Prevalence and Incidence of Carotid-Fetal-Posterior Syndrome.

INTRODUCTION: Carotid-fetal-posterior (CFP) syndrome is a posterior cerebral artery (PCA) territory ischemic stroke/TIA caused by symptomatic ≥50% carotid stenosis or occlusion via fetal posterior communicating artery. We aimed to assess the incidence of CFP syndrome and prevalence of CFP syndrome among symptomatic ≥50% carotid stenosis or occlusion as these are unknown. METHODS: We reassessed consecutive CTAs from 4,042 persons and included locally admitted patients with ≥50% carotid stenosis or occlusion. These were assessed for symptoms and signs of possible posterior circulation stroke/TIA (suspicion of CFP syndrome). Among these, those with unilateral PCA territory stroke/TIA, ipsilateral stenosis, and fetal/fetal-type PCA were considered CFP syndrome. RESULTS: We included 208 locally admitted patients with ≥50% carotid stenosis or occlusion; 33 (16%) patients had suspicion of CFP syndrome, of which 3 (9%) had CFP syndrome. The prevalence of CFP syndrome was 2.9% of symptomatic ≥50% carotid stenosis or occlusion; incidence was 4.23 per 1,000,000 person-years. Also, we found a lower prevalence of CFP syndrome (0.9%, p = 0.047) among referred patients with symptomatic ≥50% carotid stenosis or occlusion than among locally admitted patients with symptomatic ≥50% carotid stenosis or occlusion. DISCUSSION/CONCLUSION: CFP syndrome has a low incidence and low prevalence among symptomatic carotid stenosis cases. Given lower prevalence of CFP syndrome among referred cases than local, CFP syndrome seems susceptible to underdiagnosis. On the other hand, few cases with suspicion of CFP syndrome had CFP syndrome, why CFP syndrome also seems susceptible to overdiagnosis if detailed assessment is not employed.

Risk of Stroke Recurrence After Intravenous Thrombolysis in Patients with Symptomatic Carotid Stenosis.

OBJECTIVE: To assess if intravenous thrombolysis (IVT) affects the risk of recurrent preoperative cerebrovascular events before carotid surgery or stenting in patients with symptomatic ≥ 50% carotid stenosis. METHODS: Three cohorts of symptomatic ≥ 50% carotid stenosis patients were merged. To make the control group relevant, we excluded patients not presenting with stroke on the day of symptom onset. The risk of preoperative cerebrovascular events up to 30 days was compared between the IVT-treated and non-IVT-treated. RESULTS: In total, 316 patients were included, 64 (20%) treated with IVT. Those treated with IVT had similar risk of recurrent ipsilateral ischemic stroke or retinal artery occlusion (12% at day 7, 12% at day 30) as those not treated (9% at day 7, 15% at day 30; adjusted HR 0.9, 95% CI 0.4-2.2). There was a tendency (p = 0.09) towards time-dependency in the data where the recurrence risk was higher in IVT-treated at day 0 (6% in IVT-treated, 1% in non-IVT-treated, OR 5.5, 95% CI 1.2-25.4, p = 0.03). This was not significant when adjusting for co-factors (adjusted OR 4.4, 95% CI 0.9-21.8, p = 0.07) and was offset by a later risk decrease, with no remaining risk difference between IVT-treated and non-IVT-treated at day 7. CONCLUSIONS: Intravenous thrombolysis treatment does not seem to affect the risk of recurrent ipsilateral ischemic stroke in patients with symptomatic ≥50% carotid stenosis: The risk is high in both IVT-treated and non-IVT-treated. However, there might be a risk increase on the day of IVT treatment that is offset by a risk decrease during the first week.

Defining carotid near-occlusion with full collapse: a pooled analysis.

