Contrast-induced encephalopathy after Flow-diverting stents for the treatment of cerebral artery aneurysms：a Case Report

Contrast-induced encephalopathy after Flow-diverting stents for the treatment of cerebral artery aneurysms：a Case Report | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report Contrast-induced encephalopathy after Flow-diverting stents for the treatment of cerebral artery aneurysms：a Case Report Jing Huang, Zhejing Ding, Qiang Zhou, Yu Liu This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6648137/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Aneurysm interventional embolization is one of the main treatment methods for intracranial aneurysm, which has significant advantages due to its minimally invasive nature, but a variety of complications may still occur during and after surgery, among which contrast-induced encephalopathy (CIE) is a rare but potentially life-threatening neurological complication. CIE is a rare neurological complication after the use of endovascular contrast agents, usually occurring after coronary angiography, cerebral angiography, or interventional therapy, CIE usually occurs 2 to 12 hours after contrast injection, and usually disappears after 24 to 72 hours. The clinical manifestations are acute neurological impairment, including focal neurologic deficits (hemiplegia, hemianopia, cortical blindness, aphasia, and Parkinson's disease) and systemic symptoms (confusion, seizures, and coma). CT or MRI scans of the brain may be transiently positive. Case presentation A 60-year-old woman was admitted to hospital with ischemic cerebral infarction 1 year ago. The first digital subtraction angiography (DSA) identified the right middle cerebral artery (MCA) stenosis and a saccular aneurysm with daughter sac of 2 mm ∗ 3 mm in size in the C7 segment of the left internal carotid artery (ICA). At that time, surgery was performed on arterial stenosis, and the operation was successful. In order to further treat the aneurysm, the patient underwent Flow-diverting stent placement under local infiltration anesthesia, and the operation was successful, however, the patient was unable to speak, unable to understand conversation, irritable, and had no voluntary movement of the right limb after surgery. The non-contrast cerebral CT indicated widespread edema in the left cerebral hemisphere. The patient was diagnosed with CIE and treated with symptomatic supportive therapy. Eventually, the patient’s neurological deficits and cerebral edema improved significantly. Conclusions The current case emphasized the importance of early diagnosis and symptomatic treatment of CIE. Thus, CIE should be the first consideration during the differential diagnosis of a patient having acute neurological impairment after repeated DSA. Contrast-induced encephalopathy Aneurysm embolization Flow-diverting stent local infiltration anesthesia Digital subtraction angiography Figures Figure 1 Figure 2 Background With the rapid development of medical diagnosis and treatment technology, aneurysm embolization is one of the main treatment methods for intracranial aneurysms, but a variety of complications may occur after surgery. Among them, CIE is a rare but potentially life-threatening neurological complication, which usually occurs after coronary angiography, cerebral angiography, or interventional therapy, and the prevalence of contrast agents on neurological side effects is about 1%~2%[ 1 ]. The clinical manifestations are acute neurological impairment, including focal neurologic deficits (hemiplegia, hemianopia, cortical blindness, aphasia, and Parkinson's disease) and systemic symptoms (confusion, seizures, and coma) [ 2 ]. Most patients with CIE have transient and reversible clinical symptoms with no significant sequelae, but a small number of patients with CIE leave sequelae or even die [ 3 ]. Previous studies have shown that it usually occurs 2 to 12 h after contrast injection, and CIE symptoms usually disappear after 24 to 72 h without neurological deficits. However, in the absence of formal diagnostic criteria, rare cases of irreversible or even fatal CIE have occurred [ 2 , 4 , 5 ]. At present, there are few reports of concurrent CIE after aneurysm embolization. In particular, the concurrent CIE after aneurysm embolization under local infiltration anesthesia has not been reported in China. This article reports a case of contrast-agent encephalopathy after intracranial unruptured aneurysm with blood flow-directed dense mesh stent embolization under local infiltration anesthesia, summarizes its pathogenesis, and reviews relevant literature. Case presentation A 60-year-old woman presents to our hospital with ischemic cerebral infarction 1 year ago. The patient's previous history of hypertension was regular, and oral administration of amlodipine besylate and bisoprolol fumarate controlled blood pressure, and the blood pressure control was acceptable. Previous history of atrial fibrillation, regular oral rivaroxaban 10 mg once a day. No history of coronary artery disease or diabetes mellitus. Her laboratory profile, including renal and hepatic function, was normal. Neurological examination showed no obvious positive signs. Digital subtraction angiography (DSA) showed a 2 mm ∗ 3 mm saccular aneurysm