Reversible dementia and neuropathy associated with folate deficiency 16 years after partial gastrectomy

A 57-year-old woman developed dementia and peripheral neuropathy 16 years after a partial gastrectomy (Billroth II). Serum cobalamin was 198 pmol/l (reference interval 150-550), and the vitamin B12 absorption test (Schilling) showed decreased absorption (1.7% without and 2.2% with intrinsic factor). In spite of 20 months' therapy with vitamin B12, the neurological symptoms progressed. Folate deficiency was suggested by a very low erythrocyte folate and a slightly abnormal FIGLU test. There were no other signs of general malabsorption. A few months' treatment with folic acid significantly improved the massive neurological manifestations which were verified neurophysiologically as well as histologically. A common role of vitamin B12 and folate in the development of neuropathy is suggested.