Subacute combined degeneration of the cord due to folate deficiency: response to methyl folate treatment.

Subacute combined degeneration of the cord is a rare complication of folate deficiency. Disturbance of methylation reactions in nervous tissue probably underlie subacute combined degeneration of the cord arising from folate as well as vitamin B12 deficiency. Methyl tetrahydrofolate is the form in which folic acid is transported into the CNS. Therefore methyl tetrahydrofolate treatment of the neurological and psychiatric manifestations of folate deficiency would seem to be theoretically advantageous. A case of subacute combined degeneration of the cord due to dietary folate deficiency and associated with an organic brain syndrome is reported. There was striking haematological, neurological and psychiatric response to methyl folate treatment.