ABSTRACT
OBJECTIVE: To determine whether cerebrospinal fluid (CSF) methylmalonic acid (MMA) is increased in neurological patients with low serum cobalamin (Cbl, vitamin B12) concentrations as opposed to neurological patients with normal serum Cbl concentrations. MATERIAL AND METHODS: We measured MMA concentrations in serum and CSF of neurological patients with low serum cobalamin concentrations, but without overt cobalamin related manifestations such as anemia or combined disease of the cord, and neurological patients with normal serum cobalamin concentrations (controls). RESULTS: Serum and CSF MMA concentrations were significantly higher in patients than in controls. Serum MMA was elevated in 4 patients of whom 3 had clearly elevated CSF MMA concentrations. CONCLUSION: Strong indications for cobalamin deficiency can be found not only in serum but also in CSF of patients with seemingly asymptomatic low serum cobalamin concentrations.
