Clinical case of arteriovenous malformation

Arteriovenous malformation (AVM) is a congenital malformation of cerebral vessels, associated with an abnormal connection of arteries and veins. The altered locations of the cerebral vascula-ture form a conglomerate that is a direct arteriovenous shunting without intermediate capillaries. The incidence of the disease is 4 cases per 100 thousand population. Clinically, AVM debuts mainly at the age of 20 to 40, and is accompanied by intracranial hemorrhages in 50% to 60% of patients; mortality is 35%. In 27% to 70% of individuals, AVM are manifested by epileptic seizures of various focal origins. In diagnostics, X-ray computed tomography is used to detect hemorrhage in case of a ruptured malformation; magnetic resonance imaging, including angiography, to assess the AVM node, afferent vessels and venous drainage. Currently, the only radical treatment for AVM is surgical removal of the malformation. This is feasible for small and medium-sized AVMs of cerebral vessels (36% to 50% of patients), since removal of large AVMs and AVMs located in functionally important areas, even microsurgically, is associated with a high risk of death and disability. A clinical case of a 30-year-old young patient with an acute onset of the disease characterized by sudden loss of consciousness and an episode of seizures is presented. Based on the data of clinical and instrumental examination, an AVM of the left parietal lobe with parenchymal-ventricular hemorrhage was revealed. On the day of admission to the hospital in Ryazan, a surgical intervention was performed: external ventriculostomy on the left side. After 4 months the second surgical intervention, removal of AVM of the left parietal region using neurophysiological control was carried out at Burdenko Neurosurgical Hospital in Moscow, Russia. The successful surgical approach has completely eliminated the life-threatening pathology. Subsequently, the patient underwent rehabilitation in a neurological hospital at the place of residence. CONCLUSION: The topic of AVM is of great practical interest not only for neurosurgeons, but also for neurologists and radiologists, since timely diagnosis and treatment effectiveness directly depend on the coordinated work of these specialists.

Cerebral Vasospasm: Mechanisms, Pathomorphology, Diagnostics, Treatment

Cerebral vessels constriction is one of the leading causes of mortality and disability in patients with acute cerebral circulatory disorders. The most dangerous type of acute cerebrovascular disease accompanied by high mortality is ruptured cerebral aneurysms with subarachnoidal hemorrhage (SAH). Following a constriction of the cerebral vessels on the background of SAH is the reason for brain ischemia. This chapter will focus on the mechanisms of formation of cerebral vascular spasm, pathomorphological aspects of the cerebral vessels constriction, and the stages of vascular spasm—the development of constrictive-stenotic arteriopathy, contractural degeneration of smooth muscle cells, and endothelial damage. We will cover classifications of cerebral vessels constriction by prevalence and severity, modern methods of clinical and instrumental diagnostics and treatment including paroxysmal sympathetic hyperactivity syndrome associated with the development of secondary complications, a longer stay of the patients in the ICU, higher disability and mortality.

Real-Time Cerebral Vessel Segmentation in Laser Speckle Contrast Image Based on Unsupervised Domain Adaptation

Laser speckle contrast imaging (LSCI) is a full-field, high spatiotemporal resolution and low-cost optical technique for measuring blood flow, which has been successfully used for neurovascular imaging. However, due to the low signal–noise ratio and the relatively small sizes, segmenting the cerebral vessels in LSCI has always been a technical challenge. Recently, deep learning has shown its advantages in vascular segmentation. Nonetheless, ground truth by manual labeling is usually required for training the network, which makes it difficult to implement in practice. In this manuscript, we proposed a deep learning-based method for real-time cerebral vessel segmentation of LSCI without ground truth labels, which could be further integrated into intraoperative blood vessel imaging system. Synthetic LSCI images were obtained with a synthesis network from LSCI images and public labeled dataset of Digital Retinal Images for Vessel Extraction, which were then used to train the segmentation network. Using matching strategies to reduce the size discrepancy between retinal images and laser speckle contrast images, we could further significantly improve image synthesis and segmentation performance. In the testing LSCI images of rodent cerebral vessels, the proposed method resulted in a dice similarity coefficient of over 75%.

