pyridoxine neuropathy; megavitamin-B6 syndrome

Etiology

• megadose pyridoxine, 2-6 grams/day (RDA is 2 mg/day)

Pathology

• large fiber sensory loss
• intoxication & death of dorsal root ganglion cells
• peripheral & central axonal degeneration
• axonal regeneration can occur is excessive pyridoxine is eliminated

Clinical manifestations

• ataxic peripheral neuropathy
• proximal & distal parts of body affected simultaneously
• sensory neuroapathy
  • Lhermitte's sign
  • paresthesia
  • dysethesia
• sensory ataxia
• pseudoathetosis without severe weakness

More general terms

• toxicity; poisoning; overdose
• peripheral nerve disease; peripheral neuropathy

Additional terms

• pyridoxine (a vitamin B6)