Cerebral Embolism as a Cause of Stroke and Transient Ischemic Attack

Spontaneous calcific cerebral embolization revealing a calcified rheumatic mitral stenosis: a case report

BACKGROUND

Cerebral cardiac embolism accounts for an increasing proportion of ischemic strokes and transient ischemic attacks. Calcified cerebral emboli are rare and mostly iatrogenic secondary to heart or aorta catheterization. However, spontaneous cerebral calcified embolism in the case of calcified aortic valve is very rare and there are less than 10 case reports in the literature. And a more interesting fact is that such an event, in the context of calcified mitral valve disease, has never been reported, at least to our knowledge. We are reporting a case of spontaneous calcified cerebral embolism revealing a calcified rheumatic mitral valve stenosis.

CASE PRESENTATION

We report a case of a 59 year-old Moroccan patient, with a history of rheumatic fever at the age of 14 and no history of recent cardiac intervention or aortic/carotid manipulation, who was admitted to the emergency department after a transient ischemic attack. Physical examination at admission found normal blood pressure of 124/79 mmHg and heart rate of 90 bpm. A 12-lead electrocardiogram showed an atrial fibrillation, no other anomalies. Unenhanced cerebral computed tomography imaging was performed, revealing calcified material inside both middle cerebral arteries. Transthoracic echocardiography was performed, showing severe mitral leaflets calcification with a severe mitral stenosis, probably due to rheumatic heart disease. Cervical arteries Duplex was normal. A vitamin K antagonist (acenocoumarol) was prescribed, targeting an international normalized ratio of 2-3 and mitral valve replacement surgery was performed using mechanical prosthesis. Short- and long-term health, with a 1-year follow-up, were good and the patient did not experience any stroke.

CONCLUSION

Spontaneous calcified cerebral emboli secondary to mitral valve leaflet calcifications is an extremely rare condition. Replacement of the valve is the only option to prevent recurrent emboli and outcomes are still to be determined.

Transient ischemic attack analysis through non-contact approaches

The transient ischemic attack (TIA) is a kind of sudden disease, which has the characteristics of short duration and high frequency. Since most patients can return to normal after the onset of the disease, it is often neglected. Medical research has proved that patients are prone to stroke in a relatively short time after the transient ischemic attacks. Therefore, it is extremely important to effectively monitor transient ischemic attack, especially for elderly people living alone. At present, video monitoring and wearing sensors are generally used to monitor transient ischemic attacks, but these methods have certain disadvantages. In order to more conveniently and accurately monitor transient ischemic attack in the indoor environment and improve risk management of stroke, this paper uses a microwave sensing platform working in C-Band (4.0 GHz–8.0 GHz) to monitor in a non-contact way. The platform first collects data, then preprocesses the data, and finally uses principal component analysis to reduce the dimension of the data. Two machine learning algorithms support vector machine (SVM) and random forest (RF) are used to establish prediction models respectively. The experimental results show that the accuracy of SVM and RF approaches are 97.3% and 98.7%, respectively; indicating that the scheme described in this paper is feasible and reliable.

Association Between Atrial Fibrillation and the Risk of Dementia in the Korean Elderly: A 10-Year Nationwide Cohort Study

Objectives

The objective of this study was to determine the effect of atrial fibrillation (AF) on the risk of dementia in the Korean elderly.

Methods

A 10-year retrospective cohort study was conducted using the National Health Insurance Service-Senior Cohort database. We excluded those who were under 65 years of age as of January 2006 (n=46 113), those who were diagnosed with dementia between 2002 and 2005 (n=9086), and those with a history of stroke prior to AF diagnosis (n=8392). We used a Cox proportional hazards model with a time-varying covariate to determine whether AF is associated with the risk of dementia after adjusting for potential confounders.

Results

In univariable Cox regression, the hazard ratio (HR) of dementia according to AF status was 1.28 (95% confidence interval [CI], 1.23 to 1.33). After adjusting for potential confounders, AF was found to increase the risk of dementia (HR, 1.12; 95% CI, 1.07 to 1.17), Alzheimer dementia (HR, 1.12; 95% CI, 1.07 to 1.17), and vascular dementia (HR, 1.10; 95% CI, 1.03 to 1.18). In patients diagnosed with AF, the incidence of dementia was lower (HR, 0.50; 95% CI, 0.47 to 0.52) in patients who were treated with oral anticoagulants.

