eMedicine Specialties > Neurology > Electromyography and Nerve Conduction Studies

Meralgia Paresthetica

Author: Elizabeth A Sekul, MD, Associate Professor, Department of Neurology, Medical College of Georgia
Contributor Information and Disclosures

Updated: Aug 18, 2009

Introduction

Background

A painful mononeuropathy of the lateral femoral cutaneous nerve (LFCN), meralgia paresthetica is commonly due to focal entrapment of this nerve as it passes through the inguinal ligament. Rarely, it has other etiologies such as direct trauma, stretch injury, or ischemia. It typically occurs in isolation. The clinical history and examination is usually sufficient for making the diagnosis. However, the diagnosis can be confirmed by nerve conduction studies. Treatment is usually supportive. The LFCN is responsible for the sensation of the anterolateral thigh. It is a purely sensory nerve and has no motor component.

Pathophysiology

Reviewing the anatomy of the LFCN is essential for understanding the mechanism of its injury (see Media files 1-2). The LFCN originates directly from the lumbar plexus and has root innervation from L2-3. The nerve runs through the pelvis along the lateral border of the psoas muscle to the lateral part of the inguinal ligament. Here, it passes to the thigh through a tunnel formed by the lateral attachment of the inguinal ligament and the anterior superior iliac spine. The crossover into the thigh is the most common site of entrapment. The crossover typically occurs 1 cm medial to the anterior superior iliac spine; however, regional variations are common.1

Anatomy of the lateral femoral cutaneous nerve.

Anatomy of the lateral femoral cutaneous nerve.

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Anatomy of the lateral femoral cutaneous nerve.

Anatomy of the lateral femoral cutaneous nerve.



Sensory distribution of the lateral femoral cutan...

Sensory distribution of the lateral femoral cutaneous nerve.

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Sensory distribution of the lateral femoral cutan...

Sensory distribution of the lateral femoral cutaneous nerve.

Frequency

United States

In the general population, an incidence of 4.3 per 10,000 person years has been reported. 

Race

No racial predilection is known.

Sex

No gender proclivity is known.

Age

Lateral femoral cutaneous neuropathies are most common during middle age. However, they have been reported in all age groups. 

Clinical

History

  • When the LFCN is entrapped, paresthesias and numbness of the upper lateral thigh area are the presenting symptoms. The paresthesias may be quite painful.
  • Symptoms are typically unilateral.  However, they may be bilateral in up to 20% of cases.
  • Walking or standing may aggravate the symptoms; sitting tends to relieve them.

Physical

  • Examination reveals numbness of the anterolateral thigh in all or part of the area involved with the paresthesias.
  • Occasionally, patients are hyperesthetic in this area.
  • Tapping over the upper and lateral aspects of the inguinal ligament or extending the thigh posteriorly, which stretches the nerve, may reproduce or worsen the paresthesias.
  • Deep palpation just below the anterior superior iliac spine (pelvic compression testing) reproduces the symptoms. A study in 45 patients found that the pelvic compression test had a sensitivity of 95% and a specificity of 93.3% for meralgia paresthetica.2
  • Motor strength in the involved leg should be normal.

Causes

  • Pregnancy, tight clothing, and obesity predispose to compression of the nerve at the inguinal ligament.3,4,5 Tool belts worn by carpenters, duty belts worn by policemen, and body armor worn by soldiers may compress the LFCN.6  
  • Lying in the fetal position for prolonged periods also has been implicated, as has prone positioning after lumbar spinal surgery.7
  • Meralgia paresthetica is more common in diabetics than in the general population.
  • Although rare, impingement of the LFCN by masses (eg, neoplasms, contained iliopsoas hemorrhages) in the retroperitoneal space before it reaches the inguinal ligament can cause the same symptoms.

More on Meralgia Paresthetica

Overview: Meralgia Paresthetica
Differential Diagnoses & Workup: Meralgia Paresthetica
Treatment & Medication: Meralgia Paresthetica
Follow-up: Meralgia Paresthetica
Multimedia: Meralgia Paresthetica
References
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References

  1. Carai A, Fenu G, Sechi E, Crotti FM, Montella A. Anatomical variability of the lateral femoral cutaneous nerve: findings from a surgical series. Clin Anat. Apr 2009;22(3):365-70. [Medline].

  2. Nouraei SA, Anand B, Spink G, O'Neill KS. A novel approach to the diagnosis and management of meralgia paresthetica. Neurosurgery. Apr 2007;60(4):696-700; discussion 700. [Medline].

  3. Mondelli M, Rossi S, Romano C. Body mass index in meralgia paresthetica: a case-control study. Acta Neurol Scand. Aug 2007;116(2):118-23. [Medline].

  4. Chlebowski S, Bashyal S, Schwartz TL. Meralgia paresthetica: another complication of antipsychotic-induced weight gain. Obes Rev. Apr 1 2009;[Medline].

