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Classification of watershed infarction (WSI): (a) types of WSI; (b) subtypes of cortical watershed infarction (CWI); (c) subtypes of internal watershed infarction (IWI)
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Background
Whether there are differences in pathogenesis among different types and subtypes of cerebral watershed infarction (WSI) is controversial since they have been combined into a single group in most previous studies.
Methods
We prospectively identified 340 supratentorial WSI patients at Beijing Chao-Yang Hospital, Capital Medical University...
Context in source publication
Context 1
... experienced neurologists (Lei Yang and Man Li) who were unaware of the patient's clinical information typed the classification with templates [7]. CWI was defined as hyperintense areas on DWI sequence in the junctions of the anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA) territories, as a thin fronto-parasagittal wedge. CWI was further divided into anterior watershed infarc- tion (AWI, between ACA and MCA), posterior water- shed infarction (PWI, between MCA and PCA) and both-type infarction (AWI plus PWI). IWI was defined as hyperintense areas on DWI sequence between the deep and superficial perforating arteries of the MCA, and further divided into partial IWI (P-IWI, a single lesion or a chain-like, the so-called "rosary-like" pattern in the centrum semiovale) and confluent IWI (C-IWI, large cigar-shaped infarction alongside the lateral ventricle). A concurrence of CWI and IWI was identified as mixed-type infarction. Classifications of WSI, CWI and IWI is presented in Fig. ...
Citations
... Based on the characteristics of DWI lesion distribution [23,24], two groups (hypoperfusion and non-hypoperfusion groups) were divided for ease of analysis. The hypoperfusion group was defined as a mixed mechanism of simple WSI and WSI combined with embolism. ...
Purpose
Cerebral hemodynamics are important for the management of intracranial atherosclerotic stenosis (ICAS). The quantitative flow ratio (QFR) is a novel angiography-derived index for assessing the functional relevance of ICAS without pressure wires and adenosine. Good diagnostic yield with the hyperemic fractional flow reserve (FFR) have been reported, while data on the comparison of QFR to FFR are scarce.
Methods
In this prospective study 56 patients with anterior circulation symptomatic ICAS who received endovascular treatment were included. The new method of computing QFR from a single angiographic view, i.e., the Murray law-based QFR (μQFR), was applied to the examined vessels. An artificial intelligence algorithm was developed to realize the automatic delineation of vascular contour. Pressure gradients were measured before and after treatment within the lesion vessel using a pressure guidewire and the FFR was calculated.
Results
There was a good correlation between μQFR and FFR. Preoperative FFR predicted DWI watershed infarction (FFR optimal cut-off level: 0.755). Preoperative μQFR predicted DWI watershed infarction (μQFR optimal cut-off level: 0.51). Preoperative FFR predicted CTP hypoperfusion (FFR best predictive value: 0.62). Preoperative μQFR predicted CTP hypoperfusion (μQFR best predictive value: 0.375).
Conclusion
The μQFR based on DSA images can be used as an indicator to assess the functional status of the lesion in patients with ICAS.
... Micro embolism is also believed to contribute to the same from the heart or narrowed arteries. [2] Caplan suggested that hemodynamic compromise and micro embolism act together in border zone infarcts. [3] In a study by Yong et al., [1] 120 patients with border zone stroke were identified and divided into internal border zone (IBZ) and cortical border zone (CBZ) territories. ...
... Also the category of "mixed" both CBZ + IBZ was promoted for the first time in 2017 studies. [12][13][14] As most radiologists are not familiar with these refinements, it is possible we have missed mixed BI in our study (diagnosis of BI was made on MRI DWI images by radiologist blinded to clinical data). ...
... We found that hypertension, diabetes, and smoking were more common in IBZ patients as compared to CBZ patients. Similar results and the degree of cerebrovascular stenosis in different types and subtypes of cerebral watershed infarction were observed by Li Y [12] and El-Gammal et al. [13] Results of our study suggested that most BI were not severely disabling infarcts, they tend to improve rapidly, and hospital stay was short. This may in part be due to less cytotoxic edema, small infarct size, and the dynamic nature of watershed circulation. ...
... This may in part be due to less cytotoxic edema, small infarct size, and the dynamic nature of watershed circulation. Similar results were observed in the study by Akbur TM et al. [15] Recent literature comparing the prognosis between CBZ and IBZ [11][12][13]16] has shown higher chances of clinical deterioration and poorer outcomes of IBZ as compared to CBZ. Poor prognosis in IBZ may be deep white matter loss where fibers are densely packed. ...
Introduction
A border zone infarct (BI) is defined as an infarction that is localized to watersheds or border zones in the brain. BI is further classified into cortical border zone infarct (CBZ) and internal border zone infarct (IBZ). This study was conducted to explore the clinical and radiological characteristics of BI.
