Left Internal Carotid Artery Research Articles

Acute loading dose of antiplanets before Stent-assisted repair of cerebral aneurysm associated with reduced ischemic events and good outcomes (P8-5.016)

<h3>Objective:</h3> Objective is to evaluate if loading doses of aspirin and clopidogrel (LDAC) reduces TEE without increased intracranial hemorrhage (IH) and improves outcomes in SARIA. <h3>Background:</h3> There are no universal antiplatelets regimens to prevent Thromboemboembolic event (TEE) in stent-assisted repair of intracranial aneurysms (SARIA). Antiplatelets effects are highest in first 4 hours. <h3>Design/Methods:</h3> Consecutive patients underwent SARIA with LDAC; aspirin 324 mg (4 baby aspirin) and clopidogrel 300 mg in 2 to 4 hours before procedure were enrolled from 2011 to 2022. Outcome was measured using modified Rankin Scale (mRS) score. <h3>Results:</h3> 112 patients with mean age of 53 ± 13 underwent SARIA (7 ruptured and 55 symptomatic). Aneurysms are; Right internal carotid artery (ICA) 27, left ICA 35, middle cerebral artery 25, basilar artery 19 and anterior communicating artery 6. There are no intra-operative ruptures. Small left subarachnoid hemorrhage developed on a right MCA aneurysm on day 3, which resolved spontaneously. Stent thrombosis in one; resolved with intraarterial integrilin with no stroke. Clinical TEE were observed in 2 cases (1.8%); first event was in a 42 years old woman with a giant right ICA giant aneurysm and achieved mRS 1. Second event was visual distortion and diplopia in a 66 years old woman with basilar artery aneurysm and achieved mRS1. Ruptured and symptomatic were repaired and no subarachnoid hemorrhages during follow-up. Immediate complete and near complete obliteration of aneurysm was observed in 72% and subtotal in 28%. There was no mortality or permanent disability in our series. 90 days mRankins 0 and 1 was observed in 98 (92.5%), mRS 2 in 7(6.6%) at baseline and mRS 3 in 2 (1.9%), which sustained in 12 months. <h3>Conclusions:</h3> LDAC in SARIA is associated with reduced TEE without increased IH and good outcome. LDAP may be an option in SARIA to prevent TEE. Further studies are required. <b>Disclosure:</b> Dr. Lodi has nothing to disclose.

Establishment of a reproducible and minimally invasive ischemic stroke model in swine.

The need for advances in the management/treatment options for ischemic stroke patients requires that upcoming preclinical research uses animals with more human-like brain characteristics. The porcine brain is considered appropriate, although the presence of the rete mirabile (RM) prevents direct catheterization of the intracranial arteries to produce focal cerebral ischemia. To develop a reproducible minimally invasive porcine stroke model, a guide catheter and guide wire were introduced through the femoral artery until reaching the left RM. Using the pressure cooker technique, Squid-12 embolization material was deposited to fill, overflow, and occlude the left RM, the left internal carotid artery, and left circle of Willis wing up to the origins of the middle cerebral arteries (MCAs), mimicking the occlusion produced in the filament model in rodents. Longitudinal multimodal cerebral MRI was conducted to assess the brain damage and cerebral blood supply. The technique we describe here occluded up to the origins of the MCAs in 7 of 8 swine, inducing early damage 90 minutes after occlusion that later evolved to a large cerebral infarction and producing no mortality during the intervention. This minimally invasive ischemic stroke model in swine produced reproducible infarcts and shows translational features common to human stroke.

Aggressive Tumor and Challenging Location: A Case Report of Nasopharyngeal Fibroma

Nasopharyngeal angiofibroma refers to a locally aggressive benign vascular tumor composed of vasogenic and myofibroblastic elements, representing between 0.05% and 0.5% of all head and neck tumors. Here, we report a case of a 21-year-old patient with no particular personal or familial pathological history, who presented with recurrent epistaxis and anterior rhinorrhea and headaches for 1 year. Nasofibroscopy revealed a mass filling the entire left nasal cavity, streaked with blood. A face MRI revealed a highly vascularized and lytic nasopharyngeal tumor infiltrating the deep left lateral facial spaces with the beginning of endocranial infiltration, supplied by the homolateral maxillary artery, initially suggestive of a nasopharyngeal fibroma. Preoperative arteriography showed a voluminous vascular blush at the arterial time to the nasopharyngeal projection with branches arising from the left external and internal carotid arteries and multiple arterial shunts (between the left internal and maxillary carotid arteries), thus contradicting embolization. Early diagnosis is important as it is associated with a high risk of morbidity, but advances in imaging and surgical treatment methods have modified the sites associated with high morbidity risk.

