Distal Internal Carotid Artery Research Articles

Triplicated middle cerebral arteries (duplicated and ipsilateral accessory) associated with triplicated anterior cerebral arteries (accessory) diagnosed by magnetic resonance angiography.

To describe a case of duplicated middle cerebral artery (MCA) combined with ipsilateral accessory MCA, forming a triplicated MCA, associated with the accessory anterior cerebral artery (ACA), forming a triplicated A2 segment of the ACA detected incidentally on magnetic resonance (MR) angiography. A 70-year-old woman with internal carotid artery (ICA) stenosis at the origin, which was detected by ultrasound, underwent cranial MR imaging and MR angiography of the intracranial region for an evaluation of brain and cerebral arterial lesions. The MR machine was a 3-Tesla scanner. MR angiography was performed using a standard 3-dimensional time-of-flight technique. Multiple ischemic white matter lesions are observed. No significant stenotic lesions were observed in intracranial arteries. The right duplicated MCA was originated from right distal ICA. And main MCA was originated from right ICA bifurcation. Right accessory MCA was arisen from the A2 segment of the right ACA. Thus, the right MCA was triplicated. There was also an accessory ACA forming a triplicated ACA at its A2 segment. These findings were clearly identified on partial volume-rendering (VR) images. We herein report a case of triplicated MCA associated with triplicated ACA. MCA variations are relatively rare, and this is the third case of triplicated MCA reported in relevant English-language literature. To identify multiple cerebral arterial variations, creating partial VR images using MR angiographic source images is useful.

Safety and efficacy of the novel Alpha stent for the treatment of intracranial wide-necked aneurysm

The Alpha stent is an intracranial closed-cell stent with a unique mesh design to enhance wall apposition. It recently underwent structural modifications to facilitate easier stent deployment. This study aimed to evaluate the safety and efficacy of stent-assisted coil embolization for unruptured intracranial aneurysms using the Alpha stent. Between January 2021 and November 2021, 35 adult patients with 35 unruptured intracranial aneurysms in the distal internal carotid artery were prospectively enrolled. For efficacy outcomes, magnetic resonance angiography at the 6-month follow-up was evaluated using the Raymond-Roy occlusion classification (RROC). The safety outcome evaluated the occurrence of symptomatic procedure-related neurological complications up to 6 months postoperatively. Technical success was achieved in 34/35 (97.1%). Six months postoperatively, aneurysm occlusion showed RROC I in 32/35 (91.4%) and RROC II in 3/35 (8.6%) patients. Procedure-related neurologic complications occurred in one patient (2.9%) who experienced hemiparesis due to acute lacunar infarction, which resulted in a 6-month mRS score of 1. The Alpha stent demonstrated excellent efficacy and safety outcomes in stent-assisted coil embolization of unruptured distal ICA aneurysms. The recent structural modifications allowed for easier stent delivery and deployment.Clinical trial registration number: KCT0005841; registration date: 28/01/2021.

Lower Cranial Neuropathies as Presenting Symptom of Distal Extracranial Internal Carotid Artery Dissection Leading to Delay in Diagnosis and Treatment (P7-5.030)

Lower Cranial Neuropathies as Presenting Symptom of Distal Extracranial Internal Carotid Artery Dissection Leading to Delay in Diagnosis and Treatment (P7-5.030)

Bailout Distal Internal Carotid Artery Stenting after Carotid Endarterectomy: Indications, Technique, and Outcomes

Distal internal carotid artery (ICA) stenting may be employed as a bailout maneuver when an inadequate end point or clamp injury is encountered at the time of carotid endarterectomy (CEA) in a surgically inaccessible region of the distal ICA. We sought to characterize the indications, technique, and outcomes for this infrequently encountered clinical scenario. We performed a retrospective review of all patients who underwent distal ICA stenting at the time of CEA at our institution between September 2008 and July 2022. Procedural details and postoperative follow-up were reviewed for each patient. Six patients were identified during the study period. All were male with an age range of 63 to 82years. Five underwent carotid revascularization for asymptomatic carotid artery stenosis, and one patient was treated for amaurosis fugax. Three patients were on dual antiplatelet therapy preoperatively, whereas 2 were on aspirin monotherapy, and one was on aspirin and low-dose rivaroxaban. Five patients underwent CEA with patch angioplasty, and one underwent eversion CEA. The indication for stenting was distal ICA dissection due to clamp or shunt injury in 2 patients and an inadequate distal ICA end point in 4 patients. In all cases, access for stenting was obtained under direct visualization within the common carotid artery, and a standard carotid stent was deployed with its proximal aspect landing within the endarterectomized site. Embolic protection was typically achieved via proximal common carotid artery and external carotid artery clamping for flow arrest with aspiration of debris before restoration of antegrade flow. There was 100% technical success. Postoperatively, 2 patients were found to have a cranial nerve injury, likely occurring due to the need for high ICA exposure. Median length of stay was 2days (range 1-7days) with no instances of perioperative stroke or myocardial infarction. All patients were discharged on dual antiplatelet therapy with no further occurrence of stroke, carotid restenosis, or reintervention through a median follow-up of 17months. Distal ICA stenting is a useful adjunct in the setting of CEA complicated by inadequate end point or vessel dissection in a surgically inaccessible region of the ICA and can minimize the need for high-risk extensive distal dissection of the ICA in this situation.

