Sensory peripheral neuropathy of vitamin B₁₂ deficiency: A primary demyelinating disease?

In five patients with peripheral neuropathy due to vitamin B₁₂ deficiency, electrodiagnostic studies demonstrated severe reduction in sensory nerve conduction velocities compatible with a demyelinating disorder affecting sensory nerve fibres. It is suggested that in some patients lack of vitamin B₁₂ may cause primary sensory demyelinating neuropathy.