13.3.2 Nervus intermedius neuropathy attributed to Herpes zoster

Previously used term:
Ramsay Hunt syndrome.

Description:
Unilateral pain felt deeply in the auditory canal, sometimes radiating to the parieto-occipital region, associated with facial paresis and caused by Herpes zoster of the nervus intermedius.

Diagnostic criteria:
A. Unilateral facial pain fulfilling criterion C
B. Herpetic eruption has occurred in the ear and/or oral mucosa, in the territory of the nervus intermedius
C. Evidence of causation demonstrated by both of the following:

    1. pain has preceded the herpetic eruption by <7 days
    2. pain is localized to the distribution of the nervus intermedius

D. Clinical features of peripheral facial paresis
E. Not better accounted for by another ICHD-3 diagnosis.

Comments:
The most frequent cause of secondary nervus intermedius neuropathy is Herpes zoster. A very few cases are described due to other disorders such as neurovascular compression, and there are rare familial cases associated with occipital neuralgia.

In Ramsay Hunt syndrome, zoster lesions in the ear or oral mucosa accompanied by facial paresis are pathognomonic, but the original description pointed to additional symptoms such as vertigo, tinnitus, acoustic disturbances and nausea.

13.3.2 Secondary nervus intermedius neuropathy attributed to Herpes zoster should be treated with cortisone and acyclovir as early as possible.