Meralgia paresthetica: relation to obesity, advanced age, and diabetes mellitus

Analysis of outcome reporting in lateral femoral cutaneous neuropathy studies: A systematic review of the literature

PURPOSE

As a first step towards developing a core outcome set (COS) for lateral femoral cutaneous neuropathy, the goal of the current study was to perform a systematic review of the literature to identify outcome measures that have been previously reported in studies on lateral femoral cutaneous neuropathy.

METHODS

A systematic review of the literature from 2000-2024 was performed utilizing PubMed and Medical Subject Headings (MeSH). Identified articles were screened according to study inclusion/exclusion criteria. Outcome measures reported in each included study were recorded and categorized into motor, sensory, pain, patient-reported outcomes, psychological, electrodiagnostic outcomes, imaging outcomes, and other outcomes. Descriptive statistics were performed.

RESULTS

A total of 80 articles were initially identified, and 10 articles met criteria for inclusion and underwent analysis. The most common outcome domain was patient-reported outcomes, which were reported in 7 (70%) studies. However, the specific patient-reported outcomes were very heterogeneous. A pain outcome was reported in 6 (60%) studies. Motor, psychological, imaging, and electrodiagnostic outcomes were not reported in any study. Across the included studies, 14 unique outcomes were reported.

CONCLUSIONS

We have identified the outcome measures that have previously been utilized in studies on lateral femoral cutaneous neuropathy. Patient-reported and pain outcomes were most commonly used across the included studies.

Advancing the Diagnosis of Diabetic Neuropathies: Electrodiagnostic and Skin Autofluorescence Methods

INTRODUCTION

Diabetic neuropathy (DN) is a generic term for various neuropathies coexisting in a single patient. Clinical diagnosis alone can be misleading, yet routine electrodiagnostic studies in diabetes care are rare. Skin autofluorescence (SAF) is a recognized DN risk factor with potential screening value. This article highlights the diagnostic challenges and raises awareness of the often underdiagnosed neuropathic conditions in diabetes patients.

MATERIAL AND METHODS

We present common entrapment neuropathy cases from our diabetes clinic's electrodiagnosis laboratory in Iași, Romania. We selected seven type 2 diabetes patients with sensory or sensory-motor distal polyneuropathy and atypical DN presentations investigated through electroneurography (ENG) and electromyography (EMG) with the Neurosoft® EMG instrument and SAF measured by standard procedures. Subsequently, a narrative literature review was conducted.

RESULTS

Entrapment neuropathies were diagnosed in all the patients: three carpal tunnel syndromes, two ulnar neuropathies (one proximal, one distal), one peroneal neuropathy, and one case of meralgia paresthetica. The lower-limb cases showed radiculoplexopathy, and there was one case of superficial radial nerve neuropathy. The SAF values ranged from 2.5 AU to 3.4 AU.

CONCLUSIONS

Electrodiagnosis is essential for detecting focal neuropathies in patients with sensory-motor distal polyneuropathy. Elevated SAF levels may correlate with symptom severity, although further research, including large cohorts, is needed.

Clinical Insights and Optimization of Surgical Approach for Lateral Femoral Cutaneous Nerve Injury/Entrapment: A Comprehensive Analysis of 184 Cases

BACKGROUND

Entrapment or injury of the lateral femoral cutaneous nerve (LFCN) is being recognized with increasing frequency, often requiring a surgical approach to relieve symptoms. The presence of anatomic variations can lead to errors in diagnosis and intraoperative decision-making.

METHODS

This study presents the experience of a single surgeon (T.W.T.) in managing 184 patients referred with clinical issues related to the LFCN. A comprehensive review of these cases was conducted to develop a prospective surgical management algorithm. Data on the LFCN's anatomic course, pain relief outcomes, comorbidities, body mass index, and sex were extracted from patients' medical charts and operative notes. Pain relief was assessed subjectively, categorized into "excellent relief" for complete pain resolution, "good" for substantial pain reduction with some residual discomfort, and "failure" for cases with no pain relief necessitating reoperation.

RESULTS

The decision tree is dichotomized based on the mechanism of LFCN pathology: compression (requiring neurolysis) versus history of trauma, surgery, and/or obesity (requiring resection). Forty-seven percent of the patients in this series had an anatomic variation. It was found that failure to relieve symptoms of compression often indicated the presence of anatomic variation of the LFCN or intraneural changes consistent with a neuroma, even if adequate decompression was achieved. With respect to pain relief as the outcome measure, recognition of LFCN anatomic variability and use of this algorithm resulted in 75% excellent results, 10% good results, and 15% failures. Twenty-seven of the 36 failures originally had neurolysis as the surgical approach. Twelve of those failures had a second surgery, an LFCN neurectomy, resulting in 10 excellent, 1 good, and 1 persistent failure.

CONCLUSION

This article establishes an algorithm for the surgical treatment of MP, incorporating clinical experience and anatomical insights to guide treatment decisions. Criteria for considering neurectomy may include a history of trauma, prior local surgery, anatomical LFCN variations, and severe nerve damage due to chronic compression.

