Brachial plexus injuries. Prognosis of postganglionic lesions.

One hundred ninety-eight cases of postganglionic brachial plexus injury with no signs of combined damage to preganglionic sites were treated conservatively. Among them, 50 whole, 32 upper and 13 lower type injuries were followed up for at least 2 years and the course of the progression of the individual muscle was observed. In the whole type, 44% showed good functional recovery, although some of them needed reconstructive surgery. Thirty-eight percent recovered usefully only in the muscles innervated by upper roots. Three out of 50 cases did not recover at all. There were no particular differences between the whole and upper types with regard to the recovery rate of the arm muscles. However, the upper type showed better functional recovery than the whole type. If the muscles innervated by upper roots could gain a strength of M1 before 9 months after injury, and muscles innervated by lower roots reached M1 before 12 months, their final results were more than M3. But muscles with a strength of less than M2 at 18 months did not recover to more than M3. The muscular power at 24 months was almost the same as the final results. About half of the postganglionic brachial plexus injuries which did not combine preganglionic lesions showed favorable spontaneous recovery with conservative treatment. At the exploration of the brachial plexus, if the somatosensory evoked potential test is positive, which negates the possibility of root avulsion, and also if there is no definite discontinuity of the postganglionic nerves, it should be treated conservatively.(ABSTRACT TRUNCATED AT 250 WORDS)