Algorithm for evaluating ophthalmic artery pseudo-occlusion during intra-arterial chemotherapy for retinoblastoma.

Intra-arterial chemotherapy infusion for retinoblastoma is typically performed via selective catheterization of the ophthalmic artery. Anastomoses between the external carotid and the ophthalmic arteries have also been utilized when the ophthalmic artery cannot be catheterized directly. However, these are not present in every patient. A 10-month-old boy presented with bilateral retinoblastoma and underwent one round of intra-arterial chemotherapy (IAC) via direct catheterization of the ophthalmic arteries. Combined with adjuvant laser therapy, they experienced symptomatic improvement and tumour regression. However, during subsequent treatment sessions both ophthalmic arteries did not have anterograde flow and attempts to catheterize their origin were unsuccessful. Unfortunately, no targetable anastomoses between the external carotid and ophthalmic arteries were identified for drug delivery. Due to the patient's anatomy, balloon occlusion of the ECA was felt to be unsafe. As a salvage technique, a balloon was inflated in the left internal carotid artery (ICA) distal to the ophthalmic take-off to redirect flow into the ophthalmic. Repeat angiography with the distal ICA occluded showed improved flow into the ipsilateral ophthalmic artery. IAC was then successfully delivered through the left ICA. This case illustrates the importance of utilizing creative endovascular techniques for targeted intra-arterial drug delivery when other conventional measures fail as these patients often have limited, and potentially higher risk, therapeutic alternatives.

Neurofibroma of the internal carotid artery cavernous sympathetic plexus: illustrative case.

Intracranial carotid sympathetic plexus (CSP) nerve sheath tumors have rarely been reported in the literature. This study describes the first reported case of a CSP neurofibroma and the first case of a CSP nerve sheath tumor treated via an endoscopic endonasal approach followed by adjuvant radiosurgery. A 53-year-old man presented with 3 days of headaches and diplopia and was found to have a complete left abducens nerve palsy. Computed tomography (CT) revealed a smoothly dilated left carotid canal, CT angiography revealed a superiorly displaced left internal carotid artery (ICA), and magnetic resonance imaging revealed a T2-hyperintense and avidly enhancing lesion in the left cavernous sinus encasing the ICA. The patient underwent subtotal resection via an endoscopic transsphenoidal transcavernous approach followed by Gamma Knife radiosurgery. Nerve sheath tumors arising from the CSP are extremely rare but need to be considered when assessing unusual cavernous sinus lesions. The clinical presentation is dependent on the anatomical location of the tumor and its relationship to the ICA. The optimal treatment paradigm is unknown.

The Significance of the Intercarotid Distances for Transsphenoidal Pituitary Surgery: A Magnetic Resonance Imaging Study

We performed MRI to analyze the distance between the left and right internal carotid arteries (ICD) around pituitary tumors for transsphenoidal surgery (TSS). Measurements were performed using thin slice T2-weighted MRI, and/or time-of-flight MR angiography imaging for 64 non-functioning pituitary neuroendocrine tumors (NF-pitNETs), 22 growth hormone-producing pitNETs (GH producing pitNETs), and 46 normal controls. We measured the ICD at 3 anatomic levels: at the distal dural ring (ICD-A); at the most concave point of the C4-C5 bend (ICD-B); and at the most convex point of the C4 bend (ICD-C). Additionally, we measured the sagittal distance between the tuberculum selle and the junction of the sellar floor and clivus on the mid sagittal MRI (TS-C). We found that ICD-B was the longest and that ICD-A was the shortest among the three distance parameters in all groups (P<0.001). The comparison of the groups revealed that the NF-pitNET group had longer distances than the normal control group at all ICDs (P<0.001). The GH producing pitNET group had longer distance than the normal control group at ICD-B (P<0.001). Tumor volume was correlated with ICD-A and ICD-B in the NF-pitNET, and was correlated with ICD-C in the GH producing pitNET group. Among the distance parameters, ICD-B is the longest, and was approximately twice the width of the TS-C. The shape of the sella is an ellipse that is widest in the lateral dimension in TSS. A horizontal based dural incision may be more rational than a conventional X-shaped dural incision.

