title: Vitamin B12 levels of cerebrospinal fluid in patients with a variety of neurological disorders.
abstract: The vitamin B12 levels of cerebrospinal fluid were assayed microbiologically (Lactobacillus leichmannii method) using samples from 44 patients with various neurological disorders, 4 patients with megaloblastic anemia and 34 controls. Twenty-seven controls that did not receive vitamin B12 showed a mean cerebrospinal fluid vitamin B12 level of 21.5 pg/ml (range: 0-60). No decrease in cerebrospinal fluid vitamin B12 level was seen in patients with subacute myelo-optico-neuropathy (SMON). High levels of cerebrospinal fluid vitamin B12 were observed only in the patients receiving long term administration of the vitamin. Intrathecal administration of vitamin B12 caused only a slight increase in serum vitamin B12 level after four hours. The existence of blood brain barrier for vitamin B12 was suggested.
mesh_terms: D000749:Anemia, Megaloblastic / Q000134:cerebrospinal fluid; D002493:Central Nervous System Diseases / Q000134:cerebrospinal fluid* / Q000188:drug therapy; D006801:Humans; D009187:Myelitis / Q000134:cerebrospinal fluid; D009902:Optic Neuritis / Q000134:cerebrospinal fluid; D013577:Syndrome; D014805:Vitamin B 12 / Q000134:cerebrospinal fluid* / Q000627:therapeutic use
chemical_list: D014805:Vitamin B 12