Prognostic value of needle electromyography in traumatic brachial plexus injury

In this study we aimed to determine whether needle electromyographic assessment of voluntary motor unit recruitment in traumatic brachial plexus injuries could predict spontaneous motor recovery. Methods A retrospective study was performed on patients with brachial plexus injury affecting deltoid, supraspinatus/infraspinatus, and biceps brachii. The outcome measure was strength on manual muscle testing at least 1 year after injury. Good outcome was considered strength >3/5 on the Medical Research Council (MRC) scale. Results No muscles with no recruitment (n = 27) at 1‐9 months improved to MRC 4/5 strength at a mean of 2.0 years postinjury. Twenty‐five percent of muscles with discrete or severely reduced recruitment (n = 8) regained strength to >3/5 at a mean of 1.4 years postinjury ( P = .047). Discussion Absent voluntary motor unit potential recruitment at 1‐9 months predicted poor prognosis for spontaneous recovery. A high percentage of patients with discrete recruitment did not improve to >3/5 strength. These patients should be considered for early nerve transfer surgery.