacral nerve roots by variant bundles of the piriformis originating medially to the sacral foramina are an extraspinal cause of sciatica, which can be treated though a laparoscopic approach.

Laparoscopic surgical approach for the treatment of piriformis syndrome: Intrapelvic decompression technique

Introduction:

Piriformis syndrome is an uncommon disease resulting from the piriformis muscle’s compression of the sciatic nerve. Pain and numbness in the buttocks and down the leg are the most common symptoms. This study analyzes the laparoscopic surgical treatment of piriformis syndrome.

Methods:

We report three cases of piriformis syndrome diagnosed in our hospital. The first case was a 40 years old woman with a 7-year history of intermittent low back pain and sciatica on her right side. Hyperesthesia and cutaneous allodynia were observed in the right sciatic nerve dermatome. The second case was a 30 years old woman with a 2-year history of sciatica on her left side. The third case was a 30 years old woman with a 2-year history of sciatica on her right side. All the patients underwent laparoscopic decompression surgery, which was performed to release the sciatic nerve or sacral nerve roots.

Results:

The patients were reexamined at the postoperative 3rd and 6th months. Their visual analog scale (VAS) scores were found to be decreased from 10/10, 9/10, and 7/10 to 0/10, 1/10, and 0/10, respectively.

Conclusion:

Due to the very few cases in the literature, pelvic piriformis syndrome is an exclusively clinical diagnosis. If the sciatica is refractory to conservative treatments, laparoscopic exploration and decompression surgery of the pelvic nerves and piriformis muscle could be an option.

Deep Gluteal Syndrome: A Pain in the Buttock

ABSTRACT

While buttock pain is a common complaint in sports medicine, deep gluteal syndrome (DGS) is a rare entity. DGS has been proposed as a unifying term referring to symptoms attributed to the various pain generators located in this region. While not all-inclusive, the diagnosis of DGS allows for focus on pathology of regionally associated muscles, tendons, and nerves in the clinical evaluation and management of posterior hip and buttock complaints. An understanding of the anatomic structures and their kinematic and topographic relationships in the deep gluteal space is pivotal in making accurate diagnoses and providing effective treatment. Because presenting clinical features may be unrevealing while imaging studies and diagnostic procedures lack supportive evidence, precise physical examination is essential in obtaining accurate diagnoses. Management of DGS involves focused rehabilitation with consideration of still clinically unproven adjunctive therapies, image-guided injections, and surgical intervention in refractory cases.

Gross post-mortem and histological features in 27 horses with confirmed lumbosacral region pain and five control horses: A descriptive cadaveric study

BACKGROUND

There is a lack of understanding of the pathological and/or physiological nature of lumbosacral region pain.

OBJECTIVES

To describe the gross variations of the osseous and soft tissues of the lumbosacral region and report the histological findings of sections of nerve tissue in affected and control horses.

STUDY DESIGN

Descriptive post-mortem case series.

METHODS

All horses had undergone full clinical and gait assessment, including ridden exercise. Horses with a substantial response to infiltration of local anaesthetic solution around the sacroiliac joint regions were included in the affected group (n = 27). Horses for which the source(s) of pain was confirmed by diagnostic anaesthesia to be distant to the lumbosacral region were included in the control group (n = 5). The pelvic regions were isolated and the soft tissues were assessed grossly. Sections of the lumbosacral plexus and cranial gluteal, sciatic and obturator nerves were examined histologically. The osseous specimens were evaluated for anatomical variants and abnormalities. Data were analysed using descriptive statistics.

RESULTS

Gross discolouration of the sciatic or obturator nerves was observed in 7 (26%) affected and no control horses. Grade 3/3 histological abnormality scores were assigned in 22% of nerve sections from affected horses compared with 3% from control horses. Several osseous variants (bifid sacral spinous processes, straight-shaped sacroiliac joint surface, short arrow-shaped sacral alae, left-right asymmetry of sacral alae, sacral curvature, absence of the fourth to fifth and ankylosis of the fifth to sixth lumbar articular process joints, left-right asymmetry of caudocranial position of the fourth to fifth and lumbar-sacral articular process joints) and abnormalities (sacroiliac enthesopathy, extra ventral sacroiliac joint surface, lumbosacral symphyseal periarticular modelling, lumbosacral intertransverse joint pitting lesions) were more frequently observed in affected horses.

