The prevalence of intracranial stenosis in patients at low and moderate risk of stroke

Optical Spectroscopy of Cerebral Blood Flow for Tissue Interrogation in Ischemic Stroke Diagnosis

Ischemic stroke remains a leading cause of morbidity and mortality worldwide, and early diagnosis is critical for improving clinical outcomes. This paper presents an optical design framework combining speckle contrast optical spectroscopy (SCOS) with multiwavelength reflectance spectroscopy to monitor subtle changes in cerebral blood flow during ischemic events. The research aims to enable precise tissue interrogation using high-resolution, low-scatter imaging. Key to the system's accuracy is a 1.55 μm small beam waist, a grating density of 1300 grooves/mm, and a 15.53 μm depth of focus. The calculated effective focal length of 8333.33 μm enhances the resolution to 4.07 μm, improving the detection of minor changes in tissue optical properties. We investigate the sensitivity of various near-infrared wavelengths (660, 785, 800, and 976 nm) to ischemic-induced changes, with particular emphasis on the 976 nm wavelength, which demonstrates superior tissue penetration and increased sensitivity to variations in blood perfusion and tissue density during ischemia. Optical markers such as spot-size widening, spatial intensity shifts, and central intensity decrease are identified as reliable indicators of ischemia. Our findings suggest that multiwavelength reflectance analysis, particularly in the near-infrared range, provides a practical, noninvasive approach for continuously monitoring ischemic strokes. This technique indicates potential for improving early diagnosis and real-time monitoring of cerebral perfusion, which allows for continuous, noninvasive monitoring of cerebral perfusion and management of ischemic strokes, improving patient outcomes and clinical decision-making.

No relationship between right-to-left shunt with the severity of white matter hyperintensities

INTRODUCTION

Studies have shown that right-to-left shunt (RLS) is closely related to the occurrence of white matter hyperintensities (WMHs). Therefore, the detection of RLS is of great significance for the diagnosis and treatment of cerebral small vessel disease, especially for the prevention and treatment of WMHs. In this study, the c-TCD foaming experiment was selected to screen RLS, and evaluate the correlation between RLS and the severity of WMHs.

METHODS

We enrolled 334 migraineurs from a multicentre study from July 1 2019 and January 31 2020. Participants were all evaluated using contrast-enhanced transcranial Doppler, magnetic resonance imaging (MRI), and completed a questionnaire covering demographics, the main risk factors of vascular disease, and migraine status. RLS was classified into four grades (Grade 0 = Negative; Grade I = 1 ≤microbubbles (MBs)≤ 10; Grade II = MBs > 10 and no curtain; Grade III = curtain). Silent brain ischemic infarctions (SBI) and white matter hyperintensities (WMHs) were evaluated on MRI.

RESULTS

In the incidence of WMHs, we found a significant difference between patients with RLS and no RLS (p < 0.05). There is no relationship between different grades of RLS and the severity of WMHs (p > 0.05).

CONCLUSION

Overall, the positive rate of RLS is related to the incidence of WMHs. The different grades of RLS have no-relationship to do with the severity of WMHs.

Accurately Identifying Cerebroarterial Stenosis from Angiography Reports Using Natural Language Processing Approaches

Patients with intracranial artery stenosis show high incidence of stroke. Angiography reports contain rich but underutilized information that can enable the detection of cerebrovascular diseases. This study evaluated various natural language processing (NLP) techniques to accurately identify eleven intracranial artery stenosis from angiography reports. Three NLP models, including a rule-based model, a recurrent neural network (RNN), and a contextualized language model, XLNet, were developed and evaluated by internal–external cross-validation. In this study, angiography reports from two independent medical centers (9614 for training and internal validation testing and 315 as external validation) were assessed. The internal testing results showed that XLNet had the best performance, with a receiver operating characteristic curve (AUROC) ranging from 0.97 to 0.99 using eleven targeted arteries. The rule-based model attained an AUROC from 0.92 to 0.96, and the RNN long short-term memory model attained an AUROC from 0.95 to 0.97. The study showed the potential application of NLP techniques such as the XLNet model for the routine and automatic screening of patients with high risk of intracranial artery stenosis using angiography reports. However, the NLP models were investigated based on relatively small sample sizes with very different report writing styles and a prevalence of stenosis case distributions, revealing challenges for model generalization.

