Cobalamin deficiency: MRI detection of posterior columns involvement and posttreatment resolution.

Cobalamin-deficient myelopathy is a neurologic disorder manifesting progressive symptoms of paresthesiae and spastic paralysis. The pathologic changes initially involve the posterior columns of the cervical and upper thoracic cord. The authors present the case of a patient with cobalamin deficiency with preferential posterior columns involvement, as evidenced by spinal magnetic resonance imaging findings. Marked clinical and radiographic resolution occurred after administration of vitamin B12. Early recognition of this specific magnetic resonance pattern is essential, because complete recovery can be achieved with prompt treatment at this reversible stage of the disease.