Combined Aspiration and Stent Retriever Thrombectomy for Distal Carotid Artery Occlusion Using Balloon Guide versus Non-Balloon Guide Catheter.

Background: The introduction of endovascular thrombectomy dramatically changed acute stroke management and became the standard treatment. Balloon guide catheters provide flow arrest during the clot retrieval process and have several advantages.This study aimed to compare balloon guide catheters (BGCs) versus non-balloon guide catheters (NBGCs) as a part of a combined treatment modality in patients presenting with acute ischemic stroke. Methods: This retrospective study included n = 65 patients who underwent a combined endovascular stroke treatment for distal internal carotid artery (ICA) occlusion. Patients underwent aspiration and stent retriever thrombectomy with the use of BGCs (Group 1, n = 27) or NBGCs (Group 2, n = 38). Results: The groups were compared for outcomes: the National Institutes of Health Stroke Scale (NIHSSS) score change, successful recanalization, good functional outcome at three months, and in-hospital mortality. Conclusion: The two groups didn't differ in terms of the NIHSS score change compared to baseline (p > 0.05). Moreover, there were no significant differences between the two groups in terms of the successful recanalization rate, three-month favorable functional outcome rate, and in-hospital mortality (p = 0.292, p = 0.952, p = 0.178), respectively. Further prospective studies with a larger number of patients and better methodology are warranted.

Arterial Tortuosity Is a Potent Determinant of Safety in Endovascular Therapy for Acute Ischemic Stroke

Background Subarachnoid hemorrhage (SAH) associated with vessel injury during endovascular therapy for acute ischemic stroke is a known complication. Arterial anatomy may predispose to increased risk of SAH and technical safety, yet factors such as clot location, arterial size, and tortuosity have not been explored. We examined these anatomic factors with respect to SAH during thrombectomy. Methods Arterial anatomy at the site of occlusion and mechanical thrombectomy during device deployment was detailed by the STRATIS (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke) core laboratory. Luminal diameters, arterial branching, and segmental tortuosity were measured. Arterial tortuosity was quantified using the distance factor metric. Statistical analyses included descriptive variables of arterial anatomy, with univariable and multivariable modeling to predict SAH. Results Arterial tortuosity in each segment from the proximal cerebral arteries to the site of occlusion was quantified in 790 subjects treated with mechanical thrombectomy in STRATIS. Cumulative arterial tortuosity to the site of vessel occlusion was greater in distal lesions. SAH was clearly linked with more distal thrombectomy ( P = 0.02), occurring in 19.0% of distal M2, 16.7% of M3, 7.3% of distal M1, 5.8% of proximal M2, 2.4% of distal internal carotid artery, and 2.1% of proximal M1. In multivariable analysis after adjusting for arterial diameter at the site of occlusion, arterial tortuosity was a significant predictor of SAH (upper tertile versus 1: odds ratio, 3.08 [95% CI, 1.04–9.09]; P = 0.04), while arterial diameter was unrelated to SAH ( P = 0.30) when accounting for tortuosity. Conclusion This novel analysis of arterial tortuosity and angiographic anatomy during mechanical thrombectomy establishes tortuosity as a determinant of SAH, providing insight for future techniques and innovative device designs.

