Proximal Internal Carotid Artery Research Articles

Arterial floating mural thrombi are a characteristic imaging pattern in SARS-CoV-2-related ischemic stroke.

Acute ischemic stroke (AIS) is a complication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We aimed to explore neurovascular imaging patterns in patients with SARS-CoV-2-related AIS. We retrospectively analyzed clinical and radiological data of patients hospitalized with AIS and a positive PCR test for SARS-CoV-2 prior to AIS onset. The control group comprised of AIS patients from a pre-COVID-19 pandemic period matched for gender and age. Thirty-five SARS-CoV-2-related stroke patients, and 35 controls were included. Fifty-seven percent of SARS-CoV-2 patients had either mild or asymptomatic disease. A distinctive imaging pattern of floating arterial mural thrombus was detected in 5 patients of the SARS-CoV-2 group. In 4 patients thrombus was attached to a stenotic atherosclerotic plaque in the proximal internal carotid artery. In the 5th patient a cardiac CTA showed multiple floating thrombi in the descending aorta. In the control group, floating thrombus was only detected in one patient. Treatment with dual antiplatelet therapy was associated with thrombus dissolution and good clinical outcome. Patients with floating thrombi had a longer time from SARS-CoV-2 diagnosis to stroke onset (mean 7.4 versus 3.4 days). Floating arterial mural thrombi attached to atherosclerotic plaques are unique characteristic source of AIS in SARS-CoV-2 patients. They may lead to ischemic stroke in patients with mild or asymptomatic infection up to 1-2 weeks from SARS-CoV-2 diagnosis. Patients with embolic AIS and SARS-CoV-2 diagnosis should perform high resolution cranio-cervical vascular imaging to evaluate floating thrombi as a potential embolic source.

Anterior circulation location-specific results for stent-assisted coiling – carotid versus distal aneurysms: 1-year outcomes from the Neuroform Atlas Stent Pivotal Trial

BackgroundThe Neuroform Atlas Stent System is an established treatment modality for unruptured anterior and posterior circulation intracranial aneurysms. Location-specific results are needed to guide treatment decision-making. However, it is unclear...

Non-contrast-enhanced MR-angiography of Extracranial Arteries in Acute Ischemic Stroke at 1.5 Tesla Using Relaxation-Enhanced Angiography Without Contrast and Triggering (REACT).

To evaluate anovel flow-independent sequence (Relaxation-Enhanced Angiography without Contrast and Triggering (REACT)) for imaging of the extracranial arteries in acute ischemic stroke (AIS) at 1.5 T. This retrospective single-center study included 47AIS patients who received REACT (scan time: 3:01 min) and contrast-enhanced MRA (CE-MRA) of the extracranial arteries at 1.5 T in clinical routine. Two radiologists assessed scans for proximal internal carotid artery (ICA) stenosis, stated their diagnostic confidence and rated the image quality of cervical arteries, impact of artifacts and image noise. Apparent signal- and contrast-to-noise ratios (aSNR/aCNR) were measured for the common carotid artery and ICA. REACT achieved asensitivity of 95.0% and aspecificity of 97.3% for ICA stenoses in high agreement with CE-MRA (κ = 0.83) with equal diagnostic confidence (p = 0.22). Image quality was rated higher for CE-MRA at the aortic arch (p = 0.002) and vertebral arteries (p < 0.001), whereas REACT provided superior results for the extracranial ICA (p = 0.008). Both sequences were only slightly affected by artifacts (p = 0.60), while image noise was more pronounced in CE-MRA (p < 0.001) in line with higher aSNR (p < 0.001) and aCNR (p < 0.001) values in REACT for all vessels. Given its good diagnostic performance while yielding comparable image quality and scan time to CE-MRA, REACT may be suitable for the imaging of the extracranial arteries in acute ischemic stroke at 1.5 T.

Bow Hunter Phenomenon From Advanced Cerebrovascular Disease Treated With Subclavian Artery Stenting and Carotid Endarterectomy.

