COVID-19 emerged as a complex illness, primarily recognized for its impact on the respiratory system. The virus, however, can affect various organ systems throughout the body. Medical observations soon revealed its widespread effects, including those on the neurological system.
The Connection Between COVID-19 and Neurological Events
Early in the pandemic, healthcare professionals observed a higher-than-expected occurrence of neurological problems in individuals with COVID-19. Studies have since confirmed a link between COVID-19 and neurological issues, which can sometimes resemble a stroke.
Stroke-like presentations are a concern, with stroke diagnosed in about 2% of hospitalized COVID-19 patients. Stroke can even be the initial clinical manifestation, sometimes appearing in younger individuals who do not have typical stroke risk factors. The risk of stroke is particularly elevated in the days immediately following a COVID-19 diagnosis, and this increased risk can persist for up to a year.
Recognizing Stroke-Like Symptoms
Identifying stroke-like symptoms quickly is important for effective intervention. A common guide for recognizing these signs is the “FAST” acronym:
F: Face drooping, where one side of the face might sag or feel numb.
A: Arm weakness, indicating a sudden weakness or numbness in one arm, or sometimes a leg.
S: Speech difficulty, where a person’s speech may become slurred, or they might struggle to understand or produce words.
T: Time to call emergency services, emphasizing the urgency of seeking immediate medical help if any of these symptoms appear.
Other symptoms include sudden confusion, unexpected vision changes in one or both eyes, sudden trouble walking, dizziness, a loss of balance or coordination, or a sudden, severe headache with no clear cause.
Biological Mechanisms of COVID-19’s Neurological Impact
COVID-19 can lead to neurological issues, including stroke-like symptoms, through several biological pathways.
Hypercoagulability
One mechanism involves hypercoagulability, the body’s increased tendency to form blood clots. The virus can promote this state, leading to the formation of clots that may block blood vessels, potentially causing an ischemic stroke. Markers such as elevated D-dimer and fibrinogen levels often indicate this heightened clotting activity.
Inflammation and Endothelial Dysfunction
Systemic inflammation and an exaggerated immune response, sometimes referred to as a cytokine storm, also play a role. This overwhelming inflammatory response can damage blood vessels and brain tissue. Specific inflammatory molecules, like interleukins (IL-6, IL-1) and tumor necrosis factor-alpha (TNF-α), contribute to this damage. Damage to the lining of blood vessels, known as endothelial dysfunction, impairs their normal function and increases the risk of clot formation or leakage. This dysfunction can result in micro-strokes.
Direct Viral Effects and Hypoxia
The virus may also directly affect brain cells. Some research indicates that SARS-CoV-2 can infect various brain cells, including neurons, astrocytes, and endothelial cells. Viral particles have been detected in brain tissue, suggesting direct invasion.
Additionally, severe respiratory illness from COVID-19 can lead to hypoxia, a reduction in oxygen supply to the brain. Brain cells are highly sensitive to oxygen deprivation, and prolonged hypoxia can result in damage. In some instances, this can occur as “silent hypoxia,” where oxygen levels drop without obvious symptoms.
Urgent Medical Attention and Next Steps
Seeking immediate medical attention is important if someone exhibits stroke-like symptoms, regardless of whether COVID-19 is suspected. Call emergency services, such as 911, immediately. Rapid diagnosis and treatment are important because, in stroke care, every minute counts, as delays can lead to increased brain damage.
Medical professionals will conduct assessments, including imaging tests like MRI or CT scans, and blood tests to differentiate between a true stroke and other neurological issues related to COVID-19. This evaluation helps guide the most appropriate treatment strategy. Avoid self-diagnosis or waiting for symptoms to improve, as prompt medical intervention can significantly influence outcomes.