Prevalence and management of refractory meralgia paresthetica in lumbar spine surgery: 5 years of experience / Prevalência e manejo da meralgia parestésica refratária em cirurgia de coluna lombar: experiência de cinco anos / Prevalencia y manejo de la meralgia parestésica refractaria en cirugía de columna lumbar: experiencia de 5 años

ABSTRACT Objective The objective of our study was to report 5 years of experience in the recognition and management of refractory meralgia paresthetica (MP) in patients who had undergone posterior approach lumbar surgery. Methods Patients who were submitted to procedures in the lumbar spine from January 2010 to January 2015 in three different hospital centers in Belo Horizonte/MG were selected for an evaluation of the postoperative development of MP. A prospective observational comparative case series study. Level of evidence III. Evaluation of the following parameters: type of support for the patient, surgical time, body mass index. Results 367 posterior approach lumbar spine surgeries for degenerative pathologies of the lumbar spine were performed. MP was observed in 81 patients (22%). In 65 of those patients (80%), there was complete resolution of the symptoms with conservative management (local measures and medications for neuropathic pain) in less than two months. Twelve patients improved with a corticosteroid depot injection in the inguinal ligament and four patients required a surgical procedure in the third month. Pneumatic support was the least involved in the development of MP, as well as surgical time <1h and body mass index <25. Conclusion Refractory MP may occur in patients submitted to posterior approach lumbar spine surgeries. Management includes local measures, medications for neuropathic pain, and corticosteroid injection in the inguinal ligament. Decompression surgery is reserved for rare refractory cases. Level of evidence III; Prospective observational study with comparative case series.

RESUMO Objetivo O objetivo do presente estudo consiste em relatar a experiência de cinco anos no reconhecimento e manejo da meralgia parestésica (MP) refratária em pacientes submetidos a cirurgias lombares por via posterior. Métodos Pacientes submetidos a procedimentos na coluna lombar, no período de janeiro de 2010 a janeiro de 2015, em três diferentes centros hospitalares de Belo Horizonte/MG, foram selecionados para avaliação do desenvolvimento da MP pós-operatória. Estudo prospectivo observacional com série de casos comparativos. Nível III de evidência. Avaliação dos seguintes parâmetros: tipo de suporte para o paciente, tempo de cirurgia, índice de massa corporal. Resultados Foram feitas 367 cirurgias por via posterior da coluna lombar para patologias degenerativas da coluna lombar. A MP foi observada em 81 pacientes (22%). Em 65 pacientes (80%), houve resolução completa dos sintomas com manejo conservador (medidas locais e medicamentos para dor neuropática) em menos de dois meses. Doze pacientes melhoraram através de infiltração com corticoide de depósito e anestésico no local no ligamento inguinal e, em quatro pacientes houve necessidade de procedimento cirúrgico no terceiro mês. O suporte pneumático foi o menos envolvido no desenvolvimento da MP, assim como o tempo cirúrgico <1h e índice de massa corporal <25. Conclusão A MP refratária pode ocorrer em pacientes submetidos a cirurgias na coluna lombar por via posterior. O manejo inclui medidas locais, medicamentos para dor neuropática e infiltração com corticoide no ligamento inguinal. A cirurgia descompressiva está reservada para os raros casos refratários. Nível de evidência III; Estudo prospectivo observacional com série de casos comparativos.

