Результаты поиска

Blood brain barrier breaking. Is still an absolute contraindication to early surgical reperfusion of the brain?

In the early treatment of the patients with cerebrovascular insufficiency due to internal carotid artery stenosis, the presence of a cerebral infarct and especially the blood brain barrier breaking (BBB) are considered by many as a contraindication to early reperfusion by carotid endarterectomy (CEA). Generally, it has been recommended to differ the operation at least for 4-6 weeks because of the high risk to convert an ischemic infarct into an hemorrhagic one. On the other hand, because unfavorable natural history has been reported as for the progressing unstable neurological deficit as for t…

Peritumoral brain edema associated with meningioma--histological study of the tumor margin and surrounding brain.

Thirty-nine cases of intracranial meningiomas were analyzed to identify factors causing brain edema. Edema was significantly correlated with tumor size and the destruction of the leptomeninges and cortex. Meningotheliomatous meningioma tended to have more peritumoral edema. There was no correlation between the presence of edema and location of the tumor or histological features including lymphocytic infiltration and the presence of glial fibrillary acidic protein-positive cells in the tumor tissue. Larger tumors destroy the leptomeninges and cerebral cortex, allowing direct transmission of hum…

The effects of experimental brain-stem ischaemia on brain-stem auditory evoked potentials in primates.

We related intracranial auditory brain-stem evoked potentials (BAEPs) to the surface BAEP using a model of focal brain-stem ischaemia. In 17 baboons anaesthetised with alpha-chloralose, BAEPs were recorded bilaterally at the mastoids and in the caudal lateral lemniscus (LL) and inferior colliculus (IC), in response to monaural click stimulation. Electrodes at these sites were each connected to the positive input of a differential amplifier, and one other electrode, placed at the vertex, was connected to all the negative inputs. Measurements of local cerebral blood flow (CBF) by hydrogen cleara…

Computed tomography of the brain stem with intrathecal metrizamide. Part I: the normal brain stem.

In summary, the anatomic details of the brain stem are exquisitely demonstrated with metrizamide CT. The obex is the zone of transition from the closed medulla, which has a conical pear-shaped appearance to the quadriconcave open medulla. The pyramids and inferior olivary nuclei characterize the anterior surface of the open medulla, whereas the median sulcus and the cranial nerve nuclei constitute the floor of the fourth ventricle at the same level. The mushroomlike appearance of the pontomedullary junction is easily reproducible with the restiform bodies forming the posteriorly diverging bipe…

Brain metastases and possibilities of their treatment, with special reference to single-session whole-brain irradiation.

A brief review of methods used in the treatment of brain metastases is followed by a discussion of single-session whole-brain irradiation, with special reference to three important practical problems: (a) difficulties in evaluation of the clinical condition, and particularly the quality of survival, after treatment; (b) cerebral oedema induced by single-session whole-brain irradiation and methods to reduce it; (c) selection of patients. The tentative conclusion is that single-session whole-brain irradiation affords a possibility of palliative treatment of brain metastases.

Heterochronicity shapes brain network formation.

Brain network formation unfolds on a nonuniform developmental timetable, with different cortical regions generating connections at different developmental phases. Generative network models (GNMs) aim to uncover the principles underpinning the organization of connectomes by creating synthetic networks according to simple computational rules. These models capture the connectome's topology, operationalized here as the cumulative distributions of network metrics (e.g., modularity, small-worldness, rich-club structure). However, GNMs typically ignore the differential timing of connectivity formatio…

Astrocyte heterogeneity in brain metastases.

Brain metastasis is increasingly understood as a disease of reciprocal adaptation between metastatic cells and the brain microenvironment. Among host cells, astrocytes have emerged as central regulators of metastatic colonization, survival, immune remodeling, and treatment resistance. Recent studies are re-defining astrocytes to explore the functional implications of their cellular heterogeneity. Evidence in brain metastasis indicates that astrocyte responses are heterogeneous across anatomical space, stage of colonization, and tumor type. This framework helps explaining how distinct astrocyte…

Chemically enhanced brain shuttle peptides.

The blood-brain barrier (BBB) constitutes a major impediment to central nervous system pharmacotherapy due to its highly selective permeability and enzymatic defense mechanisms. Brain shuttle peptides have emerged as a promising modality for overcoming this barrier, primarily via receptor-mediated transcytosis. To enhance their pharmacokinetic properties and transcytosis efficiency, several structural and chemical optimization strategies have been employed. Cyclization and retro-enantio modifications confer proteolytic resistance while preserving receptor affinity, as demonstrated by engineere…

Brain network localization of delusions.

BACKGROUND: Delusions constitute a cross-diagnostic core symptom of schizophrenia spectrum disorders and correlate with poor functional outcomes. Despite much recent effort successfully mapping neuropsychiatric symptoms to specific brain networks, investigations focusing on network localization of delusions are still scarce. METHODS: We initially conducted a systematic review of 44 published neuroimaging studies to identify brain regions exhibiting structural and functional alterations associated with delusions. By applying functional connectivity network mapping to normative functional conne…

Radiological approach to brain death.

