Brachial plexopathy following herpes zoster infection: two cases with MRI findings.

There are few reports of brachial plexopathy following the onset of a herpes zoster skin rash. Moreover, the MRI findings of zoster-induced brachial plexopathy have rarely been described. In the present study, we describe two cases of zoster brachial plexopathy and their MRI findings. MRI of the brachial plexus demonstrated T2 hyperintensity and contrast enhancement in the part of the brachial plexus that was compatible with both the clinical symptoms and the electrophysiological findings. Especially, MR imaging reflected the functional impairments more accurately than electrophysiological studies in the acute phase, during which MRI showed more extensive inflammatory involvement of the brachial plexus. MRI findings in the present cases suggest that, in addition to electrophysiological studies, MRI of the brachial plexus could provide valuable information for evaluating the location and extent of lesions and for understanding the pathophysiological mechanisms of zoster brachial plexopathy.