RESUMEN Objetivo El objetivo del presente estudio consiste en relatar la experiencia de 5 años en el reconocimiento y manejo de la meralgia parestésica (MP) refractaria en pacientes sometidos a cirugías lumbares por vía posterior. Métodos Pacientes sometidos a procedimientos en la columna lumbar, en el período de enero de 2010 a enero de 2015, en tres diferentes centros hospitalarios de Belo Horizonte/MG, fueron seleccionados para evaluación del desarrollo de la MP postoperatoria. Estudio prospectivo observacional con serie de casos comparativos. Nivel III de evidencia. Evaluación de los siguientes parámetros: tipo de soporte para el paciente, tiempo de cirugía, índice de masa corporal. Resultados Se realizaron 367 cirugías por vía posterior de la columna lumbar para patologías degenerativas de la columna lumbar. La MP fue observada en 81 pacientes (22%). En 65 pacientes (80%) hubo resolución completa de los síntomas con manejo conservador (medidas locales y medicamentos para el dolor neuropático) en menos de 2 meses. Doce pacientes mejoraron a través de infiltración de corticoide de depósito y anestésico en el local en el ligamento inguinal y, en cuatro pacientes, hubo necesidad de procedimiento quirúrgico en el tercer mes. El soporte neumático fue el menos involucrado en el desarrollo de la MP, así como el tiempo quirúrgico <1h e índice de masa corporal <25. Conclusión La MP refractaria puede ocurrir en pacientes sometidos a cirugías en la columna lumbar por vía posterior. El manejo incluye medidas locales, medicamentos para el dolor neuropático e infiltración con corticoide en el ligamento inguinal. La cirugía descompresiva está reservada para los raros casos refractarios. Nivel de evidencia III; Estudio prospectivo observacional con serie de casos comparativos.

Evaluation Of The Origin Variability Of The Lateral Femoral Cutaneous Nerve With Clinical Significance

Background and Objectives: The lateral femoral cutaneous nerve (LFCN) of the thigh arises from the dorsalbranches of the second and third lumbar ventral rami. Several variations in the formation, course and branchesof this nerve have been reported. The regional anatomy of the lateral femoral cutaneous nerve is highly variedand may account for its susceptibility to local trauma. Knowledge of these variations is important for surgeonsto avoid injury to the nerve. The aim of this study was to evaluate the variations in the formation of LFCN of thethigh and to discuss its clinical implications.Materials And Methods: The study was conducted on 25(50 sides) adult human cadavers in the Department ofAnatomy, Sri Siddhartha Medical College, Tumkur, Karnataka, India by dissection method. The LFCN was lookedfor, bilaterally, and its formation studied. The specimens were numbered and photographed.Results: In the present study, the lateral femoral cutaneous nerve of thigh arising from dorsal divisions of L2 L3was observed in 34(68%) specimens. Variations in LFCN were observed in 16 specimens. The variationsencountered were the absence of LFCN (2%), the origin of LFCN from ventral ramus of L1 spinal nerve (2%), theorigin of LFCN from ventral rami of L1 L2 spinal nerves (8%), the origin of LFCN as a branch of femoral nerve (20%).Conclusion: The present study highlights the necessity for a thorough knowledge of the topographical features ofthe LFCN so as to increase the efficacy of diagnosis, reduce complications and increase patient comfort.

Extended duration pulsed radiofrequency for the management of refractory meralgia paresthetica: a series of five cases

Meralgia paresthetica (MP) is a sensory mononeuropathy, caused by compression of the lateral femoral cutaneous nerve (LFCN) of thigh. Patients refractory to conservative management are treated with various interventional procedures. We report the first use of extended duration (8 minutes) pulsed radiofrequency of the LFCN in a case series of five patients with refractory MP. Four patients had follow up for 1–2 years, and one had 6 months follow up. All patients reported remarkable and long lasting symptom relief and an increase in daily life activities. Three patients came off medications and two patients required minimal doses of neuropathic medications. No complications were observed.

Repair of wound on dorsum of foot with thin anterolateral thigh perforator flap with sensory nerve / 中华整形外科杂志

Objective@#To investigate the treatment and clinical effect of thin anterolateral thigh perforator flap with sensory nerve in the repair of soft tissue defect of dorsal foot.@*Methods@#During January 2012 to February 2017, 14 cases of soft tissue defect of dorsalis pedis were treated. The flap was designed according to the three-dimensional structure of the defect in the recipient area, and the lateral femoral cutaneous nerve was carried. Free transplantation was performed for repair of soft tissue defect of dorsal foot after fine thinning under microscope. The selected size of the flap ranged from 6 cm×4 cm to 15 cm×9 cm, 10 cases of donor site width is less than or equal to 8 cm with direct suture, 4 cases of donor site wound greater than 8 cm, Free skin graft on the wound surface.@*Results@#After operation, all flaps survived. Meanwhile, superficial necrosis occurred in the distal part of the flap in 1 case due to local infection, and healed after dressing change. All patients were followed up for 6-24 months, the appearance of the flap was pleasant, the texture, color and elasticity of the flap were satisfactory. In addition, Partial skin flap two-point discrimination was 6-10 mm with S2, S3 sensory recovery. During the follow-up, patients were able to walk with normal shoes, no ulcer occurred in the flap, and healed well in donor site.@*Conclusions@#The application of thin anterolateral thigh perforator flap with sensory nerve is safe and reliable in the repair of soft tissue defect of dorsal foot. After the repair, the skin flap has a good appearance and can restore part of the sensation.

