[Successful treatment with acyclovir and a corticosteroid for lower cranial polyneuropathy in zoster sine herpete: a case report].

A 62-year-old woman developed meningitis as well as acute paralysis of glossopharyngeal, vagus, and accessory nerves on the right side and also had dysfunction of the left hypoglossal nerve. Although there was no evidence of a typical cutaneous or mucosal herpetic lesion, PCR detection of varicella zoster virus (VZV)-DNA in cerebrospinal fluid confirmed the clinical diagnosis of polyneuritis cranialis due to VZV infection and zoster sine herpete. After starting intravenous acyclovir and methylprednisolone, her hypoglossal nerve palsy disappeared within a day and all other symptoms and signs dramatically improved. A rapid improvement observed in our patient suggests that the right cranial polyneuropathy could be caused by inflammation associated with epineurial edema (where the ninth, tenth, and eleventh cranial nerves pass through the right jugular foramen), whereas the exact mechanism of the twelfth cranial nerve involvement on the contralateral side is unknown. Our clinical findings indicate that acute lower cranial polyneuropathy in patients with zoster sine herpete should be treated immediately with combined administration of acyclovir and an anti-inflammatory corticosteroid.