Follow-up after carotid stenting with the CASPER stent system: A duplex ultrasound evaluation.

OBJECTIVE: To report results of duplex ultrasound evaluation of consecutive patients after carotid stenting with the double layer Carotid Artery Stent designed to Prevent Embolic Release (CASPER) stent system. METHODS: Between January 2014 and June 2017, a single-center, retrospective study of 101 consecutive patients (21.8% female; median age, 72.1 years) was performed. Patients with internal carotid artery stenosis treated with the CASPER stent were included. Eligibility criteria for stenting included stenosis of ≥70% of the vessel diameter (or ≥50% diameter with ulceration) in symptomatic carotid artery stenosis or ≥80% stenosis in asymptomatic patients at the carotid artery bifurcation or the proximal cervical internal carotid artery. Duplex ultrasound examination was performed before and within 24 hours of implantation as well as at 14 days, and 3, 6, and 12 months. RESULTS: At the 12-month follow-up visit, moderate in-stent restenosis (ISR) (≥50% and <70%) was detected in three stents (2.8%) and severe (≥70%) ISR in two (1.9%; including one case of stent occlusion). All but the two latter patients remained asymptomatic during the follow-up period. One patient required retreatment for ISR after a minor stroke and another patient with stent occlusion also re-presented with a minor stroke. Multivariable logistic regression was unable to detect any significant factors associated with ISR. CONCLUSIONS: Duplex ultrasound examination after carotid stenting is a useful tool for patient follow-up and determination of ISR. We found a low incidence of ISR assessed by duplex ultrasound examination at 12 months after CASPER stenting, but further studies are warranted.

Severe Leukoaraiosis Is Associated with Poor Outcome after Successful Recanalization of M1 Middle Cerebral Artery Occlusion Strokes.

BACKGROUND: Severe leukoaraiosis (LA) is an established risk factor for poor outcome after mechanical thrombectomy (MT) for large vessel occlusion stroke. There is uncertainty whether this association also applies to successfully recanalized patients with M1 segment middle cerebral artery (MCA) occlusions. METHODS: A retrospective single-centre study of patients with successful reperfusion (thrombolysis in cerebral infarction, TICI 2b or 3) after MT for an M1 MCA occlusion was performed over a 7-year period. LA score (LAS) was assessed using the age-related white matter change scale on pre-interventional brain imaging. RESULTS: A total of 209 patients (median age 75.0 years) were included. LAS was assessed on pre-interventional imaging by computed tomography in 177 (84.7%) patients and magnetic resonance imaging in 32 (15.3%) patients. The median LAS was 1 (IQR 0-8), and severe LA consisted of the top 25 percentile, ranging from 9 to 24. Multivariable analysis demonstrated an association of severe LA (OR 0.32, 95% CI 0.12-0.88, p = 0.023), higher NIHSS on admission (OR 0.89, 95% CI 0.84-0.94, p < 0.001), advanced age (OR 0.97, 95% CI 0.95-1.00, p = 0.039), good leptomeningeal collaterals (OR 3.65, 95% CI 1.46-8.15, p = 0.001), and TICI 3 score (OR 3.26, 95% CI 10.52-7.01) with good clinical outcome after 3 months as measured with the modified Rankin scale. CONCLUSION: Severe LA is associated with poor clinical outcome at 3 months in acute stroke patients undergoing MT due to emergent M1 MCA occlusion.

Carotid Calcium Volume and Stenosis after Stent Implantation.

