We describe a lumbosacral plexus neuropathy case in childhood in which detailed investigation, including eletromyography and magnetic resonance imaging, was normal. Muscle biopsy showed mild denervation. No underlyng condition was detected. The patient presented with pain, weakness and light atrophy in left lower limb, reduced reflex at the ankle, loss of the quadriceps reflex and paresthesy in involved limb. Recovery after one year was almost complete, with persistent slight weakness and atrophy.
lumbosacral plexus; idiopathic neuropathy