Peculiarities of Brain Hemodynamics and Heart Rhythm Variability in Young Men in Performing Modeled Cognitive Activity with Unequal Effectiveness

INTRODUCTION: Purposeful cognitive brain activity of an individual depends on blood supply to the cells of the cerebral cortex (CC), and on their autonomic innervation.&#x0D; AIM: To identify peculiarities of the brain hemodynamics and heart rhythm variability (HRV) in young men performing cognitive tasks with unequal effectiveness.&#x0D; MATERIALS AND METHODS: The study involved 42 practically healthy young men (mean age 19.40 1.20 years). The brain hemodynamics was studied using Reo-Spektr-2 rheograph (Neurosoft, Russia) in the initial condition of relative rest and in modeled purposeful cognitive activity. Synchronously with record of rheoencephalogram, rhythmocardiogram was recorded using Varicard 2.51 hardware-software complex (Ramena, Russia). Purposeful cognitive activity was modeled in Physiotest program for psychophysiological studies with use of behavioral model: Schulte Table Test in a two-color SchulteGorbov modification. In statistical data processing, cluster and correlation analyses were used.&#x0D; RESULTS: Based on the effectiveness of SchulteGorbov Table Test, the sample of subjects was divided to two clusters (n = 28 and n = 14). Comparison of clusters in the initial condition of relative physiological rest and during cognitive activity revealed differences in rheoencephalographic parameters, which reflects unequal hemodynamic supply of the brain in representatives of the given clusters. Differences in HRV parameter were found reflecting the different levels of tension of adaptation mechanisms in the initial condition and in cognitive activity. The results of the correlation analysis demonstrated different dependence between the parameters of rheoencephalogram, HRV and parameters of the effectiveness of Schulte-Gorbov Test in representatives of different clusters.&#x0D; CONCLUSIONS: (1) High-effective subjects are characterized by shorter time of propagation of the rheographic wave and longer time of slow blood filling of the right vertebral artery basin, and by higher rheographic index asymmetry coefficient in the basin of the left internal carotid artery and of vertebral arteries of both hemispheres during cognitive activity compared to low-effective subjects. (2) Physiological support of purposeful activity of an individual with unequal effectiveness of salvation of cognitive tasks is characterized not only by different levels of brain hemodynamics and activity of autonomic regulatory mechanisms, but also by certain type of correlation relationships of these parameters with parameters of purposeful behavior, in particular, with the total time of fulfilment of the task and efficiency coefficient.

Acute Tongue Swelling as a Still Unexpected Manifestation of Internal Carotid Artery Dissection: A Case Report

The diagnosis of internal carotid artery dissection (ICAD) at the stage of local signs is essential in the prevention of the life-treating cerebral complication; however, making this diagnosis has significant difficulties. We present the case of a 36-year-old female with left ICAD with asymmetric left-sided tongue swelling as an unusual and still unexpected symptom. The patient's complaints at admission were left-sided numbness of the tongue and swallowing difficulties but its movements were intact. Despite the provided treatment for suspected angioedema, no improvement was noted. Additional examination revealed left-sided tongue weakness, ipsilateral soft palate palsy, paralysis and reduced tension of the left vocal fold, and left-sided Horner's syndrome. Another suspected diagnosis was a dysfunction of the IX, X, and XII cranial nerves. A head MRI revealed an intramural hematoma of the left internal carotid artery. The radiologists suggested ICAD. The angio-MRI of the head arteries confirmed this diagnosis. The patient received dual antiplatelet therapy. The neuro-logopaedic therapy was also implemented. Currently, the patient's symptoms are gradually improving with significantly better results on follow-up neuroimaging. Among the possible local symptoms of ICAD, proper attention should be paid to asymmetric swelling of the tongue as an atypical manifestation of damage to the hypoglossal nerve.