PURPOSE: Create a new definition of near-occlusion with full collapse to predicting recurrent stroke. METHODS: Pooled analysis of two studies. Patients with symptomatic ≥ 50% carotid stenoses were included. Outcome was preoperative recurrent ipsilateral ischemic stroke or retinal artery occlusion within 28 days of presenting event. We analyzed several artery diameters on computed tomography angiography and stenosis velocity on ultrasound. RESULTS: A total of 430 patients with symptomatic ≥ 50% carotid stenosis were included, 27% had near-occlusion. By traditional definition, 27% with full collapse and 11% without full collapse reached the outcome (p = 0.047). Distal internal carotid artery (ICA) diameter, ICA ratio, and ICA-to-external carotid artery ratio were associated with the outcome. Best new definition of full collapse was distal ICA diameter ≤ 2.0 mm and/or ICA ratio ≤ 0.42. With this new definition, 36% with full collapse and 4% without full collapse reached the outcome (p < 0.001). CONCLUSIONS: Defining near-occlusion with full collapse as distal ICA diameter ≤ 2.0 mm and/or ICA ratio ≤ 0.42 seems to yield better prognostic discrimination than the traditional appearance-based definition. This novel definition can be used in prognostic and treatment studies of near-occlusion with full collapse.

Symptomatic and asymptomatic carotid near-occlusions have very similar angiographic appearance on CT-angiography.

The aim of this study was to compare the angiographic appearance of symptomatic and asymptomatic carotid near-occlusion. We have found no such previous study. The study hypothesis was that among symptomatic patients with ≥ 50% carotid stenosis, near-occlusion is more common and near-occlusions are more severe than among asymptomatic persons with ≥ 50% carotid stenosis. We reassessed consecutive CTAs from 4042 persons, 645 had ≥ 50% carotid stenosis, and 385 (60%) symptomatic. Near-occlusion was similarly common in symptomatic (105, 27%) and asymptomatic (56, 24%) cases. Among near-occlusions, the angiographic appearance was very similar between symptomatic and asymptomatic cases: mean stenosis lumen diameter (0.7 mm), distal ICA diameter (2.1 mm), and ECA ratio (0.79) were the same in both groups. Mean ICA ratio (0.46 and 0.48) and share of full collapse was very similar (45% and 42%). These findings add to the pathophysiological understanding of carotid near-occlusion.

Carotid near-occlusion is often overlooked when CT angiography is assessed in routine practice.

OBJECTIVE: Assess the sensitivity and specificity of computed tomography angiography (CTA) for carotid near-occlusion diagnosis interpreted in clinical practice against expert assessment. METHODS: CTAs were graded by two expert interpreters for near-occlusion. Findings were compared with clinical reports in 383 consecutive cases with symptomatic ≥ 50% carotid stenosis. In addition, 14 selected CTA exams (8 near-occlusions and 6 controls) were analyzed in a national effort by 13 radiologists experienced with carotid CTA. RESULTS: In clinical practice, imaging reports were 20% (95% CI 12-28%) sensitive for near-occlusion, ranging 0-58% between different radiologists; specificity was 99%. Among the 13 radiologists reviewing the same 8 near-occlusions, the average sensitivity was 8%, ranging 0-75%; specificity was 100%. CONCLUSIONS: Carotid near-occlusion is systematically under-reported in clinical routine practice, caused by limited application of grading criteria when assessing CTA. KEY POINTS: • Carotid near-occlusion is severe stenosis with distal artery collapse; this collapse is often subtle. • A fifth of near-occlusions were detected in routine practice. Many readers mistake near-occlusion for stenosis without distal artery collapse, either by not actively searching for subtle collapses or by not interpreting the collapse correctly when noticed. • On the other hand, the novice diagnostician should be cautioned to not over-diagnose near-occlusion; other causes of extracranial ICA asymmetry also exist such as distal disease and Circle of Willis anatomical variants.

Symptomatic carotid near-occlusion causes a high risk of recurrent ipsilateral ischemic stroke.

