Transcranial Doppler as a Predictor of Ischemic Events in Carotid Artery Dissection

The role of emboli detection studies in acute inpatient vertebral artery dissection

BACKGROUND

Prompt diagnosis and treatment of vertebral artery dissection (VAD) is critical for preventing stroke. The use of emboli detection studies (EDS) using Doppler ultrasonography is an emerging method that has been proposed to predict stroke risk and guide subsequent treatment. Limited data exists on the predictive value of this emerging modality in the posterior circulation. This study aims to assess the predictive value of emboli detection studies (EDS) in forecasting inpatient stroke in VAD patients and identify associated risk factors. Patients were recruited between January 2009 and January 2018.

METHODS

We performed a retrospective analysis of 104 consecutive patients with VAD who underwent EDS at our institution. Patients underwent transcranial ultrasonography for detection of microemboli and were followed clinically and radiographically thereafter for evidence of stroke.

RESULTS

A total of 104 patients with spontaneous (58 %), traumatic (39 %) or iatrogenic (4 %) VAD were included in our analysis. Stroke occurred more frequently in patients with spontaneous VAD compared to traumatic VAD (p < 0.001). Microemboli were detected in 17 patients (16 %), including 18.3 % of spontaneous VAD, 12.5 % of traumatic VAD, and 25 % of iatrogenic VAD. 61 patients (59 %) suffered a posterior circulation stroke, however there was no significant association between detection of microemboli and stroke events (60 % of patients without microemboli vs. 53 % of patients with ≥ 1 HITS during EDS; p = 0.6). Similarly, no microemboli were detected in any of the patients who went on to develop a delayed stroke.

CONCLUSIONS

In our single-institution retrospective analysis of patients with VAD, the detection of microemboli on EDS was not associated with stroke nor was it predictive of delayed stroke. Additionally, patients with spontaneous VAD may be at higher risk for stroke compared to traumatic VAD.

Treatment and Outcomes of Cervical Artery Dissection in Adults: A Scientific Statement From the American Heart Association

Cervical artery dissection is an important cause of stroke, particularly in young adults. Data conflict on the diagnostic evaluation and treatment of patients with suspected cervical artery dissection, leading to variability in practice. We aim to provide an overview of cervical artery dissection in the setting of minor or no reported mechanical trigger with a focus on summarizing the available evidence and providing suggestions on the diagnostic evaluation, treatment approaches, and outcomes. Writing group members drafted their sections using a literature search focused on publications between January 1, 1990, and December 31, 2022, and included randomized controlled trials, prospective and retrospective observational studies, meta-analyses, opinion papers, case series, and case reports. The writing group chair and vice chair compiled the manuscript and obtained writing group members' approval. Cervical artery dissection occurs as a result of the interplay among risk factors, minor trauma, anatomic and congenital abnormalities, and genetic predisposition. The diagnosis can be challenging both clinically and radiologically. In patients with acute ischemic stroke attributable to cervical artery dissection, acute treatment strategies such as thrombolysis and mechanical thrombectomy are reasonable in otherwise eligible patients. We suggest that the antithrombotic therapy choice be individualized and continued for at least 3 to 6 months. The risk of recurrent dissection is low, and preventive measures may be considered early after the diagnosis and continued in high-risk patients. Ongoing longitudinal and population-based observational studies are needed to close the present gaps on preferred antithrombotic regimens considering clinical and radiographic prognosticators of cervical artery dissection.

Antiplatelets or anticoagulants? Secondary prevention in cervical artery dissection: an updated meta-analysis

BACKGROUND

Extracranial artery dissection involving either internal carotid artery or vertebral artery is a major cause of stroke in adults under 50 years of age. There is no conclusive evidence whether antiplatelets or anticoagulants are better suited in the treatment of extracranial artery dissection.

OBJECTIVES

To determine whether antiplatelets or anticoagulants have advantage over the other in the treatment of extracranial artery dissection for secondary prevention of recurrent ischemic events or death.

