Facial (7th nerve) palsy
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.
Assessment (from BMJ
- from BMJ 15
- In patients presenting with facial weakness, the first priority is to exclude an upper motor neurone lesion; important associated signs may include concurrent limb weakness, hyper-reflexia, up going plantars, or ataxia.
- Check for causes of a lower motor neurone lesion by examining the ears, mastoid region, oral cavity, eyes, scalp, and parotid glands.
- Bell’s palsy is a diagnosis of exclusion, and oral steroids are needed within 72 hours to increase the chance of complete recovery. Prognosis is usually good compared with other causes of lower motor neurone weakness, such as tumours and Ramsay Hunt syndrome. Eye protection is crucial if lid closure is impaired.
These are reviewed here. Anatomy
Causes of 7th nerve palsy
- from BMJ 15
- most are Bells palsy
- next common is trauma, including surgical trauma (eg neurosurgery)
- next common is herpes zoster virus..Ramsey Hunt syndrome, often occurring with deafness (slower recovery)
- slowly progressive: suggests cancer; other nerves may be affected.
- acute otitis media: older patients, immunocompromised, poorly controlled diabetes
- Lyme disease
- Test for Lyme disease if living in a Lyme disease area.
- The ear and hearing should be examined carefully, in case there is another cause.
- If other cranial nerves are affected further investigations such as an MRI scan may be needed.
- ENT referral may be needed
- children need paediatric referral
- red flags from BMJ 15
- upper motor neurone (limb weakness, paraesthesia of face /limbs
- other cranial nerves
- pain in the 7th nerve area
- hearing loss same side
- acute infections
- head and neck lesions
It normally develops over 2 days, and hearing is largely unaffected. It presents acutely with loss of blinking and weak facial muscles on one side. There may be associated hearing changes and face numbness.
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.
- 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.
- 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.
- Slightly worse cases need thicker ointment such as simple eye ointment or Lacrilube three times a day. Such patients will need to tape their eye shut at night.
- 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.
- Cose the eye see.
- slightly dry ..Viscotears four times a day and Lacriblube at night.
- more severe: hourly preservative free eye drops and Lacilube at night.
- more severe: eyelids must be closed..
- Prednisolone should be started preferably within 24 hours. this may not be suitable if immunocompromised ...but may be fine if antivirals are used.
- 1mg/kg/day (maximum 80mg) for the first week, tapering in the second week.
- 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.
- 70% get a full recovery in weeks-months. 80% with steroids if started early.
- People with the most severe problem at the beginning have the greatest risk of an incomplete recovery
- recovery is quicker if prednisolone started early
City Hospital...headache nurse Julie Edwards