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.

Effective Stretching Positions of the Piriformis Muscle Evaluated Using Shear Wave Elastography.

CONTEXT: Piriformis syndrome is often associated with muscle spasms and shortening of the piriformis muscle (PM). Physical therapy, including static stretching of the PM, is one of the treatments for this syndrome. However, the effective stretching position of the PM is unclear in vivo. This study aimed to determine the effective stretching positions of the PM using ultrasonic shear wave elastography. DESIGN: Observational study. METHODS: Twenty-one healthy young men (22.7 [2.4] y) participated in this study. The shear elastic modulus of the PM was measured at 12 stretching positions using shear wave elastography. Three of the 12 positions were tested with maximum internal rotation at 0°, 20°, or 40° hip adduction in 90° hip flexion. Nine of the 12 positions were tested with maximum external rotation at positions combined with 3 hip-flexion angles (70°, 90°, and 110°) and 3 hip-adduction angles (0°, 20°, and 40°). RESULTS: The shear elastic modulus of the PM was significantly higher in the order of 40°, 20°, and 0° of adduction and higher in external rotation than in internal rotation. The shear elastic modulus of the PM was significantly greater in combined 110° hip flexion and 40° adduction with maximum external rotation than in all other positions. CONCLUSION: This study revealed that the position in which the PM was most stretched was maximum external rotation with 110° hip flexion and 40° hip adduction.

Deep Gluteal Pain Syndrome: Endoscopic Technique and Medium-Term Functional Outcomes.

BACKGROUND: Sciatic nerve entrapment is an entity that generates disabling pain, mainly when the patient is sitting on the involved side. According to some studies, the presence of fibrovascular bands has been described as the main cause of this pathology, and the sciatic nerve's decompression by endoscopic release has been described as an effective treatment generally associated with a piriformis tenotomy. The aim of this study was to present the medium-term functional results of endoscopic release of the sciatic nerve without resection of the piriformis tendon. METHODS: This prospective, observational study included 57 patients who underwent an endoscopic operation for sciatic nerve entrapment between January 2014 and January 2019. In all cases, a detailed medical history was obtained and a physical examination and a functional evaluation were performed using the modified Harris hip score (mHHS), the 12-item International Hip Outcome Tool (iHOT-12), and the visual analog scale (VAS) for pain. All patients had pelvic radiographs and magnetic resonance imaging (MRI) scans of the hip on the involved side and underwent a prior evaluation by a spine surgeon. RESULTS: This study included 20 male and 37 female patients with a mean age of 43.6 years (range, 24 to 88 years) and a mean follow-up of 22.7 months. The median mHHS improved from 59 to 85 points. The median iHOT-12 improved from 60 to 85 points. The median VAS decreased from 7 to 2. Postoperative complications occurred in 12% of patients: 1 patient with extensive symptomatic hematoma, 3 patients with hypoesthesia, and 3 patients with dysesthesia. CONCLUSIONS: Endoscopic release of the sciatic nerve by resection of fibrovascular bands without piriformis tenotomy is a technique with good to excellent functional results comparable with those of techniques in the literature incorporating piriformis tenotomy. LEVEL OF EVIDENCE: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Deep gluteal space anatomy and its relationship with deep gluteal pain syndromes.

INTRODUCTION: Increasing interest has been seen in understanding the anatomy and biomechanics involved in the Deep Gluteal Syndrome, therefore the main objective of our paper was to define the anatomy of the deep gluteal space concerning the important osseous, muscular and neurological structures. METHODS: 12 cadaveric models (24 hemipelvises) were used. We proceeded with classical anatomic dissection and evaluated numerous osseous, musculotendinous and neurologic structures and their relationships. We also determined the femoral anteversion and neck-shaft angles. RESULTS: We found that 15.4% of lower limbs examined presented variations in the sciatic nerve (SN) emergence, and this was significantly longer in men. The distance from the SN to the trochanteric region was also significantly lower in males.The average ischiofemoral distance (IFD) was 2.5 ± 1.3 cm, at the same time that the structures comprised in that space showed superior areas, such as the quadratus femoris (QF) with 5.0 ± 1.1 cm and the SN with 1.4 ± 0.3 cm widths.Besides that, we also evaluated the distance from the SN to the lesser trochanter (LT) and the ischial tuberosity (IT), in the ischiofemoral space, reaching average values of 1.1 ± 0.7 cm and 1.5 ± 0.6 cm respectively.Regarding the relationship between the proximal hamstring insertion, we verified that the LT was at an average distance of 1.6 ± 1.1 cm, that the SN was only 0.2 ± 0.3 cm lateral to it, and the PN is just 2.6 ± 1.2 cm proximal to it. CONCLUSIONS: Our study confirmed the extreme variation in the SN origin that can contribute to the Piriformis syndrome. The IFD obtained in our study showed that this distance was small for the structures contained in this space.The proximal hamstring insertion showed a significantly more extended footprint in males, which puts the pudendal nerve (PN) at higher risk of iatrogenic injury.

