Intra-arterial Air Thrombogenesis after Cerebral Air Embolism Complicating Lower Extremity Sclerotherapy

Background  Cerebral arterial gas embolism is a potentially life-threatening event. Intraarterial air can occlude blood flow directly or cause thrombosis. Sclerotherapy is an extremely rare cause of cerebral arterial gas embolism. Method  Case-report. Results  A 38-year-old female suffered acute onset of a left middle cerebral artery (LMCA) syndrome with an NIH stroke score of 11 approximately ten minutes after lower extremity sclerotherapy. CT angiogram demonstrated LMCA intraarterial air. Patient fully recovered after hyperbaric oxygen treatment with complete resolution of intraarterial air. However, thrombus replaced intraarterial air despite anticoagulation with heparin. Conclusion  We provide radiological evidence of hyperbaric oxygen therapy resolving intraarterial air but also demonstrate the thrombogenic potential of this procedural complication.     

Fatal Massive Cerebral Air Embolism in a Lung Transplant Patient

Introduction  

Massive air embolism has been described in multiple clinical scenarios, especially in critical ill patients who undergo invasive procedures. Nevertheless, air embolism is often unrecognized and a high index of suspicion is required to diagnose this entity. Two previous cases of air embolism in lung transplant patients have been described in the literature; we describe a third case of fatal massive air embolism and cardiovascular collapse in a lung transplant patient.     

Polyneuropathy Associated with Cholesterol Crystal Embolism

Introduction  

Cholesterol crystal embolism complicating arterial catheterization usually presents as a multiorgan disease with renal failure, abdominal problems, and skin manifestations.     

Clinical and Radiographic Improvement Following Cerebral Fat Emboli

Background  

Cerebral fat embolism is a well-described complication associated with long-bone fracture. However, with contemporary imaging, there is a distinct magnetic resonance imaging (MRI) pattern emerging.     

Vasospasm and cerebral infarction following isolated intraventricular hemorrhage

Introduction  

Cerebral arterial vasospasm following aneurysmal subarachnoid hemorrhage (SAH) is an important cause of delayed neurologic deterioration. Vasospasm following isolated intraventricular hemorrhage (IVH) is less common. Accepted predictors of vasospasm following SAH include poor Hunt-Hess grade, elevated transcranial Doppler velocities, and the thickness of cisternal blood on neuroimaging [1, 2]. The role of intraventricular hemorrhage in vasospasm is more controversial.     

Symptomatic cerebral air embolism during neuro-angiographic procedures: incidence and problem avoidance

Background  

While clinically symptomatic cerebral air embolism secondary to neuro-angiographic procedures is rare, the incidence in a large series of procedures is unknown. Understanding this complication’s frequency and etiology is critical if systems are to be instituted to reduce its incidence.     

Hyperventilation during orthostatic challenge in spinal cord-injured humans

Objective  

To determine whether arterial hypotension is related to hyperventilation during standing in individuals with complete spinal cord injury (SCI).     

Ischaemic stroke with malignancy may often be caused by paradoxical embolism

Background

Although ischaemic stroke with malignancy occasionally occurs, the mechanisms of stroke in such cases have not been investigated in detail.

Objective

To examine the mechanisms of ischaemic stroke with malignancy, particularly in relation to right‐to‐left shunt (RLS).

Methods

Consecutive patients with ischaemic stroke within 24 h of stroke onset were prospectively studied. Contrast saline transcranial Doppler examination was carried out for all patients, to investigate the presence of RLS. When patients with stroke had RLS, deep venous thrombosis (DVT) or pulmonary embolism was assessed to diagnose paradoxical brain embolism.

Results

Participants comprised 184 consecutive patients (115 men and 69 women) with a mean (standard deviation (SD)) age of 73 (11.8) years and mean (SD) National Institutes of Health Stroke Scale (NIHSS) score of 8 (7.4). RLS was detected in 32 of 184 (18%) patients. Malignancy was present in 11 (5%) patients. RLS was more frequent in patients with malignancy than in patients without malignancy (55% v 15%, respectively; p = 0.001). All six patients with RLS and malignancy displayed DVT or pulmonary embolism with severe disability (modified Rankin Scale 4–5) before stroke onset.