MAIN LIMITATIONS

Both control and affected horses may have had preclinical abnormalities.

CONCLUSIONS

Lumbosacral region pain may reflect the presence of a number of pathological changes. Neural pain may play an important role in some horses.

Imaging of peripheral nerve causes of chronic buttock pain and sciatica

Chronic buttock pain is a common and debilitating symptom, which severely impacts daily activities, sleep, and may affect athletic performance. Lumbar spine, posterior hip, or hamstring pathology are usually considered as the primary diagnoses; however, pelvic neural pathology may be a significant cause of chronic buttock pain, particularly if there are prolonged (>6 months) buttock and/or radicular symptoms. The subgluteal space is the site of most pelvic causes of neural-mediated buttock pain, primarily relating to entrapment neuropathy of the sciatic nerve (deep gluteal syndrome), although other nerves within the subgluteal space including the gluteal nerves, pudendal nerve, and posterior cutaneous nerve of thigh may also be involved. Additionally, cluneal nerve entrapment at the iliac crest may result in "pseudo-sciatica". Anatomical variants of the pelvic girdle muscles and functional factors, including muscle spasm and pelvic instability, may contribute to development of deep gluteal syndrome, along with neural senescence. Imaging findings primarily relate to the presence of sciatic neuritis and peri-sciatic pathology, including neural compression and peri-neural adhesions or fibrosis. This imaging review describes the causes, magnetic resonance imaging and ultrasound imaging findings and imaging-guided treatment of pelvic neural causes of chronic buttock pain and sciatica.

The deep gluteal (piriformis) syndrome

Piriformisa syndrome is a subgroup of the deep gluteal syndrome, an important differential diagnosis of sciatica. Piriformis is a short external rotator muscle of the hip joint passing close to the sciatic nerve as it passes through the great sciatic foramen. Compression causes numbness, ache or tingling in the buttocks, posterolateral aspect of the leg and foot. The causes of sciatic nerve entrapment in the deep gluteal syndrome are best shown by endoscopic exploration. The frequency of anatomical variants in normal subjects however, should caution that such anomalies are not necessarily the cause of symptoms.

Piriformis syndrome: pain response outcomes following CT-guided injection and incremental value of botulinum toxin injection

PURPOSE

Piriformis syndrome is a common pain condition affecting the buttock and posterior hip with or without radiation to the leg, and management of the condition involves many treatments. In this study, we hypothesize that a CT-guided injection with botulinum toxin is more effective in providing pain relief than a CT-guided injection without Botox.

METHODS

Overall, 97 consecutive patients with piriformis syndrome presented for a CT-guided injection of the piriformis muscle and perineural injection of the sciatic nerve. After the injection, the patients received a visual analog scale pain log to record their pain level until the follow-up appointment. P values of less than 0.2 were considered as confounder and adjusted by inverse probability of treatment weighting (IPTW) via propensity score. The effect of botulinum toxin on 48-hour response and duration of response was tested using weighted chi-square test and weighted Kaplan-Meier analysis.

RESULTS

There was a total of 97 patients in the study, and 111 injections, as some patients had bilateral injections. Patients in the Botox group had more 48-hour response than patients in the non-botulinum toxin group (P < 0.001 with IPTW, P = 0.005 without IPTW). Median pain-free survival was 30 days for Botox group and 1 day for non-Botox group (P = 0.059 with IPTW, P = 0.10 without IPTW).

CONCLUSION

CT-guided injections with botulinum toxin for patients with piriformis syndrome are more likely to lead to a positive response and a longer duration of response than patients who receive a CT-guided injection without botulinum toxin. We hope that this study facilitates future prospective randomized blind trials for patients with suspected piriformis syndrome.

