Current articles concentrate on the therapeutic aspects of Bell’s palsy. I think that clinical management is way more complex than that. But most complex is the anatomy of the facial nerve.
We use a straightforward case of facial palsy to discuss the neuroanatomy of the seventh cranial nerve and then speak about about management problems. Here are some take home messages:
- Symptoms: folklore has it that ipsilateral numbness is due to proprioceptive disturbance through motor dysfunction. Actually, via the sphenopalatine ganglion you can (as a virus) easily get to the ipsilateral V2 nerve fibres, so I (and MRI data) suggest that the numbness might be real.
- Localization: research informs us that it is not too helpful to rely on history (taste disorder, hyperacusis and so on) and examination in order to distinguish idiopathic from other forms of facial paralysis. Why? Probably the examination is too unreliable and the symptoms are not prevalent enough.
- Diagnosis: if you cannot perform an LP then you might use MEP, otherwise this test is unnecessary.
- Tests: only if there are signs or symptoms of otitis or zoster, you need to involve an HEENT, otherwise a neurologician is enough to examine the meatus acusticus externus. Get an HIV, TPHA and lyme serology. Examine the parotis. Look for signs of Melkersson-Rosenthal-syndrome.
- Quantify: grade Bell’s palsy by something like the House-Brackmann-score.
- Management: incomplete (House-Brackmann I-III) can be managed by the primary care physician with a standard program as below. High grade facial paralysis requires neurological follow-up.
- Follow-up: for severe paralysis do neurophysiological tests after 8-10d to judge prognosis (EMG, NCS).
- Therapy for idiopathic Bell’s palsy: steroids (probably high dose is better than low dose as in vestibular neuritis) – start iv, switch to po on discharge. Antivirals aren’t necessary (as in vestibular neuritis). Eye care is important. Physiotherapy is probably as effective as self treatment – we use a standard set of exercise sheets.