METHODS

Present meta-analysis followed Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 statement. Database search was done in Medline, Cochrane Central Register of Controlled Trials (CENTRAL) and ClinicalTrials.gov from inception to May 2021 using pre-defined search strategy. Additional studies were identified from reference lists from included studies, reviews and previous meta-analyses. Outcome measures were ischaemic stroke, ischaemic stroke or transient ischaemic attack (TIA), and death.

RESULTS

Two RCTs and 64 observational studies were included in the meta-analysis. While the outcome measures of stroke, stroke or TIA and death were numerically higher with antiplatelet use, there were no statistically significant differences between antiplatelets and anticoagulants.

CONCLUSION

We found no significant difference between antiplatelet and anticoagulation treatment after extracranial artery dissection. The choice of treatment should be tailored to individual cases.

Evaluation on the application of transcranial Doppler (TCD) and electroencephalography (EEG) in patients with vertebrobasilar insufficiency

BACKGROUND

To evaluate the diagnostic value of transcranial Doppler (TCD) and electroencephalography (EEG) in patients with vertebrobasilar insufficiency (VBI) during clinical diagnosis and treatment METHODS: Eighty patients diagnosed with VBI in our hospital from June 2018 to December 2019 were randomly selected as the observation group, and 80 healthy people who received physical examination in the same period were selected as the control group. The abnormal rate, main performance and results, and the peak velocity of blood flow and vertebrobasilar artery blood flow of the two groups were compared.

RESULTS

The abnormal rate of EEG and TCD in VBI patients was 38.75% (31/80) and the 93.75% (75/80), respectively. In TCD examination, ACA, PCA, MCA, and VA of both sides of the observation group were higher than those of the control group, while BA was lower than that of the control group (P < 0.05). The Vs, Vd, and Vm on both sides of BA and VA in the observation group were lower than those in the control group, while PI and RI were higher than those in the control group (P < 0.05).

CONCLUSIONS

TCD examination is highly sensitive to the degree and pattern of cerebral ischemia in VBI patients. EEG examination will define the changes of brain cell function after cerebral ischemia. Therefore, EEG and TCD have their own advantages. The application of TCD and EEG can be considered in the early diagnosis, curative effect, and prognosis evaluation of VBI patients, so as to improve the accuracy of diagnosis and prognosis.

Transcranial Doppler ultrasonography in neurological surgery and neurocritical care

Transcranial Doppler (TCD) ultrasonography is an inexpensive, noninvasive means of measuring blood flow within the arteries of the brain. In this review, the authors outline the technology underlying TCD ultrasonography and describe its uses in patients with neurosurgical diseases. One of the most common uses of TCD ultrasonography is monitoring for vasospasm following subarachnoid hemorrhage. In this setting, elevated blood flow velocities serve as a proxy for vasospasm and can herald the onset of ischemia. TCD ultrasonography is also useful in the evaluation and management of occlusive cerebrovascular disease. Monitoring for microembolic signals enables stratification of stroke risk due to carotid stenosis and can also be used to clarify stroke etiology. TCD ultrasonography can identify patients with exhausted cerebrovascular reserve, and after extracranial-intracranial bypass procedures it can be used to assess adequacy of flow through the graft. Finally, assessment of cerebral autoregulation can be performed using TCD ultrasonography, providing data important to the management of patients with severe traumatic brain injury. As the clinical applications of TCD ultrasonography have expanded over time, so has their importance in the management of neurosurgical patients. Familiarity with this diagnostic tool is crucial for the modern neurological surgeon.

Transcranial Doppler as a Predictor of Ischemic Events in Vertebral Artery Dissection

BACKGROUND AND PURPOSE

Transcranial Doppler (TCD) helps identify patients with carotid dissections at risk of ischemic events (IEs). There is paucity of data identifying independent predictors of IE in vertebral arterial dissection (VAD). We sought to investigate the clinical and ultrasound predictors of IE.

METHODS

Patients with VAD admitted between June 2017 and February 2020 were evaluated clinically and with TCD; sonographic curves, microembolic signals (MES), and the breath-holding index (BHI) test were applied. Covariates found on univariate screen (P < .25) were included in a multivariable linear regression to identify independent predictors of IEs.

