title: Clinical, nerve conduction and nerve biopsy study in vitamin B12 deficiency neurological syndrome with a short-term follow-up.
abstract: OBJECTIVE
  The frequency and type of neuropathy in vitamin B12 deficiency neurological syndrome (VBDNS) is controversial. This study reports the frequency and type of nerve dysfunction in VBDNS using nerve conduction and sural nerve biopsy and its response to treatment.
  
  
  METHODS
  Sixty-six patients with VBDNS diagnosed on the basis of low serum vitamin B12 level and/or megaloblastic bone marrow were subjected to clinical evaluation, hemoglobin, mean corpuscular volume, thyroid function test, HIV serology, and vasculitic profile. Peroneal motor and sural sensory nerve conduction studies were done. Sural nerve biopsy was done in six patients. The patients were treated with cyanocobalamin injection and followed up clinically and with nerve conduction study at 3 and 6 months.
  
  
  RESULTS
  The median age of the patients was 46 (12-80) years and 11 patients were females. The duration of symptoms was 1-96 (median 7) months. Clinical features of neuropathy were present in 46 (69.7%) patients and nerve conduction was abnormal in 36 (54.5%) patients. On nerve conduction study, 8 (22.2%) patients had axonal, 4 (11.1%) had demyelinating, and 24 (66.7%) had mixed features. Nerve biopsy revealed acute axonal degeneration in early stage and chronic axonopathy with demyelination in the late stages of disease. The nerve conduction parameters improved at 6 months along with clinical recovery.
  
  
  CONCLUSIONS
  Nearly 70% patients with VBDNS had evidence of neuropathy which is mainly axonal with some demyelinating features.
authors.forename: Jayantee
authors.initials: J
authors.lastname: Kalita
authors.forename: Satish
authors.initials: S
authors.lastname: Chandra
authors.forename: Sanjeev K
authors.initials: SK
authors.lastname: Bhoi
authors.forename: Ritu
authors.initials: R
authors.lastname: Agarwal
authors.forename: Usha Kant
authors.initials: UK
authors.lastname: Misra
authors.forename: Surala K
authors.initials: SK
authors.lastname: Shankar
authors.forename: Anita
authors.initials: A
authors.lastname: Mahadevan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000150:complications / Q000188:drug therapy / Q000473:pathology*; D009431:Neural Conduction / Q000187:drug effects*; D012189:Retrospective Studies; D014805:Vitamin B 12 / Q000627:therapeutic use; D014806:Vitamin B 12 Deficiency / Q000150:complications / Q000188:drug therapy / Q000473:pathology*; D055815:Young Adult
chemical_list: D014805:Vitamin B 12
keywords: Nerve biopsy; Neuropathy; Outcome; Subacute combined degeneration; Vitamin B12; nerve conduction study