An Unusual Case of Bilateral Meralgia Paresthetica Following Femoral Cannulations / 신경중재치료의학

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.

Utilidad de la neurografía por IRM en el diagnóstico de la meralgia parestésica / Usefulness of MRI neurography in the diagnosis of meralgia paresthetica

Objetivo: Evidenciar cómo la Imagen Resonancia magnética (IRM) con equipo de 3 Tesla, utilizando secuencias neurográficas específicas y uso de contraste endovenoso permite ubicar el área de lesión nerviosa. Caso clínico: Mujer de 17 años con hipoestesia y parestesias en la región anterior y lateral del muslo izquierdo, se le realiza un estudio de Resonancia Magnética (RM) en equipo Philips Achieva 3 T, usando protocolo neurográfico y contraste endovenoso, demostrando engrosamiento y cambios de señal del nervio y realce post-contraste característico de la neuropraxia. Conclusión: el caso presentado demuestra el valor actual de los estudios de IRM con técnica neurográfica en la evaluación de la patología de los nervios periféricos. Es fundamental utilizar secuencias adecuadas, realizar un estudio comparativo bilateral y en lo posible usar medios de contraste endovenoso para aumentar la sensibilidad. Estos hallazgos resultan de gran importancia a la hora de planificar la estrategia quirúrgica.

Objective: Demonstrate the usefulness of Magnetic Resonance Imaging (MRI) with equipment 3 Tesla using neurographics specific sequences and use of intravenous contrast can locate the area of nerve injury.Clinical case: 17 year old woman with hypoesthesia and paresthesia in the anterior and lateral region of the left thigh, the study of Magnetic Resonance Imaging (MRI) equipment Philips Achieva 3 T, using neurographic protocol and intravenous contrast, showing thickening and changes signal nerve and post-contrast enhancement characteristic in neuropraxia.Conclusión: the case presented shows the current value of MRI studies with neurographics technique in assessing the pathology of peripheral nerves. It is essential to use appropriate sequences, make a bilateral comparative study and possible use of intravenous contrast media to increase sensitivity. These findings are of great importance when planning the surgical strategy.

Microanatomy of the lateral femoral cutaneous nerve in relation to inguinal ligament and its clinical importance / Microanatomia do nervo cutâneo femoral lateral em relação ao ligamento inguinal e sua importância clínica

BACKGROUND: A better knowledge of the composition and properties of connective tissue related to the Lateral Femoral Cutaneous Nerve (LFCN) and to the Inguinal Ligament may be important to understand the diagnosis and treatment applicable to injuries such as meralgia paresthetica. OBJECTIVE: To determine the relative amounts of the non-fascicular components in the following areas: (i) proximal to the inguinal ligament [LFCN-1], (ii) deep to the inguinal ligament [LFCN-2], or (iii) distal to LFCN-2 [LFCN-3]. These amounts were discriminated as adipose [FAT] and non-adipose (connective) [NON-FAT] tissues. METHOD: Samples of LFCN-1, LFCN-2 and LFCN-3 from 21 human cadaveric samples were used. Paraffin sections of these structures were processed by Masson's trichrome stain for connective tissue. The number of fascicles was counted in each of these structures; FAT and NON-FAT areas were determined in the non-fascicular areas of the structures. RESULTS: There were more fascicles in LFCN-3 vs. LFCN-1 or LFCN-2; there was more NON-FAT vs. FAT in LFCN-2 vs. LFCN-1 and LFCN-3; inversely, there was more FAT vs. NON-FAT in LFCN-3 vs. LFCN-1 and LFCN-2. All of these comparisons were statistically significant. CONCLUSION: The presence of a higher content of NON-FAT in LFCN-2 and FAT in LFCN-3 may help to explain meralgia paresthetica resulting from compression or focal entrapment of the Lateral Femoral Cutaneous Nerve as it passes deep relative to the inguinal ligament.