Materials and Method
The study was conducted on eligible 400 acute ischemic stroke patients out of which 52 BI patients (diagnosed by the radiologist on DWI MRI images), patients >18 yrs of age were selected and divided into two groups of IBZ and CBZ infarct patients. The degree of intracranial and extracranial stenosis and characteristics on clinical presentation were assessed. The data were collected and analyzed using SPSS version 20.0 software at significance level p-value <0.05.
Results
25% and 75% of CBZ and IBZ patients, respectively, had history of presyncope or syncope before stroke. On vascular evaluation, 3.9% and 51.9% were in MCA and ICA stenosis group, respectively. Evidence of cardio embolism was found in 17.3% of patients. 53.3% of CBZ and 53.8% of IBZ patients were in ICA stenosis group, and 6.7% of CBZ and 7.7% of IBZ patients were in MCA stenosis group, with a statistically insignificant relation (p-value >0.05).
Conclusion
Association of BI with events causing hypotension or hypovolemia is well-established in our study, association of BI with large vessel atherosclerosis is common, and its contribution to CBZ and IBZ seems to be equal.
... Yet, the cause is still widely debated. To date, hemodynamic impairment from severe luminal stenosis is implicated as a determinant of internal watershed infarcts [3] with recent studies establishing stronger correlation between hemodynamic impairment and carotid steno-occlusion in its pathogenesis [4]. External watershed infarcts, conversely, are regarded as induced by micro embolism due to the lower level of cerebral vasoreactivity impairment and oxygen metabolism [5]. ...
Background and purpose:
Watershed infarcts denote ischemic lesions involving the distal territories of two major arteries. For years, hypotheses on its pathophysiological mechanisms have been proposed. Yet, the cause is still widely debated. This study aimed to determine the mechanism of watershed strokes and compare their clinical outcomes to acute ischemic stroke from other causes and predict the factors affecting clinical outcomes in patients with watershed infarcts.
Methods:
This single-center, comparative, six-years retrospective cohort study included patients with a diagnosis of Acute Ischemic Stroke. Patients were classified under watershed group or acute ischemic stroke based on their neuroimaging findings. Stroke mechanisms were determined between groups as well as the factors associated with clinical outcomes in watershed strokes.
Results:
Among the 424 patients included in the study, large artery atherosclerosis was seen in greater frequency in patients with watershed infarcts regardless of the type (EWIs: n = 68, 73% vs IWIs: n = 89, 75%). No differences observed in the clinical outcomes between groups. Multiple variable analysis showed that age, female sex, high NIHSS score and presence of underlying malignancy were associated with clinical outcomes.
Conclusion:
Clinical outcomes between watershed infarcts and acute ischemic strokes were similar. Hemodynamic compromise in the setting of severe stenosis is the underlying mechanism for both types of watershed strokes thus, the goal of treatment is to maintain adequate perfusion. High baseline NIHSS score, increased age, female gender and underlying malignancy were all poor predictors of clinical outcomes in patients with watershed strokes.
... It has been found that patients with vascular CI often show a decrease in blood flow velocity in the cerebral cortex, especially in the frontal and parietal regions [14,15]. These brain regions are known to be the watersheds of the blood supply, at the boundaries between the vascular pools [16][17][18]. These zones are more disadvantaged than any other brain region in the case of systolic and/or diastolic dysfunction of the left ventricle, valvular pathology and atrial fibrillation accompanying cardiovascular pathology, as well as during cardiac surgery [11,19]. ...
Background: The negative effects of high-grade carotid stenosis on the brain are widely known. However, there are still insufficient data on the brain state in patients with small carotid stenosis and after isolated or combined coronary and carotid surgery. This EEG-based study aimed to analyze the effect of carotid stenosis severity on associated brain activity changes and the neurophysiological test results in patients undergoing coronary artery bypass grafting (CABG) with or without carotid endarterectomy (CEA). Methods: One hundred and forty cardiac surgery patients underwent a clinical and neuropsychological examination and a multichannel EEG before surgery and 7–10 days after surgery. Results: The patients with CA stenoses of less than 50% demonstrated higher values of theta2- and alpha-rhythm power compared to the patients without CA stenoses both before and after CABG. In addition, the patients who underwent right-sided CABG+CEA had generalized EEG “slowdown” compared with isolated CABG and left-sided CABG+CEA patients. Conclusions: The on-pump cardiac surgery accompanied by specific re-arrangements of frequency–spatial patterns of electrical brain activity are dependent on the degree of carotid stenoses. The information obtained can be used to optimize the process of preoperative and postoperative management, as well as the search for neuroprotection and safe surgical strategies for this category of patients.
... At 3 months follow-up both groups showed significant improvement of mRS than on admission, yet IBZ group showed significantly less improvement than lacunar group. Likewise, bad prognosis of IBZ infarctions and good prognosis of lacunar infarctions were described by many studies [14,15]. On admission, VMR was impaired in more than half of the patients in the lacunar group and in all those in the IBZ group. ...