Magnetic Resonance Neurography for Evaluation of Peripheral Nerves

Peripheral nerve injuries (PNIs) continue to present both diagnostic and treatment challenges. While nerve transections are typically a straightforward diagnosis, other types of PNIs, such as chronic or traumatic nerve compression, may be more difficult to evaluate due to their varied presentation and limitations of current diagnostic tools. As a result, diagnosis may be delayed, and these patients may go on to develop progressive symptoms, impeding normal activity. In the past, PNIs were diagnosed by history and clinical examination alone or techniques that raised concerns regarding accuracy, invasiveness, or operator dependency. Magnetic resonance neurography (MRN) has been increasingly utilized in clinical settings due to its ability to visualize complex nerve structures along their entire pathway and distinguish nerves from surrounding vasculature and tissue in a noninvasive manner. In this review, we discuss the clinical applications of MRN in the diagnosis, as well as pre- and postsurgical assessments of patients with peripheral neuropathies.

Clinico-radiological review of peripheral entrapment neuropathies - Part 2 Lower limb

PURPOSE

This review discusses the relevant anatomy, etiopathogenesis, current notions in clinical and imaging features as well as management outline of lower limb entrapment neuropathies.

METHODS

The review is based on critical analysis of the current literature as well as our experience in dealing with entrapment neuropathies of the lower limb.

RESULTS

The complex anatomical network of nerves supplying the lower extremities are prone to entrapment by a heterogenous group of etiologies. This leads to diverse clinical manifestations making them difficult to diagnose with traditional methods such as clinical examination and electrodiagnostic studies. Moreover, some of these may mimic other common conditions such as disc pain or fibromyalgia leading to delay in diagnosis and increasing morbidity. Addition of imaging improves the diagnostic accuracy and also help in correct treatment of these entities. Magnetic resonance imaging is very useful for deeply situated nerves in pelvis and thigh while ultrasound is well validated for superficial entrapment neuropathies.

CONCLUSION

The rapidly changing concepts in these conditions accompanied by the advances in imaging has made it essential for a clinical radiologist to be well-informed with the current best practices.

Complete resolution of recurrent piriformis syndrome after piriformis resection with 3 years' follow up: A case report

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Some of piriformis syndrome intractable with conservative treatment.

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Surgery was indicated for intractable piriformis syndrome.

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Piriformis resection can be a feasible option for intractable piriformis syndrome.

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Piriformis resection decrease visual analog scale in intractable piriformis syndrome.

Introduction

Piriformis syndrome (PS) is an uncommon neuromuscular condition characterized by buttock pain radiating to the leg. Although the goal of PS treatment is symptom relief, it is difficult in some patients using conservative treatment alone.

Presentation of case

A 72-year-old male underwent piriformis resection after failed sequential steroid injection of the piriformis. The patient ultimately underwent surgery for resection of the piriformis muscle and experienced satisfactory pain relief (pain reduction > 75% according to visual analog scale for at least 12 months) following surgery and in the 3-year follow-up period.

Discussion

Conservative treatment is first-choice treatment for managing PS. Surgery was indicated when the patient did not achieve satisfactory pain relief with conservative treatment. Surgical resection of the piriformis muscle has been shown to be effective and feasible.

Conclusion

Piriformis resection is effective and can be a feasible option for the treatment of PS following failure of appropriate conservative treatment(s).

Lower extremity entrapment neuropathies

Entrapment neuropathies are frequently encountered by rheumatologists, not only because they are common but also because of their association with certain rheumatological and systemic disorders. Recognizing entrapment neuropathy early can help avoid progressive neurological deficits, as well as facilitate appropriate treatment measures, which can effectively minimize a patient's symptoms. Entrapment neuropathies may be distinguished from other musculoskeletal causes of lower extremity pain by identifying characteristic patterns of weakness and/or sensory loss, so a focused bedside neurological examination is key for diagnosis. In this chapter, we review the most common entrapment neuropathies that occur in the lower extremities, review the relevant neuroanatomy, outline a diagnostic approach to distinguish them from other mimics, and highlight appropriate management options.