Brain death is a complex clinical diagnosis with significant medical and legal implications that sometimes requires the use of ancillary tests to confirm the absence of electrical activity or cerebral blood flow (CBF). Among the ancillary tests used to assess CBF are: transcranial Doppler ultrasound, digital subtraction cerebral angiography, CT angiography (CTA), MR angiography, and scintigraphy. This article reviews these techniques, with particular emphasis on CTA, its multiphase protocol, the imaging findings that support the diagnosis of brain death, recommendations for radiology report wr…

Tinnitus Brain: A Functional Reorganization?

Background: Tinnitus is an auditory phantom perception in the absence of any corresponding acoustic stimulus whose pathophysiology remains poorly understood. This study aimed to investigate alterations in the functional organization of the brain in individuals with tinnitus using resting-state functional magnetic resonance imaging (rs-fMRI) and graph theory analysis.Methods: We conducted a study including 44 individuals with tinnitus and 32 healthy controls. Using rs-fMRI and graph theory measures, we characterized whole-brain topological properties, including network segregation, integration,…

Витамин D и здоровье мозга.

Витамин D широко известен своим влиянием на гомеостаз кальция и фосфата в организме и его участием в поддержании мускулоскелета. В своей активной форме, 1,25-дигидрокси холекалциферол, этот витамин оказывает иммуномодулятивное воздействие как на врожденную, так и на адаптивную иммунную систему. Активная форма витамина D играет нейрозащитную роль в центральной нервной системе, подчеркивая ее важность для поддержания здоровья мозга. В исследованиях отмечается роль витамина D в формировании антиоксидантов, снижении цитокина, способствующего воспалению, снижении окислительного стресса, улучшении м

Совпадение в аннотации оригинала
Vitamin D is widely known for its influence on the homeostasis of calcium and phosphate levels in the body and its involvement in maintainin … ys a neuroprotective role in the central nervous system, highlighting its importance in maintaining brain health. Studies have noted the role of vitamin D in the formation of antioxidants, reduction of pro-inflammatory cytokines, lowering of oxidative stress, improvement of mitochondrial respiratory health, and slowing of the progression of neuronal dam …

Molecular Underpinnings of Brain Metastases.

Brain metastases are the most commonly diagnosed type of central nervous system tumor, yet the mechanisms of their occurrence are still widely unknown. Lung cancer, breast cancer, and melanoma are the most common etiologies, but renal and colorectal cancers have also been described as metastasizing to the brain. Regardless of their origin, there are common mechanisms for progression to all types of brain metastases, such as the creation of a suitable tumor microenvironment in the brain, priming of tumor cells, adaptations to survive spreading in lymphatic and blood vessels, and development of …

Brain structural networks underlying language.

The unique human ability to process complex language requires the interaction of multiple brain areas located in the inferior frontal and posterior temporal cortex connected by white matter fiber tracts. These fiber tracts underlie the transfer of information between brain regions. In recent years, MRI of white matter brain networks has provided important insights into the plasticity of the structural brain basis underlying language. This structural network is shaped during childhood as a function of language learning by strengthening the connectivity between language-relevant regions mainly i…

Brain ultrasonography in neurosurgical patients.

PURPOSE OF REVIEW: Brain ultrasound is a popular point-of-care test that helps visualize brain structures. This review highlights recent developments in brain ultrasonography. There is a need to keep pace with the ongoing technological advancements and establishing standardized quality criteria for improving its utility in clinical practice. RECENT FINDINGS: Newer automated indices derived from transcranial Doppler help establish its role as a noninvasive monitor of intracranial pressure and diagnosing vasospasm/delayed cerebral ischemia. A novel robotic transcranial Doppler system equipped w…

Neural Immunoglobulins Shape Brain Circuits.

Mounting evidence challenges the view that antibodies reach the brain solely via vascular leaks. Neurons, astrocytes and microglia appear able to assemble restricted and context-dependent immunoglobulin repertoires via cryptic V(D)J recombination, splice-and-link RNA editing and retroelement-assisted rearrangements. These endogenous antibodies have been associated with complement-mediated pruning, receptor trafficking and astrocyte-neuron metabolic coupling and may change after injury. However, causal evidence from in vivo, cell-type-specific gain- or loss-of-function models remains sparse. Ac…

Scaling Synthetic Brain Data Generation.

The limited availability of diverse, high-quality datasets is a significant challenge in applying deep learning to neuroimaging research. Al … eline configurations and fault-tolerant operation. We evaluated Wirehead with SynthSeg, a synthetic brain segmentation data generation tool that requires 7 days to train a model. When deployed in parallel, Wirehead achieved a near-linear 15.7x increase in throughput with 16 generators. With 20 generators, we can train a model in 9 hours instead of 7 day …