INTRODUCTION: Internal carotid artery (ICA) stenosis could be treated with stent placement. It was hypothesized that calcium amount could be predictive of vessel stenosis after stent placement. We utilised computed tomography (CT) angiography to quantify volume of calcium material in bulbar ICA. MATERIALS AND METHODS: 28 patients with 31 treated ICA stenosis were collected and analysed using CT angiography-based calcium volume measurement. The Casper stent system (CSS) was used exclusively. Prospective data on emergent carotid stenosis were collected using serial ultrasound controls over a 12-month period. RESULTS: Median age was 76 years (interquartile range (IQR) 67.5-77.8) and the majority were men (71.4%). Plaque median calcium volume was 0.142 cm3 (IQR 0.030 - 0.227) and median average Hounsfield Units (HU) were 561.0 (414.5-675.0). We detected positive linear relationship between average HU and ICA calcium volume. Furthermore, weak positive correlation was observed between calcium volume and residual stenosis as seen on post-interventional angiography, (correlation coefficient R = 0.38, p=0.035). Stronger positive correlation emerged between plaques' average HU and residual stenosis (R = 0.42, p=0.018). Angiographic stenosis showed univariate association with late stenosis as detected 12 months after CAS. CONCLUSION: Calcium burden could be associated with residual stenosis after CSS placement. Larger studies are needed to confirm our preliminary data.

Fibrinogen consumption is related to intracranial clot burden in acute ischemic stroke: a retrospective hyperdense artery study.

BACKGROUND: Understanding the underlying mechanism of thrombus formation and its components is critical for effective prevention and treatment of ischemic stroke. The generation of thrombotic clots requires conversion of soluble fibrinogen to an insoluble fibrin network. Quantitative features of intracranial clots causing acute ischemic stroke can be studied on non-contrast enhanced CT (NECT). Here, we evaluated on-admission fibrinogen and clot burden in relation to stroke severity, final infarct volume and in-hospital mortality. METHODS: We included 132 consecutive patients with ischemic stroke and presence of hyperdense artery sign admitted within 6 h from symptom onset. Radiological parameters including clot area (corresponding to clot burden) and final infarct volume were manually determined on NECT. National Institute of Health Stroke Scale (NIHSS) was used to quantify disease severity and short-term outcome. RESULTS: Median patient age was 77, 58 % were women, and 63 % had an occlusion of the proximal middle cerebral artery segment. Thrombolysis was performed in 60 % and thrombectomy in 44 %. We identified several independent associations. Higher fibrinogen levels on admission were associated with smaller clot burden (p = 0.033) and lower NIHSS on admission (p = 0.022). Patients with lower fibrinogen had a higher clot burden (p = 0.028) and greater final infarct volume (p = 0.003). Higher fibrinogen was associated with a lower risk of in-hospital death or NIHSS score >15 if discharged alive (p = 0.028). CONCLUSIONS: Our study suggests that intracranial clot burden in acute ischemic stroke is associated with fibrinogen consumption, and shows a complex relationship with disease severity, infarct size and in-hospital survival.

Antiplatelet Usage Impacts Clot Density in Acute Anterior Circulation Ischemic Stroke.

We explored whether clot density in middle cerebral artery (MCA) occlusion is related to clinical variables, stroke etiology, blood constituents, and prestroke medication. We performed a retrospective chart review of patients with acute ischemic stroke of the anterior circulation admitted to two Central European stroke centers. The acquisition of non-contrast enhanced CT (NECT) and CT angiography (CTA) within 4.5 h of symptom onset was obligatory. We assessed the site of MCA occlusion as well as density, area, and length of the clot in 150 patients. The Hounsfield unit values for the clot were divided with contralateral MCA segment to yield relative Hounsfield Unit ratio (rHU). The site of the vessel occlusion (M1 vs. M2) and antiplatelet usage, but not stroke etiology, significantly influenced rHU. We found an inverse correlation of rHU with erythrocyte count (p < 0.001). The multivariate analysis revealed that a higher rHU (i.e., clot being more hyperdense) was more likely with the use of antiplatelets (OR 4.24, CI 1.10-16.31, p = 0.036). Erythrocyte (OR 0.18, CI 0.05-0.55, p = 0.003), and thrombocyte counts (OR 0.99, CI 0.98-0.99, p = 0.029) were associated with odds for more hypodense clots (lower rHU). Our study disclosed that antiplatelet therapy impacts the composition of intracranial clots of the anterior circulation.

Intracranial Thrombus Morphology and Composition Undergoes Time-Dependent Changes in Acute Ischemic Stroke: A CT Densitometry Study.

