Ramsay Hunt syndrome


By

Dr. T. Balasubramanian M.S. D.L.O.

Definition:

Ramsay Hunt syndrome is  a disease affecting the external auditory canal associated with the following symptom complexes:

1. Lower motor neuron type of facial nerve palsy

2. Herpetic blisters of the skin of the external auditory canal

3. Otalgia

This syndrome was first described by J. Ramsay Hunt in 1907.  He described patients with Otalgia associated with cutaneous and mucosal rashes.  He attributed it to the infection of geniculate ganglion by Herpes virus type 3.

Pathophysiology:

The primary pathophysiology is located in the geniculate ganglion of the facial nerve.  Geniculate ganglion is found to be affected by Human Herpes virus type 3 i.e. (Varicella zoster virus).  Varicella zoster virus have been identified from tears of these patients by polymerase chain reaction.  Infact Varicella zoster virus have also been identified from tears of patients with Bell's palsy. 

These patients have deep seated pain in the affected ear associated with vertigo, tinnitus, ipsilateral transient hearing loss and lower motor neuron type of facial palsy.  These symptoms develop due to involvement of the geniculate ganglion of the facial nerve located near the petrous pyramid portion of the temporal bone.  The site of rash varies from patient to  patient due to individual variations in the areas supplied by the nervous intermedius of wrisburg (sensory branch of facial nerve).  Rashes may be present in the anterior 2/3 of the tongue, soft palate, external auditory canal and the pinna. 

Morbidity / Mortality:

This disease is usually not associated with mortality.  It is a self limiting disease, with morbidity due to facial nerve palsy.  Complete recovery of the nerve is seen only in 50% of patients as compared to more than 90% in Bell's palsy.

Clinical features:

Patient has deep seated pain in the affected ear.  The pain is intermittent in nature, radiating towards the pinna of the ear.  There is associated diffuse dull aching background pain. Patients also give history of exposure to Varicella virus infections (chicken pox).  The classic Ramsay Hunt syndrome is associated with  1. Pain in the ear, 2. Vertigo and ipsilateral hearing loss, 3. Tinnitus, and 4. Facial palsy (LMN type).  Rash or blisters can also be seen along the distribution of nervus intermedius.  These herpetic blisters in the external auditory canal may become secondarily infected causing cellulitis. 

Picture showing facial palsy



















Picture showing a bleb in the external canal (otitis externa)

Investigations:

Basic investigations like blood count, ESR and electrolytes estimation must always be done in these patients. 

Virology:

1. Varicella virus the causative agent responsible for this syndrome also causes chicken pox in children

2. Serologic tests for Varicella virus is positive

3. Varicella virus can be isolated and cultured form the fluid extruding from the blisters

4. It can also be detected by PCR on samples of tear fluid from these patients.

5. Audiometry demonstrates sensorineural hearing loss

6. Unilateral caloric weakness may be present on electronystagmography (ENG).

Histology:

The affected ganglia are found to be swollen and inflammed.  The inflammatory reaction is lymphocytic in nature.  Some of the cells in the ganglia may show evidence of degeneration.

CSF analysis is not indicated in these patients.

Management:

1. Steps towards alleviating pain:  Carbamazepine can be prescribed in doses of 400 mg / day in divided doses.  Temporary relief of Otalgia in geniculate neuralgia may be achieved by applying a local anesthetic or cocaine to the trigger point, if in the external auditory canal.

2. Corticosteroids and oral acyclovir can be administered.  Steroids in the form of prednisolone can be administered orally in doses of 10mg twice a day.  Steroids should not be stopped abruptly.  The dosage needs to be tapered.  Acyclovir can be administered in doses of 800 mg orally 5 times a day. 

3. Management of vertigo: can be managed using meclizine in doses of 25 mg  orally 4 times a day.

4. Care must be taken to prevent exposure keratitis because of the inability to close the eye lids.  The patients must wear protective goggles.