Carotid Circulation Research Articles

Abstract P603: Atrial Cardiopathy and Brain Infarction in Multiple Vascular Territories in the ARCADIA Trial

Introduction: Some embolic strokes of undetermined source (ESUS) are likely caused by occult cardiac embolism. One potential cardioembolic source is atrial cardiopathy without atrial fibrillation (AF). Patients with cardiac embolism more often have brain infarcts in multiple vascular territories than those with stroke mechanisms not involving a central embolic source. Hypothesis: In patients with ESUS, atrial cardiopathy is associated with brain infarction in multiple vascular territories. Methods: The ARCADIA trial is enrolling ESUS patients, screening them for atrial cardiopathy, and randomly assigning those with atrial cardiopathy to aspirin or apixaban. In the trial, atrial cardiopathy is defined as ≥1 of the following: P-wave terminal force >5,000 μV*ms in ECG lead V 1 , serum NT-proBNP >250 pg/mL, and left atrial diameter index ≥3 cm/m 2 on echocardiogram. Site investigators report whether the index CT or MRI showed brain infarction in the left carotid, right carotid, or posterior circulation, or some combination. In this analysis, our primary outcome was brain infarction in more than one of these three vascular territories. Our secondary outcome was infarction in both the left and right carotid territories. Results: Among 1,707 ESUS patients enrolled in ARCADIA, 679 (39.8%) met the trial’s randomization criteria for atrial cardiopathy and 213 (12.5%) had multi-territorial brain infarcts. The prevalence of brain infarction in more than one vascular territory was 14.0% in those with atrial cardiopathy versus 11.5% in those without (prevalence ratio, 1.22; 95% CI, 0.95-1.57). The prevalence of brain infarction in both the left and right carotid territories was 9.1% in those with atrial cardiopathy versus 7.4% in those without (prevalence ratio, 1.24; 95% CI, 0.90-1.70). Conclusions: These preliminary analyses from ARCADIA suggest a possible association between atrial cardiopathy and brain infarction in multiple vascular territories, but further analysis of a larger sample is needed to conclusively test whether our atrial cardiopathy definition is associated with the classic neuroimaging profile of cardiac embolism.

First in Man Pilot Feasibility Study in Extracranial Carotid Robotic-Assisted Endovascular Intervention.

Robotic-assistance in endovascular intervention represents a nascent yet promising innovation. To present the first human experience utilizing robotic-assisted angiography in the extracranial carotid circulation. Between March 2019 and September 2019, patients with extracranial carotid circulation pathology presenting to Houston Methodist Hospital were enrolled. A total of 6 patients met inclusion criteria: 5 underwent diagnostic angiography only with robotic-assisted catheter manipulation, while 1 underwent both diagnostic followed by delayed therapeutic intervention. Mean age was 51 +/- 17.5 yr. Mean anesthesia time was 158.7 +/- 37.9 min, mean fluoroscopic time was 22.0 +/- 7.3 min, and mean radiation dose was 815.0 +/- 517.0 mGy. There were no technical complications and no clinical deficits postprocedure. None of the cases required conversion to manual neurovascular intervention (NVI). Incorporating robotic technology in NVI can enhance procedural technique and diminish occupational hazards. Its application in the coronary and peripheral vascular settings has established safety and efficacy, but in the neurovascular setting, this has yet to be demonstrated. This study presents the first in human feasibility experience of robotic-assisted NVI in the extracranial carotid circulation.

A review of the carotid artery and facial nerve canal systems in extant turtles.

The cranial circulation and innervation systems of turtles have been studied for more than two centuries and extensively used to understand turtle systematics. Although a significant number of studies related to these structures exists, a broader comprehension of variation across the tree has been hindered by poor sampling and a lack of synthetic studies that addressed both systems together. We here provide new insights regarding the carotid circulation and facial nerve innervation systems in a broad set of extant turtles using CT (computed tomography) scans, which allow us to trace the canals these structures form in bone and understand the interaction between both systems. We document that the palatine artery, including the lateral carotid canal, is absent in all pleurodires and carettochelyids and was likely reduced or lost several times independently within Testudinoidea. We also highlight osteological correlates for the location of the mandibular artery. We finally summarize variation regarding the placement of the mandibular artery, location of the geniculate ganglion, placement of the hyomandibular and vidian nerves, and situations where we recommend caution when assessing canals in fossils. A morphometric study confirms that the relative sizes of the carotid canals are correlated with one another. Our results have the potential for building new phylogenetic characters and investigating the circulation systems of fossil taxa, which are expected to shed light on the evolution of the circulation system of turtles and clarify some unresolved relationships between fossil turtle clades.