TEMA: Um melhor conhecimento da composição e propriedades do tecido conjuntivo relacionadas ao Nervo Cutâneo Femoral Lateral (NCFL) e ao Ligamento Inguinal pode ser importante para compreender o diagnóstico e o tratamento aplicável a lesões como a meralgia parestética. OBJETIVO: Determinar as quantidades relativas dos componentes não-fasciculares nas seguintes áreas: (i) proximal ao ligamento inguinal [NCFL-1], (ii) em profundidade ao ligamento inguinal [NCFL-2], ou (iii) distal a NCFL-2 [NCFL-3]. Esses valores foram discriminados como tecido conjuntivo adiposo [FAT] ou não-adiposo [NON_FAT]. MÉTODO: Foram utilizadas amostras de NCFL-1, NCFL-2 e NCFL-3 a partir de 21 amostras de cadáveres humanos. As secções em parafina destas estruturas foram processadas por coloração Masson para tecido conjuntivo. O número de fascículos foi contado em cada uma destas estruturas; áreas de gordura e sem gordura foram determinadas nas áreas não-fasciculares das estruturas. RESULTADOS: Foram contados mais fascículos em NCFL-3 vs. NCFL-1 ou NCFL-2; havia mais NON-FAT vs. FAT em NCFL-2 vs. NCFL-1 e NCFL-3; inversamente, houve mais FAT vs. NON-FAT em NCFL-3 vs. NCFL-1 e NCFL-2. Todas estas comparações foram estatisticamente significativas. CONCLUSÃO: A presença de um maior teor de NONFAT em NCFL-2 e FAT em NCFL-3 pode ajudar a explicar o aparecimento de paresthetica meralgia resultante da compressão ou encarceramento focal do Nervo Cutâneo Femoral Lateral que passa profundamente ao ligamento inguinal.

Ultrasound-Guided Lateral Femoral Cutaneous Nerve Conduction Study

OBJECTIVE: To verify the utility of the lateral femoral cutaneous nerve (LFCN) ultrasound-guided conduction technique compared to that of the conventional nerve conduction technique. METHODS: Fifty-eight legs of 29 healthy participants (18 males and 11 females; mean age, 42.7+/-14.9 years) were recruited. The conventional technique was performed bilaterally. The LFCN was localized by ultrasound. Cross-sectional area (CSA) of the LFCN and the distance between the anterior superior iliac spine (ASIS) and the LFCN was measured. The nerve conduction study was repeated with the corrected cathode location. Sensory nerve action potential (SNAP) amplitudes of the LFCN were recorded and compared between the ultrasound-guided and conventional techniques. RESULTS: Mean body mass index of the participants was 23.7+/-3.5 kg/m2, CSA was 4.2+/-1.9 mm2, and the distance between the ASIS and LFCN was 5.6+/-1.7 mm. The mean amplitude values were 6.07+/-0.52 microV and 6.66+/-0.54 microV using the conventional and ultrasound-guided techniques, respectively. The SNAP amplitude of the LFCN using the ultrasound-guided technique was significantly larger than that recorded using the conventional technique. CONCLUSION: Correcting the stimulation position using the ultrasound-guided technique helped obtain increased SNAP amplitude.

Ultrasound-guided Nerve Block for Skin Grafting on Large Diabetic Ulcer of Foot and Leg: A Technical Report / 대한족부족관절학회지

Skin grafting is often required for diabetic ulcerative foot lesions. In skin grafting, effective regional or local anesthesia into the donor and recipient areas plays a significant role in continuous control of pain. We report on a technique of ultrasound-guided nerve block on the femoral, sciatic, and lateral femoral cutaneous nerves in large split-thickness skin grafting for ulcer of the foot and leg.