Effects of ultrasound-guided platelet rich plasma injection in patients with piriformis syndrome.

BACKGROUND: Piriformis syndrome (PS) is the common entrapment neuropathy causing buttock pain. Patients are conventionally treated with lifestyle modification, exercise, non-steroidal anti-inflammatory drugs, corticosteroid or botulinum toxin injections. However, some patients may not respond to these conventional treatment methods. Platelet rich plasma (PRP) injection has been shown to be beneficial in various muscular injuries, but its effects have not yet been investigated in PS. OBJECTIVE: The aim of this study was to explore the effect of PRP on pain and functional status in patients with PS, and to identify any correlations between clinical changes and demographic features. METHODS: A total of 60 patients with PS were randomly separated into two groups (PRP and control groups). All patients received one session of either PRP or saline injection performed under ultrasound guidance. The pain was measured with a visual analog scale (VAS) and Oswestry Disability Index (ODI) scores were noted at three intervals in both groups: before treatment, 1 week after treatment and 1 month after treatment. RESULTS: The VAS and ODI scores were improved in both groups. The improvement was more obvious in the PRP group in the first week, and the results were similar for both groups when measured 1 month after the treatment. CONCLUSION: Ultrasound-guided PRP injection provided greater improvements in both pain and functional status in patients with PS, starting in the early period after treatment. A repeat injection might be needed for a long-term effect.

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.

Effect of integrated neuromuscular inhibition technique compared with positional release technique in the management of piriformis syndrome.

CONTEXT: Studies have indicated that the muscle energy technique (MET) and the positional release technique (PRT) are effective in the management of piriformis syndrome (PS); however, evidence is scarce regarding the combination of these techniques in the form of an integrated neuromuscular inhibition technique (INIT) in the management of individuals with PS. Although a previous trial investigated the effect of INIT for PS, that study did not integrate Ruddy's reciprocal antagonist facilitation (RRAF) method into the INIT protocol, nor did the authors diagnose PS according to established criteria. OBJECTIVES: To examine the effects of INIT with integrated RRAF compared with PRT in the management of patients diagnosed with PS. METHODS: This study was designed as a single blind randomized clinical trial in which participants diagnosed with PS were randomly allocated into INIT and PRT groups. Each group attended two treatment sessions per week for 8 weeks. Patients in the INIT group received a protocol in which the patient's tender point or trigger point was palpated in the belly of the piriformis approximately halfway between the inferior lateral angle of the sacrum and the greater trochanter, at which point the therapist applied an intermittent or sustained pressure and maintained the pressure for 20-60 seconds (depending on the participant's response to pain reduction). For INIT patients, that protocol was also followed by RRAF, a method in which a patient introduces a series of tiny/miniature contractions or efforts (20 times per 10 seconds) against a therapist's resistance. Patients in the PRT group were treated by palpating the same trigger point described in the INIT group, followed by application of light pressure at the location of the trigger point, which was maintained the pressure for 2 minutes or until the pain subsided (determined by asking the participant to report a pain score using a visual analog scale at 30 second intervals). For both groups, three repetitions of the INIT or PRT treatment were performed over 10 minutes at each clinical visit. Additionally, each group also received stretching exercises immediately after the INIT or PRT treatment session. Each participant was assessed at baseline, immediately posttreatment, and at 4 months posttreatment for pain, sciatica, functional mobility, quality of life, hip abduction, and internal rotation. A repeated measures analysis of variance (ANOVA) of within-between group interactions was used to analyze the treatment effect. RESULTS: Forty eight participants (age range, 25-47 years; mean age ± standard deviation, 32.81 ± 3.27 years) were randomized into the INIT and PRT groups, with 24 participants in each group. No significant between-group differences (p>0.05) were observed in the baseline demographic and clinical variables of the participants. A repeated-measures ANOVA indicated that there was a significant time effect for all outcomes, with a significant interaction between time and intervention (p<0.001). The Bonferroni post hoc analyses of time and intervention effects indicated that the INIT group improved significantly compared with the PRT group in all outcomes (p<0.05) immediately posttreatment and at the 4 months follow up period. CONCLUSIONS: INIT was more effective than PRT in the management of individuals with PS. It should be noted the significant improvement achieved in both the groups may have also been contributed to by the stretching exercises that were used as adjunct therapies by both groups.

