Acute Stroke and Transient Ischemic Attack in the Outpatient Clinic

Emergency medicine updates: Transient ischemic attack

INTRODUCTION

Transient ischemic attack (TIA) is a condition commonly evaluated for in the emergency department (ED). Therefore, it is important for emergency clinicians to be aware of the current evidence regarding the diagnosis and management of this disease.

OBJECTIVE

This paper evaluates key evidence-based updates concerning TIA for the emergency clinician.

DISCUSSION

TIA is a harbinger of ischemic stroke and can result from a variety of pathologic causes. While prior definitions incorporated symptoms resolving within 24 h, modern definitions recommend a tissue-based definition utilizing advanced imaging to evaluate for neurologic injury and the etiology. In the ED, emergent evaluation includes assessing for current signs and symptoms of neurologic dysfunction, appropriate imaging to investigate for minor stroke or stroke risk, and arranging appropriate disposition and follow up to mitigate risk of subsequent ischemic stroke. Imaging should include evaluation of great vessels and intracranial arteries, as well as advanced cerebral imaging to evaluate for minor or subclinical stroke. Non-contrast computed tomography (CT) has limited utility for this situation; it can rule out hemorrhage or a large mass causing symptoms but should not be relied on for any definitive diagnosis. Noninvasive imaging of the cervical vessels can also be used (CT angiography or Doppler ultrasound). Treatment includes antithrombotic medications if there are no contraindications. Dual antiplatelet therapy may reduce the risk of recurrent ischemic events in higher risk patients, while anticoagulation is recommended in patients with a cardioembolic source. A variety of scoring systems or tools are available that seek to predict stroke risk after a TIA. The Canadian TIA risk score appears to have the best diagnostic accuracy. However, these scores should not be used in isolation. Disposition may include admission, management in an ED-based observation unit with rapid diagnostic protocol, or expedited follow-up in a specialty clinic.

CONCLUSIONS

An understanding of literature updates concerning TIA can improve the ED care of patients with TIA.

Early Hemorrhagic Transformation after Reperfusion Therapy in Patients with Acute Ischemic Stroke: Analysis of Risk Factors and Predictors

Background: The standard reperfusion therapy for acute ischemic stroke (AIS) is considered to be thrombolysis, but its application is limited by the high risk of hemorrhagic transformation (HT). This study aimed to analyze risk factors and predictors of early HT after reperfusion therapy (intravenous thrombolysis or mechanical thrombectomy). Material and methods: Patients with acute ischemic stroke who developed HT in the first 24 h after receiving rtPA thrombolysis or performing mechanical thrombectomy were retrospectively reviewed. They were divided into two groups, respectively, the early-HT group and the without-early-HT group based on cranial computed tomography performed at 24 h, regardless of the type of hemorrhagic transformation. Results: A total of 211 consecutive patients were enrolled in this study. Among these patients, 20.37% (n = 43; age: median 70.00 years; 51.2% males) had early HT. Multivariate analysis of independent risk factors associated with early HT found that male gender increased the risk by 2.7-fold, the presence of baseline high blood pressure by 2.4-fold, and high glycemic values by 1.2-fold. Higher values of NIHSS at 24 h increased the risk of hemorrhagic transformation by 1.18-fold, while higher values of ASPECTS at 24 h decreased the risk of hemorrhagic transformation by 0.6-fold. Conclusions: In our study, male gender, baseline high blood pressure, and high glycemic values, along with higher values of NIHSS were associated with the increased risk of early HT. Furthermore, the identification of early-HT predictors is critical in patients with AIS for the clinical outcome after reperfusion therapy. Predictive models to be used in the future to select more careful patients with a low risk of early HT need to be developed in order to minimize the impact of HT associated with reperfusion techniques.

Contribution of Hydrogen Sulfide to Dilation of Rat Cerebral Arteries after Ischemia/Reperfusion Injury

The study examined the effect of H₂S on the tone of cerebral arteries in rats after global cerebral ischemia/reperfusion injury and cooperation between NO and H₂S in the control over cerebral circulation during the postischemic period. In control sham-operated and in experimental rats with ischemia/reperfusion injury, the diameter of pial arteries was repeatedly measured in vivo under a light microscope after removal of parietal bone and dura mater in 1 h and in 7 days after the surgery. The study established that H₂S is an important signaling molecule in pial arteries, where it is responsible for vasodilation. Interaction of H₂S and NO augmented dilation of pial arteries; in these arteries, H₂S up-regulated the effect of NO/cGMP/sGC/PKG signaling pathways. Partially, the dilating effect of H₂S is realized via activation of ATP-sensitive K⁺ channels in plasmalemma of smooth muscle cells. In the brain, ischemia/reperfusion injury degrades the ability of pial arteries to dilate via inhibition of NO-mediated signaling pathway.

