Coagulopathy and embolic signal in cancer patients with ischemic stroke

Rivaroxaban for secondary stroke prevention in patients with embolic strokes of undetermined source: Design of the NAVIGATE ESUS randomized trial

BACKGROUND

Embolic strokes of undetermined source comprise up to 20% of ischemic strokes. The stroke recurrence rate is substantial with aspirin, widely used for secondary prevention. The New Approach riVaroxaban Inhibition of Factor Xa in a Global trial versus ASA to prevenT Embolism in Embolic Stroke of Undetermined Source international trial will compare the efficacy and safety of rivaroxaban, an oral factor Xa inhibitor, versus aspirin for secondary prevention in patients with recent embolic strokes of undetermined source.

MAIN HYPOTHESIS

In patients with recent embolic strokes of undetermined source, rivaroxaban 15 mg once daily will reduce the risk of recurrent stroke (both ischemic and hemorrhagic) and systemic embolism (primary efficacy outcome) compared with aspirin 100 mg once daily.

DESIGN

Double-blind, randomized trial in patients with embolic strokes of undetermined source, defined as nonlacunar cryptogenic ischemic stroke, enrolled between seven days and six months from the qualifying stroke. The planned sample size of 7000 participants will be recruited from approximately 480 sites in 31 countries between 2014 and 2017 and followed for a mean of about two years until at least 450 primary efficacy outcome events have occurred. The primary safety outcome is major bleeding. Two substudies assess (1) the relative effect of treatments on MRI-determined covert brain infarcts and (2) the biological underpinnings of embolic strokes of undetermined source using genomic and biomarker approaches.

SUMMARY

The New Approach riVaroxaban Inhibition of Factor Xa in a Global trial versus ASA to prevenT Embolism in Embolic Stroke of Undetermined Source trial is evaluating the benefits and risks of rivaroxaban for secondary stroke prevention in embolic strokes of undetermined source patients. Main results are anticipated in 2018.

Cancer Cell-Derived Extracellular Vesicles Are Associated with Coagulopathy Causing Ischemic Stroke via Tissue Factor-Independent Way: The OASIS-CANCER Study

Background

Cancer and stroke, which are known to be associated with one another, are the most common causes of death in the elderly. However, the pathomechanisms that lead to stroke in cancer patients are not well known. Circulating extracellular vesicles (EVs) play a role in cancer-associated thrombosis and tumor progression. Therefore, we hypothesized that cancer cell-derived EVs cause cancer-related coagulopathy resulting in ischemic stroke.

Methods

Serum levels of D-dimer and EVs expressing markers for cancer cells (epithelial cell adhesion molecule [CD326]), tissue factor (TF [CD142]), endothelial cells (CD31+CD42b-), and platelets (CD62P) were measured using flow cytometry in (a) 155 patients with ischemic stroke and active cancer (116 − cancer-related, 39 − conventional stroke mechanisms), (b) 25 patients with ischemic stroke without cancer, (c) 32 cancer patients without stroke, and (d) 101 healthy subjects.

Results

The levels of cancer cell-derived EVs correlated with the levels of D-dimer and TF+ EVs. The levels of cancer cell-derived EVs (CD326+ and CD326+CD142+) were higher in cancer-related stroke than in other groups (P<0.05 in all the cases). Path analysis showed that cancer cell-derived EVs are related to stroke via coagulopathy as measured by D-dimer levels. Poor correlation was observed between TF+ EV and D-dimer, and path analysis demonstrated that cancer cell-derived EVs may cause cancer-related coagulopathy independent of the levels of TF+ EVs.

Conclusions

Our findings suggest that cancer cell-derived EVs mediate coagulopathy resulting in ischemic stroke via TF-independent mechanisms.