Conclusions

Investigating the potential risk factors of dementia in an aged society is important. We found a slightly higher risk of dementia in those with AF than in those without AF, and we therefore concluded that AF is a potential risk factor for dementia.

Arterial and venous thrombosis by high platelet count and high hematocrit: 108 521 individuals from the Copenhagen General Population Study

BACKGROUND

It is unclear whether high platelet count or high hematocrit predict risk of thrombosis in individuals from the general population.

OBJECTIVES

We tested the hypothesis that individuals from the general population with high platelet count or high hematocrit have high risk of arterial and venous thrombosis.

METHODS

We prospectively followed 108 521 individuals from The Copenhagen General Population Study for a median of 8 years. Platelet count and blood hematocrit were measured at study entry.

RESULTS AND CONCLUSION

Multivariable adjusted hazard ratios for individuals with platelet counts in the top 5 percentiles (>398 × 109 /L) vs in the 25th-75th percentiles (231-316 × 109 /L) were 1.77 (95% confidence interval [CI], 1.38-2.24) for arterial thrombosis in the brain (38 and 26 events/10 000 person-years) and 0.82 (95%, 0.61-1.11) for arterial thrombosis in the heart (23 and 28 events/10 000 person-years). For individuals with hematocrit values in the top 5 percentiles (women/men: >45/>48%) vs the 25th-75th percentiles (women/men: 38.1-42/41.1-45%), hazard ratios were 1.27 (95% CI, 0.91-1.75) for arterial thrombosis in the brain (40 and 26 events/10 000 person-years) and 1.46 (95% CI, 1.06-2.00) for arterial thrombosis in the heart (43 and 25 events/10 000 person-years). Neither high platelet count nor high hematocrit was associated with risk of venous thromboembolism. When excluding individuals with myeloproliferative neoplasia from the main analyses, results on risk of thrombosis were similar. In this prospective study, high platelet counts were associated with 1.8-fold risk of arterial thrombosis in the brain, whereas high hematocrit was associated with 1.5-fold risk of arterial thrombosis in the heart.

Distribution of ischemic strokes in patients with atrial fibrillation: The FibStroke Study

BACKGROUND

We aimed to determine the relative frequency of affected cerebrovascular territories in patients with atrial fibrillation (AF) suffering an ischemic stroke.

METHODS

Altogether, 1,976 patients who suffered their first-ever ischemic stroke during 2003-2012 and were diagnosed with AF either before or within 30 days after the event were included in this retrospective multicenter cohort study. Strokes were classified radiographically to be located either within the anterior or the posterior cerebrovascular territory, and the effect of the CHA₂DS₂-VASc score, oral anticoagulant (OAC) use, and timing of AF diagnosis on lesion localization was determined.

RESULTS

The median age of the patients was 78.4 (interquartile range: 71.7-84.2) years, 1,137 (57.5%) of them were women, their mean CHA₂DS₂-VASc score was 3.5 (95% confidence interval: 3.4-3.5), 656 (33.2%) were receiving OAC drugs, and altogether, 1,450 (73%) had a previous AF diagnosis. The localization of ischemic lesions between the anterior and the posterior cerebrovascular territories was not affected by the timing of AF diagnosis (p = 0.46), use of OACs (p = 0.70), or the CHA₂DS₂-VASc score (p = 0.10). Within the anterior territory, altogether 774 strokes (53.2%) were located in the left hemisphere and 3 (0.2%) were bilateral. The timing of AF diagnosis (p = 0.84), use of OACs (p = 0.90), or the CHA₂DS₂-VASc score (p = 0.21) did not affect the location of the ischemic lesion between the hemispheres.

CONCLUSIONS

The timing of AF diagnosis, use of OAC drugs, or the CHA₂DS₂-VASc score did not affect the distribution of ischemic strokes. Anterior territory strokes were slightly more often located within the left hemisphere.

