To: Posterior reversible encephalopathy syndrome in a child with severe multisystem inflammatory syndrome due to COVID-19 - Critical Care Science (CCS)

To: Posterior reversible encephalopathy syndrome in a child with severe multisystem inflammatory syndrome due to COVID-19 |

To the editor

We eagerly read the article by Dominguez-Rojas et al. about a 9-year-old male with a 3-day history of a gastrointestinal infection who underwent explorative abdominal surgery for acute abdomen, which was noninformative.⁽⁾ Postoperatively, the patient developed pneumonia requiring mechanical ventilation.⁽⁾ After extubation, the patient was diagnosed with multisystem inflammatory syndrome in children (MIS-C) based on the presence of elevated immunoglobulin G (IgG) antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and with posterior reversible encephalopathy syndrome (PRES), which was regarded as causally related to SARS-CoV-2.⁽⁾ The study is attractive but carries limitations that raise concerns that should be extensively discussed.

The main limitation of the study is that a causal association between PRES and SARS-CoV-2 was established, but the diagnosis remained unconfirmed. The index patient tested negative for SARS-CoV-2 by polymerase chain reaction (PCR). Only IgG antibodies were elevated. The patient was not tested for SARS-CoV-2 by PCR on bronchial secretions during mechanical ventilation.⁽⁾ There was no determination of the cytokine or chemokine levels in the serum. Since anti-SARS-CoV-2 IgG can persist for months,⁽⁾ a causal relation between PRES and COVID-19 is highly speculative.

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