Meralgia Paresthetica-An Approach Specific Neurological Complication in Patients Undergoing DAA Total Hip Replacement: Anatomical and Clinical Considerations

Introduction: Mini-invasive surgical (MIS) approaches to total hip replacement (THR) are becoming more popular and increasingly adapted into practice. THR via the direct anterior approach (MIS DAA) has become a rather controversial topic in hip arthroplasty literature in the last decades. Our retrospective observational study focuses on the prevalence of one approach-specific complication-lateral femoral cutaneous nerve (LFCN) iatrogenic lesion-and tries to clarify the possible pathogenesis of this injury. Methods: This is a retrospective single-cohort observational single-center and single-surgeon study. Our patient records were searched for the period from 2015 to 2017-after a safe period of time after the learning curve for MIS DAA. All intra- and post-operative lesions of the LFCN were recorded. Lesion of the LFCN was confirmed by a neurological examination. Minimum patient follow-up was 2 years. Results: This study involved 417 patients undergoing single-side THR via MIS DAA. Patients were examined on follow-up visits at 6 weeks, 6 months, 1 year, and 2 years after surgery. There were 17 cases of LCFN injury at the 6 weeks early follow-up visit (4.1%). All cases of clinically presenting LFCN injury resolved at the 2-year follow-up ad integrum. Discussion: Possible explanations of such neurological complications are direct iatrogenic injury, vigorous traction, hyperextension, or extreme external rotation of the operated limb. Use of a traction table or concomitant spinal pathology and deformity also play a role. Prevention involves stepwise adaptation of the approach during the learning curve period by attending cadaver lab courses, rational use of traction and hyperextension, and careful surgical technique in the superficial and deep fascial layers. Dynamometers could be used to visualise the limits of manipulation of the operated limb. Conclusions: Neurological complications are not as rare but questionably significant in patients undergoing THR via the DAA. Incidental finding of LFCN injury has no effect on the functional outcome of the artificial joint. It can lead to lower subjective satisfaction of patients with the operation, which can be avoided with careful education and management of expectations of the patients.

Meralgia paresthetica

Meralgia paresthetica is a common but probably underrecognized syndrome caused by dysfunction of the lateral femoral cutaneous nerve. The diagnosis is based on the patient's description of sensory disturbance, often painful, on the anterolateral aspect of the thigh, with normal strength and reflexes. Sensory nerve conduction studies and somatosensory evoked potentials may be used to support the diagnosis, but both have technical limitations, with low specificity and sensitivity. Risk factors for meralgia paresthetica include obesity, tight clothing, and diabetes mellitus. Some cases are complications of hip or lumbar spine surgery. Most cases are self-limited, but a small proportion of patients remain with refractory and disabling symptoms. Treatment options include medications for neuropathic pain, neurolysis, neurectomy, and radioablation, but controlled trials to compare efficacy are lacking.

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.

Nerve entrapment syndromes of the lower limb: a pictorial review

Peripheral nerves of the lower limb may become entrapped at various points during their anatomical course. While clinical assessment and nerve conduction studies are the mainstay of diagnosis, there are multiple imaging options, specifically ultrasound and magnetic resonance imaging (MRI), which offer important information about the potential cause and location of nerve entrapment that can help guide management. This article overviews the anatomical course of various lower limb nerves, including the sciatic nerve, tibial nerve, medial plantar nerve, lateral plantar nerve, digital nerves, common peroneal nerve, deep peroneal nerve, superficial peroneal nerve, sural nerve, obturator nerve, lateral femoral cutaneous nerve and femoral nerve. The common locations and causes of entrapments for each of the nerves are explained. Common ultrasound and MRI findings of nerve entrapments, direct and indirect, are described, and various examples of the more commonly observed cases of lower limb nerve entrapments are provided.Critical relevance statement This article describes the common sites of lower limb nerve entrapments and their imaging features. It equips radiologists with the knowledge needed to approach the assessment of entrapment neuropathies, which are a critically important cause of pain and functional impairment.Key points• Ultrasound and MRI are commonly used to investigate nerve entrapment syndromes.• Ultrasound findings include nerve hypo-echogenicity, calibre changes and the sonographic Tinel's sign.• MRI findings include increased nerve T2 signal, muscle atrophy and denervation oedema.• Imaging can reveal causative lesions, including scarring, masses and anatomical variants.

Meralgia Paresthetica: Relevance, Diagnosis, and Treatment

BACKGROUND

Pain and sensory disturbance in the distribution of the lateral femoral cutaneous nerve in the ventrolateral portion of the thigh is called meralgia paresthetica (MP). The incidence of MP has risen along with the increasing prevalence of obesity and diabetes mellitus and was recently estimated at 32 new cases per 100 000 persons per year. In this review, we provide an overview of current standards and developments in the diagnosis and treatment of MP.

METHODS

This review is based on publications retrieved by a selective literature search, with special attention to meta-analyses, systematic reviews, randomized and controlled trials (RCTs), and prospective observational studies.

RESULTS

The diagnosis is mainly based on typical symptoms combined with a positive response to an infiltration procedure. In atypical cases, electrophysiological testing, neurosonography, and magnetic resonance imaging can be helpful in establishing the diagnosis. The literature search did not reveal any studies of high quality. Four prospective observational studies with small case numbers and partly inconsistent results are available. In a meta-analysis of 149 cases, pain relief was described after infiltration in 85% of cases and after surgery in 80%, with 1-38 months of follow-up. In another meta-analysis of 670 cases, there was pain relief after infiltration in 22% of cases, after surgical decompression in 63%, and after neurectomy in 85%. Hardly any data are available on more recent treatment options, such as radiofrequency therapy, spinal cord stimulation, or peripheral nerve stimulation.