Optimization technique for stenting of ostial vertebral artery stenosis

Objective ‒ to develop a technique for endovascular treatment of symptomatic ostial stenosis of the vertebral arteries, which allows to minimize risks of delayed stent breakage and restenosis. Materials and methods. This is analysis of prospectively collected data from patients presenting from 2016 to 2019 in the endovascular center of the Dnepropetrovsk Regional Clinical Hospital named after I.I. Mechnikov. One hundred four stents were placed in 99 patients using the author’s complex method, which is based on our modification of Szabo technique. The principles of the method were developed based on a literature review and in vitro tests using 7 silicone models of the initial segments of the subclavian and vertebral arteries with different angles of divergence of the vertebral arteries (30, 45, 60, 90, 120, 135, 150°) and 9 balloon mounted drug-eluting stents with open-cell design Resolute (Medtronic).Results. There were no cases of displacement of the stent proximally or distally during implantation. In all cases, stents were implanted in the affected segment exactly and did not prolapse more than 1 mm beyond the ostium of the vertebral artery into the subclavian artery. There were no «clinical» ischemic complications in the early postoperative period. In 5 cases, isolated subclinical ischemic lessions in the carotid circulation were revealed during one-session stenting of ostial stenosis of the vertebral arteries and carotid stenting. In the posterior circulation, ischemic lessions on MRI in the early postoperative period were not detected in any observations.Conclusions. Developed complex stenting method based on our modification of Szabo technique allows us to achieve optimal long-term results of stenting of symptomatic ostial stenosis of the vertebral arteries.

Clinical presentation of vertebrobasilar stroke.

Vertebrobasilar (VB) stroke is responsible for 20% of all strokes and transient ischemic attacks. Due to the vast cerebral territory it supplies, VB ischemia can present with a wide range of symptoms and signs, sometimes even overlapping with carotid circulation stroke. Furthermore, brain computed tomography, usually performed as initial imaging modality, has a suboptimal visualization of the posterior fossa, making VB stroke an even more challenging diagnosis to any physician. Hence, awareness of the vertebrobasilar anatomy and the clinical presentation of VB ischemia is crucial to promote early recognition of this disorder.

Association of Neurosurgical Work Relative Value Units with Objective Markers of Operative Complexity

Relative value units (RVUs) form the backbone of health care service reimbursement calculation in the United States. However, it remains unclear how well RVUs align withobjective measures of procedural complexity within neurosurgery. The 2018 American College of Surgeons National Surgical Quality Improvement Program database was queried for neurosurgical procedures with >50 patients, using Current Procedural Terminology (CPT) codes. Length of stay (LOS), operative time, mortality, and readmission and reoperation rates were collected for each code and a univariate correlation analysis was performed, with significant predictors entered into a multivariate logistic regression model, which generated predicted work RVUs, which were compared with actual RVUs to identify undervalued and overvalued procedures. Among 64 CPT codes, LOS, operative time, mortality, readmission, and reoperation were significant independent predictors of work RVUs and together explained 76% of RVU variance in a multivariate model (R2= 0.76). Using a difference of >1.5 standard deviations from the mean, procedures associated with greater than predicted RVU included surgery for intracranial carotid circulation aneurysms (CPTs 61697 and 61700; residual RVU= 12.94 and 15.07, respectively), and infratemporal preauricular approaches to middle cranial fossa (CPT 61590; residual RVU= 15.39). Conversely, laminectomy/foraminotomy for decompression of additional spinal cord, cauda equina, and/or nerve root segments (CPT 63048; residual RVU= -21.30), transtemporal craniotomy for cerebellopontine angle tumor resection (CPT 61526; residual RVU= -9.95), and brachial plexus neuroplasty (CPT 64713; residual RVU= -11.29) were associated with lower than predicted RVU. Work RVUs for neurosurgical procedures are largely predictive of objective measures of surgical complexity, with few notable exceptions.

