September 26, 2022
A recent article in New Medical Life Sciences, “Researchers explore neurological manifestations among long COVID patients” focuses on an article that appeared in Nature Medicine regarding a published study on assessing long-term neurological sequelae in the post-acute phase of Sars-CoV-2. The data were, however, obtained from a United State Veterans Affairs department national database of 154,068 persons who lived beyond initial month of COVID-19 infections and two control groups: one of current VHA users who lacked the viral exposure and another being a historical control group pre-dating the pandemic. Each control had between 5-6 million users.
This article at least mentions the statistical approaches used in the study. Inverse probability weighting was used (assuming in the survival model) since they obtained hazard ratios. I had to go into the Nature article which the writer describes to find out what exactly was used and how and they described more in depth using cause-specific hazard models where death was a competing risk to estimate hazard ratios for incident neurologic outcomes. The study found elevated risks of cerebral venous thrombosis, hemorrhagic stroke, and ischemic stroke development. Also, elevated chance for Alzheimer’s and some other nervous system disorders. The authors mistakenly referred to the interpretation of the hazard ratios as risks throughout and no one corrected them.
The authors specified their findings as that the overall burden and risk of any pre-specified neurological sequela were estimated as 71 and 1.4 per 1,000 persons at one-year post-acute COVID-19, respectively, when compared to contemporary controls. They also stated that the risks and burdens among COVID-19 patients (vs. contemporary controls) were elevated even among patients not requiring hospital admissions in acute COVID-19, based on COVID-19 severity. Furthermore, regarding their findings, the “risks” for developing episodic disorders, mental health disorders, musculoskeletal disorders, and any neurologic disorder increased with age. In contrast, those of cognition and memory disorders, sensory disorders, and other neurological or associated disorders decreased with age.
This has definitely been one of the largest studies to date about the neurological symptoms of long-haul COVID-19, however, the generalizability is questionable due to this being a veteran’s population, however it still can be a useful basis for further studies on these outcomes.
Keywords: COVID-19, long COVID, Sars-CoV-2, neurological, VA
Paharia, Pooja T (September 26, 2022). “Researchers explore neurological manifestations among long COVID patients” https://www.news-medical.net/news/20220926/Researchers-explore-neurological-manifestations-among-long-COVID-patients.aspx
Xu, E., Xie, Y. & Al-Aly, Z. (2022). Long-term neurologic outcomes of COVID-19. Nature Medicine. doi: https://doi.org/10.1038/s41591-022-02001-z https://www.nature.com/articles/s41591-022-02001-z