CONCLUSION

The state of the evidence is limited in both quantity and quality, corresponding to evidence level 2a for surgical and non-surgical methods. Advances in imaging and neurophysiological testing have made the diagnosis easier to establish. When intervention is needed, good success rates have been achieved with surgery (decompression, neurectomy), and variable success rates with infiltration.

Chiropractic management of bilateral meralgia paresthetica: a case report

Objective

The purpose of this report is to describe the course of chiropractic care for an adult male experiencing persistent anterolateral thigh pain due to bilateral meralgia paresthetica.

Clinical features

A 40-year-old male U.S. Veteran was referred to chiropractic care for a two-year history of bilateral anterolateral thigh pain and paresthesia that worsened with inguinal pressure and hip extension activities.

Intervention and outcomes

A total of six chiropractic visits, including a combination of telehealth and in-person appointments, took place over a period of 10 weeks. Treatments included patient education, soft-tissue therapy, therapeutic exercise prescription, and spinal manipulation directed toward the lumbar spine. The patient's pain was reduced from a 6/10 rating to a 0/10, he was able to reengage in recreational activities without discomfort, and sustained improvement was reported.

Summary

In this case, a trial of chiropractic care was associated with a resolution of the patient's bilateral meralgia paresthetica symptoms.

Meralgia Paresthetica Review: Update on Presentation, Pathophysiology, and Treatment

Purpose of Review

Meralgia paresthetica (MP) is a condition characterized by paresthesias, neuropathic pain, and alterations in sensorium of the anterolateral thigh secondary to impingement of the lateral femoral cutaneous nerve (LFCN). MP is generally diagnosed by clinical history and is often a diagnosis of exclusion. When diagnosis remains a challenge, diagnostic modalities such as ultrasound, MRI, electromyography, and nerve conduction studies have been utilized as an adjunct. This review summarizes the most recent medical literature regarding MP, its pathophysiology, presentation, and current treatment options.

Recent Findings

Treatment options for patients with MP range from lifestyle modifications and conservative management to surgical procedures. Initial management is often conservative with symptoms managed with medications. When conservative management fails, the next step is regional blocks followed by surgical management. The conflicting data for treatment options for MP highlight how the evidence available does not point to a single approach that's universally effective for treating all patients with MP.

Summary

Despite the apparent success at treating MP with regional blocks and surgical interventions, much remains to be known about the dosing, frequency, and optimal interventions due to the inconclusive results of current studies. Further research including randomized controlled trials are needed to better understand the most optimal treatment options for MP including studies with a larger number of participants.

Diagnosis and treatment of meralgia paresthetica between 2005 and 2018: a national cohort study

The prevalence of meralgia paresthetica (MP), which is caused by compression of the lateral femoral cutaneous nerve (LFCN), has been increasing over recent decades. Since guidelines and large-scale studies are lacking, there are substantial regional differences in diagnostics and management in MP care. Our study aims to report on current diagnostic and therapeutic strategies as well as time trends in clinical MP management in Germany. Patients hospitalized in Germany between January 1, 2005, and December 31, 2018, with MP as their primary diagnosis were identified using the International Classification of Disease (ICD-10) code G57.1 and standardized operations and procedures codes (OPS). A total of 5828 patients with MP were included. The rate of imaging studies increased from 44% in 2005 to 79% in 2018 (p < 0.001) and that of non-imaging diagnostic studies from 70 to 93% (p < 0.001). Among non-imaging diagnostics, the rates of evoked potentials and neurography increased from 20%/16% in 2005 to 36%/23% in 2018 (p < 0.001, respectively). Rates of surgical procedures for MP decreased from 53 to 37% (p < 0.001), while rates of non-surgical procedures increased from 23 to 30% (p < 0.001). The most frequent surgical interventions were decompressive procedures at a mean annual rate of 29% (± 5) throughout the study period, compared to a mean annual rate of 5% (± 2) for nerve transection procedures. Between 2005 and 2018, in-hospital MP care in Germany underwent significant changes. The rates of imaging, evoked potentials, neurography, and non-surgical management increased. The decompression of the LFCN was substantially more frequent than that of the LFCN transection, yet both types of intervention showed a substantial decrease in in-hospital prevalence over time.

Effectiveness of the muscle energy technique on postpartum meralgia paresthetica: A randomized controlled trial

BACKGROUND

The effectiveness of the muscle energy technique (MET) on postpartum meralgia paresthetica (MP) affecting the lateral femoral cutaneous nerve is unknown.

OBJECTIVE

To investigate the effectiveness of the MET on postpartum MP affecting the lateral femoral cutaneous nerve.

METHODS

In this randomized controlled trial, 30 patients with postpartum MP were randomly allocated to study and control groups. The study group received the MET with conventional therapeutic exercises and the control group received the conventional exercises alone for four weeks (thrice a week, for 30-40 minutes duration). Lateral femoral cutaneous nerve distal latency, pain intensity, response to the prone knee bend (PKB) test and pelvic compression test were assessed.

RESULTS

Patients allocated to the MET group had improvements compared to the controls in pain intensity (MD: -1.66, 95%CI -2.39 to -0.94), distal latency (MD: -0.66, 95%CI -0.94 to -0.36), and knee range of motion in the PKB test (MD: 19.5∘, 95%CI 13 to 26.1) with high treatment effects, Cohen's d -ES = 1.71, 1.86 and 2.24 respectively. However, there was no between-group difference for the pelvic compression test (p= 0.41).