Bow Hunter syndrome (BHS) is a rare disorder characterized by mechanical occlusion of the vertebral artery (VA) during neck rotation, resulting in symptomatic, transient, and positional vertebrobasilar insufficiency. We describe a case of a 76-year-old female who presented with dizziness and right ear tinnitus triggered by right head rotation. Her symptoms would immediately resolve upon returning her head to the neutral position. CT angiogram showed 80% stenosis of the left subclavian artery origin, 50%-70% stenosis of the proximal right internal carotid artery (ICA), and near occlusive stenoses of the origins of the bilateral VAs. After failing conservative management, the patient was treated with left subclavian artery stenting, followed by a right carotid endarterectomy (CEA) 6weeks later. Follow-up at 1month showed resolution of paroxysmal symptoms and no neurological sequelae. To our knowledge, there have not yet been reported cases of patients with concurrent BHS, subclavian artery stenosis, and carotid artery stenosis. We suggest that global revascularization via subclavian artery stenting and CEA may be considered as treatment for patients with BHS complicated by other cerebrovascular disease secondary to stenoses of the ICA and subclavian artery. This approach obviates the need for more complex surgery or endovascular intervention of the VA.

Geometric changes and clinical risk factors from aortic arch to proximal internal carotid artery between normal subjects and moderate right carotid plaques

The anatomical features spanning from the aortic arch to the proximal carotid artery and the associated cardiovascular risks might significantly influence the development of right carotid plaque. Our research aimed to compare these anatomical and risk factors between individuals with no carotid plaque and those with moderate right-side carotid plaque within a Korean cohort. We conducted a retrospective, cross-sectional analysis involving 413 participants, categorized into a normal group (n = 339) and a right moderate carotid plaque group (defined as > 50% stenosis based on NASCET criteria) (n = 74). We collected data on cardiovascular risk factors and conducted laboratory tests. A 3D model of the carotid artery was constructed using cranio-cervical computed tomography angiography (CTA) data through semi-automated software. Measurements taken on this 3D model included the common carotid artery (CCA), internal carotid artery (ICA), external carotid artery (ECA), and carotid artery bifurcation (CAB) in terms of maximal vascular diameter, sectional area, angles of carotid bifurcation and ICA, and carotid tortuosity. When compared with the normal group, individuals in the right moderate carotid plaque group exhibited smaller angles at the carotid bifurcation, larger CCA diameter and sectional area (p < 0.01), advanced age, and a higher incidence of hypertension, diabetes, and stroke history (p < 0.05), along with reduced glomerular filtration rate (GFR) (p < 0.001). Multivariate analysis revealed that the sectional area of the bifurcation, calcification of the aortic bulb, and GFR were independently associated with the presence of right moderate carotid plaque (p < 0.01). Statistical analyses disclosed significant differences in both clinical risk factors and geometric changes in the region extending from the aortic arch to the proximal carotid artery among subjects with right moderate carotid plaque when compared to those without.

Prevalence and clinical implications of calcification in internal carotid artery stenosis: a retrospective study

BackgroundCalcification is common in advanced atheromatous plaque, but its clinical significance remains unclear. This study aimed to assess the prevalence of plaque calcification in the moderate-to-severe internal carotid artery stenosis and investigate its relationship with ipsilateral ischemia.MethodsThe retrospective study included 178 patients detected with proximal internal carotid artery (pICA) stenosis of ≥ 50% on multidetector computed tomography at Zhejiang Hospital from January 2019 to March 2023. Association between plaque calcification characteristics (calcification thickness, position, type, circumferential extent, calcium volume and calcium score) and ipsilateral cerebrovascular events was analyzed.ResultsThe 178 patients (mean age 71.24 ± 10.02 years, 79.78% males) had 224 stenosed pICAs overall. Plaque calcification was noted in 200/224 (89.29%) arteries. Calcification rates were higher in older age-groups. Calcification volume (r = 0.219, p < 0.001) and calcification score (r = 0.230, p < 0.001) were correlated with age. Ipsilateral ischemic events were significantly more common in the noncalcification group than in the calcification group (χ2 = 4.160, p = 0.041). The most common calcification type was positive rim sign calcification (87/200, 43.50%), followed by bulky calcification (66/200, 33.00%); both were significantly associated with ischemic events (χ2 = 10.448, p = 0.001 and χ2 = 4.552, p = 0.033, respectively). Calcification position, thickness, and circumferential extent, and calcification volume and score, were not associated with ischemic events. In multivariate analysis, positive rim signs (OR = 2.795, 95%CI 1.182–6.608, p = 0.019) was an independent predictor of ischemic events.ConclusionsPlaque calcification in proximal internal carotid artery is common, and prevalence increases with age. Calcification characteristics could be predictive of ipsilateral ischemic events. The positive rim sign within plaque is a high-risk factor for a future ischemic event.