The aim of our study was to assess whether cerebral artery clots undergo time-dependent morphological and compositional changes in acute ischemic stroke. We performed a retrospective chart review of patients admitted within 5 h from symptom onset to three European stroke centers and evaluated non-contrast-enhanced CT (NECT) for hyperdense artery signs (HAS) in 2565 scans. The occlusion site, density of HAS expressed in Hounsfield units (HU), area of HAS, and relative density (rHU) (HU clot/HU non-affected artery) were studied and related to time from symptom onset, clinical severity, stroke etiology, and laboratory parameters. A HAS was present in the middle cerebral artery (MCA) in 185 (7.2%) and further explored. The mean time from symptom onset to CT was 100 min (range 17-300). We found a time-dependent loss of density in the occluded M1 segment within the first 5 h (N = 118, 95% CI [-15, -2], p = 0.01). Further, the thrombus area in the M2 segment decreased with time (cubic trend N = 67, 95% CI [-63, -8], p = 0.02). Overall, and especially in the M2 segment, a lower clot area was associated with higher fibrinogen (-21.7%, 95% CI [-34.8, -5.8], p = 0.009). In conclusion, our results disclosed time-dependent changes of intracranial thrombi with regard to occlusion site, density and area.

Unilateral delayed post-hypoxic leukoencephalopathy: a case report.

BACKGROUND: Delayed post-hypoxic leukoencephalopathy is a rare entity following hypoxia. Clinical and radiological signs of delayed post-hypoxic leukoencephalopathy have not previously been reported following acute ischemic stroke. CASE PRESENTATION: We report a case of an 81-year-old Central European man who presented with a dissection-related occlusion of the left carotid artery. He showed clinical improvement immediately after endovascular stroke therapy, followed by a significant clinical and especially cognitive deterioration thereafter and a clinical recovery after several weeks. The clinical course of the patient was accompanied by morphological changes on magnetic resonance imaging characteristic of delayed post-hypoxic leukoencephalopathy; that is, strictly limited and localized unilaterally to the left anterior circulation. CONCLUSION: This case demonstrates that clinical symptoms and morphological changes on magnetic resonance imaging compatible with delayed post-hypoxic leukoencephalopathy do not necessarily only occur with global hypoxia, but can also occur in patients with a large vessel occlusion in the corresponding vascular territories.

Neurologist-Led Management of Implantable Loop-Recorders After Embolic Stroke of Undetermined Source.

INTRODUCTION: Upon completion of the workup for stroke, etiology cannot be identified in approximately one-third of the patients, with an embolic stroke of undetermined source (ESUS) accounting for around 50% of these cryptogenic etiologies. Whether management of complex long-term monitoring in order to detect suspected atrial fibrillation (AFib) could be initiated and managed through a neurologist is not sufficiently investigated. PATIENTS AND METHODS: We recruited all consecutive patients with ESUS who received implantation after neurological adjudication of Reveal LINQ® loop recorder between January 2016 and July 2020. We collected demographic, clinical, heart- and neuroimaging, laboratory, and electrocardiographic data assessed on prolonged baseline ECG monitoring, number of supraventricular (SVEs) and ventricular (VEs) extrasystolic complexes, and from preimplantation ECG-PQ interval. AFib detection was manually supervised and determined positive when the duration was over 120 s. RESULTS: We followed a total of 131 patients for a median of 504 days. There were 45 (34%) manually verified AFib diagnoses. In univariate analysis, earlier implantation after ESUS was associated with AFib detection (13 vs. 31 days, p = 0.011). In multivariate analysis, increased rate of AFib was associated with a more prolonged PQ interval (per 50-ms increase) (HR 1.99, 95% CI 1.39-2.85) and number of SVEs (HR 1.29, 95% CI 1.05-1.57) measured on pre-implantation ECG. CONCLUSION: We observed similar predictors for Afib after ESUS, albeit with higher frequency than previously reported. This study suggests that the neurologist-led decision, management, and evaluation of ILR after ESUS is feasible.

