title: Successive MRI Findings of Reversible Cerebral White Matter Lesions in a Patient with Cystathionine β-Synthase Deficiency.
abstract: Cystathionine β-synthase (CBS) deficiency, well known as classical homocystinuria, is a rare autosomal recessive inborn error of homocysteine and sulfur metabolism. CBS converts homocysteine to cystathionine. The clinical features of untreated CBS deficiency include myopia, ectopia lentis, mental retardation, skeletal anomalies resembling Marfan syndrome, and thromboembolic events. Cerebral white matter lesions (CWMLs), identified in magnetic resonance imaging (MRI), are related to various clinical conditions including ischemia, inflammation, demyelination, infection, a tumor, and metabolic disorders such as phenylketonuria. The presence of CWMLs is, however, believed to be a very rare condition in CBS-deficient patients. Herein, we report reversible CWMLs associated with hypermethioninemia caused by poor protein restriction and betaine therapy in a 21-year-old male with pyridoxine-nonresponsive CBS deficiency. T2-weighted images (T2WI) and fluid-attenuated inversion-recovery (FLAIR) images showed diffuse high signal intensity in subcortical areas extending to the deep white matter. Diffusion-weighted images (DWI) showed high signal intensity, while apparent diffusion coefficient (ADC) map demonstrated decreased ADC value in the lesions. The course of improvement after correct methionine restriction was successively followed by brain MRI. The CWMLs had regressed at 1 month after restriction, and disappeared after 5 months. ADC values were very low before proper methionine restriction, but normalized after 2 months. Use of betaine in the presence of elevated plasma methionine may increase the risk of reversible CWMLs in some CBS-deficient patients.
authors.affiliation: Department of Pediatrics, Graduate School of Medicine, Gifu University.
authors.forename: Hideo
authors.initials: H
authors.lastname: Sasai
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Shimozawa
authors.forename: Takahiko
authors.initials: T
authors.lastname: Asano
authors.forename: Norio
authors.initials: N
authors.lastname: Kawamoto
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kimura
authors.forename: Minako
authors.initials: M
authors.lastname: Kawamoto
authors.forename: Eiko
authors.initials: E
authors.lastname: Matsui
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Fukao
mesh_terms: D001622:Betaine / Q000627:therapeutic use; D001921:Brain / Q000473:pathology; D001929:Brain Edema / Q000209:etiology / Q000473:pathology; D002462:Cell Membrane / Q000737:chemistry; D018753:Diet, Protein-Restricted; D038524:Diffusion Magnetic Resonance Imaging; D006712:Homocystinuria / Q000178:diet therapy / Q000188:drug therapy / Q000473:pathology*; D006801:Humans; D008082:Lipotropic Agents / Q000627:therapeutic use; D008297:Male; D008715:Methionine / Q000097:blood; D066127:White Matter / Q000473:pathology*; D055815:Young Adult
chemical_list: D008082:Lipotropic Agents; D001622:Betaine; D008715:Methionine