Herpes zoster may, in some instances, cause motor paralysis as well as the usual sensory and cutaneous manifestations. It is suggested that the presence of electromyographic denervation potentials be used as the criterion of muscle paresis in order to avoid mistaking atrophy of disuse for true lower motor neuron disease. Use of the proper physical therapy procedures hastens the recovery of function and may serve to retard denervation atrophy and fibrosis in patients with muscle paralysis.