Systematics of Neotropical Spiny Mice, Genus Neacomys Thomas, 1900 (Rodentia: Cricetidae), from Southeastern Amazonia, with Descriptions of Three New Species

Species of Neacomys are small cricetid rodents that occur in forested habitats of Central and South America, from eastern Panama to central Bolivia and central/western Brazil. In order to assess species diversity of this poorly known genus, we obtained cytochrome b gene sequences from the most comprehensive taxonomic and geographic sampling analyzed to date. We also conducted morphological analyses on a large series of specimens housed in 15 museums, including types of 10 out of 14 nominal taxa. Our analyses of the genetic data recovered 17 lineages clustered in four distinct clades. Among these lineages, 11 correspond to species currently recognized as valid, and the remaining six are putative new species. In southeastern Amazonia—the geographical scope of this report—four undescribed species were discovered, three of which are named herein: Neacomys marajoara, sp. nov., from the Island of Marajo, Para state; Neacomys vossi, sp. nov., restricted to the Tapajos center of endemism (between the Tapajos and Xingu rivers); and Neacomys xingu, sp. nov., restricted to the Xingu center of endemism (between the Xingu and Araguaia/Tocantins rivers). The new species can be discriminated from other Neacomys species by the morphology of the nasal bones, zygomatic plate, interorbital region, subsquamosal fenestra, paraoccipital process, incisive foramina, auditory bullae, anterocone and anteroloph of the first upper molar, carotid circulation pattern, and karyotype. Our results substantially improve our understanding of the genus Neacomys by providing morphological, morphometric, and novel molecular insights about these poorly known rodents and demonstrate that the diversity of small Amazonian mammals is still poorly known, even in the relatively accessible southeastern part of the biome.

Preliminary Experience Using a Covered Stent Graft in Patients with Acute Ischemic Stroke and Carotid Tandem Lesion.

Endovascular treatment with a covered heparin-bonded stent graft has been shown to be feasible and safe for treatment of peripheral artery disease, but its role in carotid disease remains unclear. The purpose of this study was to determine the feasibility and safety of a covered stent graft in treating cervical carotid artery disease in a consecutive series of patients with acute ischemic stroke (AIS) due to tandem lesion in a single high-volume Comprehensive Stroke Center. A retrospective review of all patients that underwent carotid endovascular interventions during mechanical thrombectomy for AIS using a self-expanding covered stent graft at Vall d'Hebron University Hospital between 2016 and 2018 was conducted. Patient clinical and angiographical characteristics as well as postoperative outcome and follow-up were recorded. A total of eight patients were treated with the covered stents, and we observed significant improvement in stroke severity at 24h in 5/8 patients (mean NIHSS 18 ± 5 vs 12 ± 8, p = 0.02). Successful recanalization (TICI 2b-3) after thrombectomy was achieved in 5/8 (62.5%) patients. One stent occluded during the procedure. At 3-month follow-up, stents were patent in three (37.5%) patients (two with mRS 3 and one with mRS 1). The stents of the remaining four patients (62.5%) were occluded (one with mRS 2 and three with mRS 4), although the patients did not show signs of stroke recurrence. The preliminary results of our study show that the self-expanding covered stent graft did not achieve satisfactory patency at 90-days among patients with AIS and tandem lesions, suggesting that its use in the carotid circulation may not be recommended in the context of AIS.

Embolization of carotid-cavernous fistulas: A technical note on simultaneous balloon protection of the internal carotid artery

A carotid-cavernous fistula (CCF) is an abnormal connection between the carotid circulation and the cavernous sinus. Treatment of CCFs often consists of obliteration of the fistula by a transarterial or transvenous endovascular approach using embolic agents. However, fistula embolization is often halted due to the potential embolic complications that may arise from the retrograde flow of the embolic agents into the arterial circulation, which often leads to the development of fistula recurrence. Moreover, retreatment of a CCF recurrence is challenging and more complex approaches may be required. In this technical note, we describe our experience with CCF embolization in 25 patients treated at a single center. We utilized a transvenous approach for CCF embolization with simultaneous balloon occlusion of the internal carotid artery during the infusion of the embolic material into the fistula. In our series, this simultaneous protection of the internal carotid artery showed to be a safe technique to prevent embolic complications and to achieve successful obliteration of the fistula. On follow-up, 2 cases presented a recurrence, one due to technical difficulties and the other related to an undetected vascular injury. In conclusion, this technique provides a safe approach in the treatment of CCFs by decreasing the risk of embolic complications and increasing the effectiveness of the embolic agents in accomplishing the obliteration of the CCF.