Carotid Artery Dissection Caused by an Elongated Styloid Process: A Case Report

Eagle’s syndrome is caused by an elongated styloid process or calcified stylohyoid ligament that interferes with adjacent structures. Herein, we present the case of a 26-year-old man who presented to the emergency department due to sudden onset pain in the right occipital area, dysarthria, left hemiparesis, and left arm paresthesia. Computed tomography (CT) angiography revealed an intimal flap and thrombus in the proximal right internal carotid artery (ICA), indicative of carotid artery dissection, as well as direct contact between the styloid process and ICA on both sides. The patient underwent anticoagulation with intravenous heparin for 7 days, followed by 75 mg of clopidogrel per day. Following treatment, the patient gradually improved and was discharged with slight paresthesia in the left arm two weeks after symptom onset. Carotid artery dissection is a rare manifestation of Eagle’s syndrome caused by an elongated styloid process.

COmbination of Targeted temperature management and Thrombectomy after acute Ischemic Stroke (COTTIS): a pilot study

BackgroundTo evaluate the feasibility and safety of a fast initiation of cooling to a target temperature of 35°C by means of transnasal cooling in patients with anterior circulation large vessel...

Isolated internal carotid artery dissection after a motorcycle accident: A case report

Extra cranial carotid artery dissection is one of the most important complications associated with blunt head and neck trauma. It is a major cause of ischemic stroke in young adults. We report a case of internal carotid artery dissection which caused transient hemiparesis, horizontal gaze to right and anisocoria in a 19-year-old male motorcyclist involved in a collision. Unenhanced brain computed tomography scan showed well defined infarction in the right frontotemporoparietal area. Digital subtraction angiography showed complete occlusion of the proximal cervical right internal carotid artery. Moreover, intimal dissection was observed in distal cervical left internal carotid artery which did not limit blood flow to the brain. A stent was placed at the site of dissection in the left internal carotid artery. Intravenous heparin was commenced to avoid further thrombosis. He was discharged home 40 days after the accident with oral anticoagulation. Extra cranial carotid artery dissection is a rare condition which may happen after a non-significant neck trauma. Accordingly, the diagnosis of a cervical vascular dissection requires strong clinical suspicion

Treatment of Symptomatic Carotid Webs: A Single-Center Review

IntroductionCarotid webs are abnormal thin shelf-like or flap-like tissue in the carotid bulb (proximal internal carotid artery). Rarely are carotid webs detected prior to symptoms since routine carotid artery surveillance is not performed in younger individuals without traditional risk factors for carotid disease. The cause and natural history remain unknown. In general, they are not common, but should be considered in the differential diagnosis of a patient who presents with ischemic neurologic symptoms. The web can create a flow disturbance, potentiating local thrombus formation, which can embolize producing resulting in cerebral ischemia. Current treatment is to reduce thrombus formation (antithrombotics and/or anticoagulation) or to alter the flow disturbance caused by the web (surgical removal or stent). MethodsWe retrospectively identified all patients presenting with acute ischemic stroke to our Comprehensive Stroke Center that were diagnosed with carotid web from January 2020 to December 2023. Patient demographics, presentation, hospital course including treatment and complications were collected and reported. ResultsFifteen patients presented with carotid web and stroke from 2020-2023 and 13 underwent carotid artery stenting or endarterectomy with no periprocedural complications. Most (40%) carotid webs were not primarily identified by the initial radiology interpretation. DiscussionWe discuss our experience of carotid web and its management as well as review of the current literature.