with daughter sac in the C7 segment of the left internal carotid artery (Fig. 1 A). The patient underwent cranial MR examination for further evaluation before surgery, and there was no new acute ischemic cerebral infarction(Fig. 1 B). After receiving rivaroxaban 10 mg once a day and ticagrelor 60 mg twice a day, the patient underwent a flow-diverting stent placement under local infiltration anesthesia(Fig. 1 C). Immediately after the first injection of contrast during surgery, the patient develops agitation with a left-sided gaze of both eyes, which subsedes spontaneously. Dilution angiography after the operation showed that the stent was well adherent and the blood flow in the stent was smooth (Fig. 1 D), and there was no obvious intracranial hemorrhage or edema on Dyna-CT (Fig. 2 A). Approximately 3 hours after surgery, the patient developed lethargy, mixed aphasia, and decreased right muscle strength (grade 2/5) under painful stimulation. Immediate brain CT and CTA scans detected edema involving the parietal and temporal lobes in the left cerebral hemisphere without hemorrhage (Fig. 2 B). Because CTA does not show cerebral vascular stenosis, CIE is suspected. We used 10 mg of dexamethasone and 125 ml of mannitol to reduce cerebral edema. At the same time, glucose sodium chloride helps to eliminate contrast agents. There was no significant improvement in neurological deficits 24 hours after surgery, although CT showed significant improvement in left brain edema (Fig. 2 C). 72 hours after surgery, you can answer questions, understand conversations, and feel a little euphoria. Physical examination: clear, pertinent answers, limb muscle strength level 5, normal limb muscle tone. Pathologic signs were not elicited. Treatment with mannitol and dexamethasone sodium phosphate was discontinued. Five days after surgery, the patient's re-examination of the brain MR showed that the left cerebral hemisphere was swollen and did not show any swelling, and there were multiple malacia foci in the bilateral radial crown, semioval center, basal ganglia and cerebellar hemispheres, and lacunar infarcts and small ischemic foci scattered in the brain (Fig. 2 D). The patient was discharged on the 8th day after surgery with no significant neurological deficits. Discussion and conclusions Unlike irreversible brain injury due to intracerebral hemorrhage, cerebral infarction, hypoperfusion, and other causes, CIE is a contrast-induced disease of the central nervous system that presents primarily as acute, reversible, transient neurologic deficits [ 7 ]. Common clinical symptoms include nausea, vomiting, headache, aphasia, epilepsy, and cortical blindness in severe cases, and cortical edema and focal neurologic deficits in severe cases, and even cardiac arrest, among which transient cortical blindness is the most common clinical manifestation, and there may be prodromal symptoms such as mental status changes [ 8 – 9 ]. In this case, the patient developed aphasia, cortical edema, focal neurologic deficits, and altered mental status, and symptoms disappeared completely after 72 hours. The main differential diagnosis of CIE is ischemic stroke and intracranial hemorrhage, so imaging is essential in the diagnosis of CIE and should be performed as soon as possible. Imaging findings of cerebral edema or increased cortical signal are important for the diagnosis of CIE [ 10 ], but imaging findings may be absent [ 11 ]. Typical imaging changes of CIE include: 1. CT shows diffuse cortical or subcortical enhancement, or subarachnoid enhancement and striatum enhancement, and can also manifest as focal hyperdense lesions, sulci hyperdensity opacities, and cerebral edema or subarachnoid hyperdensity changes similar to those of patients with subarachnoid hemorrhage; 2. Noncontrast cranial MR scan shows angiogenic edema [ 5 – 6 ]. In this case, the cranial CT examination 3 hours after the onset of symptoms showed that the left cerebral hemisphere brain tissue was swollen, the sulcus cerebral fission was shallow, and the CTA intracranial large vessels were not obviously abnormal, which was consistent with the imaging diagnosis of CIE. In this case, the patient received a total of five iodinated contrast agents, the first was cerebral angiography under local anesthesia, the second was "percutaneous right middle cerebral artery stenting" under tracheal intubation under general anesthesia, the third and fourth times were returned to the hospital under local anesthesia for re-examination of cerebral angiography, and the fifth time was "transcatheter intracranial aneurysm stent-assisted embolization" under local anesthesia. So what is the reason for the fifth CIE in this patient? The pathogenesis of CIE is unclear, and the main pathophysiological mechanism widely accepted in the academic community is transient disruption of the blood-brain barrier (BBB) caused by the injection of iodine-containing contrast agents [ 2 ]. These include direct damage to BBB by contrast agents, such as decreased expression of tight junction proteins in endothelial cells, chemical toxicity, and other factors such as ischemic encephalopathy, which cause indirect damage to BBB and increase contrast leakage [ 12 ]. After BBB injury, the contrast agent penetrates into the brain