Cerebral ischemic events in patients with pancreatic cancer: A retrospective cohort study of 17 patients and a literature review

Stroke is a dramatic complication of pancreatic cancer with mechanisms related to oncological disease. A better description of the characteristics of cerebrovascular events would help better understand the pathogeny and protect vulnerable patients. We thus conducted a descriptive analysis of clinical, biological, and radiological features of patients from our centers and literature.We reviewed consecutive cases of patients who presented cerebrovascular events and pancreatic cancer in 4 stroke units in Lorrain (France) between January 1, 2009 and March 31, 2015, and all reported cases of literature. We identified 17 cases in our centers and 18 reported cases. Fifty-seven per cent of patients were male. Median age was 63 ± 14 years and ranged from 23 to 81 years. All cerebral events were ischemic. At the onset of stroke, pancreatic cancer had already been diagnosed in 59% of the patients in our centers for a mean time of 5.4 months. Five of them (29%) were being treated with gemcitabine and 2 (12%) with folfirinox. Adenocarcinoma at metastatic stage was reported in 82% of cases overall. Brain imaging revealed disseminated infarctions in 64%. High median levels of D-dimer (7600 ± 5 × 10 μg/L), C-reactive protein (63 ± 43 mg/L), and elevated prothrombin time (19 ± 6 seconds) were found. Thirty-six per cent of patients explored with echocardiography were diagnosed with nonbacterial thrombotic endocarditis. Ten of our patients received anticoagulant therapy as secondary stroke prevention without any documented recurrence. Nevertheless, outcome was poor with a median survival time of 28 ± 14 days after stroke onset. Cerebral ischemic events occur at advanced stages of pancreatic cancer, most likely by a thromboembolic mechanism. Disseminated infarctions and high D-dimer, C-reactive protein levels, and a high prothrombin time are the most constant characteristics found in this context. All patients should be screened for nonbacterial thrombotic endocarditis as this etiology supports the use of anticoagulant therapy.

Embolic Strokes of Unknown Source and Cryptogenic Stroke: Implications in Clinical Practice

Up to a third of strokes are rendered cryptogenic or of undetermined etiology. This number is specifically higher in younger patients. At times, inadequate diagnostic workups, multiple causes, or an under-recognized etiology contributes to this statistic. Embolic stroke of undetermined source, a new clinical entity particularly refers to patients with embolic stroke for whom the etiology of embolism remains unidentified despite through investigations ruling out established cardiac and vascular sources. In this article, we review current classification and discuss important clinical considerations in these patients; highlighting cardiac arrhythmias and structural abnormalities, patent foramen ovale, paradoxical sources, and potentially under-recognized, vascular, inflammatory, autoimmune, and hematologic sources in relation to clinical practice.

Predictors of survival for patients with cancer after cryptogenic stroke

Patients with active cancer experience ischemic stroke via cryptogenic mechanisms, with cancer-associated hypercoagulability being considered a major contributor to such strokes. Despite the remarkably shortened survival of these patients, the clinical predictors of survival are poorly understood. We determined the clinical factors including D-dimer levels serving as the predictors of overall survival in these patients. Retrospective study was conducted on cancer patients who visited our hospital for acute ischemic stroke with cryptogenic mechanisms from April 2012 through November 2014. Demographics, clinical characteristics, imaging and laboratory results including coagulation markers were collected, and overall survival was calculated from the patient medical records and a governmental national database. A high D-dimer level was defined as a D-dimer level exceeding the median value from the study population (>5.50 μg/ml). A total of 93 patients were identified, with a median survival of 62 days (interquartile range 32-223 days). A high D-dimer level (p = 0.004; hazard ratio [HR] 2.01, 95 % confidence interval [CI] 1.26-3.21), systemic metastases (p = 0.02; HR 2.08, 95 % CI 1.11-3.90), and diabetes mellitus (p = 0.03; HR 1.78, 95 % CI 1.03-3.10) were identified as independent predictors of poor overall survival using multivariate Cox proportional hazard analysis. Most of the patients (87 %) were primarily treated with low-molecular-weight heparin (dalteparin, n = 49; enoxaparin, n = 32). The type of low-molecular-weight heparin had no association with survival. A high D-dimer level, systemic metastases, and diabetes are independent predictors of poor survival in cancer patients with cryptogenic stroke.

Cancer-related Stroke due to Mural Thrombus in the Extracranial Carotid Artery

A 41-year-old man was admitted to our hospital because of a cancer-related stroke (CRS) caused by a thrombus of the extracranial carotid artery. He had undergone neoadjuvant radiochemotherapy for metastatic colorectal adenocarcinoma. The serum D-dimer values were within the normal range. We treated him with intravenous unfractionated heparin followed by warfarin. There were no recurrent stroke events over six months. The leading cause of a CRS is an embolism caused by hypercoagulopathy, mainly represented by non-bacterial thrombotic endocarditis. However, it was unusual that, in the current case, a thrombus of the extracranial carotid artery was formed with no significant residual stenosis, thus resulting in an artery-to-artery embolism.