X-ray endovascular surgery for in-hospital acute ischemic stroke

The OBJECTIVE was to determine the efficacy of endovascular surgery for in-hospital acute ischemic stroke (AIS) and to identify predictors of unfavorable AIS outcome.METHODS AND MATERIALS. We performed 42 endovascular thrombectomies for in-hospital AIS in patients treated in the hospital for another pathology. Neurological defiCIT was determined by NIHSS scale, thrombectomy efficacy was evaluated by the degree of cerebral revascularization by mTICI scale, functional outcome was determined by Rankin scale (mRS). Multivariate analysis with evaluation of clinical and laboratory, neuroimaging data, and analysis of surgical technique was performed to identify factors contributing to adverse stroke outcome.RESULTS. The mean age of patients was 73.8±11.8 years old. Neurological defiCIT before surgery was 12.8±6.7 points by to NIHSS. Thrombolytic therapy was used in one third of cases, thrombectomy in 92.9 %, and carotid artery stent ing in 2 cases. Successful revascularization (mTICI2b-3) was achieved in 83.3 % of cases. The significant reduction in neurological defiCIT after surgery was achieved to NIHSS 6.0±5.9 points, mRS 2.7±2.1. The mortality rate amounted to 16.7 % of cases. Poor functional outcome (mRS3-5) was significantly associated with: female gender, older age, presence of cardiovascular pathology, recurrent stroke, postoperative tachycardia, low renal tubular filtration rate, hypocoagulation, low cardiac ejection fraction, low aortic valve opening amplitude, high pulmonary hypertension, large left atrial volume, initial severe neurological defiCIT, poor collaterals in the area of cerebral ischemia, proximal internal carotid artery occlusion, hemorrhagic saturation, increased operation time, low degree of revascularization (mTICI0-2a).CONCLUSION. Endovascular surgery has demonstrated its safety and high efficacy in the treatment of in-hospital AIS in surgical hospitalized patients. Endovascular thrombectomies allow to significantly reduce neurological defiCIT and decrease mortality in the severe category of patients with cardioembolic AIS. clinical, laboratory, hemodynamic and neuroimaging factors influencing on poor functional outcome of in-hospital AIS have been determined.

Evaluating the association between vascular remodeling and plaque calcification patterns of the carotid artery and its effects on ischemic symptoms using CT angiography.

Arterial remodeling is a compensatory mechanism of the vessel wall in response to atherosclerotic plaque growth. However, the clinical significance of vascular remodeling of carotid lesions remains unclear. Through this study, we aimed to evaluate the association between vascular remodeling and ischemic symptoms in patients with an internal carotid artery (ICA) stenosis degree ≥50%, considering the differences in plaque calcification patterns. This retrospective cross-sectional study included adult patients with moderate-to-severe proximal ICA stenosis associated with atherosclerotic plaques admitted to the Zhejiang Hospital between September 2018 and March 2023. Parameters such as lumen diameter, plaque calcification types, calcium scores, and calcification thickness were assessed using non-contrast and contrast-enhanced computed tomography angiography (CTA). The remodeling ratio (RR) was calculated by dividing the maximum distance of the proximal ICA between the inner border of the arterial lumen at the plaque site and the outer borders of the plaque by the luminal diameter. Atherosclerosis risk factors and medications were recorded. The Mann-Whitney U test or chi-square test was used to compare the differences between groups. Correlations were measured using Pearson's correlation coefficient. Predictors of ischemic symptoms were assessed using multivariable logistic regression analysis, with results expressed as odds ratio (ORs) with 95% confidence intervals (CIs). A P value less than 0.05 (two-sided) was considered to indicate statistical significance The differences in RR among plaque calcification types and the association between vascular remodeling and clinical symptoms were analyzed. A total of 242 ICAs in 196 patients were included in this study, and 84 were symptomatic and 158 were asymptomatic. The RR in symptomatic ICA [median, 1.31 (interquartile range, 1.17-1.68)] was significantly greater than that in asymptomatic group [median, 1.20 (interquartile range, 1.05-1.45)], P=0.006). Significant differences in RR existed among plaque calcification types, among which type 5 and 6 plaques had the highest RR. About 71.5% (173/242) of all ICAs showed positive remodeling. Significant correlations were observed between RR and ischemic symptoms and between positive remodeling and calcification thickness (P<0.05 for all variables). On multivariable logistic regression analysis, calcification thickness remained significantly associated with positive remodeling of carotid arteries (OR 2.30; 95% CI: 1.06-5.01; P=0.036). Arterial remodeling exists in the ICA. A significant association between arterial positive remodeling and plaque calcification thickness was established. RR helps predict ischemic symptoms. The results of our study suggest that arterial remodeling serves as a novel measure to help ascertain the risk stratification of ischemic events in carotid atherosclerotic disease.