tissue, directly damages brain cells, destroys vascular endothelial cells, and causes cerebral edema, causing hemodynamic changes, leading to circulatory congestion and vascular occlusion [ 13 ]. In addition, etiologies include microemboli, contrast-induced immune responses, and differences in the structure and function of different brain regions [ 1 ]. In addition to contrast use, female sex, hypertension, diabetes mellitus, impaired renal function, stroke, and impaired cerebral autoregulation are risk factors for the development of CIE [ 14 ]. Moreover, foreign studies have shown that 50 percent of patients with CIE have a history of hypertension [ 15 ]. In this case, a 60-year-old woman with a history of hypertension, diabetes, and stroke increased the risk of CIE and made it easier for the contrast agent to cross the blood-cerebrospinal fluid barrier. Hou Bin has reported a case of "right posterior communicating aneurysm, right middle cerebral aneurysm embolization assisted by stent" under general anesthesia, and the symptoms and imaging manifestations of CIE appeared immediately after waking up from anesthesia, while our patient was treated with aneurysm embolization under local anesthesia. At present, there is no specific drug for the specific treatment of CIE, and the current treatment methods are mainly symptomatic supportive treatment, such as a large amount of fluid refill expansion to accelerate the excretion of contrast agent and reduce the damage of the blood-brain barrier; early use of glucocorticoids to reduce toxic damage from contrast agents; Dehydration drugs such as mannitol and glycerol fructose are given to reduce cerebral edema. In patients with seizures, appropriate use of anticonvulsants, such as benzodiazepines, is effective in controlling tics and reducing cerebral edema [ 16 ]. In patients with acute kidney injury, hemodialysis is safe and effective [ 17 ]. The prognosis for CIE is usually good, mostly self-limited, with clinical symptoms usually relieving completely, and permanent damage rarely occurring. However, some patients have a more insidious onset, may take longer to resolve symptoms, and some are at risk of permanent dysfunction [ 18 ]. Immediately after the onset of the disease, the patient was given dexamethasone sodium phosphate 10mg intravenous infusion to reduce inflammatory edema, mannitol 125mlQ8h dehydration to reduce intracranial pressure, urapidil to control blood pressure, prevent hyperperfusion and rehydration, and other supportive symptomatic treatment, the patient's symptoms disappeared completely after 72 hours, and the neurological function returned to normal. The patient's pathogenesis, clinical manifestations, ancillary examinations, and diagnosis and treatment all met the diagnostic criteria for CIE. In summary, CT or MRI of the brain is essential for the identification and diagnosis of CIE as soon as the corresponding clinical manifestations of CIE appear in clinical work. Once CIE occurs, comprehensive treatment such as glucocorticoids, dehydration and intracranial pressure reduction, blood pressure control, and fluid hydration should be used as soon as possible to minimize the harm to the patient. At present, most of the studies on CIE are case studies and reports, and there is a lack of systematic studies, in the future, we will collect the number of cases of CIE and conduct systematic analysis and research. Declarations Acknowledgements None Author contributions ZJ.D. wrote the manuscript. J.H., Q.Z. examined the patient. Y.L. analyzed the neuroimaging data. ZJ.D. prepared the manuscript and performed the interventional surgery on the patient. All the authors read and approved the final version of the manuscript. Funding None Data availability Not applicable. Ethics approval and consent to participate Not applicable. Consent for publication A signed informed consent was obtained from the patient to publish this case report and the accompanying neuroimages. Competing interests The authors declare no competing interests References Spina R, Simon N, Markus R, et al. Recurrent contrast-induced encephalopathy following coronary angiography[J]. Intern Med J. 2017;47:221–4. Leong S, Fanning NF. Persistent neurological deficit from iodinated contrast encephalopathy following intracranial aneurysm coiling. A case report and review of the literature. Interventional Neuroradiology: J Peritherapeutic Neuroradiol Surg Procedures Relat Neurosciences. 2012;18(1):33–41. MEIJER FJA, STEENS SCA, TULADHAR AM, et al. Contrast⁃induced encephalopathy ⁃ neuroimaging findings and clinical relevance[J]. Neuroradiology. 2022;64(6):1265–8. Nakao K, Joshi G, Hirose Y, Tanaka R, Yamada Y, Miyatini K, et al. Rare cases of contrast-Induced encephalopathies. Asian J Neurosurg. 2020;15(3):786–93. Zhao W, Zhang J, Song Y, Sun L, Zheng M, Yin H, et al. Irreversible fatal contrast-induced encephalopathy: a case report. BMC Neurol. 2019;19(1):46. Niimi Y, Kupersmith MJ, Ahmad S, Song J, Berenstein A. Cortical blindness, transient and otherwise, Associated with Detachable Coil Embolization of Intracranial aneurysms. Am J Neuroradiol. 