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:

Infection

Infections and facial nerve paralysis

Viral – Ramsay Hunt syndrome
  • 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
Bacterial
  • Otitis media [5]
  • Mastoiditis
  • Otitis externa and malignant otitis externa
  • Meningitis

Trauma [5]

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

  • Typically, temporal fracture with nerve transection
  • Basal skull fracture

Systemic diseases [5]

Systemic diseases which may cause facial nerve paralysis include:

  • Sarcoidosis
  • HIV
  • Polio
  • Tuberculosis
  • Multiple sclerosis
  • Guillain–Barré syndrome
  • Diabetes

Neoplasm

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

  • Parotid gland tumours [5]
  • Pontine tumours
  • Acoustic neuroma
  • Leukaemia
  • Developmental hypoplasia/aplasia [6]

Learning bite

Bell’s palsy is only one of many potential causes of facial nerve paralysis. [2,7]