Prospective study of recovery following neonatal brachial plexus injury.

The prognosis for recovery from brachial plexus injury sustained at or before birth is generally favorable. However, roughly 10% of these infants remain profoundly weak and later exhibit functional disability in the affected arm. Early identification of these at-risk infants would be helpful in selecting patients for surgical management. In our prospective study, 80 infants with brachial plexus injury were examined on a monthly basis. Complete recovery occurred in 53 (66%); in 9 (11%), mild weakness persisted. In each child, recovery to antigravity strength in the biceps, triceps, and deltoid was noted by 6 months of age. Moderate arm weakness persisted in 7 children (9%); none had antigravity strength in the deltoid at age 6 months. Eleven children (14%) had severe permanent weakness (mean follow-up: 4.4 years). At age 6 months, these individuals exhibited at best 2/5 strength proximally and typically 0-1/5 strength in the wrist and finger extensors. Our results demonstrate that detailed strength testing up to 6 months of age predicts not only complete recovery of neonatal brachial plexus injury but also those children destined for long-term severe disability.