Wednesday February 23, 2022 – Author:
ham
Cognitive problems like concentration problems and memory lapses are one of the most common symptoms of Long-Covid. Now scientists have discovered a possible cause: increased Alzheimer’s biomarkers in the blood of affected patients. The German Society for Neurology interprets the worrying results.
After a Covid-19 infection, some people have cognitive problems for a long time. that as Neuro-Covid well-known phenomenon can impair memory, concentration, thinking as such or finding words. Sometimes the deficits are reminiscent of dementia.
The causes are still largely unclear. As part of the “SNaP Acute COVID” study, scientists have now found a biomedical correlate to the symptoms that appear to be dementia: Hospitalized COVID-19 patients had the same or even higher levels of neurodegenerative biomarkers than people suffering from Alzheimer’s disease.
Suddenly elevated Alzheimer’s biomarkers in the blood
251 patients with an average age of 76 years were included in the analysis. 31 percent required mechanical ventilation, 25 percent died in hospital and 53 percent were discharged. Neurological symptoms occurred in every second patient during the hospital stay. The most common diagnoses were toxic metabolic encephalopathy (75/120) and hypoxic-ischemic brain injury (55/120). For comparison, 161 controls were subjected to the biomarker tests.
Blood tests showed that patients with newly developed cognitive deficits had increased levels of tau, NFL and UCHL. The tau protein is used to diagnose Alzheimer’s disease. NFL (= “neurofilament light chain”), is a biomarker of cognitive decline that is increased in people with Alzheimer’s or Parkinson’s disease. And UCHL1 is a neuronal biomarker that is currently being discussed as an ALS biomarker, among other things. In addition, the level of the glial fibrillary acidic protein (GFAP), which is contained in Alzheimer’s plaques, was increased.
Biomarker levels increase with disease burden
Some of these biomarkers were found in higher concentrations than in Alzheimer’s patients. The increase was higher the sicker the patients were and it correlated with an increased D-dimer level.
“Against the background of the cognitive limitations that many patients suffer from long following the SARS-CoV-2 infection, this is an interesting finding,” says Prof. Peter Berlit, Secretary General of the German Neurological Society. If this correlation were confirmed in further studies, “we would have biomarkers for post-COVID symptoms such as impaired concentration or memory.”
Neuro-Covid not comparable to Alzheimer’s
But the results sound quite worrying for those affected. Neurologist Berlit says, however, that the data should not be overinterpreted to mean that COVID-19 can trigger Alzheimer’s dementia. “This concern is unfounded, especially as the cognitive limitations in people with post- or long-COVID improve once more. This is not the case with neurodegenerative diseases such as Alzheimer’s,” says the neurologist.
It should also be taken into account that the patients examined suffered from severe forms of Covid-19. Neuro-Covid often occurs following mild infections.
The results of the study were published on January 13th in the specialist journal “Alzheimer’s & Dementia”.