Moya-Moya Disease a Case Report and Literature Review

Moya-Moya disease is a rare chronic cerebral vascular disease (arteriopathy), which can affect both children and adults and gives rise to severe clinical manifestations of ischemic or hemorrhagic origin. This angiogenic disease is an intrinsic primary pathological process, characterized by a narrowing of the distal internal carotid artery that extends to the proximal segments of the middle and anterior cerebral arteries, inducing the formation of replacement vessels that give a characteristic appearance on angiography forming a smoke cloud: Moya Moya network. The involvement of the posterior circulation is very rare. Its etiology is still poorly understood and represents 10 to 15% of the causes of strokes, with 2 age peaks where it is more frequent: children around 5 years and adults around 40 years. Its evolution can be slow with intermittent symptoms or fulminant with a rapid neurological decline. Imaging is the reference examination in the diagnosis of Moya-Moya. MRI (Magnetic Resonance Imaging) has an important and growing role in the management of the disease. We report a case of a 48 year old patient with diabetes and hypertension, hospitalized for a deep left hematoma.

Feasibility and efficiency of a new classification based on high-resolution MRI for carotid artery pseudo-occlusion and occlusion: Hybrid revascularization pilot study

Background and purposeStudies on changes in the distal internal carotid artery based on high resolution magnetic resonance imaging (HRMRI) are scarce. Herein, we propose a histological classification system for patients with carotid artery pseudo-occlusion or occlusion based on preoperative HRMRI, for which we evaluated the feasibility and clinical implications. Materials and methodsFrom January 2017 to June 2021, 40 patients with Doppler ultrasound, CTA or MRA suggesting carotid artery occlusion were enrolled in this study. A new classification system based on HRMRI was established and subsequently verified by postoperative specimens. We recorded and analyzed patient characteristics, HRMRI data, recanalization rate, requirements of additional endovascular procedures, complications, and outcomes. ResultsFour histological classifications (type Ⅰ–Ⅳ) were identified. According to our classification system, 20 patients (50.00%) were type I, nine (22.50%) were type II, 7 (17.50%) were type III, and four (10.00%) were type Ⅳ. The success rate of recanalization was 88.89% (32/36) in type I–III patients. Four (44.44%) type Ⅱ patients and five (71.43%) type Ⅲ patients suffered from intraoperative dissection. ConclusionPatients identified as types I (pseudo-occlusion) and II (thrombotic-occlusion) were able to be treated via hybrid revascularization with relatively low risk, while patients identified as type III (fibrous-occlusion) required more careful treatment. Recanalization is not suitable for patients identified as type Ⅳ. Our proposed classification system based on HRMRI data can be used as an adjunctive guide to predict the technical feasibility and success of revascularization via a hybrid technique.

Safety and efficacy of protective stent insertion to prevent carotid blowout syndrome at the distal internal carotid artery in nasopharyngeal carcinoma patients: a comparison with endovascular occlusion.

Carotid blowout syndrome (CBS) frequently occurs at the distal internal carotid artery (distal-ICA) in patients with nasopharyngeal carcinoma (NPC), and remedial treatments run a high risk for neurologic complications. A case-control study was conducted to evaluate the safety and efficacy of protective stent insertion at the distal-ICA to prevent CBS in NPC patients, with a comparison to endovascular coil occlusion. A total of 28 consecutive NPC patients at high risk of CBS from June 2019 to December 2021 in Shanghai Sixth People's Hospital (a tertiary institution) were retrospectively included and divided into a stent protection group and occlusion group. Technique feasibility, treatment outcomes and neurological deficiency were compared between the two groups by two-sample test. Kaplan-Meier analysis compared patients' survival rates at mid-term follow-up. Stent insertion was performed in 15 patients and ICA occlusion in 13 patients. The technical success rate was 100% in both groups. Procedure-related ischemic stroke was identified in 2 patients (15.4%) in the occlusion group, compared with none in the stent protection group. Bleeding was encountered in one patient in the stent protection group and one patient in the occlusion group, each. During a median follow-up of 10.5 (range, 2-31) months, 3 patients (20%) showed asymptomatic in-stent occlusion in the stent protection group. Notably, the median survival time was significantly longer in the stent protection group than in the occlusion group (23.3 vs. 15.8 months, P=0.04). Protective stenting the distal-ICA was similarly effective in preventing CBS in NPC patients but was safer than endovascular occlusion of ICA.

Risk factors of unruptured intracranial aneurysms instability in the elderly.