DWI Lesion Patterns in Cancer-Related Stroke--Specifying the Phenotype

BACKGROUND

Due to the lack of specific diagnostic markers, the diagnosis of cancer-related stroke strongly depends on its phenotype. Distinct DWI lesion patterns with involvement of multiple vascular territories have been reported repeatedly in cancer-related stroke but have not been addressed in detail in a selected cohort of prospectively recruited cancer patients with emphasis on hypercoagulable conditions.

PATIENTS AND METHODS

Ischemic stroke patients with known malignant cancer activity, laboratory evidence of strong plasmatic hypercoagulation (D-dimer levels > 3 µg/ml) and without competing stroke etiologies according to the recently introduced ASCOD (A - atherosclerosis, S - small vessel disease, C - cardiac pathology, O - other cause, and D - dissection) classification of evidence-rated etiology of stroke subtypes were included in the analysis. Cerebral MRI on admission was reviewed with respect to ischemic lesion patterns.

RESULTS

Thirty-two patients met the inclusion criteria. The mean D-dimer levels were 15.39 µg/ml (± 10.84). Acute infarction in ≥ 2 vascular territories was present in 27/32 (84%) patients. (Micro-) embolic scattering of infarction was present in 25/32 (78%) patients. Evidence for previous, potentially oligosymptomatic infarction was found in 16 (50%) patients, demonstrated by the additional presence of subacute or chronic ischemic lesions.

CONCLUSION

When excluding competing embolic and nonembolic stroke etiologies, the pattern of scattered DWI lesions in multiple vascular supply territories strongly dominates the phenotype of cancer-related stroke. Additionally, evidence of recurrent infarction is frequent in this cohort of patients. This is not only important for the diagnosis of cancer-related stroke itself but may prove helpful for the identification of cancer-related stroke patients with unknown malignancy at the time of stroke manifestation and evaluation of strategies for secondary prevention.

Comparison of Enoxaparin and Warfarin for Secondary Prevention of Cancer-Associated Stroke

Background. The aim of this study was to determine which anticoagulant is superior for secondary prevention of cancer-associated stroke, using changes in D-dimer levels as a biomarker for recurrent thromboembolic events. Methods. We conducted a retrospective, single center observational study including patients with cancer-associated stroke who were treated with either enoxaparin or warfarin. Blood samples for measuring the initial and follow-up D-dimer levels were collected at admission and a median of 8 days after admission, respectively. Multiple logistic regression analysis was conducted to evaluate the factors that influenced D-dimer levels after treatment. Results. Although the initial D-dimer levels did not differ between the two groups, the follow-up levels were dramatically decreased in patients treated with enoxaparin, while they did not change with use of warfarin (3.88 μg/mL versus 17.42 μg/mL, p = 0.026). On multiple logistic regression analysis, use of warfarin (OR 12.95; p = 0.001) and the presence of systemic metastasis (OR 18.73; p = 0.017) were independently associated with elevated D-dimer levels (≥10 μg/mL) after treatment. Conclusion. In cancer-associated stroke patients, treatment with enoxaparin may be more effective than treatment with warfarin for lowering the D-dimer levels. Future prospective studies are warranted to show that enoxaparin is better than warfarin for secondary prevention in cancer-associated stroke.

