Letter to the editor: COVID in patients with brain injury with a disorder of consciousness: a pathogenetic theory.

We recently published in this journal (Caronni and colleagues, Brain Injury, 2021-04-16) the first description of the spread of the SARS-CoV-2 infection in a cohort of brain injured patients with a disorder of consciousness (DOC). Surprisingly enough we showed that, in these patients, the COVID was moderate and did not result in fatalities. The pathogenesis of the COVID is characterized by the profound dysregulation of the immune system. To explain our findings, we speculated that the immunosuppression due to the brain injury could be protective against the development of the COVID in patients with DOC. More recently, a second group of authors (Marino and colleagues, PLoSOne, 2021-06-30) described the course of the COVID in an independent cohort of patients with DOC. Since our results were quite unexpected, we have been very comforted by the data reported by Marino and colleagues. Moreover, these data also offer a unique opportunity to further evaluate our theory regarding the COVID pathogenesis in patients with DOC. In the current Letter to the Editor it is shown that the independent data presented by Marino and colleagues do support our theory. Waiting for larger cohorts to further test it (and in case falsify it), our interpretation seems to remain valid.

Clinical course of SARS-CoV-2 infection in patients with severe acquired brain injury and a disorder of consciousness: an observational study.

Purpose: SARS-CoV-2 infection can cause the coronavirus disease (COVID), ranging from flu-like symptoms to interstitial pneumonia. Mortality is high in COVID pneumonia and it is the highest among the frailest. COVID could be particularly serious in patients with severe acquired brain injury (SABI), such as those with a disorder of consciousness. We here describe a cohort of patients with a disorder of consciousness exposed to SARS-CoV-2 early after their SABI.Materials and methods: The full cohort of 11 patients with SABI hospitalized in March 2020 in the IRCCS Fondazione Don Gnocchi rehabilitation (Milan, Italy) was recruited. Participants received SARS-CoV-2 testing and different clinical and laboratory data were collected.Results: Six patients contracted SARS-CoV-2 and four of them developed the COVID. Of these, one patient had ground-glass opacities on the chest CT scan, while the remaining three developed consolidations. No patient died and the overall respiratory involvement was mild, requiring in the worst cases low-flow oxygen.Conclusions: Here we report the clinical course of a cohort of patients with SABI exposed to SARS-CoV-2. The infection spread among patients and caused COVID in some of them. Unexpectedly, COVID was moderate, caused at most mild respiratory distress and did not result in fatalities.