The case, reported by Lamya Eissa of Alexandria Faculty of Medicine, Esra’a Alyateem of the University of Jordan, and Hassan Magdy Abdelrazek of Mansoura University, describes a completely thrombosed mycotic pseudoaneurysm of the cervical internal carotid artery in a malnourished child. A mycotic aneurysm, despite its name, has nothing to do with fungal infection in most cases; the term refers to an infected, weakened segment of an artery wall that balloons outward under arterial pressure. When such a lesion fills with clot, it loses the flowing blood signal that normally gives it away on imaging, and instead presents as a solid-appearing mass that can be nearly indistinguishable from a collection of pus.

Parapharyngeal abscesses are relatively rare in children but carry serious risk. The parapharyngeal space is a deep compartment of the neck bounded by critical structures, including the carotid sheath, which houses the internal carotid artery, the internal jugular vein, and cranial nerves. Infection in this space can spread along fascial planes toward the mediastinum, and documented vascular complications include arterial narrowing, pseudoaneurysm formation, and ischemic stroke. Prior literature, cited in the report, has described internal carotid artery pseudoaneurysms arising secondary to retropharyngeal and parapharyngeal abscesses, as well as carotid mycotic pseudoaneurysms masquerading as peritonsillar abscesses in pediatric patients.

The danger in this specific scenario is mechanical as much as infectious. If a surgeon incises what appears to be an abscess but is actually an aneurysm, the result can be catastrophic hemorrhage. A pseudoaneurysm is a false aneurysm: blood escapes through a defect in the arterial wall and is contained not by the vessel’s own layers but by surrounding tissue, forming a fragile sac. The classic ultrasound signature of a patent pseudoaneurysm is the so-called to-and-fro waveform, in which blood surges into the sac during systole and back into the artery during diastole. But when the sac is completely thrombosed, that diagnostic flow pattern vanishes, and the lesion becomes a silent impostor.

That is precisely what happened in this child. The initial contrast-enhanced CT was suboptimal, and it suggested an abscess rather than a vascular lesion. Only when the team pursued dedicated, high-quality multimodal imaging did the true nature of the mass emerge. The workup included magnetic resonance imaging with diffusion-weighted imaging and apparent diffusion coefficient mapping, magnetic resonance angiography, and three-dimensional CT angiography. Each modality contributed a different piece of evidence, and together they overturned the working diagnosis before a scalpel ever touched the neck.

The technical logic of this multimodal approach is worth unpacking. Diffusion-weighted imaging is exquisitely sensitive to restricted water diffusion, which is characteristic of pus-filled abscess cavities; on apparent diffusion coefficient maps, abscesses typically show marked hypointensity because the viscous, cellular contents of pus impede the random motion of water molecules. A thrombosed aneurysm, by contrast, contains organized clot whose diffusion characteristics differ from those of an abscess. Magnetic resonance angiography visualizes flowing blood without ionizing radiation and can demonstrate the absence of flow within the lesion as well as the relationship of the mass to the parent internal carotid artery. Three-dimensional CT angiography then provides high-resolution anatomical mapping of the cervical vasculature, delineating the aneurysm’s origin, size, and spatial relationship to the skull base and surrounding structures.

The case also highlights the role of the child’s nutritional status. Malnutrition is known to impair immune function and tissue integrity, and the report’s authors note that the patient was malnourished at presentation. Infected aneurysms in children are rare, and when they occur, they are often secondary to bacteremia, local infection spread, or, as in documented cases, deep neck abscesses eroding into the adjacent carotid artery. The report’s associated subject listings, which include primary herpetic gingivostomatitis and meningitis among related topics, reflect the infectious context in which such vascular complications arise.

What makes this case report valuable to clinicians is not the rarity of the lesion alone but the specificity of the imaging lesson it delivers. Complete thrombosis transforms a mycotic pseudoaneurysm into a mass that can easily be mistaken for an abscess without the right imaging modalities and high-quality imaging, the authors conclude. In practical terms, this means that when a deep neck mass in a child does not behave as expected, when contrast enhancement is suboptimal, or when the anatomical relationship to the carotid sheath is unclear, the workup should escalate to dedicated MRI with diffusion-weighted sequences, MR angiography, and CT angiography rather than proceeding to incision and drainage on the basis of a single imperfect scan.

