Critical care of intracerebral and subarachnoid hemorrhage

Hypersensitive MR Angiography for Diagnosis of Ischemic Stroke and Reperfusion Subarachnoid Hemorrhage

Stroke is an acute injury of the central nervous system caused by the disorders of cerebral blood circulation, which has become one of the major causes of disability and death. Hemorrhage, particularly subarachnoid hemorrhage (SAH), is one of the poorest prognostic factors in stroke, which is related to the thrombolytic therapy, and has been considered very dangerous. In this context, the MR angiography with high sensitivity and resolution has been developed based on biocompatible paramagnetic ultrasmall NaGdF4 nanoprobes. Owing to the appropriate hydrodynamic diameter, the nanoprobe can be confined inside the blood vessels and it only extravasates at the vascular injury site when the bleeding occurs. Relying on this property, the three-dimensional (3D) anatomic structures of artery occlusion of stroke rat can be precisely visualized; reperfusion-related SAH has been successfully visualized and identified. Benefiting from the long blood half-life of the nanoprobe, the observation window of MR angiography can last for the whole period of reperfusion, thereby monitoring the probable SAH in real time during thrombolytic therapy. More importantly, through reconstruction of multiparametric MRI, the arterial occlusion, cerebral ischemic region, and SAH can be simultaneously visualized in vivo in a 3D manner for the first time. Therefore, the current study provides a novel approach for both noninvasive 3D vascular visualization and hemorrhage alert, which possesses great prospects for clinical translation.

Essential topics about the imaging diagnosis and treatment of Hemorrhagic Stroke: a comprehensive review of the 2022 AHA guidelines

Intracerebral hemorrhage (ICH) is a severe stroke with a high death rate (40 % mortality). The prevalence of hemorrhagic stroke has increased globally, with changes in the underlying cause over time as anticoagulant use and hypertension treatment have improved. The fundamental etiology of ICH and the mechanisms of harm from ICH, particularly the complex interaction between edema, inflammation, and blood product toxicity, have been thoroughly revised by the American Heart Association (AHA) in 2022. Although numerous trials have investigated the best medicinal and surgical management of ICH, there is still no discernible improvement in survival and functional tests. Small vessel diseases, such as cerebral amyloid angiopathy (CAA) or deep perforator arteriopathy (hypertensive arteriopathy), are the most common causes of spontaneous non-traumatic intracerebral hemorrhage (ICH). Even though ICH only causes 10-15% of all strokes, it contributes significantly to morbidity and mortality, with few acute or preventive treatments proven effective. Current AHA guidelines acknowledge up to 89% sensitivity for unenhanced brain CT and 81% for brain MRI. The imaging findings of both methods are helpful for initial diagnosis and follow-up, sometimes necessary a few hours after admission, especially for detecting hemorrhagic transformation or hematoma expansion. This review summarized the essential topics on hemorrhagic stroke epidemiology, risk factors, physiopathology, mechanisms of injury, current management approaches, findings in neuroimaging, goals and outcomes, recommendations for lifestyle modifications, and future research directions ICH. A list of updated references is included for each topic.

Case studies in cardiac dysfunction after acute aneurysmal subarachnoid hemorrhage

Patients with acute aneurysmal subarachnoid hemorrhage (SAH) often present with more than just neurological compromise. A wide spectrum of complicating cardiopulmonary abnormalities have been documented in patients with acute SAH, presenting additional challenges to the healthcare providers who attempt to treat and stabilize these patients. The patients described in this article presented with both acute aneurysmal SAH and cardiopulmonary compromise. Education and further research on this connection is needed to provide optimal care and outcomes for this vulnerable population. Nurses play a key role in balancing the critical and diverse needs of patients presenting with these symptoms.

Cerebrovascular Dynamics With Head-of-Bed Elevation in Patients With Mild or Moderate Vasospasm After Aneurysmal Subarachnoid Hemorrhage

• Background In patients with aneurysmal subarachnoid hemorrhage, elevation of the head of the bed during vasospasm has been limited in an attempt to minimize vasospasm or its sequelae or both. Consequently, some patients have remained on bed rest for weeks.