Ultrasound-Guided Pain Interventions: A Review of Techniques for Peripheral Nerves

Ultrasound has emerged to become a commonly used modality in the performance of chronic pain interventions. It allows direct visualization of tissue structure while allowing real time guidance of needle placement and medication administration. Ultrasound is a relatively affordable imaging tool and does not subject the practitioner or patient to radiation exposure. This review focuses on the anatomy and sonoanatomy of peripheral non-axial structures commonly involved in chronic pain conditions including the stellate ganglion, suprascapular, ilioinguinal, iliohypogastric, genitofemoral and lateral femoral cutaneous nerves. Additionally, the review discusses ultrasound guided intervention techniques applicable to these structures.

Clinical and Electrophysiological Characteristics of Meralgia Paresthetica / 대한임상신경생리학회지

BACKGROUND: Meralgia paresthetica (MP) is a mononeuropathy affecting the lateral femoral cutaneous nerve. The disease is often diagnosed clinically, but electrophysiological tests play an important role. The aim of this study is to clarify clinical characteristics of MP as well as the role of sensory nerve conduction study (NCS) in the diagnosis of MP. METHODS: Sixty-five consecutive patients with clinical diagnosis of MP between March 2001 and June 2012 were retrospectively reviewed at a single tertiary center. General demographics, clinical characteristics and sensory NCS findings were investigated. Measurements of sensory NCS included the baseline-to-peak amplitude, side-to-side amplitude ratio and the conduction velocity. To compare between the normal and abnormal NCS groups, independent t-tests and chi-square test were performed. RESULTS: Sixty-five patients had male predominance (56.9%) with mean age of 48.4+/-13.4 years (range: 16-75). Seven patients (13.5%) had undergone operation or procedure before the symptom onset. The sensory nerve action potentials were obtainable in 52 (80%) of 65 clinically diagnosed MP patients. Sensory NCS revealed abnormalities in 38 patients (73.1%), and others (n=14, 26.9%) showed normal findings. Between the normal and abnormal NCS groups, there is no statistically significant difference on demographics or clinical features. CONCLUSIONS: We clarify the clinical features and sensory NCS findings of MP patients. Due to several limitations of sensory NCS, the diagnosis of MP could be accomplished both clinically and electrophysiologically.

Neurolysis for Megalgia Paresthetica

OBJECTIVE: Meralgia paresthetica (MP) is a syndrome of pain and/or dysesthesia in the anterolateral thigh that is caused by an entrapment of the lateral femoral cutaneous nerve (LFCN) at its pelvic exit. Despite early accounts of MP, there is still no consensus concerning the effectiveness of neurolysis or transaction treatments in the long-term relief for medically refractory patients with MP. We retrospectively analyzed available long-term results of LFCN neurolysis for medically refractory MP in an effort to clarify this issue. METHODS: During the last 7 years, 11 patients who had neurolysis for MP were enrolled in this study. Nerve entrapment was confirmed preoperatively by electrophysiological studies or a positive response to local anesthetic injection. Decompression of the LFCN was performed at the level of the iliac fascia, inguinal ligament, and fascia of the thigh distally. The outcome of surgery was assessed 8 weeks after the procedure followed at regular intervals if symptoms persisted. RESULTS: Twelve decompression procedures were performed in 11 patients over a 7-year period. The average duration of symptoms was 8.5 months (range, 4-15 months). The average follow-up period was 33 months (range, 12-60 months). Complete and partial symptom improvement were noted in nine (81.8%) and two (18.2%) cases, respectively. No recurrence was reported. CONCLUSION: Neurolysis of the LFCN can provide adequate pain relief with minimal complications for medically refractory MP. To achieve a good outcome in neurolysis for MP, an accurate diagnosis with careful examination and repeated blocks of the LFCN, along with electrodiagnosis seems to be essential. Possible variation in the course of the LFCN and thorough decompression along the course of the LFCN should be kept in mind in planning decompression surgery for MP.