Dexamethasone Versus Magnesium Sulfate as an Adjuvant to Local Anesthetics in the Ultra-Sound Guided Injection of Piriformis Muscle for the Treatment of Piriformis Syndrome

Background:

Piriformis Syndrome (PS) is an underdiagnosed cause of buttock, thigh and leg pain, most probably because it is thought to be a rare cause of sciatica. PS is widely believed to be myofascial in origin.

Materials and Methods:

This prospective, randomized, controlled, double-blind study was conducted at the pain management department. 50 patients aged from 20 to 60 years old were included in this study. The selected patients were randomly allocated into 2 groups containing 25 patients each; Group D received a total of 5 mL which included 2mL lidocaine 2%, 2mL (8 mg) dexamethasone and 1mL normal saline 0.9%, and Group M received a total of 5mL which included 2mL lidocaine 2%, 3mL magnesium sulphate (MgSO4) (2.5%) . Patients demographic characteristics, baseline physical examination findings of the patients as well as the duration of pain were all recorded. Patients were re-assessed immediately after injection, 1 week, 1 month, and 3 months after the injection. Numeric Rating Scale (NRS) values were used at each evaluation time to assess the pain, while patients were in sitting, standing, and lying positions. All patients were assessed immediately and for 4 hours post-injection for any side effects related to the drugs used.

Results:

In the pre-injection time, immediately after and 1 week after injection, there were no statistically significant differences between groups D and M in pain values. While, on comparison between both groups, group M, was significantly better than group D, in NRS values 1 month and 3 months after injection. In group D, pain score values were significantly better immediately, 1 week, and 1 month after injection compared to the pre-injection values, while these values were not significantly different 3 months after injection compared with the pre-injection values. In group M, pain score values were significantly better immediately, 1 week, 1 month, and 3 months after injection compared to the pre-injection values.

Conclusion:

Magnesium sulfate was more effective, especially for long term pain relief (3 months) when compared to dexamethasone as they were used as adjuvants to lidocaine, if injected into the piriformis muscle (PM) guided by ultrasound in the management of PS refractory as initial conservative treatment.

Current advances and research in ultrasound imaging to the assessment and management of musculoskeletal disorders

Currently evidence-based practice has given scientific weight to the physical therapist profession; it is essential that all medical professional and physical therapists know the usefulness of new tools that optimize the effectiveness of their interventions and allow the growing of the scientific knowledge base. The use of ultrasound imaging (USI) by physiotherapists has evolved in recent years, consolidating as an increasingly standardized technique, low cost compared to other imaging techniques, quickly of execution, feasible and reliable tool. USI offers a wide range of opportunities in clinical practice as well as in different research areas. Therefore, ultrasound has been currently used as a diagnostic tool by physicians and in recent years there has been an expansion of the use of ultrasound equipment by non-physicians professionals such as physical therapist or physical trainers, who incorporates USI as a means of assessing musculoskeletal system architecture and composition, musculoskeletal changes in dysfunction, pain or injury conditions, as an interventional technique assisting echo-guided procedures or using the visual real-time information as a biofeedback in control motor approaches, as guiding tool in clinical decisions as well as to improve the understanding of tissue adaptations to exercise or movement. The purpose of this article is to review and provide an overview about the currently research of the USI applications and their benefits for the diagnosis and management in individuals with musculoskeletal conditions.