Conclusion

Paradoxical brain embolism should be considered to be an important mechanism in patients with stroke and malignancy.Several causes of ischaemic stroke associated with malignancy have been reported previously, such as hypercoagulability and non‐bacterial thrombotic endocarditis (NBTE).¹ However, making a definite diagnosis of NBTE is difficult, as cardiological investigations cannot always detect vegetations in the heart.² NBTE is attributed to a disorder of coagulation and endothelial dysfunction.³ Paradoxical brain embolism has recently been considered to be a potential cause of cerebral infarction of unknown aetiology. Deep venous thrombosis (DVT) is the main embolic cause of paradoxical brain embolism and readily occurs under hypercoagulable conditions.⁴ Although both NBTE and DVT are likely to be found in patients with malignancy, attention has not been paid to paradoxical brain embolism. Our study aimed to investigate the frequency of paradoxical brain embolism among patients with malignancy and to examine clinical characteristics in these patients.     

Cardiac myxoma complicated with cerebral aneurysms and revealed by an ischemic stroke

Introduction

Myxoma is a rare benign primary cardiac tumor. It may cause vascular complications. Neurological symptoms may precede or accompany the diagnosis of myxoma with systemic embolization occurring most often in the cerebral circulation.

Observation

We report a case of cardiac myxoma complicated with cerebral aneurysms and revealed by an ischemic stroke in a 21-year-old patient. The cardiac myxoma was discovered during the transthoracic echocardiography performed as part of the etiological work-up. Because of the high risk of embolism, the mass was resected and mitral valve surgically repaired. The postoperative outcome was uneventful.

Conclusion

Although myxoma is a benign tumor histologically, it can lead to serious complications such as systemic embolism and sudden death.     

Practice Standards for Transcranial Doppler (TCD) Ultrasound. Part II. Clinical Indications and Expected Outcomes

ABSTRACT

INTRODUCTION

Transcranial Doppler (TCD) is a physiological ultrasound test with established safety and efficacy. Although imaging devices may be used to depict intracranial flow superimposed on structural visualization, the end‐result provided by imaging duplex or nonimaging TCD is sampling physiological flow variables through the spectral waveform assessment.

SUMMARY OF RESULTS

Clinical indications considered by this multidisciplinary panel of experts as established are: sickle cell disease, cerebral ischemia, detection of right‐to‐left shunts (RLS), subarachnoid hemorrhage, brain death, and periprocedural or surgical monitoring. The following TCD‐procedures are performed in routine in‐ and outpatient clinical practice: complete or partial TCD‐examination to detect normal, stenosed, or occluded intracranial vessels, collaterals to locate an arterial obstruction and refine carotid‐duplex or noninvasive angiographic findings; vasomotor reactivity testing to identify high‐risk patients for first‐ever or recurrent stroke; emboli detection to detect, localize, and quantify cerebral embolization in real time; RLS‐detection in patients with suspected paradoxical embolism or those considered for shunt closure; monitoring of thrombolysis to facilitate recanalization and detect reocclusion; monitoring of endovascular stenting, carotid endarterectomy, and cardiac surgery to detect perioperative embolism, thrombosis, hypo‐ and hyperperfusion.

CONCLUSION

By defining the scope of practice, these standards will assist referring and reporting physicians and third parties involved in the process of requesting, evaluating, and acting upon TCD results.     

Arterial baroreflex dysfunction in major depressive disorder

Objectives  

Patients treated for major depressive disorder are at increased risk for sudden cardiac death. Impaired arterial baroreflex function has been associated with ventricular arrhythmias. Our hypothesis was that arterial baroreflex dysfunction prevails in major depressive disorder and that electroconvulsive therapy in conjunction to medical therapy would improve both depressive symptoms and baroreflex function.     

Basilar artery dolichoectasia in childhood: evidence of vascular compromise

Introduction  

Dolichoectasia describes the elongation, dilatation and tortuosity of an arterial vessel. In adults, clinical presentation of basilar dolichoectasia (BD) is most often with ischaemic stroke. True BD has been very rarely reported in childhood, but the implication is of a congenital susceptibility.     

A longitudinal follow-up of posttraumatic stress: from 9 months to 20 years after a major road traffic accident

Background  

Although road traffic accidents (RTA) are a major cause of injury and a cause of posttraumatic stress (PTS) in the aftermath, little is known about the long-term psychological effects of RTA.     

Delayed coma in head injury: Consider cerebral fat embolism

Objective

To describe a case of a young man with delayed coma after mild head injury, suggestive of cerebral fat embolism (CFE). To underline the value of MR imaging in the differential diagnosis of secondary deterioration in mild head injury.

