Neurological symptoms persisting after a COVID-19 infection, known as neurological Long COVID or Neuro-PASC, are a growing global health concern. A recent multi-country study reveals that while these neurological effects are observed worldwide, their severity and how frequently they are reported vary significantly depending on the country. This suggests that factors beyond the virus itself – including cultural norms, healthcare access, and societal perceptions – play a crucial role in how Long COVID manifests and is reported.
Understanding Neurological Long COVID
Long COVID, or post-acute sequelae of SARS-CoV-2 infection (PASC), is characterized by symptoms that continue for at least three months after the initial COVID-19 illness. Neurological manifestations, or Neuro-PASC, are among the most common and debilitating aspects of this condition. These can include brain fog, fatigue, mood changes, cognitive impairment, headaches, and sensory disturbances. The economic impact of Long COVID is substantial, estimated at over $1 trillion annually worldwide, equivalent to approximately 1% of the global economy.
A Cross-Continental Comparison
Researchers conducted a comparative analysis of over 3,157 adults experiencing neurological symptoms of Long COVID across four countries: India, Nigeria, Colombia, and the United States. The study, published in Frontiers in Human Neuroscience on February 7, 2025, aimed to identify differences in symptom presentation and severity across diverse geographic, economic, and sociocultural contexts. Participants were categorized based on whether they required hospitalization during their initial COVID-19 infection (post-hospitalization Neuro-PASC – PNP) or not (non-hospitalized Neuro-PASC – NNP).
Key Findings: Geographic Variations in Symptom Burden
The study revealed significant variations in symptom burden and cognitive function across the four countries. The United States and Colombia consistently reported the highest number of neurological symptoms, psychological distress, and cognitive impairment, while Nigeria and India reported the lowest. Specifically, brain fog, depression, and anxiety were particularly prevalent in the US and Colombia, but reported far less frequently in Nigeria and India.
These differences were observed in both those who had been hospitalized with COVID-19 and those who had not. Statistical adjustments for age and sex did not eliminate these disparities, suggesting that factors beyond basic demographics are at play. Objective neurological examinations and cognitive testing, while utilizing locally validated but differing instruments, also showed higher rates of abnormalities in the United States and Colombia compared to Nigeria and India.
The Role of Cultural and Healthcare Factors
Researchers suggest that cultural stigma, healthcare access, health literacy, and differing expectations of illness may contribute to these observed variations. In some cultures, there may be a reluctance to report mental health symptoms or cognitive difficulties. Access to specialized neurological care and routine mental health screening may differ significantly between countries, influencing both symptom identification and reporting.
The study highlights the importance of considering these contextual factors when assessing and managing Long COVID. Variations in health-seeking behavior and the availability of resources can also influence symptom reporting. For example, individuals in countries with limited healthcare access may be less likely to seek medical attention for their symptoms, leading to underreporting.
Study Methodology and Limitations
The study utilized harmonized observational data collected between 2020 and 2025, following a common protocol developed at a U.S.-based Neuro-COVID clinic. Data included demographics, comorbidities, neurological and non-neurological symptoms, and quality-of-life measures. Cognitive function was assessed using locally validated instruments, and psychological distress was measured using tools like the Depression and Anxiety Stress Scale (DASS), though instrument availability varied by country.
Researchers acknowledge several limitations, including differences in recruitment strategies, timing of assessments, and the use of non-uniform cognitive and psychological instruments. These factors limit direct comparisons between countries. However, the consistent clustering of symptom profiles across cohorts supports the robustness of the findings.
Implications for Global Health
This study underscores the need for culturally sensitive assessment tools and standardized data collection in global Long COVID research. It also emphasizes the importance of integrating post-COVID neurological care into health systems worldwide. Recognizing that Neuro-PASC presents differently across diverse populations is crucial for developing effective prevention, diagnosis, and treatment strategies. Further research is needed to understand the underlying mechanisms driving these geographic variations and to develop targeted interventions to address the unique needs of each population.
