Hemidiaphragmatic paresis after cervical herpes zoster.

Herpes zoster generally affects sensory nerves, but occasionally motor nerves also are affected,'2 so that flaccid muscle paresis develops in the segments corresponding to the dermatomes in which cutaneous lesions appear. The site of the lesion in the motor neurone is not clear, but the absence of electromyographic fasciculations and slow motor conduction velocity point to motor axon damage. Postherpetic paresis of the diaphragm has been reported in rare instances.34 In the present case it developed on the left side after ipsilateral cervical herpes zoster, with the electromyographic signs of neurogenic paresis of other muscles in the same segments.