Causes of facial nerve palsy
| 1. Idiopathic |
| a. Bell's palsy |
| b. Melkersson–Rosenthal syndrome (recurrent alternating facial palsy, furrowed tongue, faciolabial oedema) |
| 2. Infection |
| a. Otitis media |
| b. Mastoiditis |
| c. Herpes zoster cephalicus (Ramsay–Hunt syndrome) |
| d. Chickenpox |
| e. Encephalitis |
| f. Meningitis |
| g. Poliomyelitis (type I) |
| h. Mumps |
| i. Infectious mononucleosis (glandular fever) |
| j. Malaria |
| k. Tuberculosis |
| l. Lyme disease |
| m. HIV |
| 3. Trauma |
| a. Skull base fractures |
| b. Facial injuries |
| c. Penetrating trauma to middle ear |
| d. Barotrauma (altitude paralysis/scuba diving) |
| 4. Metabolic |
| a. Diabetes mellitus |
| b. Hypertension |
| c. Acute porphyria |
| 5. Neoplastic |
| a. Cholesteatoma |
| b. Leukaemia |
| c. Haemophilia |
| d. Fibrous dysplasia |
| e. Parotid tumours |
| f. Facial nerve tumour |
| g. Cerebello-pontine angle tumours |
| 6. Toxic |
| a. Tetanus |
| b. Diphtheria |
| c. Thalidomide |
| d. Carbon monoxide |
| 7. Iatrogenic |
| a. Postimmunisation |
| b. Antitetanus serum |
| c. Vaccine for rabies |
| d. Parotid surgery |
| e. Mastoid surgery |
| f. Forceps delivery |
| 8. Autoimmune syndrome |
| a. Thrombotic thrombocytopaenic purpura |
| b. Kawasaki disease |
| c. Guillian barre/Miller–Fisher syndrome |
| 9. Neurological |
| a. Millard-Gubler syndrome (abducens palsy with contralateral haemiplegia due to lesion in the base of pons involving corticospinal tract) |
| b. Opercular syndrome (cortical lesion in facial motor area) |
| 10. Congenital |
| a. Dystrophia myotonica |
| b. Moebius syndrome (facial diplegia associated with other cranial nerve deficits) |