There are three separate neurological Ramsay Hunt syndromes. Their only connection is James Ramsay Hunt who identified them all:
- Ramsay Hunt syndrome (herpes zoster oticus or auricular herpes zoster) - described here.
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There are three separate neurological Ramsay Hunt syndromes. Their only connection is James Ramsay Hunt who identified them all:
- Ramsay Hunt syndrome (herpes zoster oticus or auricular herpes zoster) - described here.
- Ramsay Hunt cerebellar syndrome (dyssynergia cerebellaris myoclonica, dyssynergia cerebellaris progressiva, dentatorubral degeneration) is the rare entity characterised by seizures, cognitive impairment, action myoclonus and progressive ataxia.
- Ramsay Hunt syndrome III is a neuropathy of the deep palmar branch of the ulnar nerve.
The Ramsay Hunt syndrome described here occurs when the varicella-zoster virus (chickenpox) becomes reactivated in the geniculate ganglion of the VIIth cranial nerve (facial nerve) causing facial paralysis, loss of taste, vestibulocochlear dysfunction and pain. See separate Shingles and Shingles Vaccination article for more information on herpes zoster.
As a general rule, shingles is a disease of sensory nerves but Ramsay Hunt syndrome is distinctive in that there is a motor component. J. Ramsay Hunt described the various clinical presentations of facial paralysis with a rash and also recognised other frequent symptoms and signs such as tinnitus, hearing loss, nausea, vomiting, vertigo and nystagmus.
The neuroanatomy involved in Ramsay Hunt syndrome is more complex than cases of shingles of a single dermatome elsewhere in the body.
There are four cranial nerve nuclei involved in facial nerve functions. They are the motor nucleus of VII, the nucleus of the solitary tract, the superior salivatory nucleus and the spinal nucleus of V.
Motor nucleus of VII - special visceral efferent motor fibres from the motor nucleus of VII leave the brainstem and travel through the internal acoustic meatus to the bony facial canal to supply facial muscles. In Ramsay Hunt syndrome, these fibres are affected as they pass through the geniculate ganglion, impairing motor supply of the facial nerve.
Nucleus of the solitary tract - the solitary tract receives special visceral afferent taste fibres from the anterior two thirds of the tongue. These fibres travel with the chorda tympani. The cell bodies of these special visceral afferent fibres are in the geniculate ganglion which is the site of virus reactivation when vesicles erupt on the tongue. The fibres reach the brainstem via the nervus intermedius and can be affected by local inflammation as they pass through the geniculate ganglion.
Superior salivatory nucleus - special visceral efferent parasympathetic fibres to the lacrimal and salivary glands come from the superior salivatory nucleus, travel in the nervus intermedius and branch at the geniculate ganglion into the greater petrosal and chorda tympani nerves. Decreased lacrimation may result from involvement of these fibres as they branch at the level of the geniculate ganglion. Special visceral efferent sympathetic fibres originate from the carotid plexus on the internal carotid artery and join the greater petrosal nerve as they pass through the foramen lacerum. The sympathetic fibres supply the same areas as the parasympathetic fibres.
Spinal nucleus of V - this receives general somatic afferent fibres from the geniculate zone of the ear via the chorda tympani. Cell bodies of these neurons lie in the geniculate ganglia and are the site of viral reactivation in classic Ramsay Hunt syndrome, causing vesicular eruptions in geniculate zones.
- Herpes zoster is seen as a disease of older people (most commonly over 60 years old).However, it can affect all ages, although is rare in children. There has been a case report of varicella infection in utero and presentation in infancy with this syndrome.
- The incidence and severity increase with age. In one study, about 50% of cases were