Cognitive impairment after Covid-19: more evidence in adults, but don't forget the kids!
Hampshire et al reported, on a large cohort of adults living in the UK, that patients with persisting symptoms after COVID-19 present more neurocognitive deficits as compared with the no–Covid-19 group.
Patients with Long Covid had larger deficits as compared with the no–Covid-19 group (−0.42 SD; 95% CI, −0.53 to −0.31). Larger deficits were seen in participants who had SARS-CoV-2 infection during periods in which the original virus or the B.1.1.7 variant was predominant than in those infected with later variants (e.g., −0.17 SD for the B.1.1.7 variant vs. the B.1.1.529 variant; 95% CI, −0.20 to −0.13) and in participants who had been hospitalized than in those who had not been hospitalized (e.g., intensive care unit admission, −0.35 SD; 95% CI, −0.49 to −0.20). The authors state that “we found objectively measurable cognitive deficits that may persist for a year or more after Covid-19“.
Similar findings were found in a recent large cohort of Norwegian adult participants. The adjusted mean Everyday Memory Questionnaire (EMQ) scores were numerically higher (indicating worse memory problems) after a positive test than after a negative test at all time points (at 0 to 1 month after a test, 0.66 vs. 0.60; at >1 to 3 months, 0.74 vs. 0.62; at >3 to 6 months, 0.72 vs. 0.62; at >6 to 9 months, 0.71 vs. 0.62; at >9 to 12 months, 0.75 vs. 0.63; at >12 to 18 months, 0.82 vs. 0.62; and at >18 to 36 months, 0.82 vs. 0.62).
Here I want to highlight a major limitation of both studies, not mentioned yet. They only included adults, while we have major growing evidence that Long Covid affect children, brain fog and neurognitive problems, affecting daily life and impairing school performances, have been reported globally by studies and family associations. Also, small reports have documented abnormal brain metabolism in children with Long Covid and neurocognitive symptoms, like my studies in Rome and other cohorts in France. Although the evidence in children is less straightforward, as a pediatrician and researcher involved in the field, I hope with this letter we can receive attention from major funding agencies and policy makers about funding similar studies for children and adolescents. Today, pediatric Long Covid is neglected and this limit our chances to advance knowledge and care for younger patients.
IMPORTANT closing note. This content does not want to scary people. The NEJM cohort is based on a specific timing of the pandemic. Also, the cases with cognitive involvment we see in children were more frequently infected during the first years of the pandemic. Of course, negative neurocognitive outcomes can still happen after SARS-CoV-2 as well other infections, but luckily these are relatively rare complications, as most people pass the infection without problems. So, I don’t want to scare the readers, although I think it is important to acknowledge that these things can happen, unfortunately. And we need to take it seriously, not to scare, but to learn, understand, and ultimately being able to prevent and cure.