CONCLUSION

The MET can reduce pain, distal latency, and increasingly prone knee range of motion and increase the prone knee range of motion in women with MP affecting the lateral femoral cutaneous nerve.

Treatment of idiopathic meralgia paresthetica – is there reliable evidence yet?

OBJECTIVE

Meralgia paresthetica is a common condition that is usually diagnosed by its classical clinical presentation and by exclusion of a spinal origin of pain, sensory loss, and/or paresthesias in the anterolateral thigh. Treatment modalities include conservative management, local injections, and surgical therapy. To date, no level 1 evidence exists about treatment options for idiopathic meralgia paresthetica. This review article aims to give a structured overview of epidemiology, history, anatomy, diagnostics, and treatment. It focuses on the existing literature and current developments in clinical management.

METHODS

A literature search on PubMed/MEDLINE was performed on 20 December 2021, yielding 1412 results. Abstracts were screened and classified in terms of epidemiology, anatomy, diagnostics, and treatment.

RESULTS

High-quality observational data that was included in recent meta-analyses showed satisfactory results for conservative management, injections, and surgical decompression or neurectomy, but there is some major methodological criticism. For idiopathic meralgia paresthetica, the results of surgical decompression have never been compared to those of neurectomy in a randomized setup. The only study protocol published so far does not consider any extended decompression techniques (dynamic, circumferent, proximal, and distal to the inguinal ligament). A multicenter, prospective design has never been proposed.

DISCUSSION

Reliable high-quality evidence on the treatment of idiopathic meralgia paresthetica is lacking at the current state, and challenges in clinical decision-making remain.

Diabetic Mononeuropathies and Diabetic Amyotrophy

This brief review describes the etiology, pathophysiology, clinical features, therapy and prognosis of the diabetic mononeuropathies and diabetic amyotrophy and neuropathic cachexia. Mononeuropathies include cranial neuropathies, of which the oculomotor nerve is most commonly affected, and are thought to be due to microvascular occlusion. Peripherally, entrapment neuropathies occur in both the upper and lower limbs and are due to compression of an already damaged nerve in anatomically restricted channels. Diabetic radiculopathies occur in the dermatones of the thorax and abdomen, mimicking intraabdominal or intrathoracic pathology. I also describe the features of the rare but very distinctive diabetic amyotrophy and neuropathic cachexia. Overall, the prognosis from these conditions is excellent with residual pain or muscle weakness being rare with the exception of diabetic amyotrophy where the prognosis is dependent upon cooperation with intensive rehabilitation. Therapies include "watchful waiting," physical therapy and rarely surgical intervention, which may be urgently needed for nerve decompression and reversal of motor defects.

Meralgia Paresthetica

PURPOSE OF REVIEW

This review article summaries the epidemiology, etiology, clinical presentations, and latest treatment modalities of meralgia paresthetica, including the latest data about peripheral and spinal cord stimulation therapy. Meralgia paresthetica (MP) causes burning, stinging, or numbness in the anterolateral part of the thigh, usually due to compression of the lateral femoral cutaneous nerve (LFCN).

RECENT FINDINGS

There are emerging data regarding the benefit of interventional pain procedures, including steroid injection and radiofrequency ablation, and other interventions including spinal cord and peripheral nerve stimulation reserved for refractory cases. The strength of evidence for treatment choices in meralgia paraesthetica is weak. Some observational studies are comparing local injection of corticosteroid versus surgical interventions. However, more extensive studies are needed regarding the long-term benefit of peripheral and spinal cord stimulation therapy.

Ultrasound of the Lateral Femoral Cutaneous Nerve: A Review of the Literature and Pictorial Essay

We review the ultrasound (US) findings in patients who present with meralgia paresthetica (MP). The anatomy of the lateral femoral cutaneous nerve at the level where the nerve exits the pelvis and potential entrapment sites that can lead to MP are discussed. A wide range of pathological cases are presented to help in recognizing the US patterns of MP. Finally, our experience with US-guided treatment is discussed.

Common Focal Neuropathies in the Hospitalized Patient

Neuropathies are a common problem encountered by neurologist in the hospitalized setting. Nerve injury may occur secondary to compression, stretch, and direct trauma, among other causes. Common focal neuropathies include the ulnar, median, and radial nerve in the upper extremities and sciatic, peroneal, and femoral nerve in the lower extremities. Surgical and obstetric risk factors are especially important considerations in evaluation of patients with focal neuropathies. Treatment is either conservative therapy or surgery depending on the mechanism of injury and extent of recovery.

Sonographic features of the lateral femoral cutaneous nerve in meralgia paresthetica

Background

The diagnosis of meralgia paresthetica (MP) is usually based on clinical symptoms and physical examination. Therefore, the present study aimed to investigate the lateral femoral cutaneous nerve (LFCN) sonographic features in MP patients.

Methods

A total of 86 clinically suspected MP patients and 40 asymptomatic volunteers were prospectively recruited in the study. The sonographic features of the LFCN were observed by 18 MHz high-frequency ultrasound. At the level of the anterior superior iliac spine, the cross-sectional area of the LFCN was measured.

Results

Of the 86 clinically suspected MP patients, 82 (95.3%) had sonographic findings positive for MP. There were 54, 63, and 44 cases of abrupt caliber change, indistinct perineurium, and abnormal intraneural vascularity. The average value of the cross-sectional area of the LFCN at the level of the anterior superior iliac spine was 4.47±2.64 mm², and the cut-off value was 2.65 mm².