Influence of the circle of Willis on leptomeningeal collateral flow in anterior circulation occlusive stroke: Friend or foe?

BACKGROUND: Clinical outcome after large vessel occlusion (LVO) stroke depends on collateral integrity. We aimed to evaluate whether the completeness of the circle of Willis (CoW) and anterior temporal artery (ATA) determines the status of leptomeningeal collaterals (LC) in patients with acute LVO (internal carotid artery (ICA) and middle cerebral artery M1 (MCA) occlusion) treated with endovascular thrombectomy. PATIENTS AND METHODS: LC, cross-flow through the anterior communicating artery (ACoA), presence of the ipsilateral posterior communicating artery (IpsiPCoA) and presence of the ATA were evaluated using CT angiography. LC was graded as good when ≥50% collateral filling was noted compared to the unaffected hemisphere. RESULTS: We included 159 patients with a median age of 75 years (IQR 63-82), MCA M1 occlusion in 96 (60%) and good outcome in 68 (45.6%). The LC were good in 129 (81.1%) patients. Complete IpsiPCoA and incomplete ACoA status was inversely associated with good LC in LVO (OR 0.51 (95% CI 0.02-0.07)). A complete CoW was associated with good LC in ICA occlusions, OR 8.4 (p = .025). Good outcome (modified Rankin scale 0-2 at 3 months) was associated with good LC (OR 5.63 (95% CI 1.11-28.4)), small ischemic lesion volume (OR 0.94 (95% CI 0.97-0.98)) and absence of the ACoA and IpsiPCoA (OR 4.47 (95% CI 1.09-18.3)). CONCLUSIONS: ATA presence was associated with good leptomeningeal collaterals in LVO (OR 8.13 (95% CI 1.69-39.0)) and in MCA M1 patients (OR 7.9 (95% CI 1.7-36.4)). The effect of ATA was most pronounced in MCA M1 occlusions, and that of ACoA was most pronounced in ICA occlusions.

Acute treatment of stroke due to spontaneous calcified cerebral emboli causing large vessel occlusion.

INTRODUCTION: Calcified cerebral emboli (CCE) are rarely responsible for large vessel occlusion (LVO) in acute anterior stroke, and therefore therapeutic experience is scarce. We sought to expand current knowledge upon therapeutic options with three new cases and a review of current literature. METHODS: Systematic search of patients with acute anterior stroke due to LVO in one comprehensive stroke center throughout a 4 year period. Literature search for reported cases of CCE. RESULTS: In total, 21 cases (19 found in literature and 3 from our institution) are reported with a median age of 72 years (interquartile range [IQR] 63-80). Eleven patients were treated acutely, 4 of them with endovascular thrombectomy (EVT). Middle cerebral artery (MCA) M1 was the most affected segment and large artery atherosclerosis (LAA) and cardioembolism (CE) was causative in 41% of cases. EVT was significantly superior to intravenous recombinant tissue plasminogen activator (rtPA) at p = .048 (Fisher's exact test, chi square 6.7). CONCLUSIONS: Given the small sample reported in literature and no reported randomised studies, definitive recommendations could not be reached. However, considering thrombus composition, thrombolysis is most probably not sufficient and priority should be given to EVT.

Delayed Hospital Presentation and Neuroimaging in Non-surgical Spinal Cord Infarction.

BACKGROUND: Lack of timely recognition and neuroimaging may be a barrier to reperfusion efforts in acute spinal cord infarction. METHODS: We performed a retrospective study of patients diagnosed with acute non-surgical spinal cord infarction at our tertiary academic center from 2001 to 2015. We studied parameters associated with time from symptom onset to initial hospital presentation and magnetic resonance imaging (MRI) of the spinal cord. RESULTS: We identified 39 patients among whom anterior spinal artery syndrome was the most frequent presentation (87.2%) and atherosclerosis the most common etiology (56.4%). Nearly, half of the patients presented to the emergency department on the same day of symptom onset (48.7%) but only nine (23.1%) within the first 6 h. Average time from symptom onset to spinal cord MRI was 3.2 days. We could not identify clinical, radiological, or outcome patterns associated with early vs. delayed presentation and imaging. DISCUSSION: Our study found a time lag from symptom onset to hospital presentation and spinal cord MRI in patients with acute spinal cord infarction. These findings point at low clinical suspicion of spinal cord syndromes and limited recognition as a potentially treatable medical emergency.

