Millions of people worldwide who have recovered from COVID-19 face an increased risk of neurological disorders lasting months or even years after infection1 . Emerging research reveals that COVID-19 can cause lasting changes in brain structure and function, leading to cognitive decline, memory problems, and other neurological impairments2 . These long-term effects pose significant challenges for healthcare systems and patient quality of life3 .
COVID-19 and Neurological Disorder Risk
Large-scale studies have established that COVID-19 infection significantly raises the risk of developing a wide range of neurological disorders. A cohort of over 150,000 COVID-19 patients followed for one year showed a 42% increased risk of neurological sequelae compared to uninfected controls1 . These neurological complications include cognitive impairment, memory disorders, cerebrovascular events such as strokes, seizures, psychiatric disorders, headaches, and movement abnormalities1 .
💡 Did You Know? Long COVID has long-term effects on the brain, and cognitive impairment following Long COVID may be more severe in older adults20 .
This elevated risk is not limited to patients with severe illness; even those with mild COVID-19 who were not hospitalized exhibit increased neurological risks1 . The burden of these complications is substantial, with millions in the United States alone estimated to suffer long-term neurological impairments post-COVID3 . The wide spectrum of neurological issues linked to COVID-19 was unexpected and extends beyond initial expectations of the virus’s impact1 3.
Retrospective cohort studies worldwide report that over one-third of patients experience neurological signs such as headaches, altered mental status, seizures, and stroke during the acute phase of COVID-19, positioning SARS-CoV-2 as an emerging neuro-pathogen4 . The increased incidence of neurological disorders following COVID-19 infection has also been associated with higher mortality rates in affected individuals5 .
Neurological risks after COVID-19 infection include:
- Cognitive and memory disorders1
- Cerebrovascular events (e.g., ischemic stroke) 14
- Seizures and epileptic episodes1
- Psychiatric disorders including anxiety and depression1 6
- Headaches and migraine-like symptoms1
- Movement abnormalities and motor dysfunction1
These findings highlight the need for healthcare policies to address and mitigate the long-term neurological consequences of COVID-191 .
How COVID-19 Affects Brain Health
COVID-19 impacts brain health through multiple mechanisms, many of which remain under active investigation. Systemic inflammation triggered by SARS-CoV-2 infection is believed to contribute significantly to neurological damage7 . The virus may injure blood vessels supplying the brain, leading to vascular inflammation and increased risk of stroke and other cerebrovascular events8 . Additionally, SARS-CoV-2 might directly infect the nervous system, causing neuroinflammation and blood-brain barrier disruption8 7.
“However, it has been unclear as to whether there is objective evidence of cognitive impairment and, if so, is there any biological evidence of brain injury; and most importantly if patients recover over time.”
— Greta Wood, MBBS, University of Liverpool11
Neuroimaging studies reveal structural brain changes in COVID-19 survivors, including reductions in gray matter volume in critical regions such as the cingulate cortex and hippocampus, which are essential for memory and executive function1 9. These alterations may underlie the cognitive deficits observed in many patients post-infection1 . Autopsy studies have shown evidence of brain inflammation and injury months after severe COVID-19, supporting the hypothesis of persistent brain involvement2 10.
Cognitive impairments following COVID-19 resemble accelerated brain aging, with deficits comparable to 20 years of normal aging in some hospitalized patients11 . These impairments include difficulties with memory, planning, spatial reasoning, attention, processing speed, and executive function11 6. Even mild COVID-19 cases can lead to measurable cognitive decline, such as a three-point IQ loss, while severe cases requiring intensive care may experience losses equivalent to nine IQ points2 .
Fatigue and brain fog are among the most common long-term neurological symptoms, often accompanied by anxiety, depression, and sleep disturbances12 6. The blood-brain barrier, which protects the brain from harmful substances, may become "leaky" after COVID-19, allowing inflammatory molecules to enter and disrupt normal brain function2 .
COVID-19 is not only a respiratory disease but also a neuro-pathogen that can cause lasting brain injury even in mild cases. Preventive measures and vaccination remain the best tools to reduce these risks. 141524
Proposed mechanisms for COVID-19-related brain injury include:
- Systemic inflammation and cytokine release affecting the brain7
- Vascular injury and microinfarcts due to blood clotting abnormalities8 4
- Disruption of the blood-brain barrier increasing brain vulnerability2
- Direct viral invasion of neural tissue in some cases2 10
- Activation of brain immune cells such as astrocytes and microglia leading to neuroinflammation12
Women may be more vulnerable to persistent neurobehavioral symptoms after COVID-19, potentially leading to poorer long-term outcomes in those with pre-existing brain injuries13 .
“Now our group is working to understand whether the mechanisms that we have identified in COVID-19 may also be responsible for similar findings in other severe infections, such as influenza.”
— Benedict Michael, MBChB, PhD, University of Liverpool11
Importance of COVID-19 Prevention
“The work might be helpful for guiding similar studies of patients with long COVID who had milder respiratory symptoms who also report brain fog and for the development of treatment strategies.”
— Gerome Breen, PhD, King's College London11Preventing COVID-19 infection remains critical to reducing the risk of long-term neurological complications. Vaccination decreases the risk of developing Long COVID neurological symptoms by approximately 20%, though it does not offer complete protection14 . Public health measures such as mask-wearing, hand hygiene, and physical distancing continue to be effective strategies to limit virus transmission and subsequent brain injury risk15 16.
Management of underlying health conditions like diabetes and obesity is also important, as these comorbidities increase susceptibility to neurological sequelae both with and without COVID-19 infection8 17. Currently, no specific therapies exist to prevent or treat post-COVID neurological complications beyond acute antiviral treatment and supportive care3 .
Neuroimaging and biomarker studies emphasize the need for early identification and monitoring of patients at risk for cognitive decline and other brain-related symptoms after COVID-1918 19. Maintaining overall health and seeking medical care for persistent neurological symptoms are recommended for COVID survivors3 .
“That the cognitive impairments occurred alongside brain-cell injury markers and reduced brain volume on magnetic resonance imaging suggest there may be measurable biomechanisms.”
— Benedict Michael, MBChB, PhD, University of Liverpool11
Key prevention and management strategies include:
- Vaccination against COVID-19 to reduce infection and severity14
- Adherence to public health guidelines (masking, distancing, hand hygiene) 1516
- Control of comorbidities such as diabetes and obesity8
- Early recognition and medical evaluation of neurological symptoms post-infection3
- Ongoing research to develop targeted interventions for long-term brain effects3 7
The long-term burden of COVID-related brain injury poses significant challenges for healthcare systems and economies worldwide, underscoring the importance of comprehensive prevention strategies3 .