Conclusions

The sonographic diagnosis of MP may be achieved based on the following signs: nerve abrupt caliber change, indistinct perineurium of the nerve, intraneural vascularity, or increased cross-sectional area.

Peripheral Nerve Stimulation for the Treatment of Meralgia Paresthetica

Meralgia paresthetica is a condition caused by entrapment of the lateral femoral cutaneous nerve at the level of the inguinal ligament. This nerve is a purely sensory nerve and provides innervation to the anterolateral portion of the thigh. The condition can lead to numbness, paresthesia, dysesthesia, and pain over the anterolateral aspect of the thigh, which are exacerbated with walking, standing, and hip extension. First-line treatment for MP includes conservative measures such as weight loss and eliminating tight-fitted clothing. Neuropathic pain medications and corticosteroid injections are also treatment options for some patients with significant pain complaints. In more refractory cases, surgical intervention can be considered. Peripheral nerve stimulation has also been shown to be a helpful treatment modality for patients with refractory meralgia paresthetica. Here we report our experience utilizing peripheral nerve stimulation in patients with significant pain complaints related to refractory meralgia paresthetica.

Beneath the Surface: Massive Retroperitoneal Liposarcoma Masquerading as Meralgia Paresthetica

In patients presenting with focal neurologic findings involving the lower extremities, a thorough abdominal examination should be considered an integral part of the full neurologic work up.

Meralgia Paresthetica: A Case Report With an Update on Anatomy, Pathology, and Therapy

Meralgia paresthetica, a condition characterized by tingling, numbness, and burning pain in the lateral aspect of the thigh, is caused by compression of the lateral femoral cutaneous nerve. The incidence of meralgia paresthetica increases with obesity and diabetes. The unique anatomy of the nerve that tunnels through the inguinal ligament predisposes it to inflammation, trauma, and entrapment. The pathology of meralgia paresthetica parallels that of entrapment neuropathies but with additional inflammatory overlay in certain instances. The clinical diagnosis is relatively simple due to its unique clinical features. The prognosis is generally excellent, and the treatment is straightforward that includes peripheral nerve blocks, neurectomy, nerve decompression, and pulsed radiofrequency neuromodulation. This current case of meralgia paresthetica highlights the salient clinical symptoms and signs. We have also described the electrophysiological studies of the lateral femoral cutaneous nerve, its anatomical variations, and the associations of meralgia paresthetica with bariatric surgery, critical care patients, tight clothing, pregnancy, and posterior spine surgery. We have also outlined the current treatment strategies.

Meralgia paresthetica attributable to surgery in the park-bench position

OBJECTIVE

Meralgia paresthetica (MP) is an entrapment neuropathy of the lateral femoral cutaneous nerve (LFCN). We report a rare MP complication after microvascular decompression (MVD) surgery in the park-bench position in a patient with hemi-facial spasm.

CASE

The patient was a 46-year-old female (height: 155 cm, weight: 42 kg). She was neither diabetic nor a regular alcohol user. After the first MVD for right hemifacial spasm, her symptom recurred and she underwent a second MVD procedure in the park-bench position that led to the disappearance of her hemifacial spasm. However, she complained of right antero-lateral thigh pain and dysesthesia without motor weakness. The symptom was limited to the LFCN area; pelvic compression test elicited a positive Tinel-like sign. Our preliminary diagnosis was MP. As conservative therapy was ineffective she underwent LFCN block 9 months after the second MVD procedure. Her symptom improved dramatically and we made a definitive diagnosis of MP. There has been no recurrence in the course of 30 months although she reported persistent mild dysesthesia in the LFCN area.

CONCLUSION

MP is a rare complication after MVD surgery in the park-bench position. Symptom abatement and a definitive early diagnosis can be obtained by LFCN blocks.

Atypical Radiculopathy in an Oncology Patient

Practitioners face significant challenges when evaluating patients with cancer who suffer from back pain. Back pain is one of the most common reasons for patients to visit medical providers. This case study will review a patient with cancer presenting with atypical radicular pain.

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.

Decompression and Neurolysis of the Lateral Femoral Cutaneous Nerve in the Surgical Treatment of Meralgia Paresthetica and the Results

Meralgia paresthetica (MP), also known as Bernhardt–Roth syndrome, is a peripheral neuropathy of the primary sensory lateral femoral cutaneous nerve (LFCN). Its diagnosis is challenging, because it can mimic other clinical conditions particularly associated with upper lumbar spine or pelvis. Patients present with pain and paresthesia over the anterolateral thigh. Diagnosis is usually based on clinical examination and is supported by sensory nerve conduction (SNC) studies. The initial treatment is always conservative. In limited number of patients who are refractory to conservative managements, surgical treatment via decompression/neurolysis or neurectomy is concerned. There is still no consensus on which surgical technique is the best and the first choice. We retrospectively analyzed the surgical outcomes of 12 nonobese patients who underwent decompression/neurolysis between the years 2013 and 2018. Bilateral SNC studies were performed in all cases which supported the diagnosis. We applied conservative treatments for 3 months in addition to the treatments previously applied in other centers. Surgery was recommended for the patients who were refractory to these treatments. Preoperative and postoperative pain levels during follow-up visits were evaluated with visual analogue scale (VAS). A retrospective analysis was performed on preoperative and postoperative 6th month VAS scores. The mean preoperative VAS value was 8.75 ± 0.62 and the postoperative VAS value at the sixth month was 1.17 ± 0.72. A significant reduction in the pain was shown (p < 0.05). Our surgical results showed that decompression/neurolysis of the LFCN should be concerned as the primary surgical approach to avoid negative outcomes of resection surgeries.

