Bell’s Palsy and Other Causes of Facial Nerve Paralysis

Diagnosis of Bell’s palsy is reached only once other causes are excluded. In children, Bell’s palsy is a much less common cause of lower neurone facial nerve paralysis than is the case in adults.

Other causes of facial nerve paralysis may include:


Infections and facial nerve paralysis

Viral – Ramsay Hunt syndrome [6]
  • Unilateral facial nerve paralysis with herpetiform vesicular eruption and vestibulocochlear dysfunction
  • Pain often more than in Bell’s palsy
  • The cause in this case is herpes zoster virus infection
  • Mumps and herpes simplex virus are also causes of facial nerve paralysis
Lyme disease
  • Borrelia burgdorferi (spirochete)
  • Spread by the bite of ixodes genus ticks
  • Most common cause of facial nerve paralysis in children in endemic areas
  • Important cause of bilateral facial nerve paralysis
  • Otitis media [5,6]
  • Mastoiditis
  • Otitis externa and malignant otitis externa
  • Meningitis [6]

Trauma [5]

VII cranial nerve is the most commonly injured nerve in head trauma:

  • Typically, temporal fracture with nerve transection
  • Basal skull fracture [6]

Systemic diseases [5]

Systemic diseases which may cause facial nerve paralysis include:

  • Sarcoidosis [5]
  • HIV [5,6]
  • Polio [6]
  • Tuberculosis [6]
  • Multiple sclerosis [6]
  • Guillain–Barré syndrome [6]
  • Diabetes [6]

Neoplasm [6]

Typically progressive course over 3 weeks, but sudden onset does not rule out:

  • Parotid gland tumours [5,6]
  • Pontine tumours [6]
  • Acoustic neuroma [6]
  • Leukaemia

Developmental hypoplasia/aplasia [7]

Learning bite

Bell’s palsy is only one of many potential causes of facial nerve paralysis [2,8].