Have You Ever Heard about Meralgia Paresthetica?

Kim, Gun Bea; Kwon, In Ho; Park, Won Nyung; Gu, Hong Du

Abstract

Meralgia paresthetica (MP), first described in 1878, is a sensory mononeuropathy of the lateral femoral cutaneous nerve (LFCN) characterized by pain, tingling, numbness, and paresthesias localized to the anterolateral thigh. There are many etiologies for MP, including those that are spontaneous (idiopathic, metabolic or mechanical) and iatrogenic (surgery, trauma). A 46-year-old female came to our emergency department (ED) with a right hip pain that developed after two days of an altered mental status from high amounts of multiple drugs (benzodiazepine, SSRI, and antipsychotics) to commit suicide. Her past medical and surgical histories were unremarkable. In addition, her vital signs were stable and her electrocardiography was unremarkable. On the other hand, laboratory tests showed an elevated creatinine kinase 14787 IU/L (normal range, 26~140 IU/L) and urine myoglobin >1000 ng/mL (normal range, 0~10 ng/mL). She was admitted to our ED for the management of rhabdomyolysis. The patient didn't slip down and slept on her right side for a long period. An initial pelvis and femur x-ray ruled out a fracture and a straight leg raise test was negative. We took a lumbar spine x-ray to rule out a herniated intervertebral disk because she complained of pain in the second and third lumbar distribution of her right thigh. These x-rays were unremarkable. We presumed she had a hip and thigh contusion and gave her painkillers, but her symptoms did not improved. After a day, the patient complained of numbness (5/10) rather than pain. We then suspected peripheral neuropathy. Her electromyography and nerve conduction velocity confirmed right LFCN neuropathy, MP. MP is often clinically diagnosed and treated conservatively. It is a neurologic disorder due to the entrapment of the LFCN. This case shows that a long period lacking in movement can cause MP. In future cases, the possibility of peripheral neuropathy should be considered, especially in mentally altered patients after drug intoxication.