The stakes of that escalation are enormous. Misdiagnosed and incised, an infected carotid pseudoaneurysm can exsanguinate a patient within minutes, and even when recognized, management is complex, often requiring endovascular or surgical intervention combined with prolonged antimicrobial therapy. Recognized vascular complications of deep neck infections also include internal carotid artery narrowing, as documented in children with retropharyngeal lymphadenitis and abscess, and ischemic stroke secondary to carotid pseudoaneurysm, as reported in the pediatric literature. The parapharyngeal space’s proximity to the carotid sheath means that every deep neck infection carries at least a theoretical vascular risk, and this case demonstrates how that theoretical risk can become a concrete diagnostic trap.

For the broader radiology and pediatric communities, the case reinforces a principle that imaging specialists have long championed: no single modality is definitive, and the diagnosis of a deep neck mass in a child demands correlation across clinical findings, laboratory data, and complementary imaging techniques. The authors’ contribution statement indicates that the work encompassed conceptualization, imaging analysis, study design, and figure preparation, with all authors reviewing and approving the final version. Conducted in accordance with the Declaration of Helsinki and published with informed parental consent, the report adds a well-documented data point to a small but clinically critical literature. As deep neck infections continue to present in emergency departments worldwide, this child’s story stands as a warning that the most familiar diagnosis is not always the correct one, and that the tools to see the difference already exist for those who know to reach for them.

Subject of Research: Pediatric Radiology

Article Title: Thrombosed mycotic aneurysm of the cervical internal carotid artery mimicking a parapharyngeal abscess in a child: a case report of multimodal imaging diagnosis

Article References: Eissa, L., Alyateem, E., & Abdelrazek, H. M. (2026). Thrombosed mycotic aneurysm of the cervical internal carotid artery mimicking a parapharyngeal abscess in a child: a case report of multimodal imaging diagnosis. Pediatric Radiology. https://doi.org/10.1007/s00247-026-06814-9

Image Credits: AI Generated

DOI: 10.1007/s00247-026-06814-9

Keywords: mycotic aneurysm, pseudoaneurysm, internal carotid artery, parapharyngeal abscess, deep neck infection, multimodal imaging, diffusion-weighted MRI, CT angiography, pediatric radiology, thrombosis, case report, diagnostic imaging

The research team, led by Martin Vychopen of University Hospital Leipzig together with colleagues including neuroradiologist Karl-Titus Hoffmann and neurosurgeons Erdem Güresir and Johannes Wach, pooled data from six randomized controlled trials encompassing up to 3,044 patients treated for ruptured intracranial aneurysms. Rather than simply averaging outcomes across all patients, as many earlier meta-analyses have done, the investigators stratified their analysis by aneurysm location and by the neurological severity of the hemorrhage at admission, measured on the World Federation of Neurosurgical Societies scale. This anatomically informed approach matters because an aneurysm tucked into the delicate branches of the middle cerebral artery presents a fundamentally different surgical and endovascular challenge than one sitting on the internal carotid artery near the skull base.

The headline finding concerns functional outcome at one year, assessed with the modified Rankin Scale, the standard yardstick of disability after stroke. When the researchers defined a favorable outcome as a score of 0 to 2, meaning the patient is independent in daily life, coiling came out clearly ahead. Across the pooled cohort of 3,044 patients, the odds of achieving independence at one year were 60 percent higher after endovascular coiling than after microsurgical clipping, an odds ratio of 1.60 with a 95 percent confidence interval of 1.36 to 1.88 and a p-value below 0.00001. Critically, heterogeneity across the six trials was essentially zero, indicating that the trials told a remarkably consistent story despite spanning more than two decades of practice.

But here is where the analysis turns provocative. When the team re-ran the numbers using a broader cut-off, defining favorable outcome as a modified Rankin Scale score of 0 to 3, the statistically significant advantage of coiling evaporated entirely. In that analysis of 2,278 patients from three trials, the odds ratio shrank to 1.19 with a p-value of 0.12, well short of significance. The implication is striking: much of the celebrated benefit of coiling may hinge on where exactly the disability scale is divided. This echoes long-standing critiques of the original International Subarachnoid Aneurysm Trial, or ISAT, whose landmark 2005 result established coiling as the preferred treatment in many centers worldwide. Commentators had previously argued that the binary 0-to-2 versus 3-to-6 split was insufficiently sensitive, and the new pooled data, which incorporate the more recent ISAT-2 trial by Darsaut and colleagues, lend quantitative weight to that concern.

