A case of unilateral motor paralysis of the shoulder caused by herpes zoster

Herpes zoster is a characteristic, segmental, cutaneous eruption associated with sensory axonal neuropathy, but complication of motor involvement can also occasionally occur. In many cases, the loss of motor function goes unrecognized because the extent of impairment is mild. However, if it is severe, motor weakness may lead to clinical problems. We report a case of ipsilateral shoulder paralysis caused by herpes zoster infection of the left C4-6 dermatomes in which motor weakness invaded major motion of the unilateral upper limb. An electromyography and motor nerve conduction test revealed that axonal degeneration of the upper trunk level of the brachial plexus developed secondary to herpes zoster infection. Therefore, we highlight there is possibility of severe motor deficit of a corresponding site after herpes zoster.