Posterior femoral cutaneous neuropathy in piriformis syndrome: A vascular hypothesis

Piriformis syndrome is described as a neuromuscular condition which occurs when the sciatic nerve is compressed and/or irritated by the piriformis muscle. It is characterized by acute tenderness in the buttock with sciatica-like pain radiating into the posterior aspect of the thigh, leg, and foot. The neurogenic leg and foot pain experienced with this condition is consistent with involvement of the sciatic nerve. However, the posterior thigh pain associated with piriformis syndrome is due to involvement of the posterior femoral cutaneous nerve (i.e., posterior cutaneous nerve of the thigh), which is a branch of the sacral plexus independent of the sciatic nerve. This nerve is rarely mentioned relative to piriformis syndrome even though posterior thigh pain is more prevalent in patients than leg and foot pain. In the few instances when the posterior femoral cutaneous nerve is referenced relative to piriformis syndrome the neuralgic signs associated with it are attributed to compression by piriformis. Yet, given the dramatic size difference between the sciatic and posterior femoral cutaneous nerves one would expect direct piriformis compression to impact the sciatic nerve first and produce leg/foot pain at a far greater frequency than posterior thigh pain. However, the opposite is seen in the literature, which raises the question, what underlying mechanism is responsible for this phenomenon? It is hypothesized that the prevalence of posterior femoral cutaneous nerve involvement in piriformis syndrome is due to compression of the inferior gluteal vein by a hypertrophied piriformis muscle.

Deep gluteal syndrome as a cause of posterior hip pain and sciatica-like pain

Deep gluteal syndrome is an increasingly recognized disease entity, caused by compression of the sciatic or pudendal nerve due to non-discogenic pelvic lesions. It includes the piriformis syndrome, the gemelli-obturator internus syndrome, the ischiofemoral impingement syndrome, and the proximal hamstring syndrome. The concept of the deep gluteal syndrome extends our understanding of posterior hip pain due to nerve entrapment beyond the traditional model of the piriformis syndrome. Nevertheless, there has been terminological confusion and the deep gluteal syndrome has often been undiagnosed or mistaken for other conditions. Careful history-taking, a physical examination including provocation tests, an electrodiagnostic study, and imaging are necessary for an accurate diagnosis. After excluding spinal lesions, MRI scans of the pelvis are helpful in diagnosing deep gluteal syndrome and identifying pathological conditions entrapping the nerves. It can be conservatively treated with multidisciplinary treatment including rest, the avoidance of provoking activities, medication, injections, and physiotherapy. Endoscopic or open surgical decompression is recommended in patients with persistent or recurrent symptoms after conservative treatment or in those who may have masses compressing the sciatic nerve. Many physicians remain unfamiliar with this syndrome and there is a lack of relevant literature. This comprehensive review aims to provide the latest information about the epidemiology, aetiology, pathology, clinical features, diagnosis, and treatment. Cite this article: Bone Joint J 2020;102-B(5):556-567.

Schwannomas of the sciatic nerve: A rare and neglected diagnosis. A review of the literature with two illustrative cases

OBJECTIVE

Schwannomas of the sciatic nerve, which is the largest nerve of the human body, are very rare accounting for ≤ 1% of all schwannomas. They often may raise confusion with other more common causes of sciatica, such as lumbar degenerative and inflammatory diseases or spinal tumors, which may often lead to a late correct diagnosis.

PATIENTS AND METHODS

We present two cases of sciatic nerve schwannomas that were recently treated at our Institution, and we review the pertinent English literature on this topic over the last 15 years, yielding twenty three cases to analyze.

RESULTS

Even if sciatic nerve schwannomas are a rare occurrence, a thorough clinical and radiological evaluation of the sciatic nerve should be considered whenever a sciatic pain is not otherwise explained. A positive Tinel sign and a palpable mass along the course of the sciatic nerve may be strong clues to achieve the diagnosis. Combined morphological and advanced functional MRI imaging may help to differentiate benign from malignant peripheral nerve sheath tumors, avoiding unnecessary preoperative biopsy.

CONCLUSIONS

A standard microsurgical technique guided by ultrasound and neurophysiologic monitoring, allows in most of the cases a safe removal of the tumor and very satisfactory post-operative results for the patients.

