333 - Right leg weakness following extended labor in lithotomy position

Case Diagnosis: Right femoral neuropathy and L4-L5 disc herniation

Case Description: A 35-year-old woman presented with acute right leg weakness and numbness following extended labor in hip flexion using a birthing bar. Following epidural removal, her right knee buckled with weight bearing and she had persistent leg numbness. On outpatient evaluation, right hip flexor and knee extensor strength were 3/5 and 2/5, respectively. Right patellar reflex was absent and sensation was decreased from the anteromedial knee to the medial malleolus. EMG revealed denervation of the right vastus lateralis and rectus femoris, indicative of femoral neuropathy, with no evidence of radiculopathy. MRI of lumbar spine and lumbosacral plexus revealed normal appearing femoral nerve and large right L4-L5 paracentral disc herniation severely compressing the L4 nerve root. She had gradual improvement in strength over two months with physical therapy. However, due to progressively worsening lateral hip/buttock pain reproduced with slump test, she elected to undergo a right L4-L5 hemilaminectomy and microdiscectomy.

Discussions: Overlapping clinical symptoms of femoral neuropathy and L4 radiculopathy create a diagnostic and therapeutic challenge. While rare complications of vaginal delivery, prolonged pushing in hip flexion may have simultaneously caused compressive injury of the femoral nerve as well as L4-L5 disc herniation. Though early electrodiagnostic studies were suggestive of a femoral nerve injury, progressive neuropathic symptoms in the lateral hip consistent with L4 nerve root compression led to surgical intervention despite gradual improvements in strength. Post-operative follow-up to evaluate symptoms following nerve root decompression may be helpful to clarify the underlying etiology of her symptoms.

Conclusions: Multimodal diagnostic testing may be critical in cases where the clinical presentation includes symptoms consistent with both acute peripheral mononeuropathy and radiculopathy. Furthermore, shared decision making between patients and clinicians should focus on relieving the symptoms that the patient finds most debilitating, rather than solely focusing on diagnostic tests results.