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.
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