Extended pulsed radiofrequency as a part of multimodal pain management in a refractory case of Bernhardt-Roth syndrome

Bernhardt-Roth syndrome (BRS) is a neurological condition characterised by pain, burning or numbness in anterolateral thigh due to entrapment of the lateral femoral cutaneous nerve (LFCN). The possible aetiologies can be mechanical, iatrogenic, neuropathic or idiopathic. After consent for possible publication, we are discussing a case of pain management in a 38-year-old patient with BRS secondary to diabetes. The coherent history, uncontrolled glycaemic status and reduced nerve conduction velocity for LFCN helped reach the diagnosis. Initial treatment with pharmacotherapy, steroid LFCN block and conventional pulsed radiofrequency (PRF) provided moderate temporary pain relief. Extended PRF over 8 min provided significant analgesia without any complications. Physical therapy, adequate glycaemic control and extended PRF provided complete pain relief and improved function over 6 months of follow-up duration. Hence, a cautious multifaceted approach targeting the basic aetiology with extended PRF helped achieve significant analgesia in our refractory case of BRS.

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.

An Alternate Approach to Using Candy Cane Stirrups in Vaginal Surgery

BACKGROUND

Candy cane stirrups are widely used for vaginal surgery because they provide sufficient operating space. When placed in the standard perpendicular alignment, however, these stirrups cause excessive flexion, abduction, and external rotation of the thigh, which may injure the femoral, lateral femoral cutaneous, sciatic, and common peroneal nerves.

TECHNIQUE

We corrected this deficiency by positioning the stirrups parallel to the operating table, just above and tilting slightly toward its lower break. After placing the patient in stirrups, we inserted a double-layer foam pad between her knee and the stirrup and adjusted the height of each stirrup until both thighs were flexed 90 degrees and both knees flexed 100 degrees. We then pushed the L-shaped lower stirrup toward or pulled it away from the operating table until each thigh was vertical, with minimal abduction or adduction. Finally, we rotated the curved upper stirrups medially until each leg was pointing slightly laterally.

EXPERIENCE

Of 1,576 vaginal cases, there were eight (0.5%) instances of postoperative sensory neuropathy, which usually involved the lateral femoral cutaneous nerve.

CONCLUSION

This simple modification to the candy cane stirrups allows placement of patients in dorsal lithotomy with their legs in an anatomically and neurologically neutral position.

Constitutional risk factors for focal neuropathies in patients referred for electromyography

BACKGROUND AND PURPOSE

It is well established that patient-related constitutional features predispose to focal peripheral neuropathies. Some of these risk factors were investigated in common focal neuropathies encountered in patients referred for electromyography.

METHODS

Gender, age, height and body mass index (BMI) were analysed retrospectively as risk factors for 11 focal neuropathies. In all, 9686 patients (age range 18-96 years; 58% women) were included from three different centres, with identical methods and equipment.

RESULTS

High BMI was related to carpal tunnel syndrome (CTS), ulnar neuropathy at the elbow (UNE), combined CTS and UNE, meralgia paraesthetica and lumbar radiculopathy. In women, CTS and Morton's metatarsalgia were more common, whilst long thoracic neuropathies, suprascapular neuropathies and UNE were more common in men. Older age increased the risk for CTS, UNE, Morton's metatarsalgia and radiculopathies.

CONCLUSIONS

Age, gender and BMI are important risk factors for many common focal neuropathies.

Reducing Lateral Femoral Cutaneous Nerve Palsy in Obese Patients in the Beach Chair Position: Effect of a Standardized Positioning and Padding Protocol

INTRODUCTION

To report on the effectiveness of a standardized patient positioning and padding protocol in reducing lateral femoral cutaneous nerve (LFCN) palsy in obese patients who have undergone shoulder surgery in the beach chair position.

METHODS

We retrospectively reviewed the medical records of 400 consecutive patients with a body mass index (BMI) of ≥30 kg/m who underwent either open or arthroscopic shoulder surgery in the beach chair position by a single surgeon. Before June 2013, all patients were placed in standard beach chair positioning with no extra padding. After June 2013, patients had foam padding placed over their thighs underneath a wide safety strap and underneath the abdominal pannus. Flexion at the waist was minimized, and reverse Trendelenburg was used to position the shoulder appropriately. Patient demographic and surgical data, including age, sex, weight, BMI, presence of diabetes, procedure duration, American Society of Anesthesiologists (ASA) grade, and anesthesia type (general, regional, regional/general) were recorded. Symptoms of LFCN palsy were specifically elicited postoperatively in a prospective fashion and identified clinically by focal pain, numbness, and/or tingling over the anterolateral thigh.

RESULTS

The median age was 58.0 years, and the study consisted of 142 male (36%) and 258 female (64%) subjects. Five cases (3.6%) of LFCN palsy occurred with conventional beach chair positioning, and a single case (0.4%) occurred with the standardized positioning and padding technique (P = 0.02). Median age, sex, presence of diabetes, median BMI, surgery type, and surgical time were not significantly different between the patients who did and did not develop LFCN palsy. All cases resolved completely within 6 months.

DISCUSSION

The occurrence of LFCN palsy following shoulder surgery in the beach chair position remains uncommon, even among obese patients. Use of a standardized positioning and padding protocol for obese patients in the beach chair position reduced the prevalence of LFCN palsy.

