Nikhil Prasad Fact checked by:Thailand Medical News Team Sep 22, 2026 45 minutes ago
A small molecule involved in regulating inflammation and brain function may provide an important molecular clue to why some people with COVID-19 develop stroke, according to new research examining microRNA patterns in patients with and without the neurological complication.
Researchers found sharply elevated miR-124 levels in COVID-19 patients who experienced stroke
Researchers found that miR-124, a microRNA strongly associated with the nervous system, was substantially elevated in COVID-19 patients who experienced stroke. The finding raises the possibility that miR-124 could eventually help researchers understand, detect, or potentially target neurological complications associated with SARS-CoV-2 infection.
Researchers compare COVID-19 patients with healthy adults
The cross-sectional study included 100 participants: 25 COVID-19 patients with clinically confirmed stroke, 25 COVID-19 patients without stroke, and 50 healthy controls. COVID-19 was confirmed by RT-PCR, while stroke cases were assessed by a neurologist and confirmed using CT or MRI imaging. Stroke developed between three and 14 days after COVID-19 diagnosis.
The researchers measured three microRNAs—miR-124, miR-636, and miR-485-5p—in plasma samples. MicroRNAs are small, noncoding RNA molecules that help regulate gene expression and can influence inflammation, immune responses, and neurological processes.
The COVID-19 patients had a mean age of 63. Hypertension was reported in 44%, cardiovascular disease in 22%, and diabetes in 20%. All 50 COVID-19 patients experienced fever, shortness of breath, and headache, while 62% reported muscle pain and 56% had a dry cough.
miR-124 produces the clearest signal
The standout finding was the difference in miR-124 expression. Average expression reached 5.13 ± 2.48 in COVID-19 patients with stroke, compared with 1.78 ± 1.03 among COVID-19 patients without stroke and 1.69 ± 0.64 among healthy controls.
The overall difference was statistically significant at p=0.0084. Further analysis also found significant differences between stroke-positive and stroke-negative COVID-19 patients (p=0.0156) and between stroke patients and healthy controls (p=0.0333).
This
Thailand Medical News report highlights an intriguing biological question because miR-124 is abundant in the brain and contributes to neuronal differentiation, neurogenesis, synaptic plasticity, and regulation of inflammation.
The researchers suggest its increased expression could represent a compensatory response to intense neuroinflammation and ischemic injury. Alternatively, elevated circulating miR-124 could reflect ongoing neuronal damage, with microRNAs being released from injured brain cells. The study, however, cannot determine which explanation is correct.
Other microRNAs tell a different story
MiR-485-5p was also higher in stroke patients, averaging 2.15 ± 1.53 compared with 1.38 ± 1.01 in COVID-19 patients without stroke and 1.49 ± 0.98 in controls.
However, the difference wa
s not statistically significant (p=0.3594), meaning the observed pattern could not reliably be distinguished from chance in this sample.
MiR-636 showed virtually no difference: levels were 2.24 ± 1.63 in controls, 2.20 ± 1.48 in COVID-19 patients without stroke, and 2.17 ± 1.41 in those with stroke (p=0.9987).
Important limitations remain
The researchers caution that the cross-sectional design cannot establish that altered miR-124 causes stroke. Measurements were taken at only one time point, just three microRNAs were examined, and the relatively small sample may have prevented detection of subtler differences, particularly for miR-485-5p. No functional experiments were performed to establish miR-124's biological role.
Research institutions
The researchers were affiliated with Tehran University of Medical Sciences; the Iranian Society for Virology, Deputy for Education, Ministry of Health and Medical Education; Lorestan University of Medical Sciences; Kerman University of Medical Sciences; and Abadan University of Medical Sciences, all in Iran.
Conclusions
The findings identify a strong association between elevated miR-124 and stroke in COVID-19 patients, but larger longitudinal and mechanistic studies are needed before the molecule can be considered a validated diagnostic biomarker or therapeutic target.
The study findings were published in the peer reviewed Canadian Journal of Infectious Diseases and Medical Microbiology.
https://onlinelibrary.wiley.com/doi/10.1155/cjid/5657680
Read Also:
https://www.thailandmedical.news/articles/coronavirus
https://www.thailandmedical.news/articles/long-covid 
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