Clinical Relevance of Orthostatic Hypotension in Patients with Atrial Fibrillation and Suspected Transient Ischemic Attack

INTRODUCTION

Orthostatic hypotension (OH) and atrial fibrillation (AF) are both regarded as independent risk factors for transient ischemic attack (TIA). However, the clinical implication of OH in the presence of AF is unclear. This study investigates, for the first time, the association between blood pressure (BP), OH and mortality in a cohort of patients with AF and TIA symptoms.

AIM

To investigate the incidence of the association between OH, AF and TIA.

METHODS

This retrospective observational study utilised the Leicester one-stop transient TIA clinic patient database to consider the initial systolic and diastolic BP of 688 patients with a diagnosis of AF. The primary outcome was time until death. Covariant measures included status of AF diagnosis (known or new AF), cardiovascular risk factors, and primary clinic diagnosis [cerebrovascular (CV) versus non-cerebrovascular (non-CV)]. Statistical models adjusted for sex, age, previous AF diagnosis.

RESULTS

Mortality rate was higher in the over 85 age group [191.5 deaths per 1000 person years (py) (95% CI 154.0-238.1)] and lower in the aged 75 and younger age group [40.0 deaths per 1000 py (95% CI 27.0-59.2)] compared to intermediate groups. A 10 mmHg increase in supine diastolic BP was associated with a significant reduction in the hazard of mortality for patients suspected of TIA with AF [adjusted HR 0.79 (95% CI 0.68-0.92), p < 0.001]. The mortality rate for patients with OH was 119.0 deaths per 1000 py compared with a rate of 98.0 for patients without OH (rate ratio 1.2, p = 0.275).

CONCLUSION

Higher diastolic BP may be a marker for reduced mortality risk in patients with a previous AF diagnosis and non-CV diagnosis. Lower diastolic BP and the presence of AF pertain to a higher mortality risk. This study raises the importance of opportunistic screening for both OH and AF in patients presenting to TIA clinic.

Neuropsychiatric symptoms as the only acute manifestation of a stroke in the left hemisphere. Case report

We report the case of a 60-year-old female patient with a history of hypertension and dyslipidemia, who suddenly presented with a clinical picture of emotional lability, disorientation, complex visual hallucinations and persecutory delusions. There were no associated neurological findings in her initial physical examination. At a local hospital she was initially diagnosed with late-onset bipolar disorder and a manic episode with psychotic features, then referred to the mental health unit, where nuclear magnetic resonance (NMR) imaging of the brain revealed an acute ischemic stroke in the territory of the left posterior cerebral artery (PCA) with haemorrhagic reperfusion to the occipital cortex. Complete and spontaneous resolution of her clinical condition was achieved after approximately 15 days.

Elevated serum neopterin and homocysteine increased the risk of ischemic stroke in patients with transient ischemic attack

Objective: To investigate the correlation between serum neopterin, homocysteine (Hcy) and the risk of developing ischemic stroke (IS) in patients with transient ischemic attack (TIA).

Methods: Ninety-two TIA patients were prospectively recruited at the First Affiliated Hospital of the Medical College, Shihezi University, Xinjiang Autonomous Region China. Of the included patients, 27 developed ischemic stroke (IS group) and other 65 cases did not (TIA group). Peripheral venous blood was obtained within 24 hours of TIA diagnosis. Serum neopterin, Hcy and serum lipid levels were tested and compared between IS and TIA groups.

Results: Serum neopterin (6.38±1.76 ng/mL vs 5.39±1.51 ng/mL), Hcy (17.95±4.10 μmol/L vs 15.30±3.66 μmol/L), TG (1.82±0.92 mmol/L vs 1.40±0.71 mmol/L) and LDL (3.31±0.67 mmol/L vs 2.69±0.62 mmol/L) of IS group were significantly higher than those of TIA group (p<0.05). The AUC of serum neopterin, Hcy, TG and LDL for predicting the risk of developing IS in patients with TIA were 0.68 (95%CI: 0.55-0.81, 0.68 (95%CI: 0.57-0.80), 0.64 (95%CI: 0.51-0.78) and 0.75 (95%CI: 0.63-0.86), respectively.

Conclusion: Serum neopterin, Hcy, TG and LDL are promising serological markers for predicting the increased risk of developing IS for patients with TIA.

Risk factors of hemorrhagic transformation after intravenous thrombolysis with rt-PA in acute cerebral infarction

BACKGROUND

Intravenous thrombolysis is considered to be the standard reperfusion therapy for acute ischemic stroke, but its application is limited by high risk of hemorrhagic transformation (HT) after thrombolysis.

AIM

This study aimed to identify risk factors of HT after intravenous thrombolysis.

