Meralgia_Paresthetica.pptx

This presentation tells about meralgia paresthetica

1. Meralgia Paresthetica “ Entrapment of lateral femoral cutaneous nerve ” By Ali Noureldin El Sayed

2. Anatomy

3. Anatomy of lateral femoral cutaneous nerve The lateral femoral cutaneous nerve is a branch of the lumbar plexus, exiting the spinal cord between the L2 and L3 vertebrae. It emerges at the lateral edge of the psoas muscle group, below the ilioinguinal nerve, and then passes beneath the iliac fascia and the inguinal ligament. It divides into two branches – anterior and posterior – eight to ten centimeters below the spine, where it also emerges from the fascia lata. The anterior branch supplies the skin of the anterior and lateral regions of the thigh to the knee, while the posterior branch supplies the lateral portion of the thigh, from the greater trochanter in the hip, to mid-thigh, just above the knee.

4. Signs and symptoms Pain  on the outer side of the thigh, occasionally extending to the outer side of the knee, usually constant. A burning sensation, tingling, or  numbness  in the same area. Occasionally, aching in the groin area or pain spreading across the  buttocks Usually more sensitive to light touch than to firm pressure Hypersensitivity to heat (warm water from shower feels like it is burning the area) Occasionally, patients may complain of itching sensation rather than pain in the affected area.

5. Causes: Mechanical: Pregnancy (or any condition that increases abdominal pressure). Obesity. wearing tight clothing/belts in the waist area. different leg lengths. pubic symphysis (pelvic girdle) dysfunction. Metabolic: neuropathy (from diabetes). hypothyroidism. lead poisoning. Iatrogenic: Prolonged traction during spine surgery. injury to the nerve during retroperitoneal dissection.

6. Etiology

7. Etiology Reviewing the anatomy of the LFCN is essential for understanding the mechanism of its injury (see the images below). 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.

8. Investigation

9. Neurological examination: sensory testing with pinprick and light touch should show an area along the upper outer thigh that has reduced sensation to these modalities. There should be a normal motor examination, negative straight leg raise test, and no hip/knee joint abnormality. ’’No Motor Weakness’’ Physical Examination

10. Pelvic Compression: Highly sensitive and the diagnosis can often be made with this test alone. Position: Side-lying with their symptomatic side facing up Steps: . The examiner applies a downward, compression force to the pelvis and maintains pressure for 45 seconds. If the patient reports an alleviation of symptoms the test is considered positive. The test is based upon the idea that the LCNT is compressed by the inguinal ligament and a downward force to the innominate will relax the ligament and temporarily alleviate the patient's symptoms. Physical Examination

11. Pelvic Compression Test

12. Physical Examination Neurodynamic Testing : Position: Side-lying with the symptomatic side up and the bottom knee bent. Steps: The examiner stabilizes the pelvis with the cranial hand and grasps the lower extremity at the knee with the caudal hand. The examiner then bends the knee and adducts the hip in order to tension the LCNT A positive test would be the reproduction of the patient's neurologic symptoms versus feeling tension in the soft‐tissue structures of the hip.

13. Neurodynamic Testing for LFCN

14. Electrodiagnosis Nerve Conduction Study : Sensory nerve conduction velocity (SNCV): The normal range for SNCV in the lateral femoral cutaneous nerve is typically between 40-60 meters/second (m/s). Sensory nerve action potential (SNAP): The normal amplitude for SNAP in the lateral femoral cutaneous nerve is typically between 10-30 microvolts (μV). Normal motor nerve conduction: As the LFCN is a purely sensory nerve and does not supply any muscles, motor nerve conduction studies will typically be normal in meralgia paresthetica. it is important to note that, as with most studies, there are limitations to nerve conduction studies examining the LCNT. One such limitation is that among individuals with increased adipose tissue which makes this type of study difficult to perform.

15. Electrodiagnosis Lateral Femoral Cutaneous Nerve Block by Lidocaine : The patient lies on their back, and the injection site is cleaned and numbed with a local anesthetic. The needle is then inserted near the lateral femoral cutaneous nerve, and the anesthetic medication e.g: Lidocaine is injected.

16. EMG : The needle EMG study is normal in meralgia paresthetica but abnormal in characteristic patterns in radiculopathies, femoral ne uropathies, and plexopathies. Electrodiag no sis

17. Imaging Magnetic resonance imaging (MRI): This imaging technique can help to identify the cause of nerve compression, such as a herniated disc or a tumor . In meralgia paresthetica, MRI may show a thickening or compression of the lateral femoral cutaneous nerve as it passes through the inguinal ligament. Ultrasound: Ultrasound can be used to visualize the lateral femoral cutaneous nerve and may reveal compression , thickening , or swelling of the nerve. Computed tomography (CT) scan: This imaging technique can help to identify bony abnormalities that may be causing nerve compression, such as a bone spur or herniated disc .

18. Intervention

19. Intervention Treatment For most people, the symptoms of meralgia paresthetica ease in a few months. Treatment focuses on relieving nerve compression. Conservative measures Wearing looser clothing Losing excess weight Taking OTC pain relievers such as acetaminophen (Tylenol, others), ibuprofen (Advil, Motrin IB, others) or aspirin Medications: If symptoms persist for more than two months or your pain is severe, treatment might include : Corticosteroid injections. Injections can reduce inflammation and temporarily relieve pain. Possible side effects include joint infection, nerve damage, pain and whitening of skin around the injection site.

20. Physical Therapy Management Kinesio-Taping : Small-scale pilot studies assert that Kinesio-Taping must be part of the therapy in patients with MP. Kinesio-Taping would reduce the symptoms experienced by a patient. The exact physiological mechanisms are still unknown. This method is hypothesized to help increase lymphatic and vascular flow, decrease pain, enhance normal muscle function, increase proprioception, and help correct possible articular malalignments. Despite the hypothesized benefits, the current evidence is insufficient for MP. Future randomized placebo controlled trials are needed Acupuncture The benefits of Acupuncture as an intervention (e.g. needling and cupping) for MP has been shown in clinical trials. The available literature suggests that acupuncture may be effective in the treatment of MP. However, the exact physiological mechanisms are still under investigation. Further investigation is needed Neurostimulation Techniques Neurostimulation techniques including transcranial magnetic stimulation (TMS) and cortical electrical stimulation (CES), spinal cord stimulation (SCS) and deep brain stimulation (DBS) have also been found effective in the treatment of neuropathic pain as MP

21. Physical Therapy Management Transcutaneous Electrical Nerve Stimulation Transcutaneous electrical nerve stimulation (TENS or TNS) is effective in the treatment of painful peripheral neuropathy like MP. It is suggested that TENS activates central mechanisms to provide analgesia. Low frequency TENS activates μ-opioid receptors in spinal cord and brain stem while high frequency TENS produces its effect via δ-opioid receptors Exercise Exercising for just 30 minutes a day on at least three or four days a week will help you with chronic pain management by increasing: Muscle Strength Endurance Stability in the joints Flexibility in the muscles and joints

22. References

23. References 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 . 2009 Apr. 22(3):365-70.