Abstract：Maple syrup urine disease is a common amino acids metabolic disease. In most patients, onset occurs in the neonatal period and infancy. In this study, the case of a school boy with acute encephalopathy due to late-onset maple syrup urine disease is summarized. The boy (8.5 years) was admitted because of acute encephalopathy after suffering from infection for two days at the age of eight and a half years. Metabolic acidosis, hyperuricemia and decreased protein level in cerebrospinal fluid were found by general laboratory tests. Magnetic resonance imaging of the brain revealed signal intensity abnormalities in the bilateral cerebellum dentate nucleus, brainstem, thalamus, putamen, caudate nucleus and cortex of the cerebral hemispheres. On T1WI and T2WI scanning, hyperintensive signal was found. Blood leucine and valine were significantly elevated. Urinary 2-hydroxy isovaleric acid, 3-hydroxybutyric acid, 2-keto isovaleric acid, and 2-keto acid also increased. Both the blood amino acid and urine organic acid profiles led to the diagnosis of maple syrup urine disease. In the acute period, the patient was treated with a large dose of vitamin B1, glucose, L-carnitine and a protein-restrict diet. The patient′s condition improved significantly after five days of treatment, and he recovered completely two days later. Afterwards, treatment with vitamin B1, L-carnitine and a protein-restrict diet (1 g/kg/day) was continued. One and a half months later, blood amino acids and urine organic acids returned to normal. Magnetic resonance imaging of the brain also indicated a great improvement. It was concluded that inborn metabolic disease should be considered in the patients with an onset similar to acute encephalopathy. Early diagnosis and proper treatment can prevent brain damage and improve prognosis.
QU Su-Qing,YANG Li-Cai,LUAN Zuo et al. Acute encephalopathy due to late-onset maple syrup urine disease in a school boy[J]. CJCP, 2012, 14(3): 161-164.
［10］Sweetman L. Newborn screening by tandem mass spectrometry: gaining experience［J］. Clin Chem, 2001, 47 (11): 1937-1938.
［11］Ozand PT, Devol EB, Gascon GG. Neurometabolic diseases at a national referral center: five years experience at the King Faisal Specialist Hospital and Research Centre［J］. J Child Neurol, 1992, 7(Suppl): S4-S11.
［12］Cakmakci H, Pekcevik Y, Yis U, Unalp A, Kurul S. Diagnostic value of proton MR spectroscopy and diffusion-weighted MR imaging in childhood inherited neurometabolic brain diseases and review of the literature［J］. Eur J Radiol, 2010, 74(3): e161-e171.
［13］Sener RN. Maple syrup urine disease: diffusion MRI, and proton MR spectroscopy findings［J］. Comput Med Imaging Graph, 2007, 31(2): 106-110.
［16］Thimm E, Hadzik B, H-hn T. Continuous venovenous hemofiltration rapidly lowers toxic metabolites in a patient with MSUD and imminent cerebral herniation［J］. Klin Padiatr, 2010, 222(4): 264-265.
［17］Shellmer DA, Devito Dabbs A, Dew MA, Noll RB, Feldman H, Strauss KA, et al. Cognitive and adaptive functioning after liver transplantation for maple syrup urine disease: a case series［J］. Pediatr Transplant, 2011, 15 (1)：58-64.
［18］Zinnanti WJ, Lazovic J, Griffin K, Skvorak KJ, Paul HS, Homanics GE, et al. Dual mechanism of brain injury and novel treatment strategy in maple syrup urine disease［J］. Brain, 2009, 132(Pt 4): 903-918.
［19］BrunettiPierri N, Lanpher B, Erez A, Ananieva EA, Islam M, Marini JC, et al. Phenylbutyrate therapy for maple syrup urine disease［J］. Hum Mol Genet, 2011, 20 (4):631-640.
［20］Puckett RL, Lorey F, Rinaldo P, Lipson MH, Matern D, Sowa ME, et al. Maple syrup urine disease: further evidence that newborn screening may fail to identify variant forms［J］. Mol Genet Metab, 2010, 100(2): 136-142.