Movement Disorders Associated With Cerebral Artery Stenosis: A Nationwide Study

Background

Studies of secondary movement disorder (MD) caused by cerebrovascular diseases have primarily focused on post-stroke MD. However, MD can also result from cerebral artery stenosis (CAS) without clinical manifestations of stroke. In this study, we aimed to investigate the clinical characteristics of MD associated with CAS.

Materials and Methods

A nationwide multicenter retrospective analysis was performed based on the data from patients with CAS-associated MDs from 16 MD specialized clinics in South Korea, available between January 1999 and September 2019. CAS was defined as the >50% luminal stenosis of the major cerebral arteries. The association between MD and CAS was determined by MD specialists using pre-defined clinical criteria. The collected clinical information included baseline demographics, features of MD, characteristics of CAS, treatment, and MD outcomes. Statistical analyses were performed to identify factors associated with the MD outcomes.

Results

The data from a total of 81 patients with CAS-associated MD were analyzed. The mean age of MD onset was 60.5 ± 19.7 years. Chorea was the most common MD (57%), followed by tremor/limb-shaking, myoclonus, and dystonia. Atherosclerosis was the most common etiology of CAS (78%), with the remaining cases attributed to moyamoya disease (MMD). Relative to patients with atherosclerosis, those with MMD developed MD at a younger age (p < 0.001) and had a more chronic mode of onset (p = 0.001) and less acute ischemic lesion (p = 0.021). Eight patients who underwent surgical treatment for CAS showed positive outcomes. Patients with acute MD onset had a better outcome than those with subacute-to-chronic MD onset (p = 0.008).

Conclusions

This study highlights the spectrum of CAS-associated with MD across the country. A progressive, age-dependent functional neuronal modulation in the basal ganglia due to CAS may underlie this condition.

Analysis of young ischemic stroke patients in northeast China

Background

Limited research has been conducted to address stroke etiology in young patients in developing countries. We aimed to analyze risk factors and etiology of ischemic stroke (IS) in young patients of northeast China.

Methods

We retrospectively analyzed ischemic stroke patients aged 15-49 years in a single-center study from January 2013 to December 2017. Demographics and clinical information, including imaging studies, were retrieved for all patients. Patients were first compared according to sex and age. They were then divided into the first-ever and recurrent stroke groups; risk factors and stroke etiology between the two groups were compared.

Results

Of the 956 patients (median age 45 years) included, 78.9% were males. The most frequent risk factors were hypertension (60.0%), dyslipidemia (55.3%), smoking (54.1%), and alcohol consumption (49.6%). The most common etiology of stroke was large-artery atherosclerosis (LAA, 43.7%). In total, 789 patients experienced first-ever stroke and 167 patients experienced recurrent stroke. Recurrent stroke patients more often suffered from hypertension (70.7% versus 57.8%, P=0.002), diabetes (35.3% versus 24.8%, P=0.005), and coronary heart disease (10.2% versus 5.1%, P=0.011), and were less likely to be smokers (44.3% versus 56.1%, P=0.005) and consume alcohol (38.3% versus 52.0%, P=0.001). Recurrent strokes were more frequently caused by LAA (42.1% versus 52.5%, P=0.026) and less often by small-vessel disease (40.9% versus 29.9%, P=0.008).

Conclusions

LAA is the most common etiology in Chinese young stroke patients, especially in those with recurrent stroke. Our data highlight the need of screening of LAA and prevention and management of conventional stroke risk factors in young people of China.