OBJECTIVE: To assess the risk of recurrent ipsilateral ischemic stroke in patients with symptomatic near-occlusion with and without full collapse. METHODS: Included were consecutive patients eligible for revascularization, grouped into symptomatic conventional ≥ 50% carotid stenosis (n = 266), near-occlusion without full collapse (n = 57) and near-occlusion with full collapse (n = 42). The risk of preoperative recurrent ipsilateral ischemic stroke was analyzed, or, for cases not revascularized within 90 days, 90-day risk was analyzed. RESULTS: The risk of a preoperative recurrent ipsilateral ischemic stroke or ipsilateral retinal artery occlusion was 15% (95% CI 9-20%) for conventional ≥ 50% stenosis, 22% (95% CI 6-38%) among near-occlusion without full collapse and 30% (95% CI 16-44%) among near-occlusion with full collapse (p = 0.01, log rank test). In multivariate analysis, near-occlusion with full collapse had a higher risk of recurrent ipsilateral ischemic stroke (adjusted HR 2.6, 95% CI 1.3-5.3) and near-occlusion without full collapse tended to have a higher risk (adjusted HR 2.0, 95% CI 0.9-4.5) than conventional ≥ 50% stenosis. Only 24% of near-occlusion with full collapse underwent revascularization, common causes for abstaining were misdiagnosis as occlusion (31%), deemed surgically unfeasible (21%) and low perceived benefit (10%). CONCLUSIONS: Symptomatic carotid near-occlusion has a high short-term risk of recurrent ipsilateral ischemic stroke, especially near-occlusion with full collapse.

Normal findings on pretreatment transcranial ultrasound in patients treated with sonothrombolysis.

In populations with a high (≥14) median National Institute of Health Stroke Score (NIHSS), a normal finding of Thrombolysis in Brain Ischemia grade 5 (TIBI 5) in the artery of interest has been reported to be an unusual finding when transcranial ultrasound is performed during thrombolysis. In such instances, a stroke mimic can be suspected, but there are alternative pathophysiological explanations. In this case series, the median NIHSS was relatively low (5), and 33% (6/18) of the patients treated with thrombolysis had TIBI 5 in the artery of interest at the time of treatment initiation. These 6 patients had normal findings on the computerized tomography angiography. Only 33% (2/6) of these patients were stroke mimics, the remaining had either lacunar (n = 2) or cortical strokes (n = 2). These cortical stroke patients probably had a pretreatment recanalization marked by partial symptom regression before treatment onset. Compared to patients with TIBI <5 at baseline, the patients with TIBI 5 at baseline tended to be younger (p = 0.19, Mann-Whitney test) and more often have lacunar syndrome (p = 0.18, χ(2) test). Thus, among patients treated with thrombolysis and with a low median NIHSS, a finding of TIBI 5 is not unusual. This does not mean that the patient has a stroke mimic per se, and it tends to be more common among patients with lacunar syndrome than among patients with cortical syndromes.

[Promising new treatment for acute ischemic stroke--Sonothrombolysis can enhance the effect of intravenous thrombolysis]. / Ny lovande behandling vid akut ischemisk stroke--Sonotrombolys kan förstärka effekten av intravenös trombolys.

Intravenous thrombolysis has been a break-through for treatment of acute ischemic stroke. However, total recanalization is only achieved in 18%. Sonothrombolysis aims at enhancing the recanalization effect by adding continuous transcranial ultrasound. Sonothrombolysis may facilitate the recanalization rate without increased risk of intracerebral hemorrhage. This further results in decreased risk of disability compared with only intravenous thrombolysis. Intravenously applied micro-bubbles is an additive treatment to sonothrombolysis which might further increase the recanalization rate but perhaps at the expense of increased risk of intracerebral hemorrhage. In a case-series at Umeå Stroke Center, we report the results of the first 20 ischemic stroke patients treated with sonothrombolysis in Sweden. Our initial results look promising with recanalization rates similar to earlier published data. No intracerebral hemorrhage occurred among our sonothrombolysed patients.