Little needle-scalpel for piriformis syndrome: A protocol for systematic review and meta-analysis.

BACKGROUND: Piriformis syndrome (PS) is a condition in which the sciatic nerve is compressed when passing through the inferior mouth of the piriformis muscle, mainly caused by pain in one hip and leg. In severe cases, patients may experience severe buttock and lower limb pain, discomfort, difficulty walking, and claudication. It is estimated that the annual incidence of low back pain and sciatica is about 40 million cases, and the annual incidence of piriformis syndrome is about 2.4 million cases. The aim of this systematic review is to assess the effectiveness and safety of Little needle-scalpel therapy for Piriformis syndrome. METHODS: Two reviewers will electronically search the following databases: the Cochrane Central Register of Controlled Trials (CENTRAL); PubMed; EMBASE; China National Knowledge Infrastructure (CNKI); Chinese Biomedical Literature Database (CBM); Chinese Scientific Journal Database (VIP database); and Wan-Fang Database from the inception, without restriction of publication status and languages. Additional searching including researches in progress, the reference lists, and the citation lists of identified publications. Study selection, data extraction, and assessment of study quality will be performed independently by 2 reviewers. If it is appropriate for a meta-analysis, RevMan 5.4 statistical software will be used; otherwise, a descriptive analysis will be conducted. Data will be synthesized by either the fixed-effects or random-effects model according to a heterogeneity test. The results will be presented as risk ratio (RR) with 95% confidence intervals (CIs) for dichotomous data and weight mean difference (WMD) or standard mean difference (SMD) 95% CIs for continuous data. RESULTS: This study will provide a comprehensive review of the available evidence for the treatment of Little needle-scalpel with piriformis syndrome. CONCLUSIONS: The conclusions of our study will provide an evidence to judge whether Little needle-scalpel is an effective and safe intervention for patients with piriformis syndrome. ETHICS AND DISSEMINATION: This systematic review will be disseminated in a peer-reviewed journal or presented at relevant conferences. It is not necessary for a formal ethical approval because the data are not individualized. TRIAL REGISTRATION NUMBER: INPLASY2020110092.

Effects of ELDOA and post-facilitation stretching technique on pain and functional performance in patients with piriformis syndrome: A randomized controlled trial.

BACKGROUND: Piriformis syndrome (PS) is a neuro-muscular condition, which is often underdiagnosed in clinical settings. This study will determine the effects of myofascial stretching Elongation Longitudinaux Avec Decoaption Osteo Articulaire (ELDOA) and post-facilitation stretching of the piriformis muscle in patients with PS. OBJECTIVE: We aimed to compare the effects of ELDOA and post-facilitation stretching of the piriformis muscle on pain, muscle length and functional performance in patients with PS. METHODS: A randomized clinical trial was conducted with 40 PS patients including both males and females, between the ages of 30-70. Patients were randomly assigned to the ELDOA or post-facilitation group after assessments with the Numeric Pain Rating Scale (NPRS), Lower Extremity Functional Scale (LEFS), Piriformis Length Test and Straight Leg Raise (SLR). The assessments were done at baseline and at the end of the sixth week of treatment. RESULTS: The patients treated with ELDOA demonstrated significant improvement in pain (pre = 7.00 ± 2.75, post = 3.00 ± 1.75), piriformis length (pre = 27.6 ± 5.54, post = 36.8 ± 3.13), SLR (pre = 36.40 ± 7.24, post = 67.5 ± 8.36) and LEFS (pre = 26.90 ± 12.24, post = 58.10 ± 8.62), as compared with the group treated with post-facilitation stretching: pain: pre = 6.00 ± 1.00, post = 2.00 ± 1.50; piriformis length: pre = 28.55 ± 4.03, post = 38.8 ± 2.70; SLR: pre = 40.60 ± 7.48, post = 74.25 ± 5.19, and LEFS: pre = 25.20 ± 7.66, post = 66.30 ± 7.27). CONCLUSION: It can be concluded that the post-facilitation stretching technique shows more improvement in pain, muscle length, SLR, and LEFS in patients with PS as compared to ELDOA.

A new treatment modality in piriformis syndrome: Ultrasound guided dry needling treatment.

Piriformis syndrome is a painful entrapment neuropathy caused by compression of the sciatic nerve under piriformis muscle for structural or acquired reasons. Myofascial pain syndrome is the most common cause. There are physical therapy modalities, stretching exercises, injection therapies and medical treatment approaches.In this case, we planned to demonstrate a different perspective to the treatment of piriformis syndrome with the ultrasound-guided dry needling treatment.

[Effect of elongated-needle by Hui-puncture method on piriformis syndrome].

OBJECTIVE: To observe the clinical effect of elongated needle by Hui-puncture method in the treatment of piriformis syndrome. METHODS: A total of 100 piriformis syndrome patients were randomly divided into routine acupuncture group (n＝50) and elongated needle by Hui-puncture method (Hui-puncture) group (n＝50). For patients of the routine acupuncture group, Huantiao (GB30), Juliao (GB29), Zhibian (BL54), Weizhong (BL40), Yanglingquan (GB34), Juegu (GB39) and Ashi-point on the affected side of the body were punctured with filiform needles for 30 min. And for those of the Hui-puncture group, elongated needles were respectively inserted into GB30 and Ashi-point. The treatment was conducted once every other day for 10 times. The visual analog scale (VAS) pain score and the severity scores of symptoms (hip pain, lower limb pain, walking ability, straight leg elevation test, piriformis muscle tension test, piriformis muscle tenderness, 0-15 points) were measured before and after the treatment. The therapeutic effect was assessed by Criteria for Diagnosis and Assessment of Therapeutic Effect of Syndromes or Illnesses of Traditional Chinese Medicine (1994). RESULTS: After the treatment, the scores of symptoms and VAS scores of both routine acupuncture and Hui-puncture groups were significantly decreased in comparison with their own pre-treatment (P<0.05), and the scores of the two indexes of the Hui-puncture group were evidently lower than those of the routine acupuncture group (P<0.05). Of the two 50 cases in the routine acupuncture and Hui-puncture groups, 39 and 47 were effective, with the effective rate being 78.00% and 94.00%, respectively. The comprehensive therapeutic effect of the Hui-puncture group was significantly superior to that of the routine acupuncture group (P<0.05). CONCLUSION: Elongated-needle by Hui-puncture method has significant effect in treating piriformis syndrome patients and is worthy of promotion.

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.

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.

Piriformis Pyomyositis Presenting as Migratory Hip to Knee Pain: A Case Report.

CASE: The authors report a case of piriformis pyomyositis in a teenage female patient with fever and left hip pain. Her pain migrated to the knee with concurrent near resolution of hip pain. Imaging revealed an abscess in the left piriformis with pus tracking along the sciatic nerve sheath. This was complicated by internal iliac vein thrombosis and an embolus to the lung. Open drainage was performed, followed by outpatient intravenous cloxacillin and oral warfarin, with complete resolution of symptoms. CONCLUSION: Piriformis pyomyositis is a rare condition with varying presentations. The threshold for suspicion should be low even in healthy young individuals.

Ultrasound-guided dry needling decreases pain in patients with piriformis syndrome.

INTRODUCTION: Piriformis muscle syndrome (PMS) is a disorder that can lead to symptoms of buttock pain and limited hip-joint mobility, and may have an impact on quality of life. METHODS: Thirty-two patients with PMS were randomized to the treatment group, which included three sessions of ultrasound-guided dry needling (DN) of the piriformis muscle (n = 16), or a waitlist control group (n = 16). The primary outcome was pain intensity measured on the visual analog scale recorded at baseline and then at 72 hours and 1 week after treatment. RESULTS: At 1-week follow-up, pain intensity was significantly less in the DN group than in the waitlist control group (-2.16 [-1.01 to -3.32], P = .007) by an amount consistent with clinically meaningful improvement. DISCUSSION: The findings suggest that DN resulted in clinically meaningful short-term improvement in pain intensity of patients with PMS.

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.

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.

Letter to the editor involving the article 'Piriformis muscle syndrome: A cross-sectional imaging study in 116 patients and evaluation of therapeutic outcome'.

KEY POINTS: • Lack of use of local injection test to confirm the diagnosis may lead to miss the diagnosis of PMS of myofascial origin. • Piriformis muscle syndrome should be diagnosed on the basis of clinical symptoms, specific physical examinations, and positive response to local injection. • Sciatic nerve entrapment is not a must in the diagnosis of PMS and PMS is mostly myofascial in origin.

Piriformis muscle syndrome: A cross-sectional imaging study in 116 patients and evaluation of therapeutic outcome.

OBJECTIVES: To increase the clinical awareness of piriformis muscle syndrome (PMs) by reporting cross-sectional imaging findings, the clinical impact of imaging studies and treatment outcome. METHODS: Within a 10-year-period, 116 patients referred for radiological evaluation of clinically suspected PMs, with excluded lumbar pathology related to symptomatology, were prospectively studied with MRI and/or computed tomography (CT). Piriformis muscle (PM), sciatic nerve (SN), piriformis region and sacroiliac joints were evaluated. PMs was categorised into primary/secondary, according to a reported classification system. Treatment decisions were recorded. Outcome was categorised using a 3-point-scale. RESULTS: Seventy-four patients (63.8%) exhibited pathologies related to PMs. Primary causes were detected in 12 and secondary in 62 patients. PM enlargement was found in 45.9% of patients, abnormal PM signal intensity/density in 40.5% and sciatic neuritis in 25.7%. Space-occupying lesions represented the most common related pathology. Treatment proved effective in 5/8 patients with primary and 34/51 patients with secondary PMs. In 34 patients, imaging revealed an unknown underlying medical condition and altered treatment planning. CONCLUSIONS: Secondary PMs aetiologies appear to prevail. In suspected PMs, PM enlargement represented the most common imaging finding and space-occupying lesions the leading cause. Imaging had the potential to alter treatment decisions. KEY POINTS: • In clinically suspected PMs cross-sectional imaging may reveal variable pathology. • Secondary PMs aetiologies appeared to be more common than primary. • PM enlargement represented the most common imaging finding in clinically suspected PMs. • Space-occupying lesions in the piriformis region represented the leading cause of PMs. • In clinically suspected PMs cross-sectional imaging may alter treatment planning.

Wallet Neuritis - An Example of Peripheral Sensitization.

BACKGROUND: Wallet neuritis is an example of extra-spinal tunnel neuropathy concerning sciatic nerve. Its clinical appearance often gets confused with sciatica of lumbar spine origin. Wallet- induced chronic sciatic nerve constriction produces gluteal and ipsilateral lower extremity pain, tingling, and burning sensation. It was Lutz, first describing credit-card wallet sciatica in an Attorney, surfaced on Journal of American Medical Association (JAMA), 1978; however, the condition has not been well-studied in various other occupations. CASE SUMMARY: In this write-up, we take the privilege of demonstrating wallet neuritis as an example of peripheral sensitization in three different professionals' namely specialist doctor, driver, and banker first time in Bangladesh. All the three patients' demonstrated aggravated gluteal pain with radiation on the homo-lateral lower extremity while remained seated on heavy wallet for a while, fortunately improved discontinuing such stuff with. Alongside radical wallectomy, piriformis stretching exercise on the affected side had also been recommended and found worthy in terms of pain relief. CONCLUSION: long-standing use of rear pocket wallet may compress and sensitize ipsilateral sciatic nerve, generating features resembling lumbago sciatica; thereby, remains a source of patients' misery and diagnostic illusion for pain physicians as well.