Brain magnetic resonance imaging findings and radiologic review of maple syrup urine disease: Report of three cases

Maple Syrup Urine Disease: An Uncommon Cause of Neonatal Febrile Seizures

Maple syrup urine disease (MSUD) is a rare autosomal-recessive disorder. An enzyme complex called branched-chain alpha-keto acid dehydrogenase (BCKAD) metabolizes branched-chain amino acids (BCAAs), such as leucine, isoleucine, and valine, in the body. The deficiency of this enzyme causes the accumulation of BCAAs in cerebrospinal fluid, plasma, and urine. This metabolic illness is defined by abnormal levels of BCAAs. The pathognomonic illness marker alloisoleucine is produced in the absence of the BCKAD enzyme, which is part of a metabolic pathway involving three BCAAs and gets accumulated in the body. Classically, affected neonates present with feeding problems, vomiting, lethargy, and irritability, leading to seizures, coma, and death if left untreated. Blood and urine analysis reveals an accumulation of BCAAs in the plasma and urine. Here, we report the case of a neonate on day 10 of life with febrile seizures and non-acceptance of feeds, who was diagnosed with the classical form of MSUD. This is a classic case of MSUD which was evaluated exhaustively and revealed all classic features clinically and on investigations.

Imaging of Inherited Metabolic and Endocrine Disorders

"Inherited metabolic disorders represent a large group of disorders of which approximately 25% present in neonatal period with acute metabolic decompensation, rapid clinical deterioration, and often nonspecific imaging findings. Neonatal onset signifies the profound severity of the metabolic abnormality compared with cases with later presentation and necessitates rapid diagnosis and urgent therapeutic measures in an attempt to decrease the extent of brain injury and prevent grave neurologic sequela or death. Here, the authors discuss classification and clinical and imaging findings in a spectrum of metabolic and endocrine disorders with neonatal presentation."

The clinico-radiological findings of MSUD in a group of Egyptian children: Contribution to early diagnosis and outcome

Background

Maple syrup urine disease (MSUD) is an autosomal recessive inborn error of amino acid metabolism, with unique clinico‐radiological findings. This study aims to show the benefit of using the clinico‐radiological findings for early diagnosis of children with MSUD, and confirming this diagnosis using the tandem mass spectrometry (MS/MS), in order to avoid deleterious outcome.

Methods

A prospective cohort study conducted in the period from August 2016 to December 2020. Twenty‐one children were included either by selective screening or by high‐risk screening. All children had clinical and neurodevelopmental evaluation, brain magnetic resonance imaging (MRI) assessment, and blood amino acids analysis at diagnosis. Patients were followed clinically.

Results

Most children had acute onsets neuro‐developmental symptoms, with wide range of brain parenchyma involvement on MRI (hyperintensity). Diagnosis of MSUD was confirmed by detecting high serum levels of leucine/isoleucine (mean value 2085.5 μmol/L) in all patients, and elevated levels of serum valine in (81%) of children. In addition, all children showed elevated leucine: alanine ratio, and leucine: phenylalanine ratio.

Conclusions

The characteristic clinico‐radiological features can help in the early diagnosis of MSUD children, thus preventing the delay in laboratory diagnosis and improving their outcomes.