Neonatal case of classic maple syrup urine disease: Usefulness of ¹H‐MRS in early diagnosis

Abstract

We describe a male neonate with classic maple syrup urine disease (MSUD) in metabolic crisis. On day 7 of life, he was referred to hospital because of coma and metabolic acidosis with maple syrup odor. On day 4 after admission, brain magnetic resonance imaging findings were consistent with encephalopathy due to MSUD. Proton magnetic resonance spectroscopy ((1) H-MRS) showed a large methyl resonance peak at 0.9 p.p.m. The diagnosis of MSUD was confirmed on low branched-chain α-keto acid dehydrogenase complex activity in lymphocyte. (1) H-MR spectra were obtained in 10 min, while it took at least several days to obtain the results of other diagnostic examinations. In convalescence, the peak at 0.9 p.p.m. decreased. The large methyl resonance peak at 0.9 p.p.m. in brain (1) H-MRS would be one of the earliest clues to the diagnosis of classic MSUD in the neonatal period, especially in metabolic crisis.

Brain Branched-Chain Amino Acids in Maple Syrup Urine Disease: Implications for Neurological Disorders

“…N-Acetylaspartate (NAA) is the second-most abundant amino acid in the human brain [ 53 ]. Several studies have demonstrated NAA depletion in the brain of MSUD patients during acute metabolic decompensation [ 10 , 13 , 14 , 54 ]. When compared to the healthy controls, MSUD subjects exhibited significantly lower concentrations of NAA in the brain [ 9 , 12 ].…”

Expanding Role of Proton Magnetic Resonance Spectroscopy: Timely Diagnosis and Treatment Initiation in Partial Ornithine Transcarbamylase Deficiency

“…A case of neonatal MSUD is described where diagnosis was made based on large methyl resonance group prior to results of biochemical testing, providing another example of diagnostic efficacy of 1H MRS in the acute setting. 13 This case demonstrates the practicality of obtaining 1H MRS that can aid in expediting diagnosis and should be considered in any patient with unexplained encephalopathy.…”

Novel imaging technologies for genetic diagnoses in the inborn errors of metabolism

“…This corresponds to a peak at 0.9 ppm on MRS. Heindel et al [52] reported a nine-year-old patient who suffered acute metabolic decompensation. The elevated peak at 0.9 ppm was seen in the early phase of disease, during decompensation and normalized after recovery [53] .…”