Case report

A 21-year-old man admitted with mild head injury after a fall with facial fractures and long bone fractures. He was admitted to the intensive care unit and was mechanically ventilated. Weaning was not possible because of desaturations and pulmonary congestion. Low platelet count and anaemia developed. On several time points during his admission cerebral imaging data were obtained. Non-contrast CT on admission was normal while follow-up MRI showed extensive white matter abnormalities. These imaging abnormalities combined with the clinical presentation suggests cerebral fat embolism (CFE) as the most likely cause of secondary deterioration in our patient.

Conclusions

In head injured patients with long bone fractures one should consider cerebral fat embolism. When the classical clinical syndrome is not present, MR imaging is warranted for diagnosis and to exclude other causes of secondary deterioration.     

Gradient-Echo MRI in Defining the Severity of Cerebral Fat Embolism

Background

A few studies have found that abnormal findings on diffusion-weighted magnetic resonance imaging (MRI) are useful for diagnosing cerebral fat embolism in the acute stage.

Case Report

We applied serial MRI to a case of cerebral fat embolism with cognitive impairment lasting for 2 months. Although marked resolution of the previous abnormal findings was demonstrated, T2*-weighted gradient-echo MRI revealed multiple tiny lesions.

Conclusions

We suggest that T2*-weighted gradient-echo MRI is useful in defining the clinical severity of patients with cerebral fat embolism.     

Retroperitoneal infection complicated by bacterial meningitis and ventriculitis with secondary brainstem infarction

Introduction  

Retroperitoneal abscesses have been previously reported to cause infectious meningitis. Cerebral infarction is a known complication of basilar meningitis.     

Associations Between Religious Involvement and Behavioral Risk Factors for HIV/AIDS in American Women and Men in a National Health Survey

Background  

Acquired immunodeficiency syndrome (AIDS), caused by human immunodeficiency virus (HIV), is a leading cause of death.     

A porcine model of massive, totally occlusive, pulmonary embolism

Background

A reliable, animal model of massive, totally occlusive, pulmonary embolism (PE) is lacking.

Objectives

To design an animal model of totally occlusive PE and to challenge the model by a plasminogen activator.

Methods

In eight anaesthetized pigs (~ 90 kg) a massive preformed autologous thrombus was injected into the caval vein. One animal was autopsied to assess the extent of injected clot, whereas in the other animals extracorporeal life support (ECLS) was initiated and continued for three hours. These animals received 100 mg rt-PA. Blood gases, coagulation tests, creatine kinase (CK), lactate dehydrogenase (LDH), end-tidal CO2, systemic and pulmonary artery blood pressures and flow were registered.

Results

All animals went into circulatory arrest within 2 minutes after injection of the thrombus. In the animal where ECLS was not started, autopsy relieved a totally occlusive embolus of the pulmonary artery. The ECLS maintained a systemic blood flow of 6-8 L/min with adequate oxygenation and CO2-removal. However, lactate increased and base-excess became negative. Ddimer increased, fibrinogen decreased, and CK and LDH increased. All seven animals were weaned from ECLS. Despite the rt-PA treatment, the animals had at that time low end tidal CO2/PaCO2 ratio and increased mean pulmonary arterial pressure, suggesting a significant amount of embolic material remaining in the pulmonary artery.

Conclusion

This model of massive, totally occlusive, pulmonary embolism mimics well fatal PE seen in the clinic, and has the potential for use in testing of new therapeutic interventions.     

Cerebral Air Embolism Resulting in Fatal Stroke in an Airplane Passenger with a Pulmonary Bronchogenic Cyst

Introduction  Cerebral air embolism is a rare cause of stroke, but may occur in patients undergoing invasive cardiac and pulmonary procedures, as well as in divers suffering pulmonary barotrauma from rapid ascent. Cerebral air embolism during air travel, however, is particularly rare. Case  We present a case of a previously healthy gentleman who presented with an acute stroke after a commercial flight; the stroke was initially felt to be of cardioembolic origin. A large intrapulmonary cyst was noted on his imaging studies, but thought to be an incidental finding. During a return flight, he suffered another stroke and was found to have cerebral air emboli. Conclusion  This case suggests the importance of considering cerebral air embolism in patients with stroke associated with air travel; restricting air travel in patients with intrapulmonary cysts may be prudent.     

Squatting test: a dynamic postural manoeuvre to study baroreflex sensitivity

Introduction  

Squatting is an active posture test that can be used to assess baroreflex sensitivity. Indeed, the shift from squatting to standing imposes a major orthostatic stress leading to rapid and large changes in arterial blood pressure (BP) and heart rate (HR) allowing precise baroreflex assessment.