  5. Moucharafieh R, Wehbe J, Maalouf G. Meralgia paresthetica: a result of tight new trendy low cut trousers ('taille basse'). Int J Surg. Apr 2008;6(2):164-8. [Medline].

  6. Fargo MV, Konitzer LN. Meralgia paresthetica due to body armor wear in U.S. soldiers serving in Iraq: a case report and review of the literature. Mil Med. Jun 2007;172(6):663-5. [Medline].

  7. Cho KT, Lee HJ. Prone position-related meralgia paresthetica after lumbar spinal surgery : a case report and review of the literature. J Korean Neurosurg Soc. Dec 2008;44(6):392-5. [Medline].

  8. Hurdle MF, Weingarten TN, Crisostomo RA, Psimos C, Smith J. Ultrasound-guided blockade of the lateral femoral cutaneous nerve: technical description and review of 10 cases. Arch Phys Med Rehabil. Cctober 2007;77 (3):1362-4. [Medline].

  9. Tumber PS, Bhatia A, Chan VW. Ultrasound-guided lateral femoral cutaneous nerve block for meralgia paresthetica. Anesth Analg. Mar 2008;106(3):1021-2. [Medline].

  10. Grossman MG, Ducey SA, Nadler SS. Meralgia Paresthetica: diagnosis and treatment. Journal of the American Academy of Orthopaedic Sugeons. 2001;9:336-44. [Medline].

  11. Harney D, Patijn J. Meralgia paresthetica: diagnosis and management strategies. Pain Med. Nov-Dec 2007;8(8):669-77. [Medline].

  12. Jablecki CK. Postoperative lateral femoral cutaneous neuropathy. Muscle Nerve. Aug 1999;22(8):1129-31. [Medline].

  13. Seror P, Seror R. Meralgia paresthetica: clinical and electrophysiological diagnosis in 120 cases. Muscle Nerve. May 2006;33(5):650-4. [Medline].

  14. Turner OA, Taslitz N, Ward S. Lateral femoral cutaneous nerve of the thigh (meralgia paresthetica). Handbook of peripheral nerve entrapments. 1990;143-150.

  15. van Slobbe AM, Bohnen AM, Bernsen RM, et al. Incidence rates and determinants in meralgia paresthetica in general practice. J Neurol. Mar 2004;251(3):294-7. [Medline].

  16. Williams FH, Johns JS, Weiss JM, et al. Neuromuscular rehabilitation and electrodiagnosis. 1. Mononeuropathy. Arch Phys Med Rehabil. Mar 2005;86(3 Suppl 1):S3-10. [Medline].

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Further Reading

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Keywords

lateral femoral cutaneous mononeuropathy, entrapment of lateral femoral cutaneous nerve, paresthesias of upper lateral thigh area, numbness of upper lateral thigh area, meralgia paresthetica, obesity, contained iliopsoas hemorrhages, neoplasms in the retroperitoneal space, pregnancy, tight clothing

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Contributor Information and Disclosures

Author

Elizabeth A Sekul, MD, Associate Professor, Department of Neurology, Medical College of Georgia
Elizabeth A Sekul, MD is a member of the following medical societies: American Academy of Neurology, American Association of Neuromuscular and Electrodiagnostic Medicine, and Child Neurology Society
Disclosure: Nothing to disclose.

Medical Editor

Aashit K Shah, MD, Associate Professor of Neurology, Wayne State University; Program Director, Clinical Neurophysiology Fellowship, Department of Neurology, Detroit Medical Center
Aashit K Shah, MD is a member of the following medical societies: American Academy of Neurology, American Clinical Neurophysiology Society, and American Epilepsy Society
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: eMedicine Salary Employment

Managing Editor

Neil A Busis, MD, Chief, Division of Neurology, Department of Medicine, Head, Clinical Neurophysiology Laboratory, University of Pittsburgh Medical Center-Shadyside
Neil A Busis, MD is a member of the following medical societies: American Academy of Neurology and American Association of Neuromuscular and Electrodiagnostic Medicine
Disclosure: Nothing to disclose.

CME Editor

Selim R Benbadis, MD, Professor, Director of Comprehensive Epilepsy Program, Departments of Neurology and Neurosurgery, University of South Florida School of Medicine, Tampa General Hospital
Selim R Benbadis, MD is a member of the following medical societies: American Academy of Neurology, American Academy of Sleep Medicine, American Clinical Neurophysiology Society, American Epilepsy Society, and American Medical Association
Disclosure: Nothing to disclose.

Chief Editor

Nicholas Y Lorenzo, MD, Chief Editor, eMedicine Neurology; Consulting Staff, Neurology Specialists and Consultants
Nicholas Y Lorenzo, MD is a member of the following medical societies: Alpha Omega Alpha and American Academy of Neurology
Disclosure: Nothing to disclose.

 
 
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