Bilateral lower motor neurone causes

Causes include:

• Guillain-Barre syndrome (post-infective polyneuritis)
• uveoparotid fever (a manifestation of sarcoidosis)
• poliomyelitis
• lepromatous leprosy - may cause bilateral facial nerve palsies
• facial nerves may be involved bilaterally in their intracerebral course by:
  • cerebropontine angle tumours particularly acoustic neuromas)
  • leukaemic infiltration
  • granulomatous meningitis
• Melkersson's syndrome - facial palsy may be unilateral or bilateral
• Bell's Palsy - rarely may be bilateral

Bilateral facial weakness may also occur in myopathies and myasthenia gravis, which are not the result of facial nerve pathology.