• Objectives To determine how elevations of the head of the bed of 20° and 45° affect cerebrovascular dynamics in adult patients with mild or moderate vasospasm after aneurysmal subarachnoid hemorrhage and to describe the response of mild or moderate vasospasm to head-of-bed elevations of 20° and 45° with respect to variables such as grade of subarachnoid hemorrhage and degree of vasospasm.

• Methods A within-patient repeated-measures design was used. The head of the bed was positioned in the sequence of 0°-20°-45°-0° in 20 patients with mild or moderate vasospasm between days 3 and 14 after aneurysmal subarachnoid hemorrhage. Continuous transcranial Doppler recordings were obtained for 2 to 5 minutes after allowing approximately 2 minutes for stabilization in each position.

• ResultsNo patterns or trends indicated that having the head of the bed elevated increases vasospasm. As a group, there were no significant differences within patients at the different positions of the head of the bed. Utilizing repeated-measures analysis of variance, P values ranged from .34 to .97, well beyond .05. No neurological deterioration occurred.

• Conclusions In general, elevation of the head of the bed did not cause harmful changes in cerebral blood flow related to vasospasm.

Guidelines for Prevention of Stroke in Patients With Ischemic Stroke or Transient Ischemic Attack

The aim of this new statement is to provide comprehensive and timely evidence-based recommendations on the prevention of ischemic stroke among survivors of ischemic stroke or transient ischemic attack. Evidence-based recommendations are included for the control of risk factors, interventional approaches for atherosclerotic disease, antithrombotic treatments for cardioembolism, and the use of antiplatelet agents for noncardioembolic stroke. Further recommendations are provided for the prevention of recurrent stroke in a variety of other specific circumstances, including arterial dissections; patent foramen ovale; hyperhomocysteinemia; hypercoagulable states; sickle cell disease; cerebral venous sinus thrombosis; stroke among women, particularly with regard to pregnancy and the use of postmenopausal hormones; the use of anticoagulation after cerebral hemorrhage; and special approaches for the implementation of guidelines and their use in high-risk populations.

Mmp-9 deficiency enhances collagenase-induced intracerebral hemorrhage and brain injury in mutant mice

Matrix metalloproteinase-9 (MMP-9) participates in the disregulation of blood-brain barrier during hemorrhagic transformation, and exacerbates brain injury after cerebral ischemia. However, the consequences of long-term inhibition or deficiency of MMP-9 activity (which might affect normal collagen or matrix homeostasis) remains to be determined. The authors investigated how MMP-9 gene deficiency enhances hemorrhage and increases mortality and neurologic deficits in a collagenase-induced intracerebral hemorrhage (ICH) model in MMP-9-knockout mice. MMP-9-knockout and corresponding wild-type mice at 20 to 35 weeks were used to model an aged population (because advanced age is a significant risk factor in human ICH). Collagenase VII-S (0.5 microL, 0.075 U) was injected into the right basal ganglia in mice and mortality, neurologic deficits, brain edema, and hemorrhage size measured. In addition, MMP-9 activity, brain collagen content, blood coagulation, cerebral arterial structure, and expressions of several MMPs were examined. Increased hemorrhage and brain edema that correlated with higher mortality and neurologic deficits were found in MMP-9-knockout mice. No apparent structural changes were observed in cerebral arteries, even though brain collagen content was reduced in MMP-9-knockout mice. MMP-9-knockout mice did exhibit an enhanced expression of MMP-2 and MMP-3 in response to ICH. The results indicate that a deficiency of MMP-9 gene in mutant mice increases collagenase-induced hemorrhage and the resulting brain injury. The intriguing relationship between MMP-9 deficiency and collagenase-induced ICH may reflect the reduction in collagen content and an enhanced expression of MMP-2 and MMP-3.