2008;29(3):603–7. Chu YT, Lee KP, Chen CH et al. Contrast-induced encephalopathy after endovascular thrombectomy for acute ischemic stroke [J].Stroke,2020, 51(12): 3756–9. Zhang G, Wang H, Zhao L, et al. Contrast-induced encephalopathy resulting from use of ioversol and iopromide [. J] Clin Neuropharmacol. 2020;43(1):15–9. Yao LD, Zhu XL, Yang RL, et al. Cardiorespiratory arrest after iso-osmolar iodinated contrast injection: a case report of contrast- induced encephalopathy following contrastenhanced computed-tomography [J]. Med (Baltim). 2021;100(2):e24035. Kocabay G, Karabay CY, Kalayci A et al. Contrast-induced neurotoxicity after coronary angiography[J].Herz,2014,39(4):522–7. Dattani A, Au L, Tay KH et al. Contrast- induced encephalopathy following coronary angiography with no radiological features:a case report and literature review[J].Cardiology,2018,139:197–201. WANG H, LI T, ZHAO L, et al. Dynamic effects of ioversol on the permeability of the blood-brain barrier and the expression of ZO-1/occludin in rats[J]. J Mol Neurosci. 2019;68(2):295–303. Seong JM, Choi NK, Lee J, et al. Comparison of the safety of seven iodinated contrast media [J]. J Korean Med Sci. 2013;28(12):1703–10. QUINTAS-NEVES M, ARAÚJO JM, XAVIER SA, et al. Contrast-in-duced neurotoxicity related to neurological endovascular procedures: a systematic review[J]. Acta Neurol Belg. 2020;120(6):1419–24. Roberto S, Neil S, Romesh M, et al. Contrast-induced encephalopathy following cardiac catheterization [J]. Catheter Cardiovasc Interv. 2016;90(2):257–68. 10.1002/ccd.26871 . Lei P, He W, Shi Q, et al. Recurrent epileptic seizures following cardiac catheterization with iodixanol: a case report [J]. BMC Cardiovasc Disord. 2020;20(1):257–68. Guo QY, Feng XX, Wang ZJ, et al. Is it better to choose immediate dialysis treatment for renal transplant patients after PCI [J]. J Geriatr Cardiol. 2020;17(2):116–9. Tong XZ, Hu P, Hong T, et al. Transient cortical blindness associated with endovascular procedures for intracranial aneurysms [J]. World Neurosurg. 2018;119:123–31. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6648137","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":475818998,"identity":"22671006-f59d-4bbb-9d63-8c24d2d7040e","order_by":0,"name":"Jing Huang","email":"","orcid":"","institution":"Zhuhai People's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Jing","middleName":"","lastName":"Huang","suffix":""},{"id":475818999,"identity":"c5e2b424-1219-4035-8506-b269628d88bc","order_by":1,"name":"Zhejing Ding","email":"","orcid":"","institution":"Zhuhai People's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Zhejing","middleName":"","lastName":"Ding","suffix":""},{"id":475819000,"identity":"a1d0e23b-29b4-4858-aca8-76152f3f7914","order_by":2,"name":"Qiang Zhou","email":"","orcid":"","institution":"Zhuhai People's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Qiang","middleName":"","lastName":"Zhou","suffix":""},{"id":475819001,"identity":"dce1604c-6f14-404a-bcb6-6b1b9bf8960f","order_by":3,"name":"Yu Liu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA0klEQVRIiWNgGAWjYBACPmYQWcDAw8/efPBBQkUNYS1sYC0GDDKSPceSDR6cOUaEFgaIFhuDGzlmkg9bmInQws5jJs1jcJjH4MwBs4rEBjYG/vbuBAIOg2qRPN6QdiNxhwyDxJmzG4jTwnfmwLEbiWfYGAwkconUwnAjsa0gsY2ZBC0CN5LZGIjUwlZsOccgnQcYyMwSCWeO8RD0Cz//4Y033lRY2/Oz93/8+KOiRo6/vRe/FiBgkWBgaIbzeAgpBwHmDwwMdcQoHAWjYBSMgpEKADHLQVL+Kw9pAAAAAElFTkSuQmCC","orcid":"","institution":"Zhuhai People's Hospital","correspondingAuthor":true,"prefix":"","firstName":"Yu","middleName":"","lastName":"Liu","suffix":""}],"badges":[],"createdAt":"2025-05-12 15:38:11","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6648137/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6648137/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":85735372,"identity":"4eff3316-77b9-4ae5-94c3-0555e647b0ce","added_by":"auto","created_at":"2025-07-01 07:58:44","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":405572,"visible":true,"origin":"","legend":"\u003cp\u003eThe imaging examinations before CIE.\u003c/p\u003e\n\u003cp\u003e(A)DSA showed a saccular aneurysm with daughter sac in the C7 segment of the L-ICA.\u003c/p\u003e\n\u003cp\u003e(B)The brain MR（DWI）showed there was no new acute ischemic cerebral infarction.\u003c/p\u003e\n\u003cp\u003e(C)A flow-diverting stent placement under local infiltration anesthesia.\u003c/p\u003e\n\u003cp\u003e(D)The stent was well adherent and the blood flow in the stent was smooth.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-6648137/v1/20522350578619a14f48deed.png"},{"id":85735374,"identity":"22b1a84f-1c1c-4003-97d5-5178b0ca831f","added_by":"auto","created_at":"2025-07-01 07:58:44","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":326101,"visible":true,"origin":"","legend":"\u003cp\u003eBrain CT scans of the CIE patient.\u003c/p\u003e\n\u003cp\u003e(A) The Dyna-CT scan was performed immediately post-operation.\u003c/p\u003e\n\u003cp\u003e(B) The brain CT scan was performed after 3h of the procedure.\u003c/p\u003e\n\u003cp\u003e(C) The brain CT scan was performed the following day post-procedure.\u003c/p\u003e\n\u003cp\u003e(D) The brain MR（DWI） scan was performed on the 5th day postprocedure.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-6648137/v1/1fd9969f892c83803974b58e.png"},{"id":87162945,"identity":"d28e532c-c21e-4376-a6a6-25a460e06aca","added_by":"auto","created_at":"2025-07-21 05:32:53","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1241035,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6648137/v1/02b48f8d-8a1c-43ff-9e19-7e9f016440e4.