Acute cerebellar ataxia in a patient with maple syrup urine disease: a case report

Carolina Castro, Serviço de Pediatria Médica, Departamento de Pediatria, Hospital de Santa Maria – Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
Patrícia Lipari Pinto, Unidade de Doenças Metabólicas, Departamento de Pediatria, Hospital de Santa Maria – Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
Inês Carneiro, Serviço de Neuroradiologia, Departamento de Imagiologia, Hospital de Santa Maria – Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
Patrícia Janeiro, Unidade de Doenças Metabólicas, Departamento de Pediatria, Hospital de Santa Maria – Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
Joana Coelho, Unidade de Neuropediatria, Departamento de Pediatria, Hospital de Santa Maria – Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
Fátima Furtado, Serviço de Pediatria, Unidade Local de Saúde do Baixo Alentejo, Beja, Portugal
Sofia Quintas, Unidade de Neuropediatria, Departamento de Pediatria, Hospital de Santa Maria – Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
Ana Gaspar, Unidade de Doenças Metabólicas, Departamento de Pediatria, Hospital de Santa Maria – Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal

Introduction: Maple syrup urine disease (MSUD) is an inborn error of amino acid metabolism, potentially resulting in metabolic intoxication crises accompanied by neurological manifestations. Case report: This article reports a case involving a six-year-old boy with MSUD who developed a post-infectious neurological disorder following COVID-19. Initially presenting with fever, cough, and ataxia, he was diagnosed with a metabolic crisis due to COVID-19. Despite an initial recovery, the patient experienced a relapse characterized by ataxia, tremor, and dysarthria, necessitating readmission. A subsequent investigation ruled out an MSUD crisis. A lumbar puncture and MRI failed to rule out a demyelinating acute disorder. Methylprednisolone treatment yielded no improvement, prompting the initiation of intravenous immunoglobulin, which led to improvement after 14 days. Discussion: The case posed challenges due to the overlapping symptoms between MSUD crises and post-infectious neurological conditions. This highlights the complexity of managing these patients, particularly due to the potential for more vigorous manifestations and slower recovery.

Keywords: MSUD. PINS. COVID-19. Ataxia.