Sensory nerve conduction studies in neuralgic amyotrophy.

Neuralgic amyotrophy is a painful, episodic peripheral nerve disorder localized to the brachial plexus. Sensory symptoms occur in 80% of the patients. We assessed the frequency of abnormalities in sensory nerve conduction studies of the lateral and medial antebrachial cutaneous, radial sensory, median sensory, and ulnar sensory nerves in 112 patients. Sensory nerve conduction studies showed abnormalities in <20% of nerves, even when the nerve was clinically affected. The lateral and medial antebrachial cutaneous nerves were most often abnormal, in 15% and 17% of nerves. No correlation with the presence or localization of clinical deficits was found. Brachial plexus sensory nerve conduction studies seem to be of little diagnostic value in neuralgic amyotrophy. Our findings also indicate that some sensory lesions may be in the nerve roots instead of the plexus. An examination of normal sensory nerve conduction studies does not preclude neuralgic amyotrophy as a diagnosis.