The location-specific results are arguably the most clinically actionable part of the study. For aneurysms of the internal carotid artery, coiling delivered a decisive advantage in functional outcome, with an odds ratio of 0.44 favoring coiling, a difference that was highly significant with a p-value below 0.00001 and zero heterogeneity. The authors attribute this to the particular hazards of microsurgical access in this territory: internal carotid artery aneurysms, especially those arising at the ophthalmic segment or the carotid bifurcation, sit in a region where achieving proximal control of the vessel during open surgery can be difficult and may require additional measures to reduce blood flow, raising the morbidity of the surgical approach.

In contrast, no significant difference in one-year functional outcome emerged for aneurysms of the anterior cerebral artery and anterior communicating artery, the middle cerebral artery, or the posterior circulation. For anterior communicating aneurysms, which frequently rupture at small sizes and are associated with complex anatomy such as hypoplasia of the A1 segment, the pooled data support an individualized, anatomy-based decision rather than a default preference for either technique. For posterior circulation aneurysms, which carry elevated in-hospital mortality and a higher incidence of acute hydrocephalus, the analysis was limited by the underrepresentation of basilar and cerebellar aneurysms in prospective randomized trials, a caveat the authors acknowledge openly.

Where clipping decisively reasserts itself is in the durability of aneurysm closure. When the researchers examined complete occlusion confirmed on angiography twelve months after treatment, pooling four trials and 1,889 patients, surgical clipping was clearly superior, with an odds ratio of 0.35, a 95 percent confidence interval of 0.28 to 0.44, and again no heterogeneity. This overall effect, however, was driven almost entirely by one subgroup: middle cerebral artery aneurysms, where the odds of complete occlusion after clipping were more than five times those after coiling, an odds ratio of 5.21 with a p-value of 0.007. For internal carotid, anterior cerebral, and posterior circulation aneurysms, complete occlusion rates did not differ significantly between the two modalities. The anatomical explanation is compelling: middle cerebral artery aneurysms often resemble complex bifurcation lesions rather than simple sacs, frequently involving wide necks and critical branch vessels, and clipping in this location allows the surgeon to preserve distal flow while minimizing the risk of injury to small perforating arteries.

Why does complete occlusion matter so much? Because an incompletely closed aneurysm can reopen, and a reopened aneurysm can bleed again, sometimes catastrophically. The ARETA study found that roughly 20 percent of coiled aneurysms exhibit reopening or neck remnants, with about half of those requiring retreatment, while the CARAT investigation linked the risk of early rebleeding directly to the degree of aneurysm occlusion achieved. The Barrow Ruptured Aneurysm Trial further demonstrated that complete clip occlusion offers superior treatment durability, significantly reducing the need for repeat procedures, and both endovascular and microsurgical retreatment carry higher perioperative complication rates than the original intervention. Achieving complete obliteration in a single procedure therefore remains one of the central therapeutic goals in this disease.

Mortality, meanwhile, refused to pick a side. Across six trials and 2,921 patients, all-cause mortality did not differ between coiling and clipping, with an odds ratio of 0.89 and a p-value of 0.35. The severity-stratified analysis added another layer: among patients with good clinical grades, defined as WFNS grade 3 or better, coiling was associated with significantly better functional outcomes across 2,213 patients, whereas among the 168 patients with the worst grades, WFNS greater than 3, neither technique showed a significant advantage, likely reflecting the dominant influence of the initial brain injury itself on prognosis in severely affected patients.

The authors are careful about the limits of their work. The included trials span more than two decades, during which both endovascular devices and microsurgical techniques have evolved considerably, and modern adjuncts such as the Woven EndoBridge device and stent-assisted coiling are not yet represented in randomized subgroup data. Patients with posterior circulation aneurysms and high-grade hemorrhage remain underrepresented, and complete occlusion was a secondary endpoint in the original trials rather than a pre-specified primary one, introducing the possibility of distribution bias since aneurysm location was not randomly balanced across treatment arms. Risk-of-bias assessment using the Cochrane 2.0 tool rated ISAT and the Barrow Ruptured Aneurysm Trial as low risk across all domains, while other trials raised concerns ranging from unclear randomization to selective reporting. Even so, the core message stands with unusual clarity for a field long divided by tribal loyalties: for a ruptured internal carotid artery aneurysm, the catheter likely holds the edge in preserving independence at one year; for a ruptured middle cerebral artery aneurysm, the clip remains the gold standard for sealing the lesion completely and durably; and for everything in between, the decision deserves to be made aneurysm by aneurysm, patient by patient, balancing the promise of functional recovery against the imperative of permanent closure.

