Case Report
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Mar 16, 2021; 9(8): 1844-1852
Published online Mar 16, 2021. doi: 10.12998/wjcc.v9.i8.1844
Brain magnetic resonance imaging findings and radiologic review of maple syrup urine disease: Report of three cases
Yang Li, Xia Liu, Chong-Feng Duan, Xiu-Feng Song, Xun-Hui Zhuang
Yang Li, Xiu-Feng Song, Xun-Hui Zhuang, Department of Radiology, Qingdao Women and Children’s Hospital, Qingdao 266011, Shandong Province, China
Xia Liu, Department of Ultrasound, The Affiliated Hospital of Qingdao University, Qingdao 266000, Shandong Province, China
Chong-Feng Duan, Department of Radiology, The Affiliated Hospital of Qingdao University, Qingdao 266000, Shandong Province, China
Author contributions: Li Y performed the majority of the writing and prepared the figures and tables; Liu X performed the literature review and writing; Duan CF provided the input in writing the paper; Song XF designed the outline and review paper content; Zhuang XH coordinated the writing of the paper.
Informed consent statement: Informed written consent was obtained from the patient for publication of this report and any accompanying images.
Conflict-of-interest statement: There is no conflict of interest associated with any of the senior author or other coauthors who contributed their efforts in this manuscript.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Xiu-Feng Song, PhD, Director, Department of Radiology, Qingdao Women and Children’s Hospital, No. 6 Tongfu Road, Qingdao 266011, Shandong Province, China. song_sxf@126.com
Received: July 18, 2020
Peer-review started: July 18, 2020
First decision: November 30, 2020
Revised: December 12, 2020
Accepted: January 20, 2021
Article in press: January 20, 2021
Published online: March 16, 2021
Abstract
BACKGROUND

Maple syrup urine disease (MSUD) is a rare autosomal-recessive disorder that affects branched-chain amino acid (BCAA) metabolism and is named after the distinctive sweet odor of affected infants’ urine. This disease is characterized by the accumulation of BCAAs and corresponding branched-chain ketoacids of leucine, isoleucine, and valine in the plasma, urine, and cerebrospinal fluid. However, the mechanisms of MSUD-induced brain damage remain poorly defined. The accumulation of BCAAs in the brain inhibits the activity of pyruvate dehydrogenase and α-ketoglutarate, disrupting the citric acid cycle and consequently impacting the synthesis of amino acids, causing cerebral edema and abnormal myelination.

CASE SUMMARY

We report three neonates admitted to our hospital with the classic subtype of MSUD. All three patients, with a transient normal period, presented with poor feeding, vomiting, poor weight gain, and increasing lethargy after birth. Laboratory testing revealed metabolic acidosis. The serum tandem mass spectrometry amino acid profile showed elevated plasma levels of BCAAs (leucine, isoleucine, and valine). Brain magnetic resonance imaging (MRI) presented abnormal signals mainly involving the globus pallidus, thalamus, internal capsule, brainstem, and cerebellar white matter, which represent the typical myelinated areas in normal full-term neonates.

CONCLUSION

In our patients, MRI showed typical features, in concordance with the available literature. Early detection and timely treatment are very helpful for the prognosis of MSUD patients. Therefore, we discuss the neuroimaging features of MSUD to enhance the knowledge of pediatricians about this disease.

Keywords: Maple syrup urine disease, Magnetic resonance imaging, Metabolic disorders, Intramyelinic edema, Neonates, Case report

Core Tip: This article reports three patients with maple syrup urine disease with typical clinical manifestations and magnetic resonance imaging features and reviews the related literature. The pathogenesis, pathophysiological characteristics, and typical imaging findings of this rare genetic metabolic disease are discussed.