Presently, a consistent strategy for determining the stability of unruptured intracranial aneurysms (UIAs) in elderly patients is lacking, primarily due to the unique characteristics of this demographic. Our objective was to assess the risk factors contributing to aneurysm instability (growth or rupture) within the elderly population. In this study, we compiled data from follow-up patients with UIAs spanning from November 2016 to August 2021. We specifically focused on patients aged ≥ 60years. Clinical histories were gathered, and morphological parameters of aneurysms were measured. The growth of aneurysms was determined using the computer-assisted semi-automated measurement (CASAM). Growth and rupture rates of UIAs were calculated, and both univariate and multivariate Cox regression analyses were conducted. Additionally, Kaplan-Meier survival curves were plotted. A total of 184 patients with 210 aneurysms were enrolled in the study. The follow-up period encompasses 506.6 aneurysm-years and 401.4 patient-years. Among all the aneurysms, 23 aneurysms exhibited growth, with an annual aneurysm growth rate of 11.0%, and 1 (4.5%) experienced rupture, resulting in an annual aneurysm rupture rate of 0.21%. Multivariate Cox analysis identified poorly controlled hypertension (P = 0.011) and high-risk aneurysms (including anterior cerebral artery (ACA), anterior communicating artery (AcoA), posterior communicating artery aneurysm (PcoA), posterior circulation (PC) > 4mm or distal internal carotid artery (ICAd), middle cerebral artery (MCA), and PC > 7mm) (P = 0.006) as independent risk factors for the development of unstable aneurysms. In the elderly, poorly controlled hypertension and high-risk aneurysms emerge as significant risk factors for aneurysm instability. This underscores the importance of rigorous surveillance or timely intervention in patients presenting with these risk factors.

Associations between atherosclerotic luminal stenosis in the distal internal carotid artery and diffuse wall thickening in its upstream segment.

Significant atherosclerotic stenosis or occlusion in the distal internalcarotid artery(ICA) may induce diffuse wall thickening (DWT) in the upstream arterial wall. This study aimed to assess the association of atherosclerotic steno-occlusive diseases in the distal ICA with DWT in the upstream ipsilateral ICA. Individuals with atherosclerotic stenosis in the distal ICA, detected by carotid MR vessel wall imaging using 3D pre- and post-contrast T1 volume isotropic turbo spin-echo acquisition (T1-VISTA) sequence, were enrolled. The associations of vessel wall thickening, the longitudinal extent of DWT, enhancement of the upstream ipsilateral ICA, and stenosis degree in the distal ICA were examined. Totally 64 arteries in 55 patients with atherosclerotic steno-occlusive distal ICAs were included. Significant correlations were found between distal ICA stenosis and DWT in the petrous ICA (r = 0.422, p = 0.001), DWT severity (r = 0.474, p < 0.001), the longitudinal extent of DWT in the ICA (r = 0.671, p < 0.001), enhancement in the petrous ICA (r = 0.409, p = 0.001), and enhancement degree (r = 0.651, p < 0.001). In addition, high degree of enhancement was correlated with both increased wall thickness and increased prevalence of DWT in the petrous ICA (both p < 0.001). DWT of the petrous ICA is commonly detected in patients with atherosclerotic steno-occlusive disease in the distal ICA. The degree of stenosis in the distal ICA is associated with wall thickening and its longitudinal extent in the upstream segments. Diffuse wall thickening is a common secondary change in atherosclerotic steno-occlusive disease in the intracranial carotid. This phenomenon constitutes a confounding factor in the distinction between atherosclerosis and inflammatory vasculopathies, and could be reversed after alleviated atherosclerotic stenosis. • Diffuse wall thickening of the petrous internal carotid artery is commonly detected in patients with atherosclerotic steno-occlusive disease in the distal internal carotid artery. • The phenomenon of diffuse wall thickening could be reversed after stenosis alleviation. • Carotid artery atherosclerosis with diffuse wall thickening should warrant a differential diagnosis from other steno-occlusive diseases, including moyamoya diseases and Takayasu aortitis.

Classification and treatment strategy for Moyamoya disease-related aneurysms

BackgroundMoyamoya disease (MMD) is a cerebrovascular disorder characterized by progressive unilateral or bilateral stenosis of the distal internal carotid artery. As hemodynamic features in MMD patients alter, the comorbidity of intracranial aneurysm (IA) is sometimes observed clinically. We aim to investigate clinical characteristics and therapeutic strategies for the comorbidity of Moyamoya disease with intracranial aneurysms (MMD-IA).MethodsA total of 13 MMD-IA patients were recruited in this study and were manifested to be intracranial hemorrhage. We reviewed the surgical technique notes for all patients.ResultsAccording to the locations of an aneurysm, MMD-IA could be divided into several categories: (1) MMD-IA at a circle of Willis—aneurysms usually located at the trunk of Willis circle; (2) MMD-IA at collateral anastomosis—aneurysms located at the distal end of collateral anastomosis; and (3) MMA-IA at basal ganglia region. In this report, aneurysms in 10 patients located at Willis circle, 2 at the pericallosal artery, and 1 at the basal ganglia region. Among them, endovascular embolism was performed among 5 patients. Aneurysm clipping was conducted among 7 patients. A patient with an aneurysm at the basal ganglia region just accepted revascularization treatment. All the treatments were successful. Follow-up studies, ranging from 6 to 24 months, demonstrated all patients received satisfactory curative effects.ConclusionDiverse clinical presentations could be observed among MMD-IA patients. Individualized neurosurgical treatments should be chosen according to the locations of the aneurysm.

