Psychomotor Retardation, Spastic Paraplegia, Cerebellar Ataxia and Dyskinesia Associated with Low 5-Methyltetrahydrofolate in Cerebrospinal Fluid: A Novel Neurometabolic Condition Responding to Folinic Acid Substitution - Ramaekers, V T; Häusler, M; Opladen, T; Heimann, G; Blau, N (Neuropediatrics, 2002)