Eagle Syndrome with Internal Carotid Artery Compression causing Recurred Syncope: A Case Report.

We herein report a 54-year-old man with eagle syndrome who presented with repeated episodes of syncope, especially after moving his head to a downward position. Computed tomography with contrast revealed a bilateral elongated styloid process. The left internal carotid artery was obviously compressed by the left elongated styloid processes. A transcranial Doppler examination detected a significantly decreased blood flow velocity in the left middle cerebral artery when the patient slightly lowered his head position. After surgery, the positional cerebral blood flow alteration disappeared. No further similar syncope episodes have been reported to date.

Percutaneous Superficial Temporal Artery Access Facilitating Carotid Artery Stenting Performed From Distal Radial Artery.

The purpose of the study is to describe carotid artery stenting (CAS) via distal transradial access (dTRA) facilitated by additional superficial temporal artery (STA) access, in a patient with complex aortic arch vessel anatomy. A 72-year-old woman with a prior history of complex cervical surgery and radiotherapy due to laryngeal malignancy, presented with a symptomatic 90% stenosis of the left internal carotid artery (ICA). Due to high cervical lesion, the patient was rejected from carotid endarterectomy. Angiography demonstrated 90% stenosis of the left ICA and a type III aortic arch. After failure of left common carotid artery (CCA) cannulation with appropriate catheter support via dTRA and transfemoral approaches, CAS was attempted a second time. After percutaneous ultrasound guided access to right dTRA and left STA, a 0.035 inch guidewire introduced to the left CCA from the contralateral dTRA was snared and externalized via left STA to improve wire support for guiding advancement. Thereafter, the left ICA lesion was successfully stented with a 7×30 mm self-expanding stent via right dTRA. All vessels involved were patent at 6-month follow-up. The STA may be a promising adjunctive access site to increase transradial catheter support for CAS or neurointerventional procedures in the anterior circulation. Transradial cerebrovascular interventions have been gaining popularity, however, unstable catheter access to distal cerebrovascular structures limits its widespread use. Guidewire externalization technique via additional STA access may improve transradial catheter stabilty and increase procedural success with possibly low access stie complication rate.

180-degre carotid bifurcation with an internal carotid artery aneurysm.

Internal carotid artery (ICA) aneurysm is a rare pathology. In the clinical case we present, the patient had an ICA aneurysm as well as a rare anatomical variant of the carotid bifurcation. We present the case of a 45year old man, who had two episodes of TIA revealed by loss of mind. Computed tomography revealed the fusiform aneurysm of a left ICA in the first segment with maximal diameter of 16mm. There were no thrombotic mass in the dilated area. The carotid bifurcation angle was 180 degree. Although the aneurysm did not contain a thrombus mass, it was considered the source of the TIA because of turbulent blood flow. Distal and proximal ligation was performed. A 5-cm long graft from the great saphenous vein was used for ICA revascularization from common carotid artery. In our case, geometry of carotid bifurcation may have contributed to the ICA aneurysm, although there is no evidence for this correlation.

Successful treatment of vaccine-induced thrombotic thrombocytopenia in a patient with contraindication to standard-of-care early anticoagulation: A case report

