title: Vitamin B12 deficiency with combined hematological and neuropsychiatric derangements: a case report.
abstract: BACKGROUND
  Although vitamin B12 deficiency is a well-known cause of hematological and neuropsychiatric illness, the presentation of combined severe pancytopenia, demyelination and prominent psychiatric impairment is rare.
  
  
  METHODS
  We present a case of a previously healthy 55-year-old East African man with severe vitamin B12 deficiency (serum vitamin B12 22pmol/L) secondary to pernicious anemia. He had a severe hypoproliferative megaloblastic anemia with hemolysis (hemoglobin 61g/L, mean corpuscular volume 99fL, reticulocytes 0.8%, haptoglobin undetectable), leukopenia (2.7×109/L), thrombocytopenia (96×109/L), ataxia with central demyelination, and megaloblastic madness. The patient's anemia, myelopathy and psychiatric condition responded well to parenteral vitamin B12 replacement therapy, with significant improvement seen within weeks.
  
  
  CONCLUSIONS
  Hematological manifestations of vitamin B12 deficiency are typically inversely correlated with the presence and severity of neuropsychiatric impairment. Although uncommon, a presentation with severe hematological and neuropsychiatric disease can occur, as illustrated by this case. Its presence may help guide diagnosis as well as provide clinically important prognostic information.
authors.forename: Luke
authors.initials: L
authors.lastname: Rannelli
authors.forename: Rita
authors.initials: R
authors.lastname: Watterson
authors.forename: Rupang
authors.initials: R
authors.lastname: Pandya
authors.affiliation: Department of Medicine, University of Calgary, 313-4935 40 Avenue NW, Calgary, AB T3A 2N1, Canada. alexander@ualberta.net.
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Leung
mesh_terms: D000749:Anemia, Megaloblastic / Q000188:drug therapy / Q000209:etiology; D003937:Diagnosis, Differential; D003952:Diagnostic Imaging; D006801:Humans; D007970:Leukopenia / Q000188:drug therapy / Q000209:etiology; D008297:Male; D001523:Mental Disorders / Q000188:drug therapy / Q000209:etiology; D008875:Middle Aged; D013921:Thrombocytopenia / Q000188:drug therapy / Q000209:etiology; D014805:Vitamin B 12 / Q000627:therapeutic use*; D014806:Vitamin B 12 Deficiency / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy
chemical_list: D014805:Vitamin B 12