Transcranial Doppler in Childhood Moyamoya: An Underutilized Tool?

BackgroundChildren with moyamoya are at high risk for incident and recurrent stroke. Transcranial Doppler (TCD) ultrasound is an attractive option to screen high-risk populations for moyamoya and to provide stroke risk stratification information due to its safety and cost-effectiveness. We used TCD to evaluate cerebral blood flow velocities in children with presurgical moyamoya and to determine if velocities differ between children with stable and unstable disease. MethodsFourteen participants aged ≤21 years with a radiographic diagnosis of moyamoya or moyamoya-like arteriopathy underwent a research TCD at a median age of 7.2 years. TCDs were performed outside of the setting of acute stroke and before surgical revascularization. Arteriopathy was classified as unstable if the participant had a stroke or transient ischemic attack within three months preceding the TCD. ResultsMiddle cerebral artery and internal carotid artery (ICA) blood flow velocities were elevated. The median M1 velocity was 138 cm/s (interquartile range [IQR] 106 to 168). Individual M1 flow velocities were a median of 5.0 S.D.s above age-based normative values. The median distal ICA velocity was 146 cm/s (IQR 124 to 163). Individual ICA flow velocities were a median of 5.9 S.D.s above normative values. Participants with unstable arteriopathy had higher M1 velocities compared with those with stable arteriopathy (170 vs 119 cm/s, P = 0.0003). We did not identify velocity differences based on comorbid conditions or age. ConclusionsThese preliminary data suggest that TCD is a promising tool for screening for cerebral arteriopathies in high-risk pediatric populations and assessment for unstable disease.

Displace Study Shows Poor Quality of Transcranial Doppler Ultrasound for Sickle Cell Stroke Screening: An Urgent Need for Standardized Reporting

Introduction Children with sickle cell anemia (SCA) are at increased risk of stroke as compared to age-matched peers (Ohene-Frempong et al, Blood, 1998). The Stroke Prevention Trial in SCA (STOP) demonstrated that with use of transcranial Doppler ultrasound (TCD), children at highest risk for stroke could be identified and started on chronic transfusion therapy, reducing stroke risk by &amp;gt; 90% (Adams et al, NEJM, 1998). This led to the adoption of the STOP protocol as standard of care. However, many sites use the transcranial Doppler imaging (TCDi) technique in place of the original non-imaging TCD technique used in STOP. Further, the NHLBI-funded DISPLACE (Dissemination and Implementation of Stroke Prevention in SCD) study demonstrated &amp;lt; 50% of children at participating sites had annual TCD screening (Kanter et al, JPHO, 2021). This sub-study used DISPLACE data to examine TCD report quality. We hypothesized there was high variability in TCD technique, unreliable reporting of variables, inconsistent definitions for diagnosing abnormal scans and that these inconsistencies would be worse with TCDi. Methods An IRB waiver was obtained. This sub-study used data manually extracted from TCD reports in the DISPLACE database. A computer-generated algorithm randomly selected 400 TCD/TCDi reports (200 of each type) from the 12,433 reports collected in DISPLACE for an alpha of 0.05. TCD type, patient age, vessels assessed, velocities measured, and diagnosis made (abnormal/normal) were extracted. Type of TCD was separately extracted from the DISPLACE database. We surveyed study site principal investigators regarding TCD methods used in the study period (2012 - 2016). Results Three hundred and ninety-one TCD/TCDi reports were reviewed from 26 institutions. The median patient age at time of TCD was 5 years (2 - 8 years) and the median year of TCD completion was 2013 (2000 - 2016). On initial review of the TCD/TCDi reports, there was significant variability in how results were classified as “abnormal”, and reports were often inconsistent with STOP definitions of normal/abnormal. Thus, we focused on the quality and completeness of reports. Table 1 details the information included in the reports. Notable findings: • Use of TCDi was not specifically stated in 96% of TCDi reports. • 52% did not clearly identify the time averaged mean maximum velocity (TAMMV) (the key variable required per STOP criteria). • 30% of reports did not assess/did not report assessment of the distal internal carotid artery (dICA). • 14 reports (3.6%) did not include any information about which vessels were assessed. • Only 42% of scans clearly stated that classification of normal vs. abnormal was based on the correct measure (TAMMV). Surveys sent to each site to assess TCD practices from 2012-2016 were evaluated (Table 2). There was substantial variability regarding which vessels were examined for both TCD and TCDi, ranging from 1 - 5 vessels. The type of provider interpreting scans varied and only 8 institutions (35%) had ultrasound technicians who underwent formal STOP training. Conclusion TCD results have critical implications for medical decision-making in SCA, but our study reveals a lack of quality assurance and consistency with sickle cell stroke risk screening using TCD/TCDi. Notably, many reports did not identify which vessels were used to assess stroke risk, did not report on the correct velocity measurement, neglected to measure or report the TAMMV, or made diagnoses based on the wrong measurements or wrong vessels. Additionally, a large percentage of reports did not note whether a TCD or TCDi was performed. Surveys from 23 DISPLACE sites showed significant variation in the method of training for those performing TCDs. With this extreme variation, we recommend creation of a standardized template for TCD reports to be utilized across institutions. We also recommend those interpreting the scans gain expertise in reading and evaluating TCD/TCDi specifically for people with SCA. National quality improvement studies are necessary to implement these recommendations and inform further refinements, especially in the use of TCDi, and assessment of vessels beyond the middle cerebral artery and dICA. This requires engagement of stakeholders, identification of barriers to implementation, and funding. With these interventions, we continue to work towards meeting the recommended screening and interventions instituted by the NHLBI over 25 years ago.

