Differential Diagnosis of Facial Weakness
The key is to work out whether facial weakness is:
- Truly unilateral?
- Bilateral facial weakness could suggest another diagnosis e.g. Myasthenia gravis or Guillain Barre syndrome
- Upper or lower motor neuron (see next slide)?
- Additional features would suggest an alternative diagnosis i.e. other cranial nerve problems (Bell's palsy should just involve CN VII) OR symptoms / signs in the limbs that could suggest a more significant CNS problem i.e. brainstem stroke, tumour or demyelinating lesion OR no signs of a rash which might suggest an alternative cause.
