title: Vitamin B₁₂ deficiency: an unusual cause of vocal fold palsy.
abstract: OBJECTIVE
  We report an extremely rare case of vocal fold palsy secondary to vitamin B12 deficiency.
  
  
  METHODS
  Case report and English-Language review of the world literature concerning vitamin B12 deficiency and its neurological manifestations. We discuss the physiological role of vitamin B and its specific relationship to the presented patient's symptoms.
  
  
  RESULTS
  We describe a rare instance of a patient presenting with bilateral lower limb weakness and unilateral vocal fold palsy, as a manifestation of vitamin B12 deficiency. Quick recognition and treatment resulted in a full recovery.
  
  
  CONCLUSIONS
  To our knowledge, this is the first reported case of unilateral vocal fold palsy secondary to vitamin B12 deficiency. Central and peripheral neuropathies have been described; however, other than the optic nerve, the cranial nerves are very rarely affected. It is important to consider vitamin B12 deficiency as a cause, as speedy identification and treatment can help prevent permanent neurological damage.
authors.affiliation: ENT Department, Sunderland Royal Hospital, Tyne and Wear, UK. richardgreen81@hotmail.co.uk
authors.forename: R
authors.initials: R
authors.lastname: Green
authors.forename: N
authors.initials: N
authors.lastname: Kara
authors.forename: H
authors.initials: H
authors.lastname: Cocks
mesh_terms: D006685:Hoarseness / Q000188:drug therapy / Q000209:etiology; D006801:Humans; D008108:Liver Diseases, Alcoholic; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020335:Paraparesis / Q000188:drug therapy / Q000209:etiology*; D010523:Peripheral Nervous System Diseases / Q000188:drug therapy / Q000209:etiology* / Q000473:pathology; D014805:Vitamin B 12 / Q000494:pharmacology / Q000627:therapeutic use*; D014806:Vitamin B 12 Deficiency / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy; D014826:Vocal Cord Paralysis / Q000188:drug therapy / Q000209:etiology*
chemical_list: D014805:Vitamin B 12