Background
Available data collected from patients of different types of cerebrovascular strokes can detect risk factors, severity and clinical outcome of these patients. Differentiating between different types of strokes is mandatory for early diagnosis and proper management. The aim of this study is to compare between cerebral small vessel disease with lacunar infarctions and internal border zone infarctions regarding vasomotor reactivity by using transcranial color-coded duplex and its correlation with their MRI perfusion, disease severity and outcome.
Results
On admission, 56.7% of patients in lacunar stroke had impaired reactivity vs. 100% of patients in internal border zone group. At 3 months follow-up, this number dropped to 23.3% in lacunar group, but persisted as 100% in internal border zone group. On comparing the 3 perfusion parameters between the 2 groups, there was statistically significant impairment in all parameters in patients with internal border zone infarction than patients with lacunar infarction (longer time to peak, decreased cerebral blood flow and cerebral blood volume). By comparing the severity of the stroke by using National Institute of Health and Stroke Scale, it was found that patients with internal border zone infarction had higher disability than patients with lacunar infarction on admission and on discharge. At 3 months follow-up, the lacunar group had a better outcome than of the border zone group.
Conclusion
Patients having internal border zone infarction had higher clinical disability and worse prognosis, together with more impairment in vasomotor reactivity and MRI perfusion parameters than patients having lacunar infarction.
... Previous reports cite that parieto-occipital and posterior temporal lobe involvement is more affected in HII than the anterior territories, and is also confirmed by our results of the distribution of watershed injury posteriorly in 81% of all cases and perisylvian involvement in 77% of cases [2,17]. This is likely because the posterior watershed territory is the end zone of all three major intracranial arteries and therefore the most vulnerable area for watershed infarction in the brain, which can explain the high frequency of posterior watershed involvement relative to anterior watershed in patients with ulegyria [18]. ...
... Current practice, research and writing focuses on early MRI findings of HII because making an early diagnosis allows the institution of appropriate management such as head cooling. The availability of MRI scanners and DWI for early detection of parenchymal HII has driven clinical protocols and much discussion and research has revolved around the timing of the first MRI scan in the immediate and subacute postpartum period [10,18]. Early papers describing the imaging findings of HII include chronic features such as atrophy and ulegyria [7]. ...
Background
Ulegyria is an under-recognized and underreported potential sequela of hypoxic-ischemic injury (HII) in full-term neonates. Ulegyria is a unique form of parenchymal scarring that leads to a mushroom-shape of the affected gyri resulting from volume loss at the deep portions of the sulci during HII in this specific period in infantile neurodevelopment. Identifying ulegyria is important for ascribing cause and timing of HII on delayed magnetic resonance imaging (MRI) scans and because of its close association with pharmaco-resistant epilepsy.
Objective
The purpose of this study was to determine the frequency of ulegyria and characterize the anatomical distribution of watershed injury in a large database of patients who developed cerebral palsy with term HII pattern and underwent delayed MRI.
Materials and methods
Patients with term HII patterns on MRI were analyzed for ulegyria. The frequency of ulegyria overall and for each pattern of HII distribution was determined as was the anatomical distribution of watershed injury.
Results
Of the 731 children with term HII and cortical injury, 484 (66%) had ulegyria. Ulegyria was most common in those cases with a combined watershed/basal ganglia-thalamic pattern (56%) and isolated watershed pattern (40%). Watershed injury in patients with ulegyria was most common at the posterior watershed (80.6%) and perisylvian watershed (76.7%).
Conclusion
Ulegyria was present in nearly two-thirds of patients with term HII and cortical injury and should be sought to support the diagnosis of previous perinatal HII, especially in posterior and perisylvian watershed regions. The implications of ulegyria can be significant for clinical decision-making and for ascribing timing of injury to the perinatal period.
... Acute ischemic infarction was defined as lacunar infarction (LI) in the lenticulostriate artery, cerebral watershed infarction (CWI), or territorial infarction (TI) with increased signal on DWI sequence. CWI (21), ischemic lesions between two nonanastomosing main arterial territories, can be classified as either cortical watershed infarction (WSI) or internal WI (IWI). TIA was defined as a transient episode of neurological dysfunction caused by focal brain, without increased signal on DWI sequence. ...
Background and Purpose
Previous studies on the presence of asymmetrical prominent cortical and medullary vessel signs (APCV/APMV) and collateral circulation in patients with internal carotid artery occlusion internal carotid artery occlusion (ICAO) are rare, and the conclusions are inconsistent. Our study aimed to investigate the relationship between the presence of APCV/APMV and collateral circulation in patients with ICAO.