A small podocnemidoid (Pleurodira, Pelomedusoides) from the Late Cretaceous of Brazil, and the innervation and carotid circulation of side‐necked turtles

AbstractPleurodires are less diverse than cryptodires, together forming the two major lineages of crown turtles. Their fossil record, however, is rich. A particularly large number of fossil pleurodires, many belonging to the Podocnemidoidae, has been recovered from the Upper Cretaceous Bauru Group outcrops of south‐central Brazil. Herein we describe an additional pleurodire from this region, Amabilis uchoensis gen. et sp. nov., based on a partially preserved skull. A. uchoensis is recognized as belonging to the Podocnemidoidae by the small entrance to the antrum postoticum and completely developed cavum pterygoidei, being unique among other non‐podocnemidid podocnemidoids for its medially open fenestra postotica and absent basioccipital–opisthotic contact. Our cladistic analysis places A. uchoensis as a sister taxon to Hamadachelys + other podocnemidoids. We further explore the neuroanatomy of side‐necked turtles with the aid of micro‐computed tomography of specimens of the main pleurodiran lineages. Our data shed light on the different carotid circulation patterns in pleurodires, and we propose new phylogenetic characters to describe the neuroanatomical variation of the group. Optimization of these characters shows two independent acquisitions of a foramen for the palatal branch of the carotid in chelids and podocnemidoids, and a unique loss of the vidian nerve canal in chelids, in turtles in general.

Maintaining the permanence principle for death during in situ normothermic regional perfusion for donation after circulatory death organ recovery: A United Kingdom and Canadian proposal.

There is international variability in the determination of death. Death in donation after circulatory death (DCD) can be defined by the permanent cessation of brain circulation. Post‐mortem interventions that restore brain perfusion should be prohibited as they invalidate the diagnosis of death. Retrieval teams should develop protocols that ensure the continued absence of brain perfusion during DCD organ recovery. In situ normothermic regional perfusion (NRP) or restarting the heart in the donor's body may interrupt the permanent cessation of brain perfusion because, theoretically, collateral circulations may restore it. We propose refinements to current protocols to monitor and exclude brain reperfusion during in situ NRP. In abdominal NRP, complete occlusion of the descending aorta prevents brain perfusion in most cases. Inserting a cannula in the ascending aorta identifies inadequate occlusion of the descending aorta or any collateral flow and diverts flow away from the brain. In thoracoabdominal NRP opening the aortic arch vessels to atmosphere allows collateral flow to be diverted away from the brain, maintaining the permanence standard for death and respecting the dead donor rule. We propose that these hypotheses are correct when using techniques that simultaneously occlude the descending aorta and open the aortic arch vessels to atmosphere.

Carotid Intima-Media Thickness and Circulation Markers of Inflammation in Patients With Depression

Objective: Growing evidence indicates that depressive disorders (DDs) are an important risk factor for atherosclerosis. The aim of this study was to evaluate the presence of common carotid artery (CCA) intima-media thickness (IMT) and circulation inflammation markers in patients with DD. Methods: A cross-sectional prospective study was undertaken comparing 40 patients with DD to 40 individuals free of depression, matched for age and gender. The Beck Depression Inventory questionnaire, serum total cholesterol, triglycerides, high-sensitivity C-reactive protein, interleukin-6, tumor necrosis factor α, P-selectin, and E-selectin levels were measured. The CCA-IMT was assessed with duplex sonography. Results: Patients with DD were more likely to smoke (65% vs 40%; P = .03) and have higher levels of serum total cholesterol (211 mg/dL vs 181 mg/dL; P = .010), triglycerides (138 mg/dL vs 97 mg/dL; P = .005), and P-selectin (0.87 ng/mL vs 0.61 ng/mL; P = .05) and lower levels of interleukin 6 (4.4 ± 2.1 pg/mL vs 10.3 ± 1.1 pg/mL; P = .002). The CCA-IMT was similar in both groups (0.07 ± 0.02 cm vs 0.06 ± 0.01 cm; P = .31). Among those with CCA-IMT in the upper quartile, subjects in the DD group had lower levels of interleukin 6 ( P = .05) and triglycerides ( P = .01) and higher levels of soluble P-selectin ( P = .03). Conclusion: Patients with DD do not present with higher CCA-IMT than a control group, although smoking and a higher level of serum lipids are present. Inflammatory biomarkers seem to be higher in patients with DD.