Diagnostic Performance of Carotid Ring Sign on CT-Angiography in Internal Carotid True Occlusion.

To differentiate between pseudo occlusion (PO) and true occlusion (TO) of internal carotid artery (ICA) is important in thrombectomy treatment planning for patients with acute ischemic stroke. Although delayed contrast filling has been differentiated carotid PO from TO, its application has been limited by the implementations of multiphasic computed tomography angiography. In this study, we hypothesized that carotid ring sign, which is readily acquired from single-phasic CTA, can sufficiently differentiate carotid TO from PO. One thousand four hundred and twenty patients with anterior circulation stroke receiving endovascular therapy were consecutively recruited through a hospital- and web-based registry. Two hundred patients with nonvisualization of the proximal ICA were included in the analysis after a retrospective screening. Diagnosis of PO or TO of the cervical segment of ICA was made based on digital subtraction angiography. Diagnostic performances of carotid ring sign on arterial-phasic CTA and delayed contrast filling on multiphasic computed tomography angiography were evaluated and compared. One-hundred twelve patients had ICA PO and 88 had TO. Carotid ring sign was more common in patients with TO (70.5% versus 6.3%; P<0.001), whereas delayed contrast filling was more common in PO (94.9% versus 7.7%; P<0.001). The sensitivity and specificity of carotid ring sign in diagnosing carotid TO were 0.70 and 0.94, respectively, whereas sensitivity and specificity of delayed contrast filling was 0.95 and 0.92 in judging carotid PO. Carotid ring sign is a potent imaging marker in diagnosing ICA TO. Carotid ring sign could be complementary to delayed contrast filling sign in differentiating TO from PO, in particular in centers with only single-phasic CTA.

Focal finger palsy and wrist pain due to cortical infarction: a case report

Abstract Background Hand knob infarction induced focal weakness of contralateral hand or distal arm, only accounts for less than 1% of all ischemic strokes. To date, there is no case with pain during sleep as the onset symptoms being reported. The atypical symptoms of hand knob infarction might increase the risk of delaying treatment especially in the hyperacute phase of stroke. Case presentation A 70-year-old man awoke from sleep due to sudden pain of his right medial wrist and presented to the emergency department with difficulty extending his right index and middle fingers within the time window of intravenous thrombolysis. But the intravenous thrombolysis was not given based on the NIHSS score (0) and atypical symptoms. MRI showed multiple DWI hyperintense lesions, including partial left hand knob area and left posterior central gyrus. CTA showed a severe focal stenosis of proximal left internal carotid artery. Conclusions The hand knob infarction might onset with unusual pain and should be carefully inspected in patients combined with acute onset of focal hand paresis.

Spontaneous development and involution of a de novo pseudoaneurysm at the superficial temporal artery-middle cerebral artery bypass anastomotic site in a patient with moyamoya disease: illustrative case.

De novo pseudoaneurysm formation is a rare complication of extracranial-intracranial bypass surgery. The authors report the case of a 28-year-old male who presented with new-onset right temporal and occipital ischemia who was found to have bilateral proximal internal carotid artery occlusion with collateral vasculature formation consistent with moyamoya disease. The patient underwent bilateral superficial temporal artery-middle cerebral artery bypasses. A de novo pseudoaneurysm was found at the left-sided bypass distal anastomotic site recipient vessel 1 month after the surgery. The pseudoaneurysm demonstrated a progressive reduction in size and eventual complete involution at 6 months after surgery. Limited literature reports extracranial-intracranial bypass-associated aneurysms treated primarily with either clipping or resection and reanastomosis. The authors demonstrate, for the first time, a progressively benign natural history course of an extracranial-intracranial bypass distal anastomotic site pseudoaneurysm.

CT angiographic patterns predict carotid pseudo-occlusion in acute ischemic stroke.