A Case of Orbital Infarction Syndrome in a Patient with Hemophagocytic Lymphohistiocytosis

Purpose: To report a case of orbital infarction syndrome in a patient with hemophagocytic lymphohistiocytosis (HLH).Case summary: A 70-year-old woman with diabetes mellitus and hypertension was referred to the Department of Ophthalmology for sudden-onset left upper eyelid ptosis after being diagnosed with HLH. After 3 days, the best corrected visual acuity in the right eye was 0.8, while there was no light perception in the left eye. In the left eye, the ocular motility examination showed limitations in all fields of gaze. On fundus examination, optic disc pallor, retinal hemorrhage, and narrowed retinal arteries were observed in the left eye. Fluorescein angiography showed no blood flow in the retinal arteries and veins in the left eye. On neck computed tomography angiography, the left distal internal carotid artery was narrowed. Orbit computed tomography showed exophthalmos and extraocular muscle hypertrophy in the left eye. Orbit magnetic resonance imaging confirmed optic nerve edema, enhancement of the optic nerve sheath, and high signal intensity of the intraocular fat in the left eye. Slit-lamp examination revealed ischemia of the anterior segment and ischemic necrosis of the eyelid in the left eye. The patient was diagnosed with orbital infarction syndrome.Conclusions: Several factors may lead to ischemia of the orbital tissues in patients with HLH, including coagulopathy, an increased incidence of blood clots, and inflammation in the orbit. It is necessary to consider the possibility of orbital infarction syndrome when HLH patients present with visual loss, ocular movement limitations, and anterior segment ischemia.

Abstract 13325: Novel Heterozygous EFEMP2 Variant Detected in a Patient With Bilateral Internal Carotid Artery Dissection and Oligodontia

Cutis laxa is a rare connective tissue disorder characterized by sagging or inelastic skin. This phenotype is caused by multiple genotype variants. Biallelic variants in the EFEMP2 gene cause cutis laxa subtype IB characterized by aortic aneurysm, arterial tortuosity, arterial stenosis, joint laxity, arachnodactyly, emphysema, and retrognathia. EFEMP2 encodes fibulin-4, an extracellular matrix protein involved in elastogenesis and modulation of TGF-beta signaling. To date, monoallelic variants in EFEMP2 have not been described as pathogenic. Furthermore, oligodontia has not been associated previously with variants in EFEMP2 . We describe a 67-year-old male with a past medical history of left distal internal carotid artery (ICA) pseudoaneurysm and dissection, right distal ICA dissection, arterial tortuosity, and oligodontia who was found to have a heterozygous variant of uncertain significance in EFEMP2: c.1279_1289del11, p.Arg427CysfsX27. The variant has not been observed previously in large population cohorts and causes a shift in reading frame that substitutes the carboxyl terminal 17 amino acids with 26 alternative amino acids. This carboxyl terminal variant of EFEMP2 has been predicted to interact with PITX2 in yeast two-hybrid analyses. Furthermore, variants in PITX2 have been associated with dental agenesis, including oligodontia. We hypothesize that heterozygous variants in EFEMP2 represent a new syndrome characterized by arteriopathy and dental agenesis.