METHODS

Patients with acute ischemic stroke receiving rt-PA thrombolysis from February 2013 to January 2018 were retrospectively reviewed. They were divided into HT group and non-HT group based on cranial computed tomography. Data of all patients were collected and analysed by univariate analysis and stepwise logistic regression analysis.

RESULTS

A total of 403 patients were enrolled and their age ranged from 13 to 86 years, with an average age of 67.01 ± 31.88 years. 136 (33.7%) patients were females. The average time from disease onset to thrombolysis was 52.05 ± 20.12 min, and 46 patients (11.4%) had HT after thrombolysis. We found significant differences in activated partial thromboplastin time, fibrinogen value, platelet value and smoking before thrombolysis between HT and non-HT group (P < 0.05).

CONCLUSION

Smoking, prolongation of activated partial thromboplastin time, low fibrinogen levels and low platelet counts are associated with the risk of HT and could help the selection of thrombolytic patients to avoid HT.

Transient Ischemic Attack and Carotid Web

BACKGROUND AND PURPOSE

Carotid web was recognized as a cause of ischemic stroke. We sought to determine the clinical and imaging profiles of patients with a carotid web as well as its association with TIA.

MATERIALS AND METHODS

A retrospective review of carotid CT angiography studies and brain MR imaging in patients with TIA during the past 3 years (n = 135) was performed to determine the presence of carotid webs by 2 experienced neuroradiologists according to previously published criteria. Demographics and clinical and imaging characteristics are shown by descriptive statistics for patients with an identified carotid web. The agreement in the detection of carotid webs between 2 neuroradiologists was examined using κ statistics.

RESULTS

There were 12 (8.9%) carotid webs at the symptomatic bifurcation and 1 carotid web (0.7%) at the asymptomatic bifurcation, and no hyperintensity was seen on DWI of these 12 patients. Eight of these 12 (75%) patients with a carotid web were women. None of the 12 patients with a carotid web had major risk factors or other causes of TIA. Fair-to-good interobserver agreement (κ = 0.87) was seen for diagnosing a carotid web with CT angiography. The rate (10/12, 83.3%) of short-term recurrent episodes of TIA in patients with TIA with a carotid web was significantly higher than that of patients without a carotid web (15/123, 12.2%) (P < .001).

CONCLUSIONS

The incidence of carotid web in patients with TIA was 8.9%. There is an association between carotid web and patients with TIA without other identified risks. Carotid web may be an underestimated risk factor for TIA.

2D:4D Ratio Differs in Ischemic Stroke: A Single Center Experience

Background

The index to ring finger length (2D:4D) ratio is a proxy biomarker for prenatal exposure of sex hormones. Sex hormones are associated with the pathogenesis of ischemic stroke. The purpose of the study was to demonstrate the association between 2D:4D and ischemic stroke.

Methodology

This study retrospectively reviewed the data of 100 patients with first ever ischemic stroke between September, 2016 and June, 2017. The lengths of index finger and ring finger of both hands were measured using electronic calipers and calculated for 2D:4D ratios. Receive operating characteristic (ROC) mode was used to detect predicting performance of 2D:4D ratios for ischemic stroke.

Results

2D:4D ratios in ischemic stroke patients were higher than controls in both hands (P < 0.05), except right 2D:4D ratio in females. The ROC analyses showed that the area under the curve (AUC) were 0.635 (95%CI: 0.527-0.743) for left 2D:4D ratio, and 0.647 for right (95%CI: 0.539-0.755) (P < 0.05). The AUC of left and right 2D:4D ratio in male were 0.667 (95%CI: 0.514-0.820) and 0.670 (95%CI: 0.519-0.822) (P < 0.05). In female, no significance were found in ROC analysis. And there were no correlation between 2D:4D value and stroke severity (P > 0.05).

Conclusions

The current study indicated that the diagnostic value of 2D:4D ratio was limited in ischemic stroke. Further research is required to explore the role of it in screening ischemic stroke.

Recent advances in the management of transient ischemic attacks

Significant advances in our understanding of transient ischemic attack (TIA) have taken place since it was first recognized as a major risk factor for stroke during the late 1950's. Recently, numerous studies have consistently shown that patients who have experienced a TIA constitute a heterogeneous population, with multiple causative factors as well as an average 5–10% risk of suffering a stroke during the 30 days that follow the index event. These two attributes have driven the most important changes in the management of TIA patients over the last decade, with particular attention paid to effective stroke risk stratification, efficient and comprehensive diagnostic assessment, and a sound therapeutic approach, destined to reduce the risk of subsequent ischemic stroke. This review is an outline of these changes, including a discussion of their advantages and disadvantages, and references to how new trends are likely to influence the future care of these patients.