Vaccine-induced thrombotic thrombocytopenia (VITT) is a rare yet fatal side effect associated with adenoviral vector vaccines for coronavirus disease of 2019. We report a case of VITT in a previously healthy 43-year-old woman occurring 10 days after receiving the Johnson and Johnson (Ad26.COV2.S) vaccine. She presented with right-sided weakness, aphasia, and left gaze deviation. Computed tomography angiography of the head and neck revealed complete occlusion of the left internal carotid artery, left anterior carotid artery, and left middle cerebral artery with hemorrhagic conversion and midline shift. Pertinent laboratory results revealed acute thrombocytopenia and an elevated d-dimer level. She tested positive for platelet factor 4 (PF-4) antibodies, and a Doppler ultrasound revealed a deep vein thrombosis of the right femoral and popliteal veins. With these findings and the timing of vaccine administration, she had met the full criteria for VITT. While the crucial immediate treatment of VITT is therapeutic anticoagulation, its application for this case was contraindicated due to evolving hemorrhage and the need for an urgent decompressive craniectomy. An inferior vena cava filter was inserted, and intravenous immunoglobulin was administered, resulting in a suboptimal rise in platelet counts. She was then successfully treated with the addition of high-dose steroids and rituximab, eventually displaying therapeutic anticoagulation more than 2 weeks after the diagnosis. Two years after this diagnosis, she had slowly recovered from VITT. Her PF-4 antibodies are negative, and she remains only on prophylactic anticoagulation. This case highlights the importance of early recognition of symptoms to establish the correct diagnosis and the complexities of acute treatment of VITT in patients with contraindications to early therapeutic anticoagulation.

Deep Learning-based Assessment of Internal Carotid Artery Anatomy to Predict Difficult Intracranial Access in Endovascular Recanalization of Acute Ischemic Stroke

BackgroundEndovascular thrombectomy (EVT) duration is an important predictor for neurological outcome. Recently it was shown that an angle of ≤ 90° of the internal carotid artery (ICA) is predictive for longer EVT duration. As manual angle measurement is not trivial and time-consuming, deep learning (DL) could help identifying difficult EVT cases in advance.MethodsWe included 379 CT angiographies (CTA) of patients who underwent EVT between January 2016 and December 2020. Manual segmentation of 121 CTAs was performed for the aortic arch, common carotid artery (CCA) and ICA. These were used to train a nnUNet. The remaining 258 CTAs were segmented using the trained nnUNet with manual verification afterwards. Angles of left and right ICAs were measured resulting in two classes: acute angle ≤ 90° and > 90°. The segmentations together with angle measurements were used to train a convolutional neural network (CNN) determining the ICA angle. The performance was evaluated using Dice scores. The classification was evaluated using AUC and accuracy. Associations of ICA angle and procedural times was explored using median and Whitney‑U test.ResultsMedian EVT duration for cases with ICA angle > 90° was 48 min and with ≤ 90° was 64 min (p = 0.001). Segmentation evaluation showed Dice scores of 0.94 for the aorta and 0.86 for CCA/ICA, respectively. Evaluation of ICA angle determination resulted in an AUC of 0.92 and accuracy of 0.85. ConclusionThe association between ICA angle and EVT duration could be verified and a DL-based method for semi-automatic assessment with the potential for full automation was developed. More anatomical features of interest could be examined in a similar fashion.

A boxer with a pipeline stent in the brain- Should this boxer be allowed to participate in professional boxing fight?

Professional boxing is a popular combat sport which unfortunately carries a high risk of acute traumatic brain injury (TBI). The nature of the sport is such that every punch thrown to the opponent’s head is thrown with the intention of winning by causing a concussive head injury (aka a knockout). Professional boxing is regulated by various State Athletic Commissions in the United States and abroad. Most commissions require an imaging study of the brain (either a computed tomography scan or a magnetic resonance scan) prior to licensure. The primary goal of neuroimaging prior to licensure is to identify and/or exclude coincidental or clinically suspected brain lesions which may pose a risk for rupture, bleeding, or other catastrophic brain injury during a bout/training. These lesions include aneurysms, arteriovenous malformations, cavernous malformations, large venous malformations, Vein of Galan malformations among others. A boxer with history of a left ophthalmic artery aneurysm status post embolization with placement of a pipeline shield in the distal left internal carotid artery (ICA) presented for licensure. Should this boxer be allowed to participate in professional boxing is debated.

Case of Amaurosis Fugax in the Setting of a Persistent Primitive Hypoglossal Artery Requiring Carotid Endarterectomy with Regional Anesthesia.

