MR findings in subacute combined degeneration of the spinal cord caused by nitrous oxide anaesthesia--two cases.

Vitamin B12 deficiency causes haematological and neurological diseases. Subacute combined degeneration (SCD) of the spinal cord is characterized by degeneration of the posterior and lateral columns. We report two cases of SCD induced by nitrous oxide (N2O) anaesthesia. In both cases magnetic resonance imaging (MRI) of the spinal cord showed symmetric, reversible changes in the posterior columns, correlating well with patients' symptoms.