Meralgia paraesthetica
3019206
221656654
2008-06-25T14:13:12Z
Preacherdoc
1181059
Citation needed
{{Infobox_Disease
| Name = {{PAGENAME}}
| Image = Gray826-LFC.png
| Caption = Innervation of [[lateral cutaneous nerve of thigh]] (shaded area) on right leg.
| Width = 60
| DiseasesDB = 31968
| ICD10 = {{ICD10|G|57|1|g|50}}
| ICD9 = {{ICD9|355.1}}
| ICDO =
| OMIM =
| MedlinePlus =
| eMedicineSubj = neuro
| eMedicineTopic = 590
| eMedicine_mult = {{eMedicine2|orthoped|416}}, {{eMedicine2|pmr|76}}
| MeshID =
}}
'''Meralgia paraesthetica''' or '''meralgia paresthetica''' (see [[spelling differences]]) (me-ral'-gee-a par-es-thet'-i-ka) is numbness or pain in the outer thigh '''not''' caused by injury to the thigh, but by injury to a [[nerve]] that extends from the [[thigh]] to the [[spinal column]]. This [[chronic (medicine)|chronic]] [[neurological disorder]] involves a single [[peripheral nerve]], namely the [[Lateral cutaneous nerve of thigh]] (also called the ''Lateral femoral cutaneous nerve''). The term ''meralgia paraesthetica'' comprises four [[Greek language|Greek]] roots, which together denote "thigh pain involving anomalous perception."
==Aetiology==
[[Image:Gray546-LFC.png|thumb|left|[[Lateral cutaneous nerve of thigh]] and other structures passing between the left inguinal ligament and ilium, top view.]]
The lateral cutaneous nerve of thigh most often becomes injured by entrapment or compression where it passes between the upper front hip bone ([[Ilium (bone)|ilium]]) and the [[inguinal ligament]] near the attachment at the [[anterior superior iliac spine]] (the upper point of the hip bone). Less commonly, the nerve may be entrapped by other anatomical or abnormal structures, or damaged by [[diabetic neuropathy|diabetic]] or other [[neuropathy]] or trauma such as from [[seat belt]] injury in an accident.
Restrictive clothing and weight gain are two common ways that the nerve may be pinched. Pressure may also be caused by long periods of standing or leg exercise which increase tension on the inguinal ligament.
This syndrome is also known as "Calvin Klein Syndrome," from compression of the lateral femoral cutaneous nerve - L2-L3 by tight-fitting pants{{Fact|date=June 2008}}.
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== 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
* Multiple bee-sting like pains in the affected area
* Occasionally, aching in the groin area or pain spreading across the buttocks
* Usually more sensitive to light touch than to firm pressure
* Hyper sensitivity to heat (warm water from shower feels like it is burning the area)
== Diagnosis ==
Diagnosis is largely made on the description given by the patient and relevant details about recent surgeries, injury to the hip, or repetitive activities that could irritate the nerve. An examination will check for any sensory differences between the affected leg and the other leg. An abdominal and pelvic examination may be required to exclude any problems in those areas.
[[Electromyography]] (EMG) nerve conduction studies may be required. X-rays may be needed to exclude bone abnormalities that might put pressure on the nerve; likewise CT or MRI scans to exclude soft tissue causes such as a tumor.
== Treatment ==
Treatments will vary. In most cases, the best treatment is to remove the cause of the compression by modifying patient behavior, in combination with medical treatment to relieve inflammation and pain. The following treatments are examples.
* Rest periods to interrupt long periods of standing, walking, cycling, or other aggravating activity
* Weight loss in overweight individuals and exercise to strengthen abdominal muscles<ref name="UCLA">{{cite web | title=Meralgia Paresthetica | work=Peripheral Nerve Diseases & Disorders | url=http://neurosurgery.ucla.edu/Diagnoses/PeripheralNerve//PeripheralNerveDis_3.html | publisher=UCLA Neurosurgery | accessdate=2007-04-09}}</ref>
* Wearing clothing that is loose at the upper front hip area
* Heat, ice, or electrical stimulation<ref name="eMedicineOrthop">Meralgia Paresthetica {{eMedicine|orthoped|416}}</ref>
* [[Nonsteroidal anti-inflammatory]] medications for 7-10 days<ref name="UCLA">{{cite web | title=Meralgia Paresthetica | work=Peripheral Nerve Diseases & Disorders | url=http://neurosurgery.ucla.edu/Diagnoses/PeripheralNerve//PeripheralNerveDis_3.html | publisher=UCLA Neurosurgery | accessdate=2007-04-09}}</ref>
It may take time for the pain to stop and, in some cases, numbness will persist despite treatment. In severe cases a local nerve block can be done at the inguinal ligament using a combination of local anaesthetic ([[lidocaine]]) and [[corticosteroid]]s to give relief that may last several weeks. [[Chronic_pain#Pain_modifiers|Pain modifier drugs]] for [[neuralgia|neuralgic pain]] (such as [[amitriptyline]], [[carbamazepine]] or [[gabapentin]]) may be tried,<ref name="eMedicineOrthop">Meralgia Paresthetica {{eMedicine|orthoped|416}}</ref> but are often not as helpful in the majority of patients.<ref name="eMedicineNeuro">Meralgia Paresthetica {{eMedicine|neuro|590}}</ref>
In persistent and severe cases, surgery may be needed to decompress the nerve<ref name="eMedicineNeuro"/> or as a last resort to resect the nerve.<ref name="eMedicineOrthop">Meralgia Paresthetica {{eMedicine|orthoped|416}}</ref> The latter treatment results in permanent numbness in the area.
==Footnotes==
<references/>
{{PNS diseases of the nervous system}}
[[Category:Neurological disorders]]
[[de:Meralgia paraesthetica]]