A common neurologic injury from trauma (such as being hit by a car) is that of brachial plexus avulsion. The brachial plexus is susceptible to injuries that produce abduction of the thoracic limb from the body wall or a direct blow to the lateral surface of the scapula. The cardinal signs of brachial plexus avulsion are a monoplegia of one front leg, Horner's syndrome on the affected side, lack of panniculus response on the side of the lesion and a Babinski's sign in the ipsilateral rear leg. The nerve roots are stretched or torn from their origin by this trauma, since the meningeal coverings of the nerve roots are thinner than those in the peripheral nerve. The epineurium of the peripheral nerve is contiguous with the dural mater, providing extra support to the peripheral nerves. In cases where the nerve roots have been torn, recovery in unlikely without new experimental surgical techniques. The diagnosis may be confirmed by EMG examination in 5-7 days. The evidence of denervation will be evident. If there is no nerve conduction 72 hours after the injury, then avulsion is most likely.