One of the neurologic features of B12-deficiency anemia is involvement of posterior and lateral columns of the spinal cord (subacute combined degeneration or funicular myelosis).

Begins more often with a sensation of numbness, sometimes cold, tightness in the tips of the toes and in the fingertips, rarely may be severe pain. Involvement of arms and legs at the same time is  not common, onset with legs can be seen more frequent.

Spinal MRI frequently shows longitudinal T2 hypersignal lesion at posterior part of the spinal cord symmetrically distributed, often with sharply demarcated margins.