When COVID Inflammation Strikes the Brain: A Child’s Rare Battle With MIS-C and Cerebral Vein Thrombosis

When the coronavirus pandemic swept across the world, clinicians quickly realized that SARS-CoV-2 was far more than a respiratory illness. Among its most puzzling legacies is a condition known as multisystem inflammatory syndrome in children, or MIS-C, in which the immune system appears to overreact weeks after a viral infection, unleashing widespread inflammation that can damage the heart, lungs, kidneys, skin, and nervous system. A new case report published in BMC Pediatrics by researchers at the Pediatric Health Research Center of Tabriz University of Medical Sciences in Iran now adds a striking and sobering entry to the growing catalogue of MIS-C complications: a seven-year-old boy who developed a blood clot in the veins draining his brain, followed by bleeding inside his skull, seizures, loss of consciousness, and paralysis of a cranial nerve.

The case, described by Parinaz Habibi, Farinaz Amirikar, Masoud Lahouty, and Golnaz Mobayen, centers on a child whose illness began in a way that many pediatricians would recognize. Multisystem inflammatory syndrome typically emerges two to six weeks after exposure to SARS-CoV-2, often in children who either had mild or asymptomatic initial infections. The syndrome shares features with Kawasaki disease and toxic shock syndrome, including persistent fever, rash, abdominal pain, and dramatically elevated markers of systemic inflammation. What makes MIS-C dangerous is its potential to involve multiple organ systems simultaneously, and the cardiovascular system is frequently at the epicenter of the damage.

In this particular patient, the inflammatory storm took an unusual turn. Imaging revealed cerebral venous sinus thrombosis, a condition in which blood clots form within the dural venous sinuses, the specialized channels that drain deoxygenated blood away from the brain. When these channels become obstructed, venous pressure rises, and the resulting congestion can lead to swelling of brain tissue, stroke-like injury, and, in severe cases, hemorrhage. The boy in this report went on to develop intracranial hemorrhage secondary to the thrombosis, a particularly dangerous combination because the clot itself blocks drainage while the bleeding adds mass effect and direct tissue damage inside the closed space of the skull.

The clinical picture that unfolded was dramatic. The child presented with loss of consciousness accompanied by seizures, signs that the brain was under acute threat. Neurological examination revealed paralysis of the left sixth cranial nerve, known medically as the abducens nerve, which controls the lateral rectus muscle responsible for moving the eye outward. Sixth nerve palsy is a classic localizing sign in neurology, often indicating raised intracranial pressure or damage along the nerve’s long course through the skull base, and its appearance in this patient pointed to significant intracranial pathology. Beyond the brain, the boy was also found to have necrotizing pneumonia, a severe form of lung infection in which portions of lung tissue die, adding respiratory failure to the list of organ systems under assault.

Diagnosing cerebral sinovenous thrombosis in a child with MIS-C requires a high index of suspicion and specialized imaging. The gold standard in such cases is magnetic resonance venography, or MRV, an MRI technique specifically tuned to visualize blood flow through the venous sinuses of the brain. Unlike conventional angiography, MRV is noninvasive and does not require catheterization, making it suitable for pediatric patients, but it must be actively requested because the symptoms of venous sinus thrombosis, including headache, vomiting, seizures, and altered consciousness, overlap with many other conditions. In this case, the imaging findings confirmed clot within the cerebral venous system and documented the secondary hemorrhage, allowing the clinical team to piece together the full mechanism of injury.

Treatment of such a compound complication demands a delicate balancing act. On one side stands the thrombosis, which calls for anticoagulation to prevent the clot from propagating and to allow the venous sinuses to recanalize. On the other side stands the intracranial hemorrhage, which makes anticoagulation inherently risky because any additional bleeding could prove catastrophic. The clinicians in this case navigated this tension by administering both anti-inflammatory therapy, aimed at suppressing the underlying MIS-C-driven immune dysregulation, and antithrombotic treatment, targeted at the venous clot. The necrotizing pneumonia, meanwhile, required surgical intervention on the lung, underscoring how thoroughly this single patient’s illness had spread across organ systems.

The outcome, after three months of treatment and recovery, was remarkable: the boy made a complete recovery, with full resolution of his neurological symptoms. This is not a trivial result. Cerebral venous sinus thrombosis in children carries a real risk of death and long-term disability, and when it is complicated by intracranial hemorrhage, the prognosis becomes even more guarded. Complete recovery from such a constellation of injuries, including seizure activity, cranial nerve palsy, and severe lung disease, represents the best-case scenario and speaks to both the resilience of pediatric patients and the effectiveness of prompt, multidisciplinary care combining neurology, hematology, intensive care, and pediatric surgery.

Why does MIS-C predispose children to blood clots in the first place? The answer lies in the nature of the inflammatory response itself. Systemic inflammation activates the endothelial cells that line blood vessels, tips the coagulation cascade toward clot formation, and generates a prothrombotic state throughout the circulation. This hypercoagulability can manifest anywhere in the vascular tree, from pulmonary emboli to arterial strokes, and the cerebral venous sinuses appear to be particularly vulnerable, possibly because of their slow flow dynamics and their position as the final common drainage pathway for the brain. Thromboembolism is recognized as one of the less common but well-documented complications of MIS-C, and this case adds to a small but growing body of reports describing central venous sinus thrombosis in this population.

The authors of the report emphasize that their patient represents a unique form of MIS-C complication, combining central nervous system sequelae with cerebral sinus vein thrombosis and a prolonged but ultimately complete recovery. For clinicians on the front lines, the message is clear: children with MIS-C who develop neurological symptoms, particularly headaches, seizures, or altered mental status, should be evaluated promptly for cerebral venous thrombosis, and MRV should be considered early in the diagnostic workup. Recognizing this complication quickly allows anticoagulation to begin before irreversible brain injury occurs, and it prepares the care team for the possibility of hemorrhagic transformation, which fundamentally changes management priorities.

As the acute phase of the COVID-19 pandemic recedes into history, cases like this one serve as reminders that SARS-CoV-2 continues to generate downstream consequences that medicine is still learning to recognize and treat. Multisystem inflammatory syndrome in children remains a condition defined by its unpredictability, capable of striking weeks after an infection that may have gone unnoticed and of manifesting in virtually any organ system. Each carefully documented case, such as this one from Tabriz, expands the collective map of what MIS-C can do, and each successful recovery offers both reassurance and a template for the clinicians who will inevitably encounter the next child whose fever is only the beginning of the story.

Subject of Research: Cerebral venous sinus thrombosis and intracranial hemorrhage as complications of multisystem inflammatory syndrome in children following SARS-CoV-2 infection

Article Title: A 7-year-old boy with cerebral vein thrombosis in favor of multisystem inflammatory syndrome: a case report

Article References: Habibi, P., Amirikar, F., Lahouty, M., & Mobayen, G. (2026). A 7-year-old boy with cerebral vein thrombosis in favor of multisystem inflammatory syndrome: a case report. BMC Pediatrics. https://doi.org/10.1186/s12887-026-07642-4

Image Credits: AI Generated

DOI: 10.1186/s12887-026-07642-4

Keywords: MIS-C, multisystem inflammatory syndrome in children, cerebral venous sinus thrombosis, SARS-CoV-2, intracranial hemorrhage, magnetic resonance venography, pediatric neurology, thromboembolism, COVID-19, necrotizing pneumonia, case report, BMC Pediatrics