Isolated anterior interosseous nerve palsy following herpes zoster infection: a case report and review of the literature.

A 64-year-old lady noticed weakness of her thumb within two weeks of having developed "shingles" causing vesicular lesions on her arm and hand. Clinical and neurophysiological testing confirmed a lesion of the anterior interosseous nerve. Although motor involvement after herpes zoster infection is recognised, this usually has a myotomal distribution; isolated involvement of a branch of a peripheral motor nerve has not previously been described.