Contralateral Carotid Occlusion With Sufficient Circle of Willis is not Associated With A Higher Incidence of Neurologic Events During Carotid Endarterectomy Without Shunting

Introduction: Whereas large studies identified that contralateral carotid occlusion (CCO) has higher perioperative stroke risk in patients who underwent carotid endarterectomy (CEA), single-center studies have not confirmed this. Circle of Willis (CoW) is considered an important collateral network to maintain blood flow during cross-clamping in carotid endarterectomy (CEA). The aim of this study was to evaluate the impact of the CCO in association with CoW on immediate neurological event (INE) after CEA without shunt protection. Methods: We reviewed the clinical data and outcomes of 114 patients (80 males mean age 65.9±8.7 years) who underwent CEA with CCO under general anesthesia between 01.01.2013 and 30.06.2018. Patients who had CEA with shunt (46) and with inadequate intracranial imaging (16) were excluded. Indications were asymptomatic (75%) and symptomatic (25%) carotid artery disease. CTAs were reviewed independently by two vascular radiologists who were blinded for treatment outcomes. Imaging assessment included the vertebral and carotid circulation and each segment of the CoW. Segments were classified as normal, hypoplastic (diameter ˂ 1mm) or absent. CoW was assessed for short semicircle (ipsilateral P1 and Pcom) and long (from the contralateral P1 to the ipsiA1) semicircles considered as sufficient if there were normal segments between the basilar and the ipsilateral middle cerebral artery (MCA). INE was defined as any transient ischemic attack (TIA) and stroke diagnosed immediately after the procedure. Results: Of the 52 included patients only two had a stroke (3.8%) in the postoperative period. From the two strokes one was immediate after the surgery. In addition of this stroke there were 3 immediate TIAs giving the 4 (7.7%) INE. Only one third of this study population (n=18; 34%) had normal, 17 patients (33%) had at least one hypoplastic segments and other 17 (33%) had missing segments between the clamped carotid and the basilar artery - short semicircle. There was no neurologic event with normal short semicircle. From the 4 INE two patients had hypoplastic and two had absent short semicircle. In all INE cases the other, long semicircle was insufficient as well. Conclusion: Contralateral carotid occlusion carries insignificant risk of INE or stroke after CEA with cross-clamping without shunt protection, when CoW collateral flow support is sufficient. In patients with CCO shunting is recommended when the collateral flow between the ipsilateral MCA and the basilar artery is compromised. Disclosure: Nothing to disclose

Limitation of Near Infrared Spectroscopy Cerebral Oximetry in Predicting Neurologic Intolerance during Carotid Artery Stenting with Proximal Protection

AbstractProximal balloon occlusion prior to carotid artery stenting is considered a relatively safe practice during endovascular treatment of carotid artery stenosis. Transient neurological deterioration affecting the ipsilateral hemisphere is seen soon after balloon inflation, when placed proximal to the stenotic segment. This occurs in cases of bilateral carotid disease due to insufficient collateral blood flow from the contralateral side. Near infrared spectroscopy cerebral oximetry (NIRS) is a valuable tool in detecting hypoperfusion- induced cerebral tissue desaturation (rSO2) during these procedures. This helps the interventional radiologist to deflate the balloon at the earliest to re-establish the cerebral blood flow. The non-invasive nature and continuous real-time interpretation make NIRS an attractive adjunct in the neuroanesthesiolgist's armamentarium for monitoring cerebral ischemia. However, significant contribution from chromophores in the extra-cerebral tissues and external carotid artery circulation can limit its sensitivity during occlusion of the internal carotid artery. In our case, it did not reflect brain ischemia during hypotension and when the neurologic symptoms were obvious. Commonly available cerebral oximetry sensors placed over the frontal region do not cover the parietal lobe where ischemia is likely to occur during occlusion of the carotid artery. In such scenarios, it has been shown that multi-channel NIRS has a better sensitivity in detecting cerebral ischemia. This case report highlights the importance of frequent neurological examination during carotid stenting as rSO2 values might not always suggest cerebral ischemia.

