[Monoparesis due to the brachial plexus neuritis by herpes zoster virus--report of a case].

A 73-year-old woman suffering from the acute onset monoparesis of her right arm which followed the skin eruption with mild sensory disturbance of right C4-6 level, was reported. Electrophysiological examinations revealed the brachial plexus neuritis and axonal degeneration of the proximal portion, with the evidence of herpes zoster infection. Her paresis of the right arm gradually improved without any medication during her hospital course. It was concluded that herpes zoster should be considered to be one of the causes of acute onset brachial plexopathy.