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Contrast-induced encephalopathy after Flow-diverting stents for the treatment of cerebral artery aneurysms：a Case Report","fulltext":[{"header":"Background","content":"\u003cp\u003eWith the rapid development of medical diagnosis and treatment technology, aneurysm embolization is one of the main treatment methods for intracranial aneurysms, but a variety of complications may occur after surgery. Among them, CIE is a rare but potentially life-threatening neurological complication, which usually occurs after coronary angiography, cerebral angiography, or interventional therapy, and the prevalence of contrast agents on neurological side effects is about 1%~2%[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. The clinical manifestations are acute neurological impairment, including focal neurologic deficits (hemiplegia, hemianopia, cortical blindness, aphasia, and Parkinson's disease) and systemic symptoms (confusion, seizures, and coma) [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Most patients with CIE have transient and reversible clinical symptoms with no significant sequelae, but a small number of patients with CIE leave sequelae or even die [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Previous studies have shown that it usually occurs 2 to 12 h after contrast injection, and CIE symptoms usually disappear after 24 to 72 h without neurological deficits. However, in the absence of formal diagnostic criteria, rare cases of irreversible or even fatal CIE have occurred [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. At present, there are few reports of concurrent CIE after aneurysm embolization. In particular, the concurrent CIE after aneurysm embolization under local infiltration anesthesia has not been reported in China. This article reports a case of contrast-agent encephalopathy after intracranial unruptured aneurysm with blood flow-directed dense mesh stent embolization under local infiltration anesthesia, summarizes its pathogenesis, and reviews relevant literature.\u003c/p\u003e"},{"header":"Case presentation","content":"\u003cp\u003eA 60-year-old woman presents to our hospital with ischemic cerebral infarction 1 year ago. The patient's previous history of hypertension was regular, and oral administration of amlodipine besylate and bisoprolol fumarate controlled blood pressure, and the blood pressure control was acceptable. Previous history of atrial fibrillation, regular oral rivaroxaban 10 mg once a day. No history of coronary artery disease or diabetes mellitus. Her laboratory profile, including renal and hepatic function, was normal. Neurological examination showed no obvious positive signs. Digital subtraction angiography (DSA) showed a 2 mm ∗ 3 mm saccular aneurysm with daughter sac in the C7 segment of the left internal carotid artery (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA). The patient underwent cranial MR examination for further evaluation before surgery, and there was no new acute ischemic cerebral infarction(Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eB). After receiving rivaroxaban 10 mg once a day and ticagrelor 60 mg twice a day, the patient underwent a flow-diverting stent placement under local infiltration anesthesia(Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eC). Immediately after the first injection of contrast during surgery, the patient develops agitation with a left-sided gaze of both eyes, which subsedes spontaneously. Dilution angiography after the operation showed that the stent was well adherent and the blood flow in the stent was smooth (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eD), and there was no obvious intracranial hemorrhage or edema on Dyna-CT (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eA). Approximately 3 hours after surgery, the patient developed lethargy, mixed aphasia, and decreased right muscle strength (grade 2/5) under painful stimulation. Immediate brain CT and CTA scans detected edema involving the parietal and temporal lobes in the left cerebral hemisphere without hemorrhage (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eB). Because CTA does not show cerebral vascular stenosis, CIE is suspected. We used 10 mg of dexamethasone and 125 ml of mannitol to reduce cerebral edema. At the same time, glucose sodium chloride helps to eliminate contrast agents. There was no significant improvement in neurological deficits 24 hours after surgery, although CT showed significant improvement in left brain edema (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eC). 72 hours after surgery, you can answer questions, understand conversations, and feel a little euphoria. Physical examination: clear, pertinent answers, limb muscle strength level 5, normal limb muscle tone. Pathologic signs were not elicited. Treatment with mannitol and dexamethasone sodium phosphate was discontinued. Five days after surgery, the patient's re-examination of the brain MR showed that the left cerebral hemisphere was swollen and did not show any swelling, and there were multiple malacia foci in the bilateral radial crown, semioval center, basal ganglia and cerebellar hemispheres, and lacunar infarcts and small ischemic foci scattered in the brain (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eD). The patient was discharged on the 8th day after surgery with no significant neurological deficits.