Endovascular Treatment for Bilateral Carotid Stenosis: a Case Report

Abstract Carotid artery stenosis is usually a consequence of thromboembolism or atheroembolism, or it can be secondary to a low-velocity status in the carotid circulation. This disease can also represent an important cause of stroke, being responsible for 7% of all stroke cases. Endovascular techniques were recently proposed as alternative interventions for patients with high risk for endarterectomy. We present the case of a 70-year-old patient, accusing headache, vertigo, and fatigue. Angiography indicated bilateral carotid artery stenosis. Interventional surgery and angioplasty were performed, crossing the stenotic lesions of the left internal carotid artery, followed by the implantation of a Carotid WALLSTENT endoprosthesis. Evolution of the patient was favorable after the endovascular intervention, with significant improvement of the symptoms caused by bilateral carotid stenosis. As a conclusion, decision-making must be modulated in each patient, according to the patient’s anatomy and comorbidities, and the experience of the team performing the procedure.

A1 asynchrony, a potential risk factor for the rupture of anterior communicating artery aneurysms: A computational fluid dynamics study

Introduction and objectivesThe anterior communicating complex is one the most common locations for aneurysm development. It receives blood from both carotid circulations and the effect of synchrony on the arrival of blood flow has not been previously studied. The objective of this study was to compare the asynchrony conditions of the A1 pulse and its effects on the haemodynamic conditions of anterior communicating artery (ACoA) aneurysms. Materials and methodsFrom 2008 to 2017, 54 anterior communicating artery aneurysms treated at our centre were included in the study. Computational fluid dynamics (CFD) techniques were employed and simulations consisted of complete conditions of synchrony and introducing a delay of 0.2s in the non-dominant A1 artery. Time-averaged wall shear stress (TAWSS), low shear area (LSA), A1 diameter and ACoA angles were measured. ResultsThe difference in the LSA in conditions of synchrony and asynchrony resulted in a broad range of positive and negative values. The symmetry index (p=0.04) and A1/A2 angle on the dominant artery (p=0.04) were associated with changes in LSA. ConclusionsIn asynchrony, LSA increased in the absence of A1 asymmetry and low A1/A2 angles, potentially increasing the risk of aneurysm rupture in this location.

Neurovascular anatomy of the protostegid turtle Rhinochelys pulchriceps and comparisons of membranous and endosseous labyrinth shape in an extant turtle

AbstractChelonioid turtles are the only surviving group of reptiles that secondarily evolved marine lifestyles during the Mesozoic Early chelonioid evolution is documented by fossils of their stem group, such as protostegids, which yield insights into the evolution of marine adaptation. Neuroanatomical features are commonly used to infer palaeoecology owing to the functional adaptation of the senses of an organism to its environment. We investigated the neuroanatomy and carotid circulation of the early Late Cretaceous protostegid Rhinochelys pulchriceps based on micro-computed tomography data. We show that the trigeminal foramen of turtles is not homologous to that of other reptiles. The endosseous labyrinth of R. pulchriceps has thick semicircular canals and a high aspect ratio. Comparisons among turtles and other reptiles show that the endosseous labyrinth aspect ratio is not a reliable predictor of the degree of aquatic adaptation, contradicting previous hypotheses. We provide the first models of neuroanatomical soft tissues of an extant turtle. Turtle brain morphology is not reflected by the brain cavity, and the endosseous labyrinth provides an incomplete reflection of membranous semicircular duct morphology. Membranous labyrinth geometry is conserved across gnathostomes, which allows approximate reconstruction of the total membranous labyrinth morphology from the endosseous labyrinth despite their poor reflection of duct morphology.

Spotty Calcium on Cervicocerebral Computed Tomography Angiography Associates With Increased Risk of Ischemic Stroke.