Intravenous thrombolysis in acute ischemic stroke after dabigatran reversal with idarucizumab - a case report.

Much excitement has been generated with the approval of idarucizumab, a humanized monoclonal antigen-binding antibody fragment that is capable of reversing the anticoagulant activity of dabigatran. Here, we describe our initial experience of using tissue plasminogen activator (tPA) in an acute posterior circulation ischemic stroke after dabigatran reversal with idarucizumab. Both treatments were well tolerated and no hemorrhagic or procoagulatory complications were observed. We propose that the option of dabigatran reversal needs to be considered for contemporary treatment concepts of acute ischemic stroke.

Ignoring floor and ceiling effects may underestimate the effect of carotid artery stenting on cognitive performance.

INTRODUCTION: Data on neuropsychological outcome after carotid artery stenting (CAS) remain inconsistent, furthermore cognitive outcome seems to be unpredictable in the individual case. Previous studies reporting improvement or decline might be due to ceiling and floor effects of the applied cognitive tests. We applied cognitive testing before and after CAS, avoiding the pitfall of ceiling and floor effects. METHODS: In our prospective database, we identified 72 patients free of clinical stroke with ≥70% carotid artery stenosis, who were treated with CAS. They were administered a neurocognitive test battery before and 3 months after CAS to compare cognitive performance before and after CAS. To avoid ceiling and floor effects of test performances, we additionally analysed subgroups of patients without baseline floor and ceiling cognitive performance. RESULTS: Pre-interventional to post-interventional cognitive performance improved significantly in the subtests measuring verbal episodic memory; deterioration was observed in spatial memory. The subgroups of patients without baseline floor and ceiling cognitive performance improved in measures of global cognition, verbal episodic memory (patients with left-sided CAS) and divided attention (patients with right-sided CAS); we observed no significant effects in the other domains. CONCLUSIONS: Ignoring floor and ceiling effects may underestimate the impact of CAS on cognitive performance.

Cerebral hypoperfusion during carotid artery stenosis can lead to cognitive deficits that may be independent of white matter lesion load.

Studies investigating cognitive impairment in stroke-free patients with carotid artery stenosis have led to inconsistent results. Furthermore, the pathophysiological mechanism leading to cognitive impairment remains unclear. Cerebral hypoperfusion and arterio-arterial microembolization are discussed. The aims of our study were (1) to delineate patterns of cognitive impairment in stroke-free patients with carotid artery stenosis and (2) to investigate if cognitive impairment is independent of white matter lesion load in brain MRI. We identified 212 (93 women, mean age 70.2) stroke free, non-demented patients, who were referred for carotid artery stenting or because of subjective cognitive impairment. All patients completed a neurocognitive test battery measuring verbal fluency, constructional praxis, figural memory, verbal short-term- and long-term-memory, verbal recognition memory, semantic processing, speed of cognitive processing and divided attention. Grade of maximum carotid artery stenosis was categorized into three groups (mild, moderate, or severe). White matter lesion load was graded using a visual rating scale. Cognitive test scores of groups with different grades of carotid artery stenosis were compared. Univariate regression analysis was used to measure the predictive value of carotid artery stenosis. Multivariate logistic regression analysis was performed when integrating carotid artery stenosis and white matter lesion load. Carotid artery stenosis negatively correlated with measures of verbal fluency, constructional praxis, verbal short-term-memory, semantic processing, speed of cognitive processing, and divided attention. After adjustment for white matter lesions, carotid artery stenosis did not independently predict divided attention. Significance persisted in all other cognitive domains. In our selected group of patients, a higher grade of carotid artery stenosis is associated with cognitive decline. This process is independent of white matter lesion load. Possible pathophysiological implications are discussed.