Introduction
This is a paralysis of one side of the muscles surround
the eye. This is due to damage of the nerve supplying the muscles,
the seventh nerve.
The condition is explained for patients here and www.bellspalsy.org.uk.
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It normally develops over 2 days, and hearing is largely unaffected.
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It
presents
acutely with loss of blinking and weak facial muscles on one
side.
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There may be associated hearing changes and face
numbness
7th nerve pathways
These are reviewed here. Anatomy
Causes and investigations
This is explained well here for professionals. The condition may be due to herpes
simplex or zoster. Herpes simplex is the same virus that causes
cold sores, and many of us have infections from time to time. Herpes
zoster is the same virus that causes chickenpox and shingles.
Causes etc: 50% idiopathic; 1% bilateral; 60% have a viral prodrome
Tests
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(see)
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Test for lyme disease if living in a lyme disease area.
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The ear and hearing should be examined carefully, in case there
is another cause.
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If other cranial nerves are affected further investigations such
as an MRI scan may be needed.
Treatment
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If the eye does not close properly it will probably get dry. If the cornea gets very dry it may become infected and scarred and even perforate.
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The dry eye MUST be kept lubricated. If there is still some power
in the eye muscles and some blinking does occur, lubricants such
as viscotears four times a day may be need.
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Slightly worse cases
need thicker ointment such as simple eye ointment or lacrilube
three times a day. Such patients will ned to tape their eye shut
at night.
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The eye must be examined., even more protection
is needed. Some patients need their eye closing with stitched
(tarsorraphy) or even an injection of botulinum toxin. Botulinum
works for 6 weeks but may cause a little double vision. By then
the eye muscles may have started to recover.
Prednisolone should be started preferably within 24 hours
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this may not be suitable if immunocompromised...but may be fine
if antivirals are used.
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1mg/kg/day (maximum 80mg) for the first week, tapering in the
second week.
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give 'steroid' advice..avoid contact with people with infections
etc
Antivirals (see) . Latest reports indicate they do not speed recovery
and may therefore are not needed (2009). Valciclovir and famcyclovir,
or if not available acyclovir should be used in the 'herpes zoster'
dose.
Recovery
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70% get a full recovery in weeks-months.
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People with the most
severe problem at the beginning have the greatest risk of an incomplete
recovery
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recovery is quicker if prednisolone started early
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