Supplementary Material for: A first case of acute flaccid myelitis related to enterovirus D-68 in Belgium

Introduction We describe the first case of acute flaccid myelitis (AFM) related to enterovirus D-68 (EV-D68) infection in Belgium. The clinical and radiological presentation of AFM associated with EV-D68 although well described currently remains a challenging diagnosis. Through this interesting clinical case, we aimed to review the differential diagnosis of acute flaccid palsy in a child and discuss the specific point of interest related to AFM. Case presentation We present the case of a 4-year-old girl with a torticollis associated with an acute palsy of the right upper limb. The magnetic resonance imaging (MRI) revealed an increased T2 signal intensity of the entire central gray matter of the cervical cord with involvement of the posterior brainstem. A polymerase-chain-reaction (PCR) conducted on a naso-pharyngeal swab was found positive for EV-D68. The definition of AFM proposed by the Center for Disease Control and Prevention (CDC) is an acute-onset flaccid weakness of one or more limbs in the absence of a clear alternative diagnosis and the radiological evidence of gray matter involvement on an MRI-picture, and our case fits these two criteria. A prompt and detailed work-up is required to distinguish this emergent disease from other forms of acute flaccid palsy. The functional prognosis of AFM is poor, and there are no evidence-based treatment guidelines so far. Conclusion AFM is an emerging pathology that requires the attention of pediatricians to quickly rule out differential diagnoses and adequately manage the patient. Further research is needed to optimize treatments, improve outcomes, and provide scientifically based guidelines.