Exercise-induced bilateral anterior tibial compartment syndrome without pain.

We report the case of a 41 year old man who complained of a severe bilateral deficit of the anterior tibial compartment two hours after prolonged exercise. On admission there was no spontaneous or evoked pain, no objective sensory deficit but total loss of dorsiflexion of feet and toes. Electrophysiological investigation showed no voluntary or evoked electrical activity in tibial and extensor digitorum muscles; while peroneus longus and gastrocnemius muscles showed a near-normal pattern. On the other hand a weak motor response was obtained by direct stimulation of the anterior tibial muscle belly. An early bilateral fasciotomy was followed by almost complete recovery of the spontaneous and evoked motor activities of the tibial anterior muscles. On the basis of these findings we discuss the possible pathogenetic role of a neuroapraxic block of the deep peroneal nerve where it crosses the anterior fibular septum and supply a possible interpretation of the absence of pain.