Abstract
Background: Postpartum femoral nerve injury is not common, but neurologic insult with primary motor manifestation of quadriceps palsy is even rarer. This case reports the onset, neurophysiologic examination, and intervention in a 26-year-old primipara with such injury.
Study Design: A single-subject case report.
Case Description: Eleven days postparturition electrophysiologic examination and measurement of muscle performance were completed. Nerve conduction velocity showed significant axonal loss in the right femoral nerve, with mild slowing of conduction velocity. Electromyography noted isolated decreased recruitment and evidence of motor unit disintegration in the right femoral nerve distribution. Maximal voluntary isometric force of the right knee extensors was decreased by 67%. To facilitate recovery of quadriceps strength, daily neuromuscular electrical stimulation to maximal tolerance was initiated.
Outcomes: Two weeks after examination, the right maximal voluntary isometric force improved from 14 to 37 lb. Two weeks later, it improved to 74 lb. A second electromyography/nerve conduction velocity at 6 weeks revealed a 4-fold increase in axonal recruitment of the right femoral nerve to within 70% of the left. Electromyography failed to reveal any signs of denervation, with nearly full motor unit recovery.
Discussion: Quadriceps, but not iliopsoas, involvement suggested femoral nerve entrapment distal to the inguinal ligament-a rare presentation with more common symptoms being only sensory (ie, meralgia paresthestica) or involving the iliopsoas. Greater than 50% axon loss initially, but less than 50% at 6 weeks, suggested neuropraxia with rapidly recovering partial conduction block underlying the neurophysiologic findings. Early identification and supportive neuromuscular electrical stimulation for motor recovery likely facilitated resolution of the impairment.