BACKGROUND A persistent primitive hypoglossal artery (PPHA) is a rare congenital anomaly leading to persistent carotid-basilar anastomosis. This is a report of an 83-year-old man with a PPHA presenting with amaurosis fugax of the left eye requiring carotid endarterectomy under regional anesthesia. CASE REPORT An 83-year-old man presented with 2 weeks of intermittent self-resolving visual disturbances, followed by an episode of left eye amaurosis fugax. The patient had been referred to the hospital for further investigation of symptoms 1 day following the amaurosis fugax event. Carotid Doppler ultrasound demonstrated a greater than 90% stenosis of the left internal carotid artery. Computed tomography carotid and Circle of Willis angiography confirmed a mixed, ulcerated plaque and revealed a persistent left hypoglossal artery originating from the left internal carotid artery and continuing as the basilar artery. On day 3 of admission, left carotid endarterectomy was performed under conscious sedation and regional anesthesia to permit continuous monitoring of neurological status and avoid the need for intraoperative shunting. "Permissive hypertension" by targeting a systolic blood pressure of 190 to 200 mmHg was sought for the duration of clamp time. There was no deterioration of neurological function during clamping of the carotid vessels. The patient recovered well and was discharged 2 days after surgery, with no residual neurology. CONCLUSIONS This report has presented a rare case of PPHA to highlight awareness of this congenital vascular anomaly when undertaking carotid endarterectomy.

A Novel Rat Model of Embolic Cerebral Ischemia Using a Cell-Implantable Radiopaque Hydrogel Microfiber.

The failure of neuroprotective treatment-related clinical trials, including stem cell therapies, may be partially due to a lack of suitable animal models. We have developed a stem cell-implantable radiopaque hydrogel microfiber that can survive for a long time in vivo. The microfiber is made of barium alginate hydrogel containing zirconium dioxide, fabricated in a dual coaxial laminar flow microfluidic device. We aimed to develop a novel focal stroke model using this microfiber. Using male Sprague-Dawley rats (n=14), a catheter (inner diameter, 0.42 mm; outer diameter, 0.55 mm) was navigated from the caudal ventral artery to the left internal carotid artery using digital subtraction angiography. A radiopaque hydrogel microfiber (diameter, 0.4 mm; length, 1 mm) was advanced through the catheter by slow injection of heparinized physiological saline to establish local occlusion. Both 9.4-T magnetic resonance imaging at 3 and 6 h and 2% 2,3,5-triphenyl tetrazolium chloride staining at 24 h after stroke model creation were performed. Neurological deficit score and body temperature were measured. The anterior cerebral artery-middle cerebral artery bifurcation was selectively embolized in all rats. Median operating time was 4 min (interquartile range [IQR], 3-8 min). Mean infarct volume was 388 mm3 (IQR, 354-420 mm3) at 24 h after occlusion. No infarction of the thalamus or hypothalamus was seen. Body temperature did not change significantly over time (P = 0.204). However, neurological deficit scores before and at 3, 6, and 24 h after model creation differed significantly (P < 0.001). We present a novel rat model of focal infarct restricted to the middle cerebral artery territory using a radiopaque hydrogel microfiber positioned under fluoroscopic guidance. By comparing the use of stem cell-containing versus non-containing fibers in this stroke model, it would be possible to determine the efficacy of "pure" cell transplantation in treating stroke.

A case of limb shaking transient ischaemic attack due to internal carotid artery dissection: an unusual presentation of fibromuscular dysplasia

BackgroundFibromuscular dysplasia (FMD) has a high prevalence of associated nontraumatic carotid artery dissection, which could further result in transient ischaemic attack (TIA) or stroke. Limb shaking TIA is an unusual form of TIA that is commonly discribed in elderly patients with atherosclerotic backgrounds, while there are limited data about it in patients with FMD. Furthermore, discussions of limb shaking TIA in nonelderly patients are scarce.Case presentationAn Asian 47-year-old female presented with intermittent involuntary movement of the left upper limb accompanied by neck torsion. The episode stopped soon after changing to the supine position. On native source images of time-of-flight magnetic resonance angiography (TOF-MRA), the right internal carotid artery showed a "dual lumen sign" with an intimal flap. On contrast-enhanced magnetic resonance angiography and sagittal black-blood T1WI, an intravascular haematoma with irregular lumen stenosis was observed, which overall indicated right internal carotid artery dissection. Digital subtraction angiography showed the characteristic “string-of-beads” appearance in the left internal carotid artery, and the presence of this sign pointed to the diagnosis of FMD. The patient was finally diagnosed with limb shaking TIA due to internal carotid dissection with fibromuscular dysplasia. The patient was prescribed dual anti-platelet therapy. The limb shaking vanished soon after admission with no reoccurrence in the three-month follow-up.ConclusionsThis case demonstrates that limb shaking TIA can present in patients with FMD. Limb shaking TIA in nonelderly patients can be caused by multiple diseases, and more detailed patient guidance is required in clinical practice.