A Case of Lateral Femoral Cutaneous Neuropathy after Renal Transplantation / 대한신장학회지

A few cases of Lateral femoral cutaneous neuropathy that developed after renal transplantation have been reported in western literature but there is no reported case in Korea. It may develop from one to nine days after surgery; the clinical course is favorable but the incidence is not low. According to the reported cases of western literature, the major causes of lateral femoral cutaneous neuropathy after renal transplantation included steal phenomenon, clamping the internal iliac artery during surgery, direct surgical damage to the vessels supplying the femoral nerve, and direct compression of the femoral nerve. We experienced one case of lateral femoral cutaneous nerve neuropathy after renal transplantation that developed at postoperative day (POD) 7. It was partially improved symptomatically after POD 60, so we reported this case with a brief review of literatures.

Ultrasound-guided Lateral Femoral Cutaneous Nerve Block in Meralgia Paresthetica

Meralgia paresthetica is a rarely encountered sensory mononeuropathy characterized by paresthesia, pain or sensory impairment along the distribution of the lateral femoral cutaneous nerve (LFCN) caused by entrapment or compression of the nerve as it crossed the anterior superior iliac spine and runs beneath the inguinal ligament. There is great variability regarding the area where the nerve pierces the inguinal ligament, which makes it difficult to perform blind anesthetic blocks. Ultrasound has developed into a powerful tool for the visualization of peripheral nerves including very small nerves such as accessory and sural nerves. The LFCN can be located successfully, and local anesthetic solution distribution around the nerve can be observed with ultrasound guidance. Our successfully performed ultrasound-guided blockade of the LFCN in meralgia paresthetica suggests that this technique is a safe way to increase the success rate.

Pulsed Radiofrequency Neuromodulation Treatment on the Lateral Femoral Cutaneous Nerve for the Treatment of Meralgia Paresthetica

We describe a rare case of pulsed radiofrequency treatment for pain relief associated with meralgia paresthetica. A 58-year-old female presented with pain in the left anterior lateral thigh. An imaging study revealed no acute lesions compared with a previous imaging study, and diagnosis of meralgia paresthetica was made. She received temporary pain relief with lateral femoral cutaneous nerve blocks twice. We performed pulsed radiofrequency treatment, and the pain declined to 25% of the maximal pain intensity. At 4 months after the procedure, the pain intensity did not aggravate without medication. Pulsed radiofrequency neuromodulation treatment on the lateral femoral cutaneous nerve may offer an effective, low risk treatment in patients with meralgia paresthetica who are refractory to conservative medical treatment.

Prone Position-Related Meralgia Paresthetica after Lumbar Spinal Surgery : A Case Report and Review of the Literature

Lateral femoral cutaneous neuropathy occurring during spinal surgery is frequently related to iliac bone graft harvesting, but meralgia paresthetica (MP) can result from the patient being in the prone position. Prone position-related MP is not an uncommon complication after posterior spine surgery but there are only few reports in the literature on this subject. It is usually overlooked because of its mild symptoms and self-limiting course, or patients and physicians may misunderstand the persistence of lower extremity symptoms in the early postoperative period to be a reflection of poor surgical outcome. The authors report a case of prone position-related MP after posterior lumbar interbody fusion at the L3-4 and reviewed the literature with discussion on the incidence, pathogenesis, and possible risk factors related to this entity.

Repair of dorsal skin defects of the foot with nerved anterolateral thigh flap / 中国微创外科杂志

Objective To discuss the use of anterolateral thigh flap for the repair of large defects of soft tissues in dorsum of the foot.Methods A total of 38 cases of dorsal skin defects of the foot was repaired with the anterolateral thigh flap containing the lateral femoral cutaneous nerves.Corresponding vessels and sensory nerves were anastomosed. Results The flaps survived in all the cases.The sensation in dorsum of the foot recovered completely within 2~4 months after operation and the touch,pain,and temperature sensation of the donor area recovered within 3~6 months after operation.Follow-up observations in the 38 cases for 4~18 months(mean,9 months) showed flaps with normal color,texture,and appearance.Conclusions It is recommended to repair large-scale defects in dorsum of the foot with nerved anterolateral thigh flap.