\u003c/p\u003e "},{"header":"Discussion and conclusions","content":"\u003cp\u003eUnlike irreversible brain injury due to intracerebral hemorrhage, cerebral infarction, hypoperfusion, and other causes, CIE is a contrast-induced disease of the central nervous system that presents primarily as acute, reversible, transient neurologic deficits [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Common clinical symptoms include nausea, vomiting, headache, aphasia, epilepsy, and cortical blindness in severe cases, and cortical edema and focal neurologic deficits in severe cases, and even cardiac arrest, among which transient cortical blindness is the most common clinical manifestation, and there may be prodromal symptoms such as mental status changes [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e–\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. In this case, the patient developed aphasia, cortical edema, focal neurologic deficits, and altered mental status, and symptoms disappeared completely after 72 hours.\u003c/p\u003e\u003cp\u003eThe main differential diagnosis of CIE is ischemic stroke and intracranial hemorrhage, so imaging is essential in the diagnosis of CIE and should be performed as soon as possible. Imaging findings of cerebral edema or increased cortical signal are important for the diagnosis of CIE [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e], but imaging findings may be absent [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Typical imaging changes of CIE include: 1. CT shows diffuse cortical or subcortical enhancement, or subarachnoid enhancement and striatum enhancement, and can also manifest as focal hyperdense lesions, sulci hyperdensity opacities, and cerebral edema or subarachnoid hyperdensity changes similar to those of patients with subarachnoid hemorrhage; 2. Noncontrast cranial MR scan shows angiogenic edema [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e–\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. In this case, the cranial CT examination 3 hours after the onset of symptoms showed that the left cerebral hemisphere brain tissue was swollen, the sulcus cerebral fission was shallow, and the CTA intracranial large vessels were not obviously abnormal, which was consistent with the imaging diagnosis of CIE.\u003c/p\u003e\u003cp\u003eIn this case, the patient received a total of five iodinated contrast agents, the first was cerebral angiography under local anesthesia, the second was \"percutaneous right middle cerebral artery stenting\" under tracheal intubation under general anesthesia, the third and fourth times were returned to the hospital under local anesthesia for re-examination of cerebral angiography, and the fifth time was \"transcatheter intracranial aneurysm stent-assisted embolization\" under local anesthesia. So what is the reason for the fifth CIE in this patient? The pathogenesis of CIE is unclear, and the main pathophysiological mechanism widely accepted in the academic community is transient disruption of the blood-brain barrier (BBB) caused by the injection of iodine-containing contrast agents [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. These include direct damage to BBB by contrast agents, such as decreased expression of tight junction proteins in endothelial cells, chemical toxicity, and other factors such as ischemic encephalopathy, which cause indirect damage to BBB and increase contrast leakage [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. After BBB injury, the contrast agent penetrates into the brain tissue, directly damages brain cells, destroys vascular endothelial cells, and causes cerebral edema, causing hemodynamic changes, leading to circulatory congestion and vascular occlusion [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. In addition, etiologies include microemboli, contrast-induced immune responses, and differences in the structure and function of different brain regions [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. In addition to contrast use, female sex, hypertension, diabetes mellitus, impaired renal function, stroke, and impaired cerebral autoregulation are risk factors for the development of CIE [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Moreover, foreign studies have shown that 50 percent of patients with CIE have a history of hypertension [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. In this case, a 60-year-old woman with a history of hypertension, diabetes, and stroke increased the risk of CIE and made it easier for the contrast agent to cross the blood-cerebrospinal fluid barrier. Hou Bin has reported a case of \"right posterior communicating aneurysm, right middle cerebral aneurysm embolization assisted by stent\" under general anesthesia, and the symptoms and imaging manifestations of CIE appeared immediately after waking up from anesthesia, while our patient was treated with aneurysm embolization under local anesthesia.