Case report and review of the potential role of the Type A piriformis muscle in dynamic sciatic nerve entrapment variant of piriformis syndrome

Piriformis syndrome (PS) is an underdiagnosed but common cause of chronic buttock pain and sciatica. Anatomical variants of the piriformis muscle and sciatic nerve have not been thought to be significant in the pathophysiology of PS however, recent description of the piriformis musculotendinous junction has identified a common variant that we believe frequently results in dynamic sciatic nerve entrapment at the infra-piriformis fossa. We performed ultrasound guided low-dose Botulinum Toxin-A (BTX-A) injection to the lower piriformis muscle belly in an elite Australian Rules football player with PS and Type A piriformis muscle to relieve symptomatic sciatic nerve compression. Positive response to targeted BTX-A piriformis muscle injections support the hypothesis that sciatic nerve compression by Type A piriformis muscles may contribute to the pathophysiology of neuropathic PS, along with other functional factors. Sciatic nerve compression due to Type A piriformis at the infra-piriformis fossa has not been described previously and is a potentially common cause of neuropathic PS, especially when combined with other functional factors such as piriformis muscle spasm/hypertrophy and sacroiliac joint counternutation.

[The piriformis syndrome-a special indication for botulinum toxin]

The piriformis syndrome (PiS) is a possible cause of gluteal pain radiating into the legs. From a pathophysiological anatomical point of view a division into primary and secondary PiS is made. A primary PiS is based on variants of the course of the sciatic nerve with respect to the piriformis muscle. A secondary PiS occurs as a result of hypertrophy, tension and hardening of the piriformis muscle. Muscular hypertrophy causes an impingement syndrome with pressure on the sciatic nerve in the infrapiriform foramen more often than course variants. A tentative diagnosis of PiS can be made based on anamnestic information, clinical signs of strain and the flexion adduction internal rotation (FAIR) test. If asymmetry or hypertrophy exists, the tentative diagnosis is substantiated with the representation of the piriformis muscle in computed tomography (CT). Thus, a CT-supported botulinum injection (BTX) into the piriformis muscle is indicated. This is a pathogenetic treatment approach leading to a reduction in volume. In most cases a single treatment is sufficient. Since there are no adverse consequences, the BTX into the piriformis muscle is also justified from a diagnostic and therapeutic point of view in cases of primary PiS if the clinical indications are clear and other causes can be ruled out. In an in-house case series the tentative diagnosis of PiS could be made for 19 patients and the effectiveness of BTX was confirmed.

Targeted Ultrasound-Guided Perineural Hydrodissection of the Sciatic Nerve for the Treatment of Piriformis Syndrome

Piriformis syndrome is a common cause of lumbar, gluteal, and thigh pain, frequently associated with sciatic nerve symptoms. Potential etiologies include muscle injury or chronic muscle stretching associated with gait disturbances. There is a common pathological end pathway involving hypertrophy, spasm, contracture, inflammation, and scarring of the piriformis muscle, leading to impingement of the sciatic nerve. Ultrasound-guided piriformis injections are frequently used in the treatment of these pain syndromes, with most of the published literature describing injection of the muscle. We describe a safe, effective ultrasound-guided injection technique for the treatment of piriformis syndrome using targeted sciatic perineural hydrodissection followed by therapeutic corticosteroid injection.

Coronal STIR sequence, a simple adjustment to routine MRI protocol for extra-spinal sciatica and sciatica-like symptoms

Background

The value of adding coronal STIR images to MR imaging of sciatica aiming to detect extra-spinal abnormalities.

Results

Additional coronal STIR images detected extra-spinal abnormalities in 20% of the patients, thereby downgraded the normal studies from 21 to 13%. The extra-spinal abnormalities included bone abnormalities (36.4%), soft tissue abnormalities (4.5%), neurological abnormalities (2.3%), gynecological abnormalities (50%), and miscellaneous (6.8%). In 6.9% of patients, the extra-spinal abnormalities explained the patients’ pain and influenced their management. Extra-spinal causes of pain significantly correlated to positive trauma and neoplasm history, normal routine protocol images, and absent nerve root impingement. Extra-spinal abnormalities were more prevalent in age groups (20–39 years).