Diagnostic yield of echocardiography in cancer patients with ischemic stroke

The yield of echocardiography in cancer patients with acute ischemic stroke is unknown. We identified adult patients with active systemic cancer diagnosed with acute ischemic stroke at a tertiary-care cancer center from 2005 through 2009 who underwent transthoracic (TTE) or transesophageal echocardiography (TEE). Two neurologists independently reviewed all clinical data, including TTE and TEE reports, and adjudicated whether echocardiographic studies revealed a definite or possible source of stroke according to pre-defined criteria. Patients were classified as having suspected cardioembolic strokes if imaging showed embolic-appearing infarcts in more than one vascular territory. Among 220 patients with cancer and ischemic stroke who underwent echocardiography, 216 (98%) had TTE and 37 (17%) had TEE. TTE revealed a definite source in 15 (7%, 95% CI 4-10%) patients and a possible source in 42 (19%, 95% CI 14-25%), while TEE revealed a definite source in 10 (27%, 95% CI 12-42%) patients and a possible source in 14 (38%, 95% CI 21-54%). In 92 patients with suspected cardioembolic strokes who underwent TTE, 6 (7%, 95% CI 1-12%) had a definite source, including 4 with marantic endocarditis, and 20 (22%, 95% CI 13-30%) had a possible source. Twenty-one of these patients also underwent TEE, which demonstrated a definite or possible source in 16 (76%, 95% CI 56-96%) patients, including marantic endocarditis in 4 (19%). The yield of TTE for detecting marantic endocarditis and other cardiac sources of stroke in cancer patients is low, but TEE may provide a higher yield in targeted patients.

Association between incident cancer and subsequent stroke

OBJECTIVE

A study was undertaken to examine the association between incident cancer and the subsequent risk of stroke.

METHODS

Using the Surveillance, Epidemiology, and End Results-Medicare linked database, we identified patients with a new primary diagnosis of breast, colorectal, lung, pancreatic, or prostate cancer from 2001 through 2007. These patients were individually matched by age, sex, race, registry, and medical comorbidities to a group of Medicare enrollees without cancer, and each pair was followed through 2009. Validated diagnosis codes were used to identify a primary outcome of stroke. Cumulative incidence rates were calculated using competing risk survival statistics.

RESULTS

Among 327,389 pairs of cancer patients and matched controls, the 3-month cumulative incidence of stroke was generally higher in patients with cancer. Cumulative incidence rates were 5.1% (95% confidence interval [CI] = 4.9-5.2%) in patients with lung cancer compared to 1.2% (95% CI = 1.2-1.3%) in controls (p < 0.001), 3.4% (95% CI = 3.1-3.6%) in patients with pancreatic cancer compared to 1.3% (95% CI = 1.1-1.5%) in controls (p < 0.001), 3.3% (95% CI = 3.2-3.4%) in patients with colorectal cancer compared to 1.3% (95% CI = 1.2-1.4%) in controls (p < 0.001), 1.5% (95% CI = 1.4-1.6%) in patients with breast cancer compared to 1.1% (95% CI = 1.0-1.2%) in controls (p < 0.001), and 1.2% (95% CI = 1.1-1.3%) in patients with prostate cancer compared to 1.1% (95% CI = 1.0-1.2%) in controls (p = 0.085). Excess risks attenuated over time and were generally no longer present beyond 1 year.

INTERPRETATION

Incident cancer is associated with an increased short-term risk of stroke. This risk appears highest with lung, pancreatic, and colorectal cancers.

Cryptogenic subtype predicts reduced survival among cancer patients with ischemic stroke

BACKGROUND AND PURPOSE

Cryptogenic stroke is common in patients with cancer. Autopsy studies suggest that many of these cases may be because of marantic endocarditis, which is closely linked to cancer activity. We, therefore, hypothesized that among patients with cancer and ischemic stroke, those with cryptogenic stroke would have shorter survival.

METHODS

We retrospectively analyzed all adult patients with active systemic cancer diagnosed with acute ischemic stroke at a tertiary care cancer center from 2005 through 2009. Two neurologists determined stroke mechanisms by consensus. Patients were diagnosed with cryptogenic stroke if no specific mechanism could be determined. The diagnosis of marantic endocarditis was restricted to patients with cardiac vegetations on echocardiography or autopsy and negative blood cultures. Patients were followed until July 31, 2012, for the primary outcome of death. Kaplan-Meier statistics and the log-rank test were used to compare survival between patients with cryptogenic stroke and patients with known stroke mechanisms. Multivariate Cox proportional hazard analysis evaluated the association between cryptogenic stroke and death after adjusting for potential confounders.

