Clinical-electromyography correlation in infants with obstetric brachial plexopathy.

PURPOSE: The real utility of needle electromyography (EMG) for evaluation of infants with obstetric brachial plexopathy remains controversial. The objective of this paper is to evaluate how EMG correlates with clinical evaluation of these patients.

METHODS: We performed EMG in 41 infants (42 arms) with severe obstetric brachial plexopathy who were from 3 to 12 months of age. We correlated the EMG interference pattern with the clinical assessment of infraspinatus, deltoid, biceps, triceps, and extensor digitorum communis muscles.

RESULTS: Motor unit potentials were always present, and abnormal spontaneous activity was not common in proximal muscles. The correlation between EMG interference pattern and clinical assessment was not good, except for extensor digitorum communis. EMG showed higher scores than clinical evaluation for infraspinatus, deltoid, and biceps muscles. Respiratory synkinesis was present in 19 patients, or 45% of the affected arms, and it could involve any muscle innervated from C5 to T1.

CONCLUSIONS: Needle EMG fails to estimate or overestimates clinical recovery in proximal muscles in this age group.