LAUSR

BACKGROUND Acute flaccid myelitis (AFM) and transverse myelitis (TM) are serious conditions that may be difficult to differentiate, especially at onset of disease. In this study we compared clinical features of pediatric AFM and TM and evaluated current diagnostic criteria, aiming to improve early and accurate diagnosis. METHODS Two cohorts of children with enterovirus D68-associated AFM and clinically diagnosed TM were compared regarding presenting clinical features, additional investigations and outcome. Current diagnostic criteria for AFM and TM were applied to evaluate their specificity. RESULTS Children with AFM (n=21) compared to those with TM (n=36) were younger (median 3 vs. 10 years), more often had a prodromal illness (100% vs. 39%), predominant proximal weakness (69% vs. 17%) and hyporeflexia (100% vs. 44%), and less often had sensory deficits (0% vs. 81%), bowel and/or bladder dysfunction (12% vs. 69%) and hyperreflexia (0% vs. 44%). On MRI, brainstem involvement was more common in AFM (74% vs. 21%), while supratentorial abnormalities were only seen in TM (0% vs. 40%). When omitting the criterion of a sensory level, 11/15 (73%) children with AFM fulfilled the diagnostic criteria for TM. Of children with TM, 4/33 (12%) fulfilled the diagnostic criteria for probable/definite AFM. CONCLUSION While there is considerable overlap between AFM and TM in children, we found important early differentiating clinical and diagnostic features. Meeting diagnostic criteria for AFM in children with TM and vice versa, underlines the importance of thorough clinical examination and early and accurate diagnostic studies.