Since the beginning of the pandemic, COVID has been associated with a variety of unusual and seemingly unrelated symptoms. More recent studies have shown that many of these symptoms occur from chronic inflammation which can manifest in various tissues, blood vessels, or even organs.
This inflammation in nerves has created a variety of nerve conditions in both the central and peripheral nervous systems. Central neurologic symptoms like “brain fog” and memory loss are frequently recognized as common problems in Long COVID. Also noted are other neurologic issues like peripheral nerve pain and sensations described as “needles and pins” over different joint and muscle areas.
A widely quoted article was just published in the prestigious journal Nature Medicine regarding Long COVID and a possible association with major neurologic symptoms. In this article, researchers at Washington University studied a large Veterans Administration population. They compared 150,000 people with COVID and 11 million without COVID and found some interesting results revealing that those individuals who had COVID were more likely to have 44 neurologic abnormalities with more frequency than those who were not registered as having COVID. The authors even concluded that long-term issues like Alzheimer’s were observed in higher frequency in COVID patients than those without COVID.
The shocking conclusion that Alzheimer’s can occur from COVID needs closer examination.
The mechanism of development of Alzheimer’s must be addressed. Alzheimer’s takes years to develop in patients. The thought that COVID could accelerate this process is intriguing but needs strong proof. COVID has been shown to increase brain inflammation in some individuals so there is a potential mechanism. However, there was no mention of imaging either of the brain or biopsy data so the diagnoses may not have been uniform.
Another problem is the diagnosis of Alzheimer’s. The authors need to ensure the patients who were diagnosed with the disease had COVID be related to the diagnosis. Instead, no causality was established between COVID and Alzheimer’s.
The most important aspect of the study to examine is its methodology and whether that gives the study any limitations. This study was performed in a Veterans Administration population database. There were no direct examinations or interviews for the study. People who saw neurologists and other doctors were much more likely to be assigned more symptoms than someone who was not seen as frequently in the VA Clinics. Also, VA populations notoriously have higher numbers of neurological issues than other populations due to higher risks of cardiovascular disease, smoking, and other comorbidities. Logically, if these individuals were seen more often as is the case with a COVID history, these patients would have more of these unrelated problems detected. A better methodology would have been a prospective study with all baseline issues identified first and then following the patients for any neurologic problems after the developed COVID.
A variety of other issues also question the likelihood this Alzheimer’s association is a truly related finding. These data were analyzed in a fewer number of patients compared to the control population and extrapolation can lead to false results. Most of these data were also from patients prior to the availability of vaccines. Since Long COVID may occur less with vaccinated individuals, current data needs to compare these results.
Long COVID has many serious problems that cause debilitating illnesses. Neurologic issues and possibly Alzheimer’s have already been added to that list. The best strategy is the prevention of this major public health problem by vaccination and minimizing COVID cases. Further studies will need to describe all these issues so that victims of this disease will receive the proper treatment.