Assessment of acute spontaneous intracerebral hematoma by CT perfusion imaging

Increased perihematomal neuron autophagy and plasma thrombin-antithrombin levels in patients with intracerebral hemorrhage: An observational study

Animal studies have demonstrated that autophagy was involved in neuronal damage after intracerebral hemorrhage (ICH). Several studies showed thrombin-antithrombin (TAT) plasma levels were elevated in patients with ICH. In this study, we aimed to evaluate if autophagy occurred in patients with ICH; and the relationship between the severity of brain injury and plasma TAT levels.A novel tissue harvesting device was used during hematoma removal surgery to collect loose fragments of tissue surrounding the affected brain area in 27 ICH patients with hematoma volumes of >30 mL in the basal ganglia. Control tissues were obtained from patients who underwent surgery for arteriovenous malformation (n = 25). Transmission electron microscopy (TEM) and immunohistochemistry for autophagy-related proteins were used to evaluate the ultrastructural and morphologic cellular characteristics; and the extent of autophagy in the recovered tissue specimens. Stroke severity was assessed by using the Glasgow Coma Scale (GCS) and the National Institutes of Health Stroke Scale (NIHSS). An enzyme-linked immunosorbent assay (ELISA) was used to measure plasma TAT levels.Transmission electron microscopy showed autophagosomes and autolysosomes exist in neurons surrounding the hematoma, but not in the control tissues. The number of cells containing autophagic vacuoles correlated with the severity of brain injury. Immunohistochemistry showed strong LC3, beclin 1, and cathepsin D staining in ICH tissue specimens. Plasma TAT levels correlated positively with autophagic cells and ICH severity (P < .01).Autophagy was induced in perihematomal neurons after ICH. Autophagy and plasma TAT levels correlated positively with severity of brain injury. These results suggest that autophagy and increased plasma TAT levels may contribute to the secondary damage in ICH patients.

Experimental intracerebral hemorrhage: avoiding pitfalls in translational research

Intracerebral hemorrhage (ICH) has the highest mortality of all stroke subtypes, yet treatments are mainly limited to supportive management, and surgery remains controversial. Despite significant advances in our understanding of ICH pathophysiology, we still lack preclinical models that accurately replicate the underlying mechanisms of injury. Current experimental ICH models (including autologous blood and collagenase injection) simulate different aspects of ICH-mediated injury but lack some features of the clinical condition. Newly developed models, notably hypertension- and oral anticoagulant therapy-associated ICH models, offer added benefits but further study is needed to fully validate them. Here, we describe and discuss current approaches to experimental ICH, with suggestions for changes in how this condition is studied in the laboratory. Although advances in imaging over the past few decades have allowed greater insight into clinical ICH, there remains an important role for experimental models in furthering our understanding of the basic pathophysiologic processes underlying ICH, provided limitations of animal models are borne in mind. Owing to differences in existing models and the failed translation of benefits in experimental ICH to clinical practice, putative neuroprotectants should be trialed in multiple models using both histological and functional outcomes until a more accurate model of ICH is developed.

Novel approaches to the treatment of intracerebral haemorrhage

Intracerebral haemorrhage is the most devastating subtype of stroke. It affects approximately two million patients worldwide every year and is a major cause of morbidity and mortality. After decades of research, we still face the fact that there is no evidence-based treatment strategy for this disease. However, research has contributed to a better understanding of the pathophysiology of intracerebral haemorrhage and also to the identification of new treatment targets. Several novel aspects of treatment of spontaneous intracerebral haemorrhage are reviewed in the present article.

Neuroimaging of hemorrhage and vascular defects

Intracranial hemorrhage is the third most common cause of stroke and involves the accumulation of blood within brain parenchyma or the surrounding meningeal spaces. Accurate identification of acute hemorrhage and correct characterization of the underlying pathology, such as tumor, vascular malformation, or infarction, is a critical step in planning appropriate therapy. Neuroimaging studies are required not only for diagnosis, but they also provide important information on the type of hemorrhage, etiology, and the pathophysiological process. Historically, computed tomography (CT) scan has been the diagnostic imaging study of choice; however, there is growing evidence suggesting that magnetic resonance imaging (MRI) is at least as sensitive as CT to detect intraparenchymal hemorrhages in the hyperacute setting, and actually superior to CT in the subacute and chronic settings. Unique MRI and CT characteristics differentiate secondary causes of hemorrhage from the more common hypertensive hemorrhage. Baseline and serial studies can be used to identify patients who might benefit from acute interventions. In addition, new imaging modalities, (such as magnetic resonance spectroscopy, diffusion tensor imaging, and 320-row CT) are promising research techniques that have the potential to enhance our understanding of the tissue injury and recovery after intracranial hemorrhages.

Treatment and prevention of spontaneous intracerebral hemorrhage: comparison of EUSI and AHA/ASA recommendations

Stroke is a leading cause of death and the primary cause of permanent disability in adults in Western countries and has an enormous socioeconomic impact. Among all stroke subtypes, intracerebral hemorrhage is the deadliest form, especially in patients with intraventricular hemorrhage. In recent years, intracerebral hemorrhage has become a major focus within stroke research. The latest data from randomized controlled trials, however, have shown disappointing results. In 2006, the European Stroke Initiative published recommendations for the management of spontaneous intracerebral hemorrhage, followed by an updated recommendation by the American Heart Association/American Stroke Association in 2007. This review gives a comprehensive overview and comparison of the two recommendations. Finally, we provide an overview of ongoing clinical trials in intracerebral hemorrhage.

Evidence against a perihemorrhagic penumbra provided by perfusion computed tomography

BACKGROUND AND PURPOSE

Several recent studies analyzing perfusion changes in acute intracerebral hemorrhage fed the debate whether there is secondary ischemic tissue damage in the vicinity of intracerebral hemorrhage. We used perfusion CT to address this question.

METHODS

We examined 36 patients between 2001 and 2002 with acute intracerebral hemorrhage (within 24 hours after symptom onset). A subgroup of 8 patients was examined serially on day 1, between days 2 and 4, and after day 5. Nonenhanced CT images and maps of cerebral blood flow, cerebral blood volume, and time to peak were evaluated by region of interest analysis.

RESULTS

In comparison to the contralateral hemisphere, perfusion values were clearly reduced around the hematoma (relative values: cerebral blood flow 0.51, cerebral blood volume 0.62, time to peak 1.7 seconds). There was no difference in size between the area of reduced perfusion and the area of edema (5.17 versus 5.75 cm(2), respectively) surrounding the hematoma. At time point 2, the edema grew significantly.

CONCLUSIONS

In accordance with previous studies, we found reduced perfusion as well as edema surrounding acute intracerebral hemorrhage. Regarding ischemic tissue damage, we did not detect an initial mismatch between the perfusion deficit and the edema and therefore could not identify any tissue at risk of ischemia. We therefore interpret the reduced perfusion as a secondary phenomenon, ie, reduced oxygen demand of tissue damaged by pressure and clot components, not as the cause of any tissue damage associated with acute intracerebral hemorrhage.