Abstract 11906: Targeting Metabolic Alterations in Smooth Muscle Cells Associated With an Acta2 Pathogenic Variant Prevents Moyamoya-Like Cerebrovascular Disease

Pathogenic variants disrupting arginine 179 ( R179 ) in ACTA2 (encodes smooth muscle α-actin) predispose to moyamoya ( MMD )-like cerebrovascular disease, characterized by occlusion of the distal internal carotid arteries by cells that stain positive for smooth muscle cell ( SMC ) markers. SMCs explanted from mice with a SMC-specific knock-in of the Acta2 R179C mutation ( Acta2 SMC-R179C/+ [PMID: 35878552]) fail to fully differentiate, maintain stem cell marker expression, and proliferate and migrate faster than wild-type ( WT ) SMCs. Consistent with a stem cell-like phenotype, Seahorse assays and metabolomics analyses found that Acta2 SMC-R179C/+ SMCs have increased glycolytic flux and decreased oxidative respiration ( OXPHOS ) associated with reduced mitochondrial DNA ( mtDNA ) and complex I activity when compared to WT SMCs. Exposing Acta2 SMC-R179C/+ SMCs to nicotinamide riboside ( NR ), a NAD+ analogue, decreases glycolysis and increases OXPHOS by enhancing complex I activity, and with this metabolic switch, Acta2 SMC-R179C/+ SMCs increase differentiation and decrease migration. With left carotid artery ligation ( LCAL ), 21% of Acta2 SMC-R179C/+ mice die of strokes within 5 days, and at postop day 21, 100% of the surviving Acta2 SMC-R179C/+ mice have enlarged left carotid arteries occluded with cells positive for SMC marker; compared to only 8% of the WT mice. The Acta2 SMC-R179C/+ mice 21 days post LCAL also have increased leptomeningeal collateral remodeling and Circle of Willis (CoW) narrowing and straightening based on CT imaging with liposomal-iodinated contrast agent. NR treatment reduces deaths with LCAL in the mutant mice (p=0.20), resolves intraluminal occlusive lesion formation (p&lt;0.05), attenuates CoW narrowing and straightening (p&lt;0.05), and prevents aberrant collateral remodeling (p&lt;0.001). These results define the pathogenesis of MMD lesions associated with ACTA2 R179 variants: the mutation disrupts the differentiation of stem cells into SMCs, leading to increased SMC migration and proliferation and MMD-like lesions with LCAL, and identify a potential therapeutic that alters SMC metabolism to drive differentiation and decrease migration, and ultimately attenuate MMD-like cerebrovascular disease in Acta2 SMC-R179C/+ mice.

Recurrent Stroke in Young Adult as a Manifestation of Moyamoya Disease: Case Report

Background: Moyamoya disease is a chronic cerebrovascular disorder characterized by progressive narrowing of the intracranial portions of the distal internal carotid artery, the initial proximal components of the middle cerebral artery, anterior cerebral artery, and posterior cerebral artery. Moyamoya disease can manifest as a stroke in young adult. Methods: This report presents a young female patient with Moyamoya disease in Siloam Hospital Denpasar, Bali, Indonesia, diagnosed using MRI and Digital Subtraction Angiography. Case Report: A 29-year-old woman with recurrent stroke, presented with right-side hemiparesis, urinary incontinence, disinhibition syndrome, hypertension, and a history of left hemiparesis from a previous stroke. The MRI brain showed hyperintensity throughout the sulci (ivy sign) in the bilateral frontoparietal with acute infarct in the left frontomedial region, chronic infarct in right frontomedial, occlusion of bilateral carotid arteries (supraclinoid segment), bilateral MCA and ACA. The cerebral DSA study showed stenosis in the right ICA, stenosis in the M1-M2 junction with poor collateral to ACA territory with a puff of smoke appearance, occlusion in the left ICA (supraclinoid segment), and severe stenosis in M1. The patient had undergone direct bypass in the right MCA and right superficial temporal artery. Unfortunately, the bypass did not succeed because of infection of the bypass site and the patient got oral medication with a single antiplatelet (asetosal) and angiotensin receptor blocker (valsartan). Discussion: Moyamoya disease is a rare chronic cerebrovascular disorder that can manifest as an ischaemic stroke in young adult. This patient had a recurrent ischaemic stroke due to Moyamoya disease. According to a global multicenter stroke database, 90% of Moyamoya disease patients initially presented with an ischemic stroke, 7.5% with a transient ischemic attack, and 2.5% with a hemorrhagic stroke. DSA showed that the intracranial collateral system failed to fulfill the demand for brain circulation when the stroke occurred. The patient had failure to grow collateral after direct bypass surgery from the right superficial temporal artery to MCA and single oral antiplatelet as a secondary prevention for ischaemic stroke. Conclusion: Moyamoya disease is a rare disease that needs further studies for its treatment to halt the progression and prevent secondary complications. Young patients with ischaemic stroke needed to be asses with brain MRI, MRA, and DSA to evaluate the etiology of ischaemic stroke. Keywords: Moyamoya disease, Digital Substraction Angiography,ischaemic stroke