Diagnosis and treatment approaches for simultaneous onset of subarachnoid hemorrhage and thyroid storm: a case report

BackgroundSubarachnoid hemorrhage and thyroid storm are similar in their clinical symptomatology, and diagnosis of these conditions, when they occur simultaneously, is difficult. Here, we report a rare case of concurrent subarachnoid hemorrhage and thyroid storm we encountered at our hospital.Case presentationThe patient was a 52-year-old woman. While bathing at home, the patient experienced a sudden disturbance of consciousness and was brought to our hospital. The main physical findings upon admittance were Glasgow Coma Scale score of E1V2M4, elevated blood pressure (208/145 mmHg), and tachycardia with atrial fibrillation (180 bpm) along with body temperature of 36.1 °C. Brain computed tomography revealed subarachnoid hemorrhage associated with a ruptured aneurysm of the posterior communicating artery branching from the left internal carotid artery, and aneurysm clipping was performed. Blood tests upon admission revealed high levels of free T3 and free T4 and low levels of thyroid-stimulating hormone. Upon determining that the patient had hyperthyroidism, thiamazole was administered. However, due to continuous impaired consciousness, fever, and persistence of tachycardia, the patient was diagnosed with thyroid storm. Oral potassium iodide and hydrocortisone were added to the treatment. The treatment was successful as the patient’s symptoms improved, and she became lucid.In this case, we believe that in the presence of untreated hyperthyroidism, the onset of subarachnoid hemorrhage induced thyroid storm. Tachycardia of 130 bpm or higher, which is the diagnostic criterion for thyroid storm, rarely occurs with subarachnoid hemorrhage. Therefore, we believe it is an important factor for recognizing the presence of the thyroid storm. In this case, clipping surgery was prioritized which resulted in a favorable outcome. However, it is possible that invasive surgery may have exacerbated thyroid storm, suggesting that treatment should be tailored as per patient’s condition.ConclusionIf a pulse rate of 130 bpm or higher is observed alongside subarachnoid hemorrhage, we recommend considering the possibility of concomitant thyroid storm and testing for thyroid hormone. If concomitant thyroid storm is present, we believe that a treatment plan tailored to the patient’s condition is critical, and early diagnosis will lead to a favorable outcome for the patient.

Abstract Number ‐ 80: Embolization of Carotid Cavernous Fistula Through Occluded Inferior Petrosal Sinus Access

