Tuesday, November 2, 2010

Ramsay Hunt Syndrome

What is it? Ramsay Hunt syndrome is defined as an acute peripheral facial neuropathy associated with erythematous vesicular rash of the skin of the ear canal, auricle (also termed herpes zoster oticus,Hunt's Syndrome ), and/or mucous membrane of the oropharynx.
This syndrome is also known as geniculate neuralgia or nervus intermedius neuralgia. Ramsay Hunt syndrome can also occur in the absence of a skin rash, condition known as zoster sine herpete.

Ramsay Hunt syndrome is defined as VZV infection of the head and neck that involves the facial nerve, often the seventh cranial nerve (CN VII). Other cranial nerves might be also involved, including CN VIII, IX, V, and VI (in order of frequency). This infection gives rise to vesiculation and ulceration of the external ear and ipsilateral anterior two thirds of the tongue and soft palate, as well as ipsilateral facial neuropathy (in CN VII), radiculoneuropathy, or geniculate ganglionopathy.

VZV infection causes 2 distinct clinical syndromes. Primary infection, also known as varicella or chickenpox, is a common pediatric erythematous disease characterized by a highly contagious generalized vesicular rash. The annual incidence of varicella infection has significantly declined after the introduction of mass vaccination programs in most countries of the world. After chickenpox, VZV remain latent in neurons of cranial nerve and dorsal root ganglia. Subsequent reactivation of latent VZV can result in localized vesicular rash, known as herpes zoster. VZV infection or reactivation involving the geniculate ganglion of CN VII within the temporal bone is the main pathophysiological mechanism of Ramsay Hunt syndrome.

Ramsay Hunt syndrome is not usually associated with mortality. It is a self-limiting disease; the primary morbidity results from facial weakness. Unlike Bell palsy, this syndrome has a complete recovery rate of less than 50%.

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