Background and Purpose- Cervicocerebral vascular calcification on computed tomography angiography is a known sign of advanced atherosclerosis. However, the clinical significance of calcification pattern remains unclear. In this study, we aimed to investigate the potential association between spotty calcium and acute ischemic stroke. Methods- This study included patients with first-time nonlacunar ischemic stroke (N=50) confirmed by brain magnetic resonance imaging or nonenhanced head computed tomography, as well as control subjects with asymptomatic carotid atherosclerosis (N=50) confirmed by carotid ultrasonography. Subjects in both groups underwent contrast-enhanced cervicocerebral computed tomography angiography within a week after the initial imaging examination. Spotty calcification was evaluated at 11 arterial segments commonly affected by atherosclerosis along the carotid and vertebrobasilar circulation. Statistical analysis was performed comparing the frequency and spatial pattern of spotty calcification between the 2 groups. Results- Spotty calcification in the Stroke group was markedly more prevalent than that in the Control group (total SC count: 8.74±4.96 versus 1.84±1.82, P<0.001). The odds ratio (95% CI) for stroke was 2.49 (1.55-4.00) for spotty calcification at bilateral carotid bifurcation, 1.52 (1.13-2.04) at carotid siphon, and 1.98 (1.45-2.69) at all evaluated locations. A total number of 3 spotty calcifications were determined as the optimal cutoff threshold for increased risk of stroke. Spotty calcium showed significantly greater area under the receiver operating characteristics curve than total calcium volume irrespective of size (0.88 versus 0.77). Within the Stroke group, ipsilateral lateral side showed significantly more spotty calcium than the contralateral side (5.18±3.05 versus 3.56±2.67, P<0.001). Conclusions- Nonlacunar ischemia stroke was associated with markedly increased incidence of spotty calcification with a distinct spatial pattern on cervicocerebral computed tomography compared with subclinical atherosclerosis, suggesting the potential role of spotty calcification for improving the risk stratification for ischemic stroke.

Abstract TP74: Spotty Calcification on Cervicocerebral Computed Tomography Angiography Associates With Increased Risk of Acute Ischemic Stroke

Introduction: Cervicocerebral vascular calcification on cervicocerebral computed tomography angiography is a known sign of advanced atherosclerosis. However, the clinical significance of calcification pattern remains unclear. This study aimed to investigate the potential association between spotty calcium (SC) and acute ischemic stroke. Methods: This study included patients with first-time nonlacunar ischemic stroke (N=50) confirmed by brain MRI or non-enhanced head CT, as well as age and sex-matched control subjects with asymptomatic carotid atherosclerosis (N=43) confirmed by carotid ultrasonography. Subjects in both groups underwent contrast-enhanced cervicocerebral CTA within a week after the initial imaging exam. Spotty calcification was evaluated at eleven arterial segments commonly affected by atherosclerosis along the carotid and vertebrobasilar circulation. Statistical analysis was performed comparing the frequency and spatial pattern of spotty calcification between the two groups. Results: Spotty calcification in the stroke group was markedly more prevalent than that in the control group (total SC count: 8.74±4.96 vs 1.84±1.77, p&lt;0.001). The relative risk for stroke of spotty calcification at bilateral carotid bifurcation, carotid siphon, and all evaluated locations were (95% confidence interval): 2.521 (1.530~4.155), 1.441 (1.073~1.937), and 1.971 (1.434~2.709), respectively. A total number of 3 spotty calcifications was determined as the optimal cutoff threshold for increased risk of stroke. Spotty calcium showed significantly greater area under the receiver-operating characteristics curve (ROC) than that of total calcium irrespective of size (0.88 versus 0.77). Within the stroke group, ipsilateral lateral side showed significantly more spotty calcium than the contralateral side (5.18±3.05 vs. 3.56±2.67, p&lt;0.001). Conclusions: Nonlacunar ischemia stroke was associated with markedly increased incidence of spotty calcification with a distinct spatial pattern on cervicocerebral computed tomography compared with subclinical atherosclerosis, suggesting the potential role of spotty calcification for improving the risk-stratification for ischemic stroke.

Stochastic game of data transmission in the presence of buffers of finite capacity

Current research aimed to investigate informational content of brainstem acoustic evoked potentials (BAEPs) and auditory cognitive event-related potential — mismatch negativity (MMN) in assessment of brain functional status and cognitive functions in patients with ischemic stroke. MMN is a component of auditory event-related potential with peak latency at 100–250 ms, which reflects automatic process of difference detection between stimuli and neurodynamic processes in auditory cortex at pre-attentive stage. Clinical and neurophysiological examination, including registration of BAEPs and MMN was performed for 22 patients (12 — with ischemic stroke in carotid circulation, 10 — without cerebrovascular diseases). According to results obtained using scales of MMSE, FAB, test with 10 words repetition and Schulte tables, patients with IS demonstrated cognitive impairment as compared to control group. During BAEPs examination, functional changes in brainstem were observed (increased latency of wave V and elongation of interpeak intervals III-V on both sides and III–V ipsilaterally) in patients with ischemic stroke. Also they demonstrated increased peak latency and decreased amplitude of MMN. It points at a decline in auditory discrimination accuracy, shortened lifetime of memory traces and deficit in involuntary attention switching and also indicates of cognitive impairment.