RESULTS

Of 88 patients with 100 VAD, 75 (85.2%) were females with a mean age 37.9 ± 7.5 years. All patients received antiplatelet treatment. TCD monitoring lasted an average of 21 ± 2.1 minutes. TCD was abnormal in 23 cases (26.1%); 21 patients had abnormal sonographic curves in the vertebral/basilar arteries, while in 4 cases, MES were present and in 5 (4.5%), BHI was abnormal. None of the patients with a normal TCD had an IE. Six strokes occurred during follow up. On univariate analysis, male sex, diabetes, dyslipidemia, a previous myocardial infarct, migraine, time of consultation to the ER, bilateral VAD, MES, BHI abnormalities, post stenotic flow in the basilar artery (PFB), and basilar/vertebral velocities were significantly associated with the risk of IEs. In the multivariate analysis, only the presence of PFB was a significant predictor of IE (OR: 68.6, 95% CI 5-937, <.001).

CONCLUSIONS

TCD in VAD predicts patients at high risk of IE.

Cervical Artery Dissections with and without stroke, risk factors and prognosis: a Chilean prospective cohort

We aimed to characterize spontaneous cervical artery dissection (CeAD) patients with and without stroke and describe risk factors for cerebrovascular complications in a Chilean prospective cohort.

METHODS

Consecutive CeAD patients admitted to a Chilean center confirmed by neuroimaging. Logistic regression was used.

RESULTS

168 patients were included, median follow-up time was 157 days. Stroke occurred in 49 (29.2%) cases, 4 (2%) patients died, all of whom had a stroke, and 10 (6%) presented CeAD recurrence. In univariate analyses, men (odds ratio [OR] 3.97, 95% confidence interval [CI] 1.97-8.00, P < 0.001), internal carotid artery CeAD (OR 2.82, 95% CI 1.38-5.78, P = 0.005) and vessel occlusion (OR 4.45, 95% CI 1.38-14.38, P = 0.035) increased stroke risk. Conversely, vertebral artery dissection (OR 0.35, 95% CI 0.16-0.74, P = 0.006) and longer symptom onset to admission (O-A) time (OR 0.79, 95% CI 0.70-0.90, P < 0.001) were associated to decreased stroke risk. After multivariate analysis, men (OR 2.88, 95% CI 1.32-6.27, P = 0.008) and O-A time (OR 0.80, 95% CI 0.69-0.92, P = 0.002) remained independently associated with stroke.

CONCLUSION

CeAD presented commonly as a non-stroke entity, with favorable prognosis. Albeit to a higher frequency of CeAD in women, stroke occurred predominantly in men, who were admitted earlier.

Relationship of spontaneous microembolic signals to risk stratification, recurrence, severity, and mortality of ischemic stroke: a prospective study

Introduction

The presence of microembolic signals (MES) during the acute phase of stroke is poorly understood, and its role and clinical application in relation to risk stratification and prognosis in patients remain uncertain. We assessed the prevalence of spontaneous MES in acute stroke and their relationship with risk stratification, stroke recurrence, morbidity, and mortality.

Patients and methods

This was a prospective cohort study conducted in the Stroke Unit. The MES presence was evaluated by transcranial Doppler (TCD) in patients with ischemic stroke within 48 h. The outcomes (risk stratification, morbidity, mortality, and recurrence of a stroke) were followed up for 6 months. The relationship between risk stratification and MES was obtained by odds ratios and that between MES and stroke recurrence, morbidity, and mortality using multiple logistic regression; considering statistical significance at P < 0.05.

Results

Of the 111 patients studied, 70 were men (63.1%) and 90 were white (81.1%), with a median age of 68 years. The MES frequency was 7%. There was a significant relationship between MES and symptomatic carotid disease (OR = 22.7; 95% CI 4.1–125.7; P < 0.001), a shorter time to monitoring (OR = 12.4; 95% CI  1.4–105.4; P = 0.02), and stroke recurrence (OR = 16.83; 95% CI 2.01–141; P = .009).

Discussion

It was observed that the stroke recurrence adjusted for prior stroke was higher and earlier among patients with MES detection. In conclusion, MES demonstrated a significant correlation with symptomatic carotid disease and a shorter DELAY until monitoring, and could be a predictor for the early recurrence of stroke in the long term.