Subject of Research: Comparative effectiveness of endovascular coiling versus microsurgical clipping for ruptured intracranial aneurysms

Article Title: Efficacy and safety of endovascular coiling compared to microsurgical clipping in aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis of randomized trials

Article References: Vychopen, M., Hoffmann, K.-T., Güresir, E., & Wach, J. (2026). Efficacy and safety of endovascular coiling compared to microsurgical clipping in aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis of randomized trials. Journal of Neurology, 273(10), Article 650. https://doi.org/10.1007/s00415-026-14150-z

Image Credits: AI Generated

DOI: 10.1007/s00415-026-14150-z

Keywords: aneurysmal subarachnoid hemorrhage, endovascular coiling, microsurgical clipping, intracranial aneurysm, meta-analysis, randomized controlled trials, modified Rankin Scale, middle cerebral artery, internal carotid artery, complete occlusion, ISAT, neurosurgery

The rationale for the study rests on a well-documented but poorly understood phenomenon. As people age, total cerebral blood flow and the brain vessels’ ability to respond to metabolic demands both decline, and these declines independently predict higher dementia risk even after accounting for other cardiovascular factors. At the same time, aging vasculature accumulates oxidative stress, an imbalance between reactive oxygen species and the body’s antioxidant defenses. Excess reactive oxygen species degrade nitric oxide, the signaling molecule that blood vessel linings use to relax and widen. If oxidative stress is indeed strangling the aging brain’s arteries, then flooding the system with a potent antioxidant should, in principle, loosen the grip.

To test that idea, the team recruited generally healthy young adults aged 18 to 29 and middle-aged and older adults aged 55 to 79 from the Newark, Delaware area, excluding smokers, pregnant or breastfeeding women, and anyone with cardiovascular, neurological, autoimmune, or major psychiatric conditions. Each participant completed two laboratory visits separated by at least four days, receiving an intravenous ascorbic acid infusion on one occasion and a saline placebo on the other, in a randomly assigned order. The dosing protocol, adapted from earlier vascular aging studies, delivered a priming bolus of 0.06 grams of vitamin C per kilogram of fat-free mass over 20 minutes, followed by a continuous drip of 0.02 grams per kilogram maintained until all post-infusion measurements were complete. In a small subset where blood samples survived analysis, serum vitamin C levels rose roughly sevenfold, from about 1.2 to 8.6 milligrams per deciliter, confirming the infusion pushed concentrations well above physiological norms.

The study’s centerpiece was a clever probe of cerebrovascular endothelial function. When carbon dioxide in the blood rises abruptly, vessels downstream of the internal carotid artery dilate, increasing turbulent flow and shear stress along the carotid wall. That shear stress triggers the endothelium to release nitric oxide, which widens the artery further. By using a dynamically controlled gas delivery system to raise participants’ end-tidal carbon dioxide by 9 millimeters of mercury for just 30 seconds, and imaging the internal carotid artery with high-resolution duplex ultrasound, the researchers could quantify how well the extracranial vessel lining responded to a nitric oxide–dependent stimulus. Before infusion, this response was significantly blunted in the older group: relative internal carotid artery reactivity averaged about 3.4 percent in young adults versus roughly 3.0 percent or lower in the middle-aged and older group, with the deficit most pronounced in the vitamin C visit’s baseline measurements.

After the vitamin C infusion, the picture changed markedly for the older participants. Their relative internal carotid artery reactivity rose significantly, and the absolute diameter change climbed from a mean of about 0.056 millimeters to 0.32 millimeters, effectively erasing the age gap with the young group. In striking contrast, the same participants showed no such improvement after saline, and the young adults’ responses were essentially flat regardless of which infusion they received. This pattern, improvement only where function was impaired, is exactly what the pharmaco-dissection approach predicts if oxidative stress is suppressing nitric oxide–mediated dilation in aged vessels. Notably, the carbon dioxide stimulus itself was matched across conditions, with end-tidal changes of roughly 8 to 9 millimeters of mercury in every group and time point, so the differences could not be attributed to unequal challenges.

