[Clinical study of arteriovenous malformation of the brain based on 410 cases].
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Adolescent↗
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MR-based brain and cerebrospinal fluid measurement after traumatic brain injury: correlation with neuropsychological outcome.
PURPOSE: To determine the magnitude and time course of changes in the volume of brain and intracranial cerebrospinal fluid (CSF) spaces in patients who have sustained traumatic brain injury and to assess the relationship between these findings and long-term cognitive traumatic outcome. METHODS: Axial intermediate and T2-weighted MR images of 123 patients with traumatic brain injury were quantified using a multispectral segmentation algorithm. Measurements were corrected for differences in age, sex, and head size using a previously reported normative database. Brain morphology was compared across groups formed on the basis of chronicity of injury. Cognitive functioning and severity of injury were statistically correlated with brain measurements. RESULTS: Time-dependent expansion of CSF spaces and decreases in brain volume were observed. Increases in ventricular CSF volume, particularly in the temporal horns and third ventricle, preceded subsequent changes in total brain and subarachnoid CSF. High and moderate correlation was observed between volume measures and cognitive outcome and injury severity. Particularly strong was the relation between the volume of the left temporal horn and verbal IQ scores. CONCLUSION: Predictable time-dependent atrophic changes occurring after traumatic brain injury can be quantified using MR volumetric studies. Our results suggest significant contributions by both diffuse and focal mechanisms of injury. In the postacute period (more than 70 days after injury), MR volumetric studies may be predictive of eventual cognitive outcome.
Adolescent↗
[Histophysiologic characteristics of the effector innervation of the arteries of the base of the brain during rat ontogenesis].
The development of adren- and cholinergic nervous plexuses in the brain base arteries was studied by histochemical methods of Falck and Kelle in animals and fetuses of 10-22 days, newborn rats, animals of 10, 20, 30, 40, 60 and 120 days of life and 1 and 2 years old rats. The cholinergic nerve fibres were first found in the basilar, vertebral and internal carotid arteries on the 15th and 16th days of ontogenesis. Specific fluorescence of adrenergic conductors on the same arteries is revealed somewhat later--from the 17th and 18th days of the intrauterine development. Further formation of the cholin- and adrenergic innervation of the arteries of the Willis' circle goes on synchronously. The number of nerve fibres increases with the growth of the artery diameter. The concentration of catecholamines and the activity of AChE in them gradually increases. The greatest density of nerve fibres per 1 mm2 is determined in 20-day-old rats. The number of cholinergic nerve fibres on the arteries of the brain base is equal to that of adrenergic fibres during the whole period of postnatal ontogenesis. By the 30th day the effector nervous apparatus has a definite structure. In old rats the activity of AChE and the content of catecholamines drop, the amount and concentration of nerve fibres decrease.
Animals↗
[Prolonged spasm of the arteries of the base of the brain during experimental fibrinolysis in the subarachnoid space].
An ex tempore mixture of fibrinogen (1%--4 ml) and 0.2 ml thrombin solutions forming a compact clot of fibrin in the subarachnoid space was introduced into the cisterna magna of dogs. To dissolve the fibrin clot 2 ml of a fibrinolysin solution with an activity of 400 units were introduced into the same cisterna 10--15 minutes thereafter. A total of 26 experiments were set up, of which 13 were served as controls with separate introduction of the mixture ingredients. Through serial vertebral angiography with a 50 per cent urotrast solution it was found that following introduction of the fibrinogen and thrombin mixture the lumen of the basilar artery and of its branches contracts on the average up to 89.2 +/- 1 per cent. After introduction of fibrinolysis the diameter of the artery initially increases up to 116.3 +/- 2.5 per cent. In 3 hours time a pronounced spasm of the basilar artery and of its branches is seen to develop up to 80.9 +/- 3.6 per cent and after 24 hours -- up to 73.9 +/- 2.1 per cent. The spasm persists for up to 10 days, but its intensity gradually declines. During subsequent 11--18 days the diameter of the brain base arteries returns back to normal. In control experiments no development of protracted spasm was demonstrated. Hence, it is established that the appearance of fibrinolysis products formed in the spinal fluid consequent upon dissolution of a clot of fibrin containing no blood cells is attended by the development of a protracted spasm involving major arteries of the brain.
Animals↗
[Technic of ultrasonic dopplerography in the diagnosis of occlusive lesions of the arteries of the base of the brain (doppleroangiographic study)].
Use was made for the first time of the ultrasonic dopplerography method for diagnosing occlusions of the brain base arteries in patients with cerebrovascular diseases. For this purpose a functional-compression examination technique was developed that enabled one to evaluate indirectly the patency of the intracranial arteries. Dopplerographic criteria of occlusions of individual arteries were determined. A comparison of the diagnosis made with the use of the ultrasonic dopplerography with the data of subsequent cerebral angiography showed that the results coincided in 83.3% of occlusions in the basilar arteries; 90% of occlusions in the terminal parts of the vertebral arteries: 90% of occlusions in the anterior and posterior communicating arteries; 86% of occlusions of internal carotid arteries in the siphon region, and 80% of occlusion of the median cerebral arteries. The results obtained give one grounds to recommend the ultrasonic dopplerography for practical use as a simple and sufficiently reliable method for diagnosing occlusions of the brain basin arteries.
Adult↗
A neuron model based on brain biochemical principles.
The electrical activity and excitation of the brain is based on certain biochemical processes, particularly, the activity of transmitter-receptor-ion channel system and the DNA-RNA-Pr (Pr:protein) system. There have already been some neuron models relating to the ion channel, but the kinds and numbers of transmitters, receptors, and ion channels are directly or indirectly conditioned by the DNA-RNA-Pr system. To reflect these facts, we present a new neuron model based on the important biochemical chains of the brain. This model is applied to both the simulation research of electrical activity and the information processing function of the brain. In this demonstration, we will introduce: 1) How to express the connection between the neuron excitation and the transmitter-receptor-ion channel system; 2) How to express the connection between the transmitter-receptor-ion channel system of neuron and the DNA-RNA-Pr system; 3) How to express the connection among 16,000 artificial neurons on the basis of