MRI and clinical characteristics of suspected cerebrovascular accident in nine cats

Objectives Cerebrovascular accidents (CVAs) are infrequently reported in cats. To date, clinical characteristics, including lesion localisation and MRI findings, have only been reported in two cats. The aim of the current study is to document MRI findings in cats presenting with CVAs over an 11 year period. Cases were reviewed according to initial clinical presentation, subsequent physical and neurological findings, predisposing systemic disease and short- and long-term (when available) outcome with a view to identifying any typical pattern in disease occurrence. Methods Patient records of cats presenting to a single referral centre from January 2005 to September 2016 with acute onset, non-progressive (after 24 h) intracranial signs compatible with a CVA and where an MRI was performed within 72 h were retrospectively reviewed. Results Nine cats met the inclusion criteria. All cats had ischaemic CVAs (presumptively diagnosed in eight cats and confirmed in one cat following post-mortem examination). No cases of haemorrhagic CVAs were identified. Four cats presented with territorial infarcts that were confined to the territory of the rostral or caudal cerebellar arteries (n = 4). Lacunar infarcts were identified in five cats in the location of the cerebrum (n = 1), the thalamus/midbrain (n = 2) and the medulla oblongata (n = 2). Concurrent systemic disease was identified in most (n = 8/9). In the present study short-term prognosis was favourable and 8/9 cats survived to 48 h following admission. Conclusions and relevance CVAs in cats occur in the same vascular territories as in dogs and have similar MRI features. This study notes that the presenting cats had a high likelihood of concurrent disease (8/9 cases) but had a favourable short-term prognosis, if neither the clinical presentation nor concurrent disease were severe.

Atrial fibrillation and cognitive decline in the Framingham Heart Study

BACKGROUND

There is a paucity of longitudinal research investigating the relations between atrial fibrillation (AF) and domain-specific cognitive performance.

OBJECTIVE

The purpose of this study was to investigate the association between AF and cognitive performance cross-sectionally and longitudinally.

METHODS

Eligible participants were dementia- and stroke-free at the time of baseline neuropsychological (NP) assessment and underwent at least 1 additional NP assessment with at least 1-year inter-test interval. AF status was examined as a 2-level variable (prevalent AF, no AF) in cross-sectional analyses and then separately as a 3-level variable (prevalent AF, interim AF, no AF) in longitudinal analyses. We examined the association between AF status and cognitive performance with linear regression. We first adjusted models for age and sex and then for vascular risk factors and apolipoprotein ε4 (APOE4) status.

RESULTS

We studied 2682 participants of the Framingham Heart Study original and offspring cohorts. At the baseline NP assessment, 112 participants (4%) had AF (mean age 72 ± 9 years; 32% women). After adjustment for vascular risk factors and APOE4 status, prevalent AF was significantly associated with poorer attention; sex differences were also noted with men performing worse on tests of abstract reasoning and executive function, while women did better on a measure of executive function. Prevalent AF was significantly associated with longitudinal decline in executive function in the original cohort, and interim AF was significantly associated with longitudinal decline in executive function in the offspring cohort.

CONCLUSION

After accounting for vascular risk factor burden and APOE4 status, AF was associated with a vascular profile of change in cognitive function.

The cerebral circulation and cerebrovascular disease II: Pathogenesis of cerebrovascular disease

In this paper, we review the cerebral circulation and cerebrovascular disease (CVD) with an overview of the major types of CVD pathogenesis. These, as categorized here, are as follows: occlusive injury intrinsic to blood vessels, occlusive injury extrinsic to blood vessels, cerebral hypoperfusion, and cerebral hemorrhage. Following an overview of each of these categories, we conclude with a discussion of cerebral edema to illustrate how the pathological origins we covered can progress clinically. The content of this paper sets the stage for the detailed, clinically oriented discussion of stroke with which our series culminates in its subsequent Part III.

Association between atrial fibrillation and volumetric magnetic resonance imaging brain measures: Framingham Offspring Study

BACKGROUND

The increased risk of stroke and cognitive impairment associated with atrial fibrillation (AF) is well documented. However, there is a paucity of research investigating the relations between AF and brain morphology.

OBJECTIVE

The purpose of this study was to investigate the association between AF and brain volume measures on magnetic resonance imaging (MRI).

METHODS

The study sample included stroke- and dementia-free participants who attended the Framingham Heart Study offspring cohort 7th examination cycle (1999-2005) and underwent contemporaneous MRI. We examined the association between prevalent AF and brain volume measures (total cerebral volume, frontal lobe volume, temporal lobe volume, temporal horn volume, hippocampal volume, and white matter hyperintensity volume) with linear regression. We first adjusted models for age and sex, and then for vascular risk factors and APOE4.

