Prognostic value of thumb pain sensation in birth brachial plexopathy.

Objective: To evaluate the prognostic value of absent thumb pain sensation in newborns and young infants with birth brachial plexopathy.

Methods: We evaluated 131 patients with birth brachial plexopathy with less than two months of age. Pain sensation was evoked by thumb nail bed compression to evaluate sensory fibers of the upper trunk (C6). The patients were followed-up monthly. Patients with less than antigravity elbow flexion at six months of age were considered to have a poor outcome.

Results: Thirty patients had absent thumb pain sensation, from which 26 showed a poor outcome. Sensitivity of the test was 65% and specificity was 96%.

Conclusion: Evaluation of thumb pain sensation should be included in the clinical assessment of infants with birth brachial plexopathy.