Identifying carotid pseudo-occlusion (PO) from true occlusion (TO) has implications in determining the candidacy and feasibility of successful endovascular thrombectomy (EVT) in acute ischemic stroke (AIS). We reviewed the computed tomography angiographic (CTA) patterns differentiating a PO from a TO and analyzed the rate of successful recanalization after EVT. Patients with AIS and proximal internal carotid artery (ICA) occlusion who underwent EVT from 2014 to 2021 were identified. The patterns of carotid occlusion in CTA were classified into beak, dome, and flat patterns and correlated with microcatheter digital subtraction angiography (DSA) as PO and TO. The rates of successful recanalization in PO and TO were analyzed. Of the 24 patients, 16 (66%) had ICA PO and eight (33%) had TO in DSA. A beak pattern of the proximal ICA on CTA was significantly higher among the PO group patients (87.5% vs. 25%, P = 0.005), and a flat pattern was significantly higher among the TO group patients (50% vs. 12%, P = 0.005). A gradual contrast decline of the proximal ICA on CTA images was seen only in PO group patients (85.7% vs. 0%, P = 0.05). There was no significant difference in the rate of successful recanalization between PO and TO group patients (81.25% vs. 62.5%, P = 0.362). Beak pattern and gradual contrast decline at the proximal ICA occlusion site in CTA are suggestive of carotid PO. Identification of PO in CTA can help in planning intervention strategies and prognostication.

The Usefulness of Extradural Anterior Clinoidectomy for Lower-Lying Posterior Communicating Artery Aneurysms : A Cadaveric Study.

To confirm the usefulness of the extradural anterior clinoidectomy during the clipping of a lower riding posterior communicating artery (PCoA) aneurysm through cadaver dissection. Anatomic measurements of 12 adult cadaveric heads (24 sides total) were performed to compare the microsurgical exposure of the PCoA and internal carotid artery (ICA) before and after clinoidectomy. A standard pterional craniotomy and transsylvian approach were performed in all cadavers. The distance from the ICA bifurcation to the origin of PCoA (D1), pre-anterior clinoidectomy distance from the ICA bifurcation to tentorium (D2), post-anterior clinoidectomy distance from the ICA bifurcation to tentorium (D3), pre-anterior clinoidectomy distance from the tentorium to the origin of PCoA (D4) and post-anterior clinoidectomy distance from the tentorium to the origin of PCoA (D5) and the distance of the ICA obtained after anterior clinoidectomy (D6) were measured. We measured the precise thickness of the blade for the Yasargil clip with a digital precision ruler to confirm the usefulness of the extradural anterior clinoidectomy. Twenty-four sites were dissected from 12 cadavers. The age of the cadavers was 79.83±6.25 years. The number of males was the same as the females. The space from the proximal origin of the PCoA to the preclinoid-tentorium (D4) was 1.45±1.08 mm (max, 4.01; min, 0.56). After the clinoidectomy, the space from the proximal origin of the PCoA to the postclinoid-tentorium (D5) was 3.612±1.15 mm (max, 6.14; min, 1.83). The length (D6) of the exposed proximal ICA after the extradural clinoididectomy was 2.17±1.04 mm on the lateral side and 2.16±0.89 mm on the medial side. The thickness of the Yasargil clip blade used during the clipping surgery was 1.35 mm measured with a digital precision ruler. The proximal length obtained by performing an external anterior clinoidectomy is about 2 mm, sufficient for proximal control during PCoA aneurysm surgery, considering the thickness of the aneurysm clips. In a subarachnoid hemorrhage, performing an extradural anterior clinoidectomy could prevent a devastating situation during PCoA aneurysm clipping.

Abstract 115: Carotid Intraluminal Thrombus Obscuring Underlying Carotid Web: Case Report