\u003c/p\u003e\u003cp\u003eAt present, there is no specific drug for the specific treatment of CIE, and the current treatment methods are mainly symptomatic supportive treatment, such as a large amount of fluid refill expansion to accelerate the excretion of contrast agent and reduce the damage of the blood-brain barrier; early use of glucocorticoids to reduce toxic damage from contrast agents; Dehydration drugs such as mannitol and glycerol fructose are given to reduce cerebral edema. In patients with seizures, appropriate use of anticonvulsants, such as benzodiazepines, is effective in controlling tics and reducing cerebral edema [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. In patients with acute kidney injury, hemodialysis is safe and effective [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. The prognosis for CIE is usually good, mostly self-limited, with clinical symptoms usually relieving completely, and permanent damage rarely occurring. However, some patients have a more insidious onset, may take longer to resolve symptoms, and some are at risk of permanent dysfunction [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Immediately after the onset of the disease, the patient was given dexamethasone sodium phosphate 10mg intravenous infusion to reduce inflammatory edema, mannitol 125mlQ8h dehydration to reduce intracranial pressure, urapidil to control blood pressure, prevent hyperperfusion and rehydration, and other supportive symptomatic treatment, the patient's symptoms disappeared completely after 72 hours, and the neurological function returned to normal.\u003c/p\u003e\u003cp\u003eThe patient's pathogenesis, clinical manifestations, ancillary examinations, and diagnosis and treatment all met the diagnostic criteria for CIE. In summary, CT or MRI of the brain is essential for the identification and diagnosis of CIE as soon as the corresponding clinical manifestations of CIE appear in clinical work. Once CIE occurs, comprehensive treatment such as glucocorticoids, dehydration and intracranial pressure reduction, blood pressure control, and fluid hydration should be used as soon as possible to minimize the harm to the patient. At present, most of the studies on CIE are case studies and reports, and there is a lack of systematic studies, in the future, we will collect the number of cases of CIE and conduct systematic analysis and research.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eZJ.D. wrote the manuscript. J.H., Q.Z. examined the patient. Y.L. analyzed the neuroimaging data. ZJ.D. prepared the manuscript and performed the interventional surgery on the patient. All the authors read and approved the final version of the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA signed informed consent was obtained from the patient to publish this case report and the accompanying neuroimages.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eSpina R, Simon N, Markus R, et al. Recurrent contrast-induced encephalopathy following coronary angiography[J]. Intern Med J. 2017;47:221\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLeong S, Fanning NF. Persistent neurological deficit from iodinated contrast encephalopathy following intracranial aneurysm coiling. A case report and review of the literature. Interventional Neuroradiology: J Peritherapeutic Neuroradiol Surg Procedures Relat Neurosciences. 2012;18(1):33\u0026ndash;41.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMEIJER FJA, STEENS SCA, TULADHAR AM, et al. Contrast⁃induced encephalopathy ⁃ neuroimaging findings and clinical relevance[J]. Neuroradiology. 2022;64(6):1265\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNakao K, Joshi G, Hirose Y, Tanaka R, Yamada Y, Miyatini K, et al. Rare cases of contrast-Induced encephalopathies. Asian J Neurosurg. 2020;15(3):786\u0026ndash;93.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhao W, Zhang J, Song Y, Sun L, Zheng M, Yin H, et al. Irreversible fatal contrast-induced encephalopathy: a case report. BMC Neurol. 2019;19(1):46.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNiimi Y, Kupersmith MJ, Ahmad S, Song J, Berenstein A. Cortical blindness, transient and otherwise, Associated with Detachable Coil Embolization of Intracranial aneurysms. Am J Neuroradiol. 2008;29(3):603\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChu YT, Lee KP, Chen CH et al. Contrast-induced encephalopathy after endovascular thrombectomy for acute ischemic stroke [J].Stroke,2020, 51(12): 3756\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang G, Wang H, Zhao L, et al. Contrast-induced encephalopathy resulting from use of ioversol and iopromide [. J] Clin Neuropharmacol. 2020;43(1):15\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYao LD, Zhu XL, Yang RL, et al. Cardiorespiratory arrest after iso-osmolar iodinated contrast injection: a case report of contrast- induced encephalopathy following contrastenhanced computed-tomography [J]. Med (Baltim). 2021;100(2):e24035.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKocabay G, Karabay CY, Kalayci A et al. Contrast-induced neurotoxicity after coronary angiography[J].Herz,2014,39(4):522\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDattani A, Au L, Tay KH et al. Contrast- induced encephalopathy following coronary angiography with no radiological features:a case report and literature review[J].Cardiology,2018,139:197\u0026ndash;201.