Conduction studies of the long thoracic nerve in serratus anterior palsy of different etiology.

We studied nerve conduction in 24 patients with serratus anterior palsy of different etiology. On the unaffected control side, the latency of the evoked motor responses after stimulation of the long thoracic nerve in the supraclavicular fossa increased 0.2 msec per 10-mm increase in conduction distance, corresponding to a velocity of 67m-s. The method was valuable in determining whether the lesion was partial or complete and in revealing regeneration after wallerian degeneration.