Spontaneous non-traumatic anterior compartment syndrome with peroneal neuropathy and favorable outcome.

We report a girl who spontaneously developed an anterior compartment syndrome with an associated deep peroneal neuropathy. Initial nerve conduction studies (NCS) recorded from the extensor digitorum brevis muscle demonstrated prolongation of the distal latency to 7.8 msec (normal contralateral side, 3.6 msec), and reduction in amplitude of the compound muscle action potential to 0.1 mV (normal contralateral side, 9.9 mV). Electromyography of the tibialis anterior muscle showed an absence of motor unit potentials. Serum creatine kinase was markedly elevated to 12,769 IU. Computed tomography (CT) showed evidence of necrotic muscle. One month later, the foot drop, repeat NCS, and CT demonstrated a significant improvement with conservative management.