Many people who tested positive for COVID-19 have abnormal electroencephalographic (EEG) activity that reflects brain fog and mild cognitive impairment even months after the acute phase of infection. A panel of experts from the University of Kentucky’s Sanders-Brown Center on Aging conducted a systematic review to present compelling evidence that cognitive deficits due to COVID-19 and Alzheimer’s disease and related dementia (ADRD) are driven due to overlapping pathologies and neurophysiological abnormalities, that result, at least in part, from neuroinflammatory mechanisms and astrocyte reactivity. Thus, they detected that the EEG abnormalities observed in patients with COVID-19 are strikingly similar to those observed in the early stages of neurodegenerative diseases, in particular mild cognitive impairment.
The study, which brought together experts from various fields of neuroscience and whose results have been published in Alzheimer’s & Dementiahighlights a possible similarity in the brain disorders of these conditions that could pave the way for new avenues of research and treatment.
Yang Jiang, a professor in the Department of Behavioral Sciences, and his team focused their work on understanding the brain fog that many COVID-19 survivors experience, even months after recovering from the virus. This fog includes memory problems, confusion, and difficulty concentrating. According to Jiang, “the slowdown and abnormality of intrinsic brain activity in COVID-19 patients resemble those observed in Alzheimer’s and related dementias.”
This research sheds light on the connection between the two conditions, suggesting they may share underlying biological mechanisms. Both long COVID-19 and Alzheimer’s disease involve neuroinflammation, activation of brain support cells known as astrocytes, and abnormal brain activity. These factors can cause significant cognitive impairments, making it difficult for patients to think clearly or remember information.
Research reveals that cognitive problems caused by COVID-19 reflect underlying brain changes similar to those of dementia, which is a significant advance. “People don’t often connect COVID-19 with Alzheimer’s disease,” Jiang said. “But our review of emerging evidence suggests otherwise.”
Routine checks to detect cognitive impairment in patients with COVID-19
The study findings emphasize the importance of regular brain function checks for these populations, particularly through the use of affordable and accessible tools such as electroencephalography (EEG). The study not only highlights shared traits between long COVID and Alzheimer’s, but also points to the importance of further research. “The new discovery opens avenues for future research and clinical practice, particularly in the study of brain oscillations related to neural biomarkers of mild cognitive impairment in people with long COVID,” Jiang said.
One of the key findings is the role of astrocytes, support cells in the brain that have not been studied as thoroughly as neurons. Research suggests that damage or activation of these cells by COVID-19 can cause synaptic dysfunctions, leading to the abnormal brain activity seen in both conditions. This discovery is significant because it may help explain why EEG patterns in COVID-19 patients resemble those seen in the early stages of neurodegenerative diseases such as Alzheimer’s. The researchers believe this work could have a direct impact on patient care. Researchers advocate for routine EEG screening to detect early brain changes in both COVID-19 survivors and those at risk of cognitive decline.
“EEG patterns in patients with COVID-19 resemble those seen in early neurodegenerative diseases,” says Chris Norris, professor in the Department of Pharmacology and Nutritional Sciences. “These similarities may be due to shared problems such as brain inflammation, astrocyte activity, low oxygen levels and damage to blood vessels,” says Bob Sompol, associate professor in the same department.
By detecting these changes early, healthcare providers could potentially identify at-risk individuals sooner and implement interventions to prevent or slow the progression of cognitive decline.
As research continues, the team is particularly interested in how EEG monitoring can predict long-term outcomes in patients with COVID-19 and evaluate the effectiveness of treatments aimed at preventing cognitive decline.
Source: University of Kentucky