Conclusion

Coronal STIR images (field of view: mid abdomen to the lesser trochanters) identify extra-spinal abnormalities that maybe overlooked on routine MRI protocol. It is of additional value in young adults, trauma, neoplasm, and negative routine images.

Piriformis Syndrome: A Narrative Review of the Anatomy, Diagnosis, and Treatment

Piriformis syndrome is a form of sciatica caused by compression of the sciatic nerve by the piriformis muscle. It is a relatively uncommon, but not insignificant, cause of sciatica. The diagnosis of piriformis syndrome is complicated by the large differential diagnosis of low back and buttock pain with many diagnoses having overlapping symptoms. This narrative review highlights the relevant anatomy, history, physical exam maneuvers, electrodiagnostic findings, and imaging findings that are used to diagnose piriformis syndrome. Also discussed are posterior gluteal myofascial pain syndromes that mimic piriformis syndrome. The review then outlines the different treatment options for piriformis syndrome including conservative treatment, injections, and surgical treatment. In addition, it provides the reader with a clinical framework to better understand and treat the complex, and often misunderstood, diagnosis of piriformis syndrome.

Recent Advances in Pediatric Brain, Spine, and Neuromuscular Magnetic Resonance Imaging Techniques

Magnetic resonance imaging (MRI) is a powerful radiologic tool with the ability to generate a variety of proton-based signal contrast from tissues. Owing to this immense flexibility in signal generation, new MRI techniques are constantly being developed, tested, and optimized for clinical utility. In addition, the safe and nonionizing nature of MRI makes it a suitable modality for imaging in children. In this review article, we summarize a few of the most popular advances in MRI techniques in recent years. In particular, we highlight how these new developments have affected brain, spine, and neuromuscular imaging and focus on their applications in pediatric patients. In the first part of the review, we discuss new approaches such as multiphase and multidelay arterial spin labeling for quantitative perfusion and angiography of the brain, amide proton transfer MRI of the brain, MRI of brachial plexus and lumbar plexus nerves (i.e., neurography), and T2 mapping and fat characterization in neuromuscular diseases. In the second part of the review, we focus on describing new data acquisition strategies in accelerated MRI aimed collectively at reducing the scan time, including simultaneous multislice imaging, compressed sensing, synthetic MRI, and magnetic resonance fingerprinting. In discussing the aforementioned, the review also summarizes the advantages and disadvantages of each method and their current state of commercial availability from MRI vendors.

Effect of Mannitol plus Vitamins B in the management of patients with piriformis syndrome

BACKGROUND

Piriformis syndrome (PS) is an entrapment of the sciatic nerve by the piriformis muscle, or myofascial pain from the piriformis muscle.

OBJECTIVE

The aim of this study was to investigate the effectiveness of Mannitol plus Vitamins B regime in the management of PS.

METHODS

Twenty two patients were included in this study and received 250 ml of mannitol 20% intravenous infusion for 5 days + Vitamins B (vitamin B1 10 mg + vitamin B2 10 mg + vitamin B12 50 μg PO) for 6 weeks. Clinical outcomes were assessed systematically by clinical tests (tenderness, FAIR test, Beatty's, Freiberg's and Pace's maneuver), Numeric Rating Scale (NRS), Likert Analogue Scale (LAS), and MR examination.

RESULTS

The clinical evaluations showed a significant reduction (p< 0.05) of tenderness, FAIR test, Beatty's maneuver, Freiberg's maneuver and Pace's maneuver when compared with baseline evaluation during the 3rd and 6th month follow-ups. A statistically significant improvement of pain was measured by NRS at resting (p< 0.001), at night (p< 0.001) and during activities (p< 0.001) and LAS with prolonged sitting (p< 0.001), standing (p< 0.001) and lying (p< 0.001). Concomitantly, swelling of SN revealed a significant reduction (p= 0.003) from 86.4% to 18.2%.

CONCLUSIONS

Mannitol plus Vitamins B is effective in the management of piriformis syndrome and it could be an alternative regime in treating PS.