The researchers also examined the middle cerebral artery, an intracranial vessel whose response to sustained, three-minute hypercapnia is far less dependent on nitric oxide. Using transcranial Doppler ultrasound, they measured blood velocity and, by normalizing to beat-by-beat mean arterial pressure, calculated cerebrovascular conductance. At baseline, older adults showed significantly lower conductance-based reactivity than young adults. Vitamin C infusion again improved middle cerebral artery reactivity in the older group, whether expressed as velocity change or conductance change, while saline did not. The authors suggest this intracranial effect likely operates through different pathways than the carotid response, potentially involving pH regulation, red blood cell ATP release, potassium and calcium channels, prostaglandins, or reactive oxygen species acting directly as vasodilators. The precise mechanism, they caution, remains unresolved.

Not every measurement cooperated with the tidy narrative. Total cerebral blood flow, estimated from internal carotid and vertebral artery flows, was unexpectedly higher in the older group than the young group before infusion, contradicting the large body of literature showing age-related declines. The authors note that women in their sample, who tend to have higher cerebral blood flow, made up 71 percent of the older subgroup with usable data versus 44 percent of the young subgroup, and that global flow estimates cannot capture regional perfusion differences. Vitamin C did not significantly alter total cerebral blood flow in either age group. Meanwhile, brachial artery flow-mediated dilation, the standard test of peripheral endothelial function, was lower in older adults at baseline but showed only a non-significant trend toward improvement after vitamin C. In a small subset with paired data, peripheral and cerebral endothelial responses were uncorrelated, suggesting the two beds reflect distinct endothelial physiology and should not be treated as interchangeable windows on vascular health.

The study’s limitations are considerable and the authors are candid about them. Sample sizes were small and varied across outcomes, with complete internal carotid data available for only 10 to 11 participants per infusion visit and middle cerebral artery data for 17 to 20. A freezer malfunction destroyed most serum samples, preventing direct measurement of oxidative stress markers or nitric oxide metabolites in the full cohort, which means the proposed mechanism remains inferential. The transcranial Doppler technique assumes the middle cerebral artery does not itself dilate during hypercapnia, an assumption challenged by MRI studies. No comparable vasodilatory control condition was included, so the effect cannot be definitively pinned to nitric oxide–dependent pathways. And the analysis relied on pre-specified contrasts without multiple-testing correction, appropriate for hypothesis-driven designs but demanding cautious interpretation.

Even with those caveats, the central result stands out for its clarity: antioxidant-responsive mechanisms appear to be implicated in age-related impairments of both extracranial and intracranial cerebrovascular reactivity. The authors are careful to stress that this was a mechanistic experiment, not a therapy trial, and that nothing in the data supports self-treatment with high-dose vitamin C. Oral supplementation cannot reproduce the serum concentrations achieved intravenously, and whether repeated infusions would produce lasting benefit, or whether improved reactivity translates into preserved cognition, are questions for future studies with larger and more diverse cohorts. What the trial does establish is a model: a safe, reversible intervention that selectively restores cerebrovascular function in older adults, giving researchers a tool to dissect the redox pathways that may one day be targeted to keep aging brains well perfused.

Subject of Research: Effects of intravenous ascorbic acid infusion on age-related cerebrovascular dysfunction in adults

Article Title: Supraphysiological ascorbic acid infusion attenuates cerebrovascular dysfunction in middle‐aged and older adults

Article References: DeConne, T. M., Sanjana, F., Habash, E. M., Decker, K. P., Nichols, W., Hobson, J. C., Rizzi, N. A., & Martens, C. R. (2026). Supraphysiological ascorbic acid infusion attenuates cerebrovascular dysfunction in middle‐aged and older adults. Physiological Reports, 14(19), Article e71120. https://doi.org/10.14814/phy2.71120

Image Credits: AI Generated

DOI: 10.14814/phy2.71120

Keywords: ascorbic acid, cerebrovascular reactivity, vascular aging, oxidative stress, nitric oxide, cerebral blood flow, internal carotid artery, middle cerebral artery, hypercapnia, endothelial function, dementia risk, randomized crossover trial