Anatomical Considerations of the Lateral Femoral Cutaneous Nerve Related to Nerve Conduction Study

OBJECTIVE: Lateral femoral cutaneous nerve (LFCN) conduction study is an objective measure for the diagnosis of meralgia paresthetica. Sensory nerve action potential of LFCN is not frequently evoked because of anatomical variations around inguinal area. The purpose of this study is to support the diagnosis of meralgia paresthetica by considering anatomical variations of LFCN in Korean adult cadavers. METHOD: Eighteen lower limbs of total nine adult cadavers were studied. Men were five and women were four. The points that LFCN or the main branch of LFCN met the imaginary line from anterior superior iliac spine (ASIS) to pubic tubercle and to lateral border of patella were recorded, respectively and distances from ASIS to those points were measured. RESULTS: The distance from ASIS to the point that LFCN or the main branch of LFCN met the imaginary line from ASIS to pubic tubercle and to lateral border of patella was respectivlely 1.36+/-0.68 cm (minimal 0.2, maximal 3.0) and 10.74+/-5.68 (minimal 3.3, maximal 20.1) cm. There was no significant distance difference between men and women. CONCLUSION: This study showed anatomic variations of LFCN around ASIS and femoral part. This knowledge may help LFCN conduction study for the diagnosis of meralgia paresthetica.

Anatomical variation course of the lateral femoral cutaneous nerve as it exits the pelvis in Thais from the central region.

The aim of this study was to examine in detail the course and location of lateral femoral cetaneous nerve (LFCN) as it emerges from the pelvis in Thais. The anatomy of the LFCN was studied through the dissection of 107 halves of formalin-embalmed Thai cadavers ranging in age from 37 to 94 years. The LFCN is formed by the union of posterior divisions of ventral rami of the second and third lumbar spinal nerves (L2 – L3). The site at which the nerve exits the pelvis is quite variable. Depending on the anatomical location which varies from superficial and posterior, to medial and deep, to anterior superior iliac spine (ASIS) and origin of the sartorius muscle, five different types as identified by Aszman et all1 were confirmed : type A, posterior to the anterior superior iliac spine across the iliac crest (1.86%); type B, medial to the anterior superior iliac spine and ensheathed in the inguinal ligament (9.34%); type C, medial to the anterior superior iliac spine and ensheathed in the tendinous origin of the sartorius muscle (46.72%); type D, medial to the anterior superior iliac spine located in the interval between sartorius muscle and iliopsoas muscle deep to the inguinal ligament (40.18%); type E, medial to the anterior superior iliac spine, deep to the inguinal ligament, overlying the iliopsoas fascia, and contributing the femoral branch of genitofemoral nerve (1.46%). The majority of the LFCN course and location as it exits the pelvis are type C (46.72%), and type D (40.18%). There is no statistical difference with regard to either gender or side of thigh.

Lateral Femoral Cutaneous Nerve SomatosensoryEvoked Potential Study in Normal Adults / 영남의대학술지

BACKGROUND: Meralgia paresthetica(MP) which is characterized by paresthesias and sensory impairment without motor weakness in the anterolateral aspects of the thighis produced by compression of the lateral femoral cutaneous nerve(LFCN). Even though the diagnosis of MP is mostly based on the clinical symptoms, electrophysiologic study is mandatory to confirm the disease objectively. It has been known that Somatosensory evoked potential(SSEP) study of LFCN is a simple and very useful method to evaluate MP, so we studied SSEP of LFCN in normal adults and offer normal values. MATERIALS AND METHODS: Thirty six normal adults(23 males and 13 females) ages from 21 to 73 years old(mean+/-SD:42.06+/-15.74) were studied SSEP of LFCN bilaterally. The stimulation site was anterolateral aspect of thighs and the recording site was Cz'. RESULTS: The mean values(msec+/-SD) of LPo, SPdegree, LN, and SN1 of all subjects were 35.10(+/-2.42), 33.80(+/-2.4), 43.68(+/-1.88) and 42.16(+/-2.12) and the mean values(msec+/- SD) of DPo, DNl and DA(tw+/-SD) were 1.3O(fi1.14), 1.52(+/-1.38) and 0.32(+/-0.33). CONCLUSION: For the diagnosis of MP, comparison of latency difference between both sides is more reliable than simple value of latency itself because of individual differences of body types. According to our results, the latency difference should be less than 2 msec and the amplitude difference was less than 1.6 times in normal adults.