Abstract 098: Symphony of Risk: A Case Report of Carotid Artery Dissection Associated with Violin Playing

Introduction Carotid artery dissection (CAD) is an uncommon and potentially life‐threatening condition that can have a delayed presentation. More commonly associated with blunt cervical trauma, CAD due to repetitive stress to the neck goes under‐recognized, making it challenging to diagnose. Herein, we aim to shed light on a unique instance of CAD after continuous microtrauma, as well as highlight diagnostic challenges associated with CAD. Methods We present a case of a 57‐year‐old man who presented with a one‐week course of unequal pupils, left‐sided headaches, left sided ptosis, and intermittent blurry vision. Exam revealed a callous where he held a violin against his left neck, having endorsed playing for several years with repeated contortion of his head to the left (Figure 1A). Magnetic resonance angiogram (MRA) of the head and neck revealed an acute dissection of the left internal carotid artery (ICA) (Figure 1B). A diagnosis of Horner’s syndrome secondary to acute dissection of the left cervical ICA was made. Consent to share this information was obtained from the patient and witnessed by another physician. Results MRA head and neck showed a 2.5 cm irregularity of the distal left ICA with high signal on fat saturated T1‐weighted images consistent with an acute dissection (Figure 1B). The patient underwent an apraclonidine test and was positive for left sided Horner’s syndrome with reversal of anisocoria after application of drops (Figure 1C). Given no evidence of stroke or thrombus on imaging, he was placed on dual antiplatelet therapy (DAPT) for three months. He was advised not to play violin for a month and to restart cautiously with a pad between his neck and the instrument. Follow‐up imaging showed eventual resolution of the CAD, while physical exam revealed improvement in ptosis and miosis. Conclusion While playing the violin involves repetitive stress on the neck, there is limited research on this specific activity as a cause of carotid artery dissection, making it a rare occurrence. Common clinical manifestations of CAD include neck pain, headache, Horner’s syndrome, tinnitus, stroke, and lower cranial nerve palsies, occurring suddenly or over time. Diagnosing CAD typically involves a combination of thorough history, physical examination, and diagnostic imaging. Ongoing research in the optimal management of CAD focuses on minimizing the risk of stroke, after factoring in variables such as location of dissection and whether it is symptomatic or not.

Cranial nerve VII on gadolinium contrast-enhanced magnetic resonance imaging in the case of Bell’s palsy

Bell’s palsy is a rapid unilateral peripheral paralysis of cranial nerve VII whose etiology is varied, most commonly associated with an acute infectious or inflammatory demyelinating process. Nerve injury can result in edema because of increased permeability of vascular structures, which can sometimes be seen as a locus of enhancement of magnetic resonance imaging (MRI). Bell’s palsy is typically considered a clinical diagnosis and the specificity and sensitivity of imaging have been poorly studied. Herein is describe a case of a 73-year-old male who presented to the emergency department with left-sided facial droop and no other focal neurological abnormalities. With a history of a Janus kinase 2 (JAK2) mutation and the new initial facial drooping, acute cerebrovascular insult was high on the differential. Initial labs and computerized tomography (CT) head were inconclusive, but MRI showed pronounced enhancement of the left distal internal carotid artery (ICA) with contiguous enhancement of the labyrinthine, geniculate, and tympanic segments of the left facial nerve. Diagnosing Bell’s palsy can be a challenge as there are numerous postulated etiologies stemming from trauma, infection, and neoplasm; with infection (particularly viral) postulated to be the most likely source. Though MRI is currently not validated as a tool in expediting Bell’s palsy diagnosis, findings such as the enhancement seen here provide some insight into the benefit of MRI as a diagnostic modality in some cases. This case is unique both for the diagnostic dilemma between stroke and Bell’s palsy and the potential for MRI imaging to help guide clinical decision-making into treatment.