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWANG H, LI T, ZHAO L, et al. Dynamic effects of ioversol on the permeability of the blood-brain barrier and the expression of ZO-1/occludin in rats[J]. J Mol Neurosci. 2019;68(2):295\u0026ndash;303.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSeong JM, Choi NK, Lee J, et al. Comparison of the safety of seven iodinated contrast media [J]. J Korean Med Sci. 2013;28(12):1703\u0026ndash;10.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eQUINTAS-NEVES M, ARA\u0026Uacute;JO JM, XAVIER SA, et al. Contrast-in-duced neurotoxicity related to neurological endovascular procedures: a systematic review[J]. Acta Neurol Belg. 2020;120(6):1419\u0026ndash;24.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRoberto S, Neil S, Romesh M, et al. Contrast-induced encephalopathy following cardiac catheterization [J]. Catheter Cardiovasc Interv. 2016;90(2):257\u0026ndash;68. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1002/ccd.26871\u003c/span\u003e\u003cspan address=\"10.1002/ccd.26871\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLei P, He W, Shi Q, et al. Recurrent epileptic seizures following cardiac catheterization with iodixanol: a case report [J]. BMC Cardiovasc Disord. 2020;20(1):257\u0026ndash;68.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGuo QY, Feng XX, Wang ZJ, et al. Is it better to choose immediate dialysis treatment for renal transplant patients after PCI [J]. J Geriatr Cardiol. 2020;17(2):116\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTong XZ, Hu P, Hong T, et al. Transient cortical blindness associated with endovascular procedures for intracranial aneurysms [J]. World Neurosurg. 2018;119:123\u0026ndash;31.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Contrast-induced encephalopathy, Aneurysm embolization, Flow-diverting stent, local infiltration anesthesia, Digital subtraction angiography","lastPublishedDoi":"10.21203/rs.3.rs-6648137/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6648137/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAneurysm interventional embolization is one of the main treatment methods for intracranial aneurysm, which has significant advantages due to its minimally invasive nature, but a variety of complications may still occur during and after surgery, among which contrast-induced encephalopathy (CIE) is a rare but potentially life-threatening neurological complication. CIE is a rare neurological complication after the use of endovascular contrast agents, usually occurring after coronary angiography, cerebral angiography, or interventional therapy, CIE usually occurs 2 to 12 hours after contrast injection, and usually disappears after 24 to 72 hours. The clinical manifestations are acute neurological impairment, including focal neurologic deficits (hemiplegia, hemianopia, cortical blindness, aphasia, and Parkinson's disease) and systemic symptoms (confusion, seizures, and coma). CT or MRI scans of the brain may be transiently positive.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCase presentation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA 60-year-old woman was admitted to hospital with ischemic cerebral infarction 1 year ago. The first digital subtraction angiography (DSA) identified the right middle cerebral artery (MCA) stenosis and a saccular aneurysm with daughter sac of 2 mm ∗ 3 mm in size in the C7 segment of the left internal carotid artery (ICA). At that time, surgery was performed on arterial stenosis, and the operation was successful. In order to further treat the aneurysm, the patient underwent Flow-diverting stent placement under local infiltration anesthesia, and the operation was successful, however, the patient was unable to speak, unable to understand conversation, irritable, and had no voluntary movement of the right limb after surgery. The non-contrast cerebral CT indicated widespread edema in the left cerebral hemisphere. The patient was diagnosed with CIE and treated with symptomatic supportive therapy. Eventually, the patient’s neurological deficits and cerebral edema\u003c/p\u003e\n\u003cp\u003eimproved significantly.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe current case emphasized the importance of early diagnosis and symptomatic treatment of CIE. Thus, CIE should be the first consideration during the differential diagnosis of a patient having acute neurological impairment after repeated DSA.\u003c/p\u003e","manuscriptTitle":"Contrast-induced encephalopathy after Flow-diverting stents for the treatment of cerebral artery aneurysms：a Case Report","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-07-01 07:58:39","doi":"10.21203/rs.3.rs-6648137/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"4ceebf01-5d13-4cc9-a526-c0a375d2c9a8","owner":[],"postedDate":"July 1st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-07-21T05:23:36+00:00","versionOfRecord":[],"versionCreatedAt":"2025-07-01 07:58:39","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6648137","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6648137","identity":"rs-6648137","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}