Monday, July 10, 2006

Hanging leg syndrome sciatic & femoral nn

Scherer et al. Hanging leg syndrome: COmbined bilateral femoral and sciatic neuropathies. Neurology 2006; 66:1124-1125.

A 43 year old man fell asleep after etoh intoxication with both legs hanging over the end of the bed. He awoke 12 hours later unable to feel or move his legs. Bowel, bladder and sexual function were normal.

Two months later with persisting paraparesis he was evaluated. He had an impression at the gluteal fold. He had paralysis of bilateral knee extensors, foot dorsiflexors, and plantar flexors with a flicker of contraction at the knee flexors. Hip flexion, abduction and adduction were normal bilaterally. He had absent DTR's in the patellae and Achilles reflexes and toes were mute.

NCS showed absent bilateral peroneal motor and sural and superfical peroneal sensory responses. and right femoral motor responses. Peroneal response recording from the tibialis anterior was absent. Needle EMG showed fibrillation potentials and positive sharp waves in bilateral vastus lateralis, anterior tibialis, medial gastrocnemius, and short and long head of the biceps femori. Lumbar paraspinal muscles showed rare denervation at one or two levels.

The mechanism suspected for femoral injuries are traction and compression of the inguinal nerve as it passes over the fulcrum of the superior pubic ramus. Compressive sciatic neuropathies occur from sitting on toilet seats or prolonged sitting in the lotus position.

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