[Functional diagnosis of brachial plexus injuries].

We evaluated 10 patients with verified brachial plexus injuries and root avulsion. In 100%, dermatomal somatosensory evoked potentials (DSSEPs) were abnormal. Compound muscle action potentials (CMAPs) by magnetic stimulation revealed 90% abnormal findings on the affected side, but also revealed abnormality in adjacent segments. Dissociation of CMAPs and DSSEPs revealed the apparent continuity of motor and sensory nerves. The use of both techniques for the examination of the function of proximal peripheral nerve revealed increased latencies over the motor and/or sensory pathways in all patients. The technique of non-invasive stimulation of the motor pathway therefore provides an additional tools to detect and quantify subclinical and clinically apparent lesions in patients with defined brachial plexus injuries and root avulsions.