Introduction Carotid webs (CaW) have been increasingly recognized as a unique cause of recurrent ischemic strokes.1 They are defined as thin, intraluminal, shelf‐like lesions along the posterior aspect of the carotid bulb.1,2 Despite more awareness and ongoing studies into their pathogenesis, diagnosis, and management,3 they are still overlooked in clinical practice as a primary carotid ischemic etiology. Our case describes a patient with right extracranial internal carotid artery (ICA) thrombus secondary to later‐diagnosed CaW on close follow‐up imaging. Methods We report a 55‐year‐old African American man with history of hypertension, type 2 diabetes mellitus and hyperlipidemia presented with acute onset slurred speech and left facial droop (FP). His last known well was 24 hours prior to presentation, and NIHSS upon arrival was 3 (FP 2, dysarthria 1). CT angiography (CTA) of the head and neck demonstrated a nearly occlusive thrombus of the distal right M2 segment MCA as well as non‐hemodynamic stenosis of the proximal right ICA with possible underlying sidewall filling defect‐appearing lesion concerning for a posterior wall thrombus without underlying atherosclerosis at the bulb or otherwise. The patient was admitted to the neurovascular intensive care unit and started on aspirin and high‐risk heparin drip. His MRI Brain demonstrated multiple acute/subacute right MCA territory strokes, predominately in the right posterior insula, right frontal lobe, and right posterior corona radiata. His stroke workup was otherwise unrevealing, and he was discharged on apixaban 5mg BID. Results Close surveillance follow‐up imaging with CTA head and neck was planned and obtained one month later, which demonstrated resolution of the filling defect that was obscuring the currently visualized underlying right CaW pocket (Figure‐1). The prevalence of CaWs has been reported to be between 1.2% and 2.5% of patients with acute ischemic stroke. CaWs are most frequently seen in younger, female patients, and patients with these lesions are at increased risk of recurrent stroke.4,5 Determining the optimal management for these lesions remains essential, but the available data thus far have not been conclusive. Most patients are treated with antiplatelet therapy, but some elect to treat with anticoagulation due to the focal hemostasis caused by CaWs.6 However, multiple studies have suggested that medical management alone is likely not sufficient in reducing the recurrent stroke risk caused by CaWs.5,7 Neuro‐interventional procedures including carotid artery stenting have been reported as secondary prevention strategies in patients with recurrent strokes.5,7,8 Although data regarding the rate of recurrence of strokes secondary to these lesions remains unclear, the current data does suggest benefit and safety in pursuing carotid stenting to prevent recurrent strokes.5‐8 Conclusion In young patients with proximal ICA thrombosis without underlying atherosclerosis or other conventional stroke risk factors, CaW should be considered among other differentials including hypercoagulable status. Following acute medical management, short‐term surveillance imaging is essential to confirm or rule out the diagnosis. In our case, the patient’s proximal ICA thrombus resolved after short course of anticoagulation and was determined to be secondary to the obscured underlying CaW.

Abstract 103: Acute Onset Rhythmic Tremor In Acute Frontal Cortical Infarction: A Case Report

Introduction Acute ischemic stroke varies in presentation, and it is crucial to quickly identify patients presenting with stroke for timely intervention. Secondary movement disorders occurring after a delayed period following ischemic stroke have been well‐documented, though rare. Holmes tremor specifically has been described as a delayed result of ischemic infarction involving subcortical structures such as mollaret triangle, thalamus, and basal ganglia. However, it is novel for frontal cortical infarcts to present with acute‐onset contralateral limb tremor, especially as an isolated symptom. Our case suggests a “secondary insult” involving the frontal cortex can disinhibit the motor pathway that leads to tremor in preexisting midbrain and thalamic lesions. We present a 67‐year‐old male with acute onset, constant, rhythmic tremor in the setting of acute ischemic frontal cortical infarction. Methods n/a, case report Results A 67‐year‐old male with medical history of pineal gland cyst status‐post shunt placement and hypertension who presented for evaluation of acute onset right upper extremity rhythmic tremor that started 24 hours prior. He did not have any associated weakness, numbness, vision changes, nausea, or vomiting. He had never had this tremor before. Neurologic examination was significant for a 4.0 Hz rhythmic resting tremor that was present throughout exam and was non‐distractible. This tremor remained consistent even with kinetic movements and postures. Electroencephalogram (EEG) was performed STAT during this tremor and was not based in seizure. Non‐contrast head computerized tomography (CT) was negative for any acute hemorrhage or intracranial pathology. CT angiogram head and neck showed left internal carotid artery (ICA) long segment tapered occlusion from the proximal cervical ICA to the distal petrous segment, likely dissection of undetermined chronicity. Magnetic resonance imaging (MRI) Brain with and without contrast was significant for acute punctate foci involving the precentral cortex of the left frontal lobe consistent with acute ischemic infarction. Encephalomalacia was also present involving the bilateral posterior thalami and left midbrain chronic ischemic infarctions. This suggests the tremor was caused by disinhibition of the motor pathway from the ischemic insult to the frontal cortex, as he had pre‐existing asymptomatic ischemic insult to the typical structures known to cause this tremor. He was outside of the Tenecteplase window and was given a load of Aspirin followed by aspirin 81 mg daily. He was trialed on propranolol for treatment of symptomatic tremor however this was discontinued before discharge as it was ineffective and patient preferred to hold off on other treatments. He is now awaiting outpatient Neurology follow up. Conclusion This case suggests that acute onset Holmes tremor can be the sole presenting sign in acute ischemic frontal cortical infarction. The pre‐existing asymptomatic infarctions in the midbrain and thalamus also support that a “second hit” located in the frontal cortex can disinhibit the motor pathway between the cortex and rubral tract. This is important as Holmes tremor is more commonly known to be from a mechanism of damage to the red nucleus or thalamic structures in a delayed manner, typically at least two weeks after stroke. This knowledge will help identify rare strokes in a timely manner.

