Table 1

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)