RESULTS

Among 263 patients with cancer and ischemic stroke, 133 (51%) were cryptogenic. Median survival in patients with cryptogenic stroke was 55 days (interquartile range, 21-240) versus 147 days (interquartile range, 33-735) in patients with known stroke mechanisms (P<0.01). Cryptogenic stroke was independently associated with death (hazard ratio, 1.64; 95% confidence interval, 1.25-2.14) after adjusting for age, systemic metastases, adenocarcinoma histology, and functional status.

CONCLUSIONS

Cryptogenic stroke is independently associated with reduced survival in patients with active cancer and ischemic stroke.

Risk factors and biomarkers of ischemic stroke in cancer patients

BACKGROUND AND PURPOSE

Stroke is common among cancer patients. However, risk factors and biomarkers of stroke in cancer patients are not well established. This study aimed to investigate risk factors and biomarkers as well as etiology of ischemic stroke in cancer patients.

METHODS

A retrospective review was conducted in cancer patients with ischemic stroke who were admitted to a general hospital in Busan, Korea, between January 2003 and December 2012. The risk factors and biomarkers for stroke and stroke subtypes in cancer patients were compared with age- and sex-matched noncancer patients with ischemic stroke who were admitted to the same hospital during the same period.

RESULTS

One hundred fifty-six cancer patients with ischemic stroke were identified. Cancer patients with ischemic stroke were found to have a significantly lower proportion of hypertension, atrial fibrillation, hyperlipidemia, and ischemic heart disease than noncancer patients with ischemic stroke. However, stroke biomarkers, such as erythrocyte sedimentation rate and high-sensitivity C-reactive protein, fibrinogen, pro-brain natriuretic peptide, and D-dimer levels, were significantly increased in cancer patients with ischemic stroke than in noncancer patients. Large-artery atherosclerosis and stroke of undetermined cause were more common in cancer patients with ischemic stroke than in noncancer patients with ischemic stroke.

CONCLUSIONS

Cancer patients with ischemic stroke showed different risk factors, stroke biomarkers, and stroke etiology compared with noncancer patients with ischemic stroke.

Recurrent thromboembolic events after ischemic stroke in patients with cancer

OBJECTIVE

To determine the cumulative rate and characteristics of recurrent thromboembolic events after acute ischemic stroke in patients with cancer.

METHODS

We retrospectively identified consecutive adult patients with active systemic cancer diagnosed with acute ischemic stroke at a tertiary-care cancer center from 2005 through 2009. Two neurologists independently reviewed all electronic records to ascertain the composite outcome of recurrent ischemic stroke, myocardial infarction, systemic embolism, TIA, or venous thromboembolism. Kaplan-Meier statistics were used to determine cumulative outcome rates. In exploratory analyses, Cox proportional hazard analysis was used to evaluate potential independent associations between a priori selected clinical factors and recurrent thromboembolic events.

RESULTS

Among 263 study patients, complete follow-up until death was available in 230 (87%). Most patients had an adenocarcinoma as their underlying cancer (60%) and had systemic metastases (69%). Despite a median survival of 84 days (interquartile range 24-419 days), 90 patients (34%; 95% confidence interval 28%-40%) had 117 recurrent thromboembolic events, consisting of 57 cases of venous thromboembolism, 36 recurrent ischemic strokes, 13 myocardial infarctions, 10 cases of systemic embolism, and one TIA. Kaplan-Meier rates of recurrent thromboembolism were 21%, 31%, and 37% at 1, 3, and 6 months, respectively; cumulative rates of recurrent ischemic stroke were 7%, 13%, and 16%. Adenocarcinoma histology (hazard ratio 1.65, 95% confidence interval 1.02-2.68) was independently associated with recurrent thromboembolism.

CONCLUSIONS

Patients with acute ischemic stroke in the setting of active cancer (especially adenocarcinoma) face a substantial short-term risk of recurrent ischemic stroke and other types of thromboembolism.

Ischemic stroke in patients with solid gynecologic tract tumors and coagulopathy

AIM

Patients with gynecological neoplasms often suffer ischemic stroke. This study aimed to clarify the underlying mechanisms of ischemic stroke in patients with gynecological tract tumors.

