We report the clinical case of a nine-year-old girl who presented with progressive motor neuropathy, revealed via the detection of a higher delay in F-wave recording using digitalized nerve conduction/electromyography. Since the lupus anticoagulant (LAC) positivity, detected using diluted Russell viper venom time (dRVVT), switched to persistent serological anticardiolipin immunoglobulin G (IgG) positivity, a possible non-thrombotic antiphospholipid antibody (aPL)-related clinical manifestation was suspected, and intravenous immunoglobulin treatment (IVIG) was started. The IVIG treatment was well tolerated and the complete resolution of motor impairment was obtained after the third IVIG infusion. Our findings suggest that it could be useful to check for antiphospholipid antibodies in children with a rapid onset of progressive neurological signs in order to provide the beneficial use of IVIG in the treatment of pediatric aPL neurological conditions. Video S1: Functional motor outcome before and after IVIG treatment. Author Contributions: Conceptualization, C.B., M.L., D.M.R., R.M.; methodology, C.B., M.L., G.N., R.S., G.F., E.M.; software, C.B., G.N., D.M.R.; validation, C.B., M.L., D.M.R., B.B., R.M., E.M.; formal analysis, C.B., M.L., D.M.R., R.S., G.F., M.P.; investigation, C.B., M.L., R.M., D.M.R.; resources, C.B., M.L., E.M., M.P.; data curation, C.B., M.L., D.M.R., R.S., G.F.; writing-original draft preparation, C.B., M.L., R.M.; writing-review and editing, C.B., M.L., D.M.R., B.B., R.M., M.P.; visualization, C.B., M.L., D.M.R., B.B., R.M., E.M., M.P.; supervision, C.B., M.L., D.M.R., B.B., R.M., M.P.; project administration, C.B., M.P.; funding acquisition, C.B., M.P. All authors have read and agreed to the published version of the manuscript. Funding: This research received no external funding.
Conflicts of Interest:The authors declare no conflict of interest.