Immunoreactivity and a new staining method of monocarboxylate transporter 1 located in endothelial cells of cerebral vessels of human brain in distinguishing cerebral venules from arterioles

Distinguishing brain venules from arterioles with arteriolosclerosis is less reliable using traditional staining methods. We aimed to immunohistochemically assess the monocarboxylate transporter 1 (MCT1), a specific marker of venous endothelium found in rodent studies, in different caliber vessels in human brains. Both largeand small-caliber cerebral vessels were dissected from four autopsy donors. Immunoreactivity for MCT1 was examined in all autopsied human brain tissues, and then each vessel was identified by neuropathologists using hematoxylin and eosin stain, the Verhoeff’s Van Gieson stain, immunohistochemical stain with antibodies for α-smooth muscle actin and MCT1 in sequence. A total of 61 cerebral vessels, including 29 arteries and 32 veins were assessed. Immunoreactivity for MCT1 was observed in the endothelial cells of various caliber veins as well as the capillaries, whereas that was immunenegative in the endothelium of arteries. The different labeling patterns for MCT1 could aid in distinguishing various caliber veins from arteries, whereas assessment using the vessel shape, the internal elastic lamina, and the pattern of smooth muscle fibers failed to make the distinction between small-caliber veins and sclerotic arterioles. In conclusion, MCT1 immunohistochemical staining is a sensitive and reliable method to distinguish cerebral veins from arteries.

Correlation Of Functional Disorders In Cerebral Blood Flow With Cognitive Style Of Freshmen Students

In 97 healthy male freshmen students, we studied the parameters of arterial blood flow intensity (index of vascular resistance RI, amplitude-frequency index AFI), venous outflow (venous outflow index VOI), and tone and elasticity of cerebral vessels (diastolic index DIA, dicrotic index DIC, maximum blood velocity of fast filling in the artery Vmax, average blood velocity of slow filling in the artery Vav). Separately, we assessed the effectiveness of such mental operations as classification and analysis and studied the cognitive styles. In 35.9% of male freshmen, we revealed the functional dystonia of cerebral vessels with a pronounced inter-lacunar redistribution of blood flow to the region of internal carotid arteries. Their cognitive style had low rigidity, flexible control, strong cognitive automation, and low information processing speed. The cognitive style in freshmen without dystonic disorders was characterized by a balance of rigidity and flexibility of thinking, with a medium information processing speed.

Transcranial Doppler ultrasonography (uses, limitations, and potentials): a review article

Background The additional information that transcranial Doppler can provide as part of a multimodal imaging protocol in many clinical settings has not been evaluated. Main body Transcranial Doppler is a bedside procedure used to assess cerebral blood flow velocity via cerebral circulation and pulsatility index (PI). Many diseases can lead to cerebral vessels vasospasm as in subarachnoid hemorrhage and trauma. Cerebral vessels vasospasm represented by abnormal elevation of cerebral blood flow velocity. Intracranial pressure can be monitored by pulsatility index which reflects blood flow resistance in cerebral vessels. Transcranial Doppler ultrasonography is also the unique modality for detection of micro emboli in high-risk patients. Also, it can be used for evaluation of circulatory arrest with subsequent confirmation of brain death Conclusion Transcranial Doppler ultrasonography is the only diagnostic modality that provides a reliable assessment of cerebral blood flow patterns in real time. The physiological information obtained from TCD is complementary to the anatomical details obtained from other neuroimaging modalities. TCD is relatively cheap, can be performed bedside, and allows monitoring in acute emergency settings.

The effect of absent blood flow on the zebrafish cerebral and trunk vasculature

The role of blood flow in vascular development is complex and context-dependent. In this study, we quantify the effect of the lack of blood flow on embryonic vascular development on two vascular beds, namely the cerebral and trunk vasculature in zebrafish. We perform this by analysing vascular topology, endothelial cell (EC) number, EC distribution, apoptosis, and inflammatory response in animals with normal blood flow or absent blood flow. We find that absent blood flow reduced vascular area and endothelial cell number significantly in both examined vascular beds, but the effect is more severe in the cerebral vasculature, and severity increases over time. Absent blood flow leads to an increase in non-EC-specific apoptosis without increasing tissue inflammation, as quantified by cerebral immune cell numbers and nitric oxide. Similarly, while stereotypic vascular patterning in the trunk is maintained, intra-cerebral vessels show altered patterning, which is likely to be due to vessels failing to initiate effective fusion and anastomosis rather than sprouting or path-seeking. In conclusion, blood flow is essential for cellular survival in both the trunk and cerebral vasculature, but particularly intra-cerebral vessels are affected by the lack of blood flow, suggesting that responses to blood flow differ between these two vascular beds.