Methods
Patients with acute ischemic stroke with ICAO were recruited in this study. All 74 patients were divided into two groups depending on the presence of APCV and APMV. The status of the cerebral arterial circle (CAC) was graded as poor or good. The poor CAC was defined as MCA was invisible. Severe stroke was defined as cerebral watershed infarction (CWI) or territorial infarction (TI). Clinical and radiological markers were compared between these two groups. Logistic regression was used to investigate the association between the APCV/APMV and clinical and radiological markers.
Results
A total of 74 patients with ICAO were enrolled. Forty-three patients (58.1%) presented with an APCV and APMV was found in 35 (47.2%) patients. Compared with patients with non-APCV, patients with APCV had a more severe stroke (P = 0.038) and had a significantly higher incidence of poor CAC (P = 0.022) than those with APCV. Patients with APMV had a more severe stroke (P = 0.001). Logistic regression showed that poor CAC was independently associated with APCV and severe stroke were independently associated with APMV.
Conclusions
Our study demonstrates that poor CAC was independently associated with the presence of the APCV in patients with ICAO. Severe stroke was independently associated with the APMV.
... For the cases of mildly symptomatic ICA occlusion, the forecast of neurological deterioration after hospitalization depends on whether the watershed infarction is internal (IWI) or cortical (CWI) [141]. IWI is associated with hemodynamic impairment and critical stenosis of ICA, it leads to worse hospital courses, early [142] and midterm [143] prognosis compared to CWI. Supposedly, severity of IWI is related to reduced perfusion altering blood flow currents and prompting microembolism to reach the blood vessels with the least efficient blood flow [144]. ...
Background: Recently, rapid fluctuations of ambient temperature were found to be associated with hospital admission for cardiovascular diseases in general and the ischemic stroke in particular. Objective: to test if climatic factors predict the incidence of stroke reliably and to study the predictive potential of risk factors for a stroke. Materials and methods: In a retrospective design, we studied 566 patients admitted to the stroke unit in 2016-2019. A distributed lag nonlinear model was used to explore immediate and delayed effects of weather and clinicodemographic risk factors on the stroke incidence. Supervised machine learning was used to build models predictive of the mRS score. We assessed model performance by calculating
$\text{R}^{2}$
, mean absolute error and root-mean-square error. Results and conclusions: We found a non-correlation between the weather parameters and statistics on stroke. The disparities in their trends lead us to investigate behind time effects of the environment with distributed lag models and a concordant impact of all the settings - with machine learning models. If categorized into two classes by severity and functional outcomes, the cases have few disparities in the weather parameters within a week before the stroke onset. In contrast to the groups classified by severity, the ones grouped by outcomes have a significant difference in age, nationality, the presence of background diseases and smoking status. We ranked environmental and individual risk factors by the information gain that they provide to the models. Inclusion of the weather parameters into the machine learning model predicting the mRS score provides a slight boost in performance.
... Cerebral hemodynamics play a key role in the stroke risk of CAS (6). Strokes in patients with high grade stenosis, in combination with inadequate collateral pathways in the circle of Willis (CoW), are likely to have a hemodynamic etiology due to a critical flow reduction ipsilateral to the stenosis (7). Furthermore, cerebral hemodynamics may play a role in the prevention of symptomatic CAS, given that patent collaterals have been associated with a reduced risk of stroke and transient ischemic attack (TIA) (8)(9)(10). ...
Management of asymptomatic carotid artery stenosis (CAS) relies on measuring the percentage of stenosis. The aim of this study was to investigate the impact of CAS on cerebral hemodynamics using magnetic resonance imaging (MRI)-informed computational fluid dynamics (CFD) and to provide novel hemodynamic metrics that may improve the understanding of stroke risk. CFD analysis was performed in two patients with similar degrees of asymptomatic high-grade CAS. Three-dimensional anatomical-based computational models of cervical and cerebral blood flow were constructed and calibrated patient-specifically using phase-contrast MRI flow and arterial spin labeling perfusion data. Differences in cerebral hemodynamics were assessed in preoperative and postoperative models. Preoperatively, patient 1 demonstrated large flow and pressure reductions in the stenosed internal carotid artery, while patient 2 demonstrated only minor reductions. Patient 1 exhibited a large amount of flow compensation between hemispheres (80.31%), whereas patient 2 exhibited only a small amount of collateral flow (20.05%). There were significant differences in the mean pressure gradient over the stenosis between patients preoperatively (26.3 vs. 1.8 mmHg). Carotid endarterectomy resulted in only minor hemodynamic changes in patient 2. MRI-informed CFD analysis of two patients with similar clinical classifications of stenosis revealed significant differences in hemodynamics which were not apparent from anatomical assessment alone. Moreover, revascularization of CAS might not always result in hemodynamic improvements. Further studies are needed to investigate the clinical impact of hemodynamic differences and how they pertain to stroke risk and clinical management.
