Acute disseminated encephalomyelitis in a COVID-19 pediatric patient.

The authors present a case of acute disseminated encephalomyelitis in a COVID-19 pediatric patient with positive SARS-CoV2 markers from a nasopharyngeal swab. A previously healthy 12-year-old-girl presented with a skin rash, headache, and fever. Five days after that, she had an acute, progressive, bilateral, and symmetrical motor weakness. She evolved to respiratory failure. Magnetic resonance imaging (MRI) of the brain and cervical spine showed extensive bilateral and symmetric restricted diffusion involving the subcortical and deep white matter, a focal hyperintense T2/FLAIR lesion in the splenium of the corpus callosum with restricted diffusion, and extensive cervical myelopathy involving both white and gray matter. Follow-up examinations of the brain and spine were performed 30 days after the first MRI examination. The images of the brain demonstrated mild dilatation of the lateral ventricles and widespread widening of the cerebral sulci, complete resolution of the extensive white matter restricted diffusion, and complete resolution of the restricted diffusion in the lesion of the splenium of the corpus callosum, leaving behind a small gliotic focus. The follow-up examination of the spine demonstrated nearly complete resolution of the extensive signal changes in the spinal cord, leaving behind scattered signal changes in keeping with gliosis. She evolved with partial clinical and neurological improvement and was subsequently discharged.

HINT1 founder mutation causing axonal neuropathy with neuromyotonia in South America: A case report.

BACKGROUND: Recessive loss-of-function mutations in HINT1 are associated with predominantly motor axonal peripheral neuropathy with neuromyotonia. Twenty-four distinct pathogenic variants are reported all over the world, including four confirmed founder variations in Europe and Asia. The majority of patients carry the ancient Slavic founder variant c.110G>C (p.Arg37Pro) that shows a distribution gradient from east to west throughout Europe. METHODS: We report a case of HINT1 neuropathy in South America, identified by massive parallel sequencing of a neuropathy gene panel. To investigate the origin of the variant, we performed haplotyping analysis. RESULTS: A Brazilian adolescent presented with recessive axonal motor neuropathy with asymmetric onset and fasciculations. Neuromyotonia was found on needle electromyography. His parents were not consanguineous and had no European ancestry. The patient carried biallelic pathogenic p.Arg37Pro alterations in the first exon of HINT1. Both alleles were identical by descent and originated from the same ancestral founder allele as reported in Europe. CONCLUSION: Our findings expand the geographic distribution of HINT1 neuropathy to South America, where we describe a recognized founder variant in a Brazilian adolescent with no apparent European ancestry. We confirm the association of the hallmark sign of neuromyotonia with the disease.