Abstract 126: Bilateral Limb Shaking TIA secondary to Severe Bilateral Carotid Stenosis

Introduction A case describing bilateral limb shaking episodes in a patient with severe bilateral carotid disease ‐ a rare manifestation of limb‐shaking TIA. Methods '‐ Results CASE A 71‐year‐old male patient with a past medical history significant for type 2 diabetes mellitus and bilateral carpal tunnel syndrome is being followed for symptomatic management of known axonal sensorimotor diabetic polyneuropathy in the neuromuscular clinic. He reported on one of his follow‐up visits that he had been experiencing an eight‐month history of presyncopal to syncopal events occurring solely in the standing position, not followed by postictal state but amnesia to the syncope itself, and resulting in falls with mild injuries. He was experiencing new‐onset dry eyes and mouth but denied anhidrosis or early satiety, and cardiac event monitoring during one of these events was unremarkable for rhythmic causes. Examination was unchanged from previously and was significant for findings consistent with length‐dependent sensory loss with hyporeflexia/areflexia. The constellation of symptoms was suggestive of autonomic dysfunction, and while this may be seen with diabetic polyneuropathy, workup for alternative autonomic neuropathies (including SSA/SSB antibodies, paraneoplastic antibody panel, serum protein electrophoresis with immunofixation, serum free light chains, transthyretin amyloid) was obtained with plan for follow‐up. A few months later, he presented to the ED with intermittent upper extremity shaking (more pronounced on the right than on the left) preceding the syncopal events, which only occurred in the standing position or during physical activity and resolved with rest. There were no (transient) focal neurological deficits, including monocular vision loss or hemispheric syndrome. CTA of the head/neck was obtained and was notable for severe to critical stenoses of the bilateral internal carotid arteries (see figure 1). Duplex US revealed 80‐99% stenosis of both right and left proximal internal carotid arteries. The constellation of findings was most suggestive of bilateral limb‐shaking TIA secondary to bilateral carotid stenosis. He was started on secondary stroke prevention and referred to vascular surgery for evaluation of revascularization. The patient underwent left carotid endarterectomy briefly afterward and experienced resolution of the events – he later also underwent carotid endarterectomy of the right side and remains asymptomatic. DISCUSSION: Limb‐shaking TIA is a well‐described yet underrecognized manifestation of severe carotid disease reported by C.M. Fisher in 1962. The “limb shaking” episodes are typically unilateral, affecting the arm or leg, and are often mistaken for seizures [1]. Pathogenesis involves hemodynamic impairment related to extracranial/intracranial carotid stenosis or occlusion resulting in stereotypical recurrent contralateral limb shaking episodes precipitated by physical activity [2], [3]. The constellation of “limb shaking” spells precipitated upon standing or physical activity with resolution after activity cessation should raise suspicion for limb‐shaking TIA and warrant vascular imaging. Treatment includes medical secondary stroke prevention and revascularization procedures [4], which can alleviate or even resolve the transient symptoms [2]. Conclusion Limb‐shaking TIA is an important yet underrecognized manifestation of relative cerebral hypoperfusion related to severe cerebrovascular disease. This case describes bilateral limb shaking episodes in a patient with severe bilateral carotid disease ‐ a rare manifestation of limb‐shaking TIA.