RESULTS

We studied 2144 individuals (mean age 61.8 ± 9.3 years; 54% women); 73 participants (3.4%) had prevalent AF at the time of MRI. In age- and sex-adjusted models, AF was inversely associated with total cerebral brain volume, frontal brain volume, and temporal brain volume. After further adjustment for vascular risk factors and APOE4, AF remained associated with frontal brain volume.

CONCLUSION

After accounting for vascular risk factor burden, prevalent AF was associated with lobar indexes of vascular brain aging but not with expected white matter changes.

Percutaneous balloon commissurotomy reduces incidence of ischemic cerebral stroke in patients with symptomatic rheumatic mitral stenosis

Whether percutaneous balloon commissurotomy reduces cerebral stroke in patients with symptomatic rheumatic mitral stenosis remains obscure. This study enrolled 170 such patients undergoing either medical therapy alone (n=71) or balloon commissurotomy (n=99). In the short term, balloon commissurotomy was successfully accomplished in 99% patients without embolic complications. At follow-up (mean 4.2+/-3.2 years), patients undergoing commissurotomy encountered significantly rarer ischemic stroke than the medicine group (2% vs. 13%, p=0.043). Multivariate Cox regression analysis further confirmed balloon commissurotomy as a negative predictor for ischemic stroke (hazard ratio 0.135, p=0.011). These results lead to the conclusion that percutaneous balloon commissurotomy could substantially decrease the long-term incidence of ischemic cerebral stroke in eligible patients with symptomatic rheumatic mitral stenosis.

Immediate and late outcomes of patients undergoing transseptal left-sided heart catheterization for symptomatic valvular and arrhythmic diseases

BACKGROUND

The transseptal technique has been widely used for diagnostic and therapeutic left-sided heart catheterization. However, its differential immediate and late outcomes among patients with various valvular and arrhythmic diseases are not yet determined.

METHODS

Beginning from 1993, all patients undergoing transseptal procedures were screened and categorized into diagnosis, arrhythmia, and valvuloplasty groups according to the purposes of the catheterization. Incidences of transseptum-related acute major events (cardiac perforation, embolic stroke, and bradyarrhythmia during the procedure) and late complications (residual atrial septal defect [ASD], embolic stroke, bradyarrhythmia, and death up to 18 months) were analyzed and compared between groups.

RESULTS

From January 1993 to May 2003, a total of 176 patients underwent 184 transseptal procedures for diagnosis of valvular heart diseases (n = 8), catheter ablation of arrhythmogenic foci (n = 29), and mitral valvuloplasty (n = 147). The immediate outcome was similar among the 3 groups, with an overall acute complication incidence of 3.8%. At follow-up, the incidences of bradyarrhythmia, embolic stroke, and death were not different among the 3 groups. Patients undergoing valvuloplasty had a significantly higher prevalence of residual ASD, especially for those with more severe mitral stenosis and less valvuloplasty success. However, presence of ASD did not impose disadvantage over the 1.5-year prognosis.

CONCLUSION

Transseptal left-sided heart catheterization can be safely applied to patients with different categories of cardiac diseases with comparably good immediate and late outcomes. Although patients undergoing percutaneous valvuloplasty have a higher chance of permanent ASD creation, their prognosis is not influenced.

Near Field Flow Characteristics of the Bjork-Shiley Monostrut Valve in a Modified Single Shot Valve Chamber

In certain mechanical heart valves, cavitation has been shown to develop during closure and rebound, leading to valve damage, blood damage, and strokes. Whereas it is uncertain what causes mechanical heart valve related strokes, some evidence suggests that stable bubbles may be the culprits. Previous work has indicated that vortex cavitation may contribute to stable bubble growth. Therefore, in an effort to understand the vortex cavitation, laser Doppler velocimetry data are collected in a plane parallel to and 3 mm away from the major orifice during closure and rebound of a Bjork-Shiley Monostrut mechanical heart valve. A modified single shot chamber is used that incorporates a more realistic near valve geometry than those used in previous studies. The results show the formation of a vortex during closure, which intensifies during rebound and dissipates during the final closing cycle. A regurgitant jet with mean velocities up to 3 m/s through the clearance gap of the valve provides energy to the vortex. During the final closing cycle, the vortex breaks up into asymmetrical, small scale flow patterns. This study provides further evidence that stable bubble formation may stem from the intense vortex cavitation occurring during valve closure and rebound.