Facial weakness and Bell's palsy

  • See also

    Acute otitis media
    Hypertension

    Background

    Facial weakness in children may be idiopathic, or caused by infection, inflammation, tumour, trauma or a vascular event. Bell's palsy is an isolated lo wer motor neuron lesion of the whole facial nerve.  The cause is usually unknown. Most children recover completely.  Assessment of Bell's palsy is aimed at confirming the diagnosis and excluding the other important causes of facial weakness.

    History and examination

    • Ask about the evolution of weakness. Bell's palsy usually comes on very quickly (over hours or no more than a couple of days).
    • Ask about preceding viral infections or trauma to the head or face.
    • Ask about hyperacusis (increased sensitivity to sound) and altered taste. Both are common in Bell's palsy.  
    • Ask about facial pain. Mild pain in the face or behind the ear is common in Bell's palsy. Severe pain suggests that the lesion may be caused by the varicella zoster virus (VZV). 
    • Confirm that all facial nerve branches are involved diffusely (with particular reference to the muscles of the upper half of the face, which are spared in upper motor neuron lesions).  
    • Perform a thorough neurological examination (rest of cranial nerves, peripheral power, tone, reflexes and coordination).
    • Examine for signs of otitis media, mastoiditis or parotitis.
    • Look for skin lesions or blisters on the face or in the ear canal.
    • Confirm that blood pressure and temperature are normal. Hypertension may rarely be associated with Bell's palsy.
    • Also see Management flow chart

    Management

    Bells_T.gif

    Management flow chart

    Idiopathic or post-viral facial palsy is uncommon in very young children, especially infants.
    All children <2 years of age, or with atypical features on history or examination, should be discussed with a neurologist and admission considered for further workup including possible neuroimaging

     Eye care: All children with any inability to completely close their eye should have eye care:

    • Lubricating (hypromellose) ocular drops at least three times during the day.
    • Pad eye shut at night after application of lubricating ocular ointment.

    Steroids: The role in treatment of Bell's palsy in children is unclear, however streroids appear to benefit adults, particularly if given within 72 hours of onset and if complete palsy present. Prednisolone (1mg/kg/day PO daily for 10 days) may be considered for Bell's palsy presenting within 72 hours of onset. 

    Antivirals: aciclovir may only be considered if vesicular rash present.

    Notes

    Counsel parents and child about:

    • In the first three weeks, facial weakness may get worse. Any deterioration beyond this time should be investigated.
    • Many children will recover within 6 weeks of onset. More than 95% of children have a full recovery by 12 months,
    • Children may also experience a temporary change in hearing or how much saliva they appear to make.
    • Eye care is important to prevent scratches to the eye.

    Follow-up:

    Referral to a neurologist is suggested for children < 2 years of age (see above), atypical features on history or examination or in the absence of any recovery by 4 weeks.
    Referral to ENT should occur if evidence of otitis media, mastoiditis or parotitis.
    For the other cases, a paediatrician or general practitioner should review in 3-5 days, then as needed to monitor for corneal ulceration.

    • Bell's palsy  Parent handout (Print version PDF)
    • Bell's palsy parent handout (HTML version)