Introduction Carotid cavernous fistula (CCF) is an abnormal communication between arteries and veins within the cavernous sinus. The most common presenting symptoms are proptosis, chemosis, orbital bruit and headache. Visual disturbances such as diplopia, ophthalmoplegia and cranial nerve deficits can also occur. Pulsatile tinnitus is an unusual finding which necessitates further workup in this population. Endovascular obliteration with transvenous embolization for indirect fistulas is the preferred approach for CCF closure. Navigation is achieved through the inferior petrosal sinus or facial and superior ophthalmic vein. Here, we describe a case of carotid cavernous fistula that was successfully treated through occluded right inferior petrosal sinus access using coil and Onyx embolic material. Methods A 56‐year‐old‐male with no past medical history presented with right eye proptosis and pulsatile tinnitus. His eye symptoms progressively worsened with decrease in visual acuity, gaze restriction and exophthalmos which correlated with the resolution of pulsatile tinnitus. MRI demonstrated significant inflammation involving the right orbit and atypical enhancement of basal frontal lobe adjacent to orbit. MRA suggested early opacification of the right superior ophthalmic vein and subtle flow voids in posterior lateral aspect of right cavernous sinus. Further evaluation with cerebral angiogram revealed a Barrow Type D right carotid cavernous fistula supplied by meningo‐hypophyseal branches of bilateral internal carotid arteries and right internal maxillary branch. It demonstrated high flow retrograde shunting in right superior ophthalmic vein and a basal frontal isolated cortical vein. There was near complete occlusion of the right sigmoid sinus and inferior petrosal sinus due to significant thrombus burden as well as stenosis of the right internal jugular vein. Results Patient underwent embolization of right carotid cavernous fistula with transvenous approach. A microcatheter was advanced to the origin of the intercavernous sinus but was not able to cross due to exceptionally small channels connecting both cavernous sinuses. The right internal jugular vein was subsequently identified and injection demonstrated occlusion of right sigmoid sinus due to near complete occlusive thrombus in addition to occlusion of the major channels of the inferior petrosal sinus. The microcatheter was blindly advanced into the inferior petrosal sinus maintaining the symmetry from contralateral inferior petrosal sinus trajectory. We were able to reach the fistulous point in the posterior medial aspect of the right cavernous sinus using an Echelon 1045 microcatheter. Coils were subsequently deployed and fistula was noted to be occluded. Onyx was injected through the microcatheter to avoid recanalization of fistula. A follow‐up left internal carotid artery and right common carotid artery injections confirmed angiographic cure of the fistula. Conclusions Carotid cavernous fistula is a rare but treatable cause of rapidly progressive vision loss with pulsatile tinnitus as an unusual finding. We present a case of challenging access and successful treatment with transvenous approach through near complete occlusion of the inferior petrosal sinus.

Abstract Number ‐ 223: Spontaneous Revascularization of Completely Occluded Internal Carotid Artery: Case Report

Introduction Occlusion of the internal carotid artery (ICA), caused by atherosclerotic thrombosis, arterial embolism, or dissection, is associated with high morbidity and mortality of acute stroke. Commonly, these lesions are managed with aggressive medical treatment due to their chronic and usually irreversible nature. Spontaneous recanalization of the occluded ICA has been described in rare instances. Methods We present a report here on three cases with spontaneous recanalization of complete occluded carotid arteries. Results Our first patient was a 62‐year‐old male with a history of hypertension, who presented with transient left eye vision loss. CT angiography of the head and neck (CTA HN) demonstrated left ICA complete occlusion while the left middle cerebral artery (MCA) and anterior cerebral arteries (ACA) were patent. He was treated with apixaban. At the two‐month follow‐up, the repeat CTA HN demonstrated complete recanalization of the left ICA. The etiology of the occlusion remained cryptogenic. Our second patient was a 71‐year‐old male with a prior history of right carotid endarterectomy, peripheral vascular disease, coronary artery disease, hypertension, and dyslipidemia, who presented with acute right MCA stroke. Work‐up with CTA HN demonstrated right ICA complete occlusion. He was treated medically with aspirin and clopidogrel. Six months later, he presented with a two‐week history of intermittent confusion and left‐sided weakness. His MRI brain was negative foracute stroke. Interestingly, CTA HN demonstrated that the right ICA had complete recanalization. The cause of carotid thrombosis remained cryptogenic. Our third patient was a 46‐year‐old female with a history of hypertension, hyperlipidemia, remote low‐speed vehicle collision, and cervical spine chiropractic treatment (the last neck manipulation was about two years prior), presenting with sudden onset dizziness, right‐sided neck pain, and left homonymous hemianopia. Brain MRI showed acute right posterior cerebral artery (PCA) stroke. CTA HN revealed occlusion of the right ICA with a flare‐up appearance suggestive of a carotid dissection. She also had a right fetal PCA. She was treated medically with rivaroxaban. Four months later, a follow‐up MR angiogramof the neck showed a fully revascularized right ICA. Her hypercoagulable workup revealed that she had a rare form of breast cancer. Conclusions Although ICA occlusion is generally considered chronic and irreversible, our case series suggests that the lesion can have spontaneous recanalization with medical treatment. Further studies of characterizing carotid occlusion to predict recanalization are warranted.