METHODS

We retrospectively reviewed 6 patients with gynecologic tumors and hypercoagulability who were being treated for acute ischemic stroke between 2006 and 2012. Diffusion-weighted magnetic resonance imaging (DW-MRI), cardiovascular risk factors including plasma D-dimer levels, and histologic examination of the patients' solid tumors were performed. All 6 patients underwent transesophageal echocardiography (TEE) for nonbacterial thrombotic endocarditis (NBTE) and paradoxical embolism.

RESULTS

All 6 patients showed elevated plasma D-dimer levels. In 1 patient, paradoxical embolism was diagnosed. In the remaining 5 patients, DW-MRI scans showed numerous lesions in multiple vascular territories, and in 4 of these 5 patients, TEE demonstrated vegetations on the mitral valve, leading to the diagnosis of NBTE. Interestingly, 2 of these 4 patients had benign uterine tumors, whereas the other 2 had ovarian cancer.

CONCLUSIONS

NBTE was the main etiology for ischemic stroke in patients with gynecologic tract tumors and coagulopathy. Both malignant and benign tumors of the gynecologic tract can cause NBTE.

Biomarkers for stroke

Background

Major stroke clinical trials have failed during the past decades. The failures suggest the presence of heterogeneity among stroke patients. Biomarkers refer to indicators found in the blood, other body fluids or tissues that predicts physiologic or disease states, increased disease risk, or pharmacologic responses to a therapeutic intervention. Stroke biomarkers could be used as a guiding tool for more effective personalized therapy.

Main Contents

Three aspects of stroke biomarkers are explored in detail. First, the possible role of biomarkers in patients with stroke is discussed. Second, the limitations of conventional biomarkers (especially protein biomarkers) in the area of stroke research are presented with the reasons. Lastly, various types of biomarkers including traditional and novel genetic, microvesicle, and metabolomics-associated biomarkers are introduced with their advantages and disadvantages. We especially focus on the importance of comprehensive approaches using a variety of stroke biomarkers.

Conclusion

Although biomarkers are not recommended in practice guidelines for use in the diagnosis or treatment of stroke, many efforts have been made to overcome the limitations of biomarkers. The studies reviewed herein suggest that comprehensive analysis of different types of stroke biomarkers will improve the understanding of individual pathophysiologies and further promote the development of screening tools for of high-risk patients, and predicting models of stroke outcome and rational stroke therapy tailored to the characteristics of each case.

Clinical manifestation of cancer related stroke: retrospective case-control study

Cancer related stroke may have different phenotypes from non-cancer stroke, especially in terms of stroke progression and recurrence. We performed a case-control study to identify their incidences and risk factors in cancer related stroke. Between January 2001 and December 2009, we conducted a retrospective review of acute ischemic stroke patients with cancer who were admitted to Seoul National University Hospital, Seoul, Korea. The stroke patients without cancer served as control. We collected demographic variables, vascular risk factors, stroke phenotype, clinical course, and cancer information including diagnosis, stage, and treatment status. Among cancer stroke patients, the potential risk factor of stroke recurrence was evaluated. The mean age of the 102 cancer patients was 66.4 ± 10.8 years, and 64.7 % were men. The mean time interval from cancer diagnosis to stroke onset was 39.7 ± 60.9 months. The principal lesion pattern of cancer stroke was multiple dots extending single vascular territory (39.2 %), and they were associated with low hemoglobin and high fibrinogen levels. Stroke progression and recurrence were noted in 9.8 and 27.5 % of cancer stroke patients, and in 9.3 and 12.7 % of control patients, respectively. The stroke subtype was independently associated with recurrence of cancer stroke after multiple logistic regression (odds ratio = 3.165, 95 % confidence interval = 1.080-9.277, p = 0.036). Cancer related stroke has a distinct phenotype in terms of infarction pattern and laboratory findings. Stroke recurrence is frequently observed among cancer stroke patients, and its risk is related with stroke subtype.

Clues to occult cancer in patients with ischemic stroke

Background

We hypothesized that hidden malignancy could be detected in patients with cryptogenic stroke without active cancer when they showed the distinctive characteristics of cancer-related stroke.

