Herpes zoster infection complicated by motor paralysis.

We reviewed a total of 1,432 patients diagnosed with cutaneous herpes zoster at Hyogo College of Medicine Hospital between 1989 and 1997 for epidemiologic assessment and outcome in patients with zoster paralysis referred for rehabilitation. Of the 1,432 herpes zoster patients (624 males and 808 females, mean age 54.3 years), 12 were referred to our department of rehabilitation medicine for muscle weakness: one had myelitis, and eleven others had lower motor neuron damage. Except for one 43-year-old man with myelodysplastic syndrome, all the lower motor neuron deficit patients were over 60 years of age. Involved myotomes were more widespread than involved dermatomes in eight patients. Electromyography in four patients demonstrated denervation of involved muscles. Five patients experienced complete or near complete recovery from their muscle weakness. The muscle weakness related to herpes zoster was occasionally diagnosed by electromyography as motor neuron damage. Manifestations of motor neuron complications were not noticed but might in fact be more common than was the clinical muscle weakness.