Recurrent Encephalopathy During Febrile Illnesses in a 6-Year-Old Boy

Area of Science:

• Neurology
• Metabolic Disorders
• Genetics

Background:

• Acute encephalopathy often stems from infections or intoxications, but metabolic or autoimmune causes are critical considerations, especially in recurrent presentations.
• A 6-year-old male presented with symptoms suggestive of influenza A, leading to an initial diagnosis of influenza A encephalitis.
• Subsequent recurrent episodes of encephalopathy prompted a broader diagnostic investigation.

Purpose of the Study:

• To investigate the underlying cause of recurrent unexplained encephalopathy in a pediatric patient.
• To highlight the importance of considering inborn errors of metabolism in the differential diagnosis of encephalopathy.
• To underscore the potential for intermittent presentations of metabolic disorders like MSUD.

Main Methods:

• Clinical presentation analysis including neurological examination and laboratory findings (hypoglycemia, metabolic acidosis).
• Cerebrospinal fluid analysis and brain MRI.
• Urine organic acid profiling and genetic testing for BCKDHB gene variants.

Main Results:

• Initial presentation attributed to influenza A encephalitis, characterized by confusion, somnolence, and MRI findings of restricted diffusion.
• Recurrent episodes revealed hypoglycemia and metabolic derangements.
• Urine organic acid profile indicated elevations consistent with maple syrup urine disease (MSUD).
• Genetic testing confirmed compound heterozygosity for pathogenic variants in the BCKDHB gene, diagnosing MSUD.

Conclusions:

• This case underscores the necessity of including inborn errors of metabolism in the workup for unexplained encephalopathy, particularly in recurrent cases.
• Maple syrup urine disease (MSUD) can present with intermittent symptoms, potentially delaying diagnosis until early childhood.
• Broadening diagnostic considerations beyond infectious etiologies is vital for accurate and timely diagnosis of rare metabolic disorders.