Methods and Findings

Among 2,562 consecutive patients with acute ischemic stroke, patients with cryptogenic stroke were analyzed and categorized into two groups according to the presence of active cancer: cryptogenic stroke with active cancer (cancer-related stroke, CA-stroke) group and without active cancer (CR-stroke) group. Patients with active lung cancer without stroke were also recruited for comparison purposes (CA-control). Clinical factors, lesion patterns on diffusion-weighted MRI (DWI), and laboratory findings were analyzed among groups. A total of 348 patients with cryptogenic stroke were enrolled in this study. Among them, 71 (20.4%) patients had active cancer at the time of stroke. The D-dimer levels were significantly higher in patients with CA-stroke than those with CR-stroke or CA-control (both p<0.001). Regarding lesion patterns, patients with CA-stroke mostly had multiple lesions in multiple vascular territories, while more than 80% of patients with CR-stroke had single/multiple lesions in a single vascular territory (P<0.001). D-dimer levels (OR 1.11 per 1 µg/mL increase; 95% CI 1.06–1.15; P<0.001) and DWI lesion patterns (OR 7.13; 95% CI 3.42–14.87; P<0.001) were independently associated with CA-stroke. Workup for hidden malignancy was performed during hospitalization in 10 patients who showed elevated D-dimer levels and multiple infarcts involving multiple vascular territories but had no known cancer, and it revealed hidden malignancies in all the patients.

Conclusion

Patients with CA-stroke have distinctive D-dimer levels and lesion patterns. These characteristics can serve as clues to occult cancer in patients with cryptogenic stroke.

Deficiency of NG2+ cells contributes to the susceptibility of stroke-prone spontaneously hypertensive rats

AIMS

The purpose of this study is to investigate whether the NG2(+) cells, a class of oligodendrocyte progenitor cells, is involved in the pathophysiology of stroke in stroke-prone spontaneously hypertensive rat (SHR-SP).

METHODS

SHR-SP, SHR, Wistar-Kyoto rats (WKY), and C57BJ/6 mice were used. Immunohistochemistry was conducted to evaluate the number of NG2(+) cells in frozen brain sections. Demyelination was evaluated by Sudan black staining and serum level of myelin basic protein. Middle cerebral artery occlusion (MCAO) was performed to prepare experimental stroke model.

RESULTS

The number of NG2(+) cells was significantly decreased in infarct core and increased in penumbra in WKY rats after MCAO. In brain sections of 6-month-old SHR-SP, the number of NG2(+) cells was significantly (P < 0.01) less than that in age-matched SHR and WKY rats. However, this phenomenon was not observed in 3-month-old rats. Demyelination was found in 6-month-old SHR-SP but not in 3-month-old SHR-SP. Pharmacological treatment of cuprizone in mice induced demyelination and enlargement of cerebral infarction after MCAO.

CONCLUSION

The decline of NG2(+) cells may cause demyelination and contribute to the susceptibility of SHR-SP to ischemic brain injury.

Ischemic stroke and cancer: stroke severely impacts cancer patients, while cancer increases the number of strokes

Background

Cancer and ischemic stroke are two of the most common causes of death among the elderly, and associations between them have been reported. However, the main pathomechanisms of stroke in cancer patients are not well known, and can only be established based on accurate knowledge of the characteristics of cancer-related strokes. We review herein recent studies concerning the clinical, laboratory, and radiological features of patients with cancer-related stroke.

Main Contents

This review covers the epidemiology, underlying mechanisms, and acute and preventive treatments for cancer-related stroke. First, the characteristics of stroke (clinical and radiological features) and systemic cancer (type and extent) in patients with cancer-specific stroke are discussed. Second, the role of laboratory tests in the early identification of patients with cancer-specific stroke is discussed. Specifically, serum D-dimer levels (as a marker of a hypercoagulable state) and embolic signals on transcranial Doppler (suggestive of embolic origin) may provide clues regarding changes in the levels of coagulopathy related to cancer and anticoagulation. Finally, strategies for stroke treatment in cancer patients are discussed, emphasizing the importance of preventive strategies (i.e., the use of anticoagulants) over acute revascularization therapy in cancer-related stroke.

Conclusion

Recent studies have revealed that the characteristics of cancer-related stroke are distinct from those of conventional stroke. Our understanding of the characteristics of cancer-related stroke is essential to the correct management of these patients. The studies presented in this review highlight the importance of a personalized approach in treating stroke patients with cancer.