LEVEL OF EVIDENCE

Level III (prognostic).

Entrapment Neuropathies of the Lower Extremity

Entrapment neuropathies in the lower limbs are a common neurologic problem and may present in any medical setting. Accurate identification and management of these nerve palsies can prevent pain, sensory loss, incoordination, and muscle weakness that may significantly affect a patient's functional mobility. In this article, the authors focus on the cause, signs and symptoms, diagnosis, and treatment of select entrapment neuropathies of the lower extremity, including palsies of the common peroneal, lateral femoral cutaneous, femoral, and posterior tibial nerves.

Sartorius muscle tear presenting as acute meralgia paresthetica

We present an unusual case of sartorius muscle tear presenting as acute meralgia paresthetica. A healthy 67-year old male was referred to our department with a one-week history of pain, numbness and bruising over his hip and anterolateral thigh. Extended ultrasound assessment revealed an intramuscular tear of sartorius, with acute hematoma surrounding the adjacent lateral femoral cutaneous nerve. Meralgia paresthetica from acute trauma is rare, with only three published cases relating to fractures of the anterior superior iliac spine. To our knowledge, this is the first case caused by muscular tear in the literature. The presence of features attributable to neuropraxia of the lateral femoral cutaneous nerve allowed for proper localization and diagnosis of the patient's injury.

Meralgia Paresthetica After Spine Surgery on the Jackson Table

Meralgia paresthetica is a non-life-threatening neurological disorder characterized by numbness, tingling, and burning pain over the anterolateral thigh due to impingement of the lateral femoral cutaneous nerve. This disorder has been seen in patients with diabetes mellitus and obesity, but has also been observed in patients after procedures such as posterior spine surgery, iliac crest bone grafts, lumbar disk surgery, hernia repair, appendectomies, and pelvic osteotomies that ultimately lead to compression or damage to the lateral femoral cutaneous nerve. Overall, permanent sequelae of meralgia paresthetica are rare, however, some cases do require intervention.

Prevalence and Risk Factors for Lateral Femoral Cutaneous Nerve Palsy in the Beach Chair Position

PURPOSE

To report on the prevalence of lateral femoral cutaneous nerve (LFCN) palsy in patients who had undergone shoulder surgery in the beach chair position and to identify patient and surgical risk factors for its development.

METHODS

We retrospectively reviewed the medical records of 397 consecutive patients who underwent either open or arthroscopic shoulder surgery in the beach chair position by a single surgeon. Patient demographic and surgical data including age, gender, weight, body mass index (BMI), diabetes, procedure duration, and anesthesia type (general, regional, regional/general) were recorded. LFCN palsy symptoms were recorded prospectively at the initial postoperative visit and identified clinically by focal pain, numbness, and/or tingling over the anterolateral thigh.

RESULTS

The median patient age was 59.0 years and consisted of 158 males (40%) and 239 (60%) females. Five cases of LFCN palsy were identified for a prevalence of 1.3%. These patients had a higher median weight (108.9 kg vs 80.7 kg, P = .005) and BMI (39.6 vs 29.4, P = .005) than the patients who did not develop LFCN palsy. Median age, gender, diabetes, and surgical time were not significantly different between the groups. All cases resolved completely within 6 months.

CONCLUSIONS

LFCN palsy after shoulder surgery in the beach chair position in our study has a prevalence of 1.3%, making it an uncommon complication. Patients with elevated BMI should be counseled about its possible occurrence after shoulder surgery in the beach chair position.

LEVEL OF EVIDENCE

Level IV, prognostic.

Correlation of Histopathology and Clinical Symptoms in Meralgia Paresthetica

Meralgia paresthetica is a neuropathic pain disorder resulting from an entrapment neuropathy of the lateral femoral cutaneous nerve. This condition results in pain, paresthesias and numbness over the anterolateral aspect of the thigh. We present a case of meralgia paresthetica and discuss both the clinical and histopathological findings as they relate to one another. We report a case of meralgia paresthetica refractory to conservative treatment who underwent neurectomy with successful treatment of symptoms. Histopathological examination revealed moderate loss of myelinated axons with some axonal atrophy. The distinct pathologic findings were axonal regeneration clusters and thinly myelinated axons as well as moderate perineurial thickening. These findings corresponded well to the patient’s preoperative symptoms of paresthesias and pain. This case serves to shed light on the pathophysiology of meralgia paresthetica and its clinical presentation. It also shows the role of surgical treatment in cases refractory to conservative management in order to alleviate painful symptoms

An Unusual Case of Bilateral Meralgia Paresthetica Following Femoral Cannulations

Meralgia paresthetica (MP) is a sensory mononeuropathy of the lateral femoral cutaneous nerve (LFCN). MP has rarely been reported after a femoral intervention approach. We report a case of bilateral meralgia paresthetica following bilateral femoral cannulation. A 64-year-old male received cardiac catheterization and treatment via a bilateral femoral vein. After cardiac catheterization, the patient presented with paresthesia in the anterolateral aspect of the bilateral thigh. After performing nerve conduction studies and electromyography, he was diagnosed as MP. Although a bilateral LFCN lesion following a femoral approach is very rare, MP might require caution regarding potential variations in LFCN when performing the femoral approach.

Differences between healthy adults and patients with type 2 diabetes mellitus in reactivity of toe microcirculation by ultrasound combined with a warm bath test

The aim of this study was to explore the feasibility and clinical value of ultrasound combined with a warm bath test in assessing the differences in reactivity of toe microcirculation between healthy adults and patients with type 2 diabetes mellitus (T2DM).A total of 56 T2DM patients were recruited as case group, whereas 50 healthy volunteers were enrolled as control group.Fasting blood glucose, glycated hemoglobin, total cholesterol, triglyceride, low-density lipoprotein cholesterol in T2DM group were significantly higher than in control group. Under stationary condition, peak systolic velocity (PSV), end-diastolic velocity (EDV), and mean velocity (MV) were lower, but pulsatility index (PI) and resistance index (RI) were higher in patients with T2DM than in controls both in dorsalis pedis artery (DPA) and plantar digital artery (PDA). On response to the warm test, PSV, EDV, and MV increased and PI and RI decreased both in DPA and PDA in these 2 groups. Moreover, the change rate in PSV, EDV, MV, PI, and RI of PDA was significantly lower in T2DM group than in control group.Color Doppler combined with a warm bath test may be used as a new method in evaluating the differences in reactivity of distal limb microvascular between healthy adults and patients with T2DM.

Evaluating the evidence: is neurolysis or neurectomy a better treatment for meralgia paresthetica?

BACKGROUND

Meralgia paresthetica is a mononeuropathy of the lateral femoral cutaneous nerve (LCFN). Surgical treatment involves transection or decompression of the LCFN. There is no clear consensus on the superiority of one technique over the other. We performed a systematic review of the literature to answer this question.

METHODS

Eligible studies included those that compared neurolysis versus neurectomy for the treatment of meralgia paresthetica after failure of conservative therapy. Our outcome of interest was resolution of symptoms. We performed a computerized search of MEDLINE (PubMed; all years) and of the Cochrane Central Register of Controlled Trials. Eligible studies had to include the words "meralgia paresthetica" and "surgery." All patients regardless of age were included, and there was no language restriction. We then reviewed the articles' titles and abstracts. All studies that compared neurolysis to neurectomy were included in the analysis.

RESULTS

Of the studies identified, none were randomized controlled trials. There were two German language articles that were translated by a third researcher. Each study was evaluated by two independent researchers who assigned a level of evidence according to American Association of Neurologist algorithm and also performed data extraction (neurolysis vs. neurectomy and resolution of pain symptoms). Each study was found to be level four evidence.

CONCLUSION

After reviewing the data, there was insufficient evidence to recommended one method of treatment over the other. This highlights the importance of keeping a national registry in order to compare outcomes between the two methods of treatment.

Lateral Femoral Cutaneous Nerve Palsy After Spinal Fusion for Adolescent Idiopathic Scoliosis (AIS)

STUDY DESIGN

Prospective study of consecutive patients.

OBJECTIVE

The purpose of the study was to evaluate the incidence, risk factors, and time to resolution of lateral femoral cutaneous nerve palsy (LFCNP) after posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

No prior studies have prospectively evaluated the prevalence of LFCNP exclusively in the treatment of AIS.

METHODS

Between June 2014 and May 2015, patients undergoing PSF for AIS were examined preoperatively, postoperatively, and at follow-up clinic visits until the resolution of the LFCNP. All neurologic examinations were performed by attending pediatric orthopedic surgeons. Patients who underwent staged, revision or anterior procedures, had preoperative neurologic deficits or neuropathy, were excluded.

RESULTS

A total of 55 patients with an average age of 14 years (10-21) were enrolled. Twenty-five percent (14/55) of patients had a postoperative LFCNP. There were no other postoperative neurologic deficits. Of the 14 patients with an LFCNP, 57% of these were bilateral. Fourteen percent (2/14) of these patients had absent sensation to light touch, whereas 85% (12/14) had decreased sensation. No patients reported experiencing pain associated with the LFCNP or tenderness when the anterolateral thigh was palpated. The LFCNP did not limit postoperative mobilization or prolong hospital stay. The LFCNP was noted to resolve in an average of 3.6 days (1-18); 6/14 (43%) resolved after 1 day. No correlation was observed between occurrence of LFCNP and sex, age, height, body mass index, length of fusion, Cobb angle, or blood loss. The occurrence of LFCNP was associated with heavier weight (P = 0.032) and longer operative times (P = 0.016). Resolution of the LFCNP was associated with longer operative time (P = 0.010).

CONCLUSION

LFCNP occurred in 25% of AIS patients undergoing PSF. Risk of LFCNP increased with longer operative times and heavier patient weight. On average, LFCNP resolved in less than 4 days and did not cause any pain or limitations.

LEVEL OF EVIDENCE

2.

Meralgia Paresthetica after Prone Positioning Ventilation in the Intensive Care Unit

Meralgia paresthetica (MP) is a mononeuropathy of the lateral femoral cutaneous nerve (LFCN) caused by external compression of the nerve during its course close to the anterior superior iliac spine. We present a case of a patient with acute respiratory distress induced by Legionella pneumonia who was admitted to the intensive care unit (ICU) for mechanical ventilation. In the ICU, the patient received one session of prone position ventilation for 8.5 consecutive hours. At evaluation six months later, the patient reported persistent bilateral numbness of the anterolateral thigh, which he complained had begun right after he woke up at the ICU. He was referred for further neurological and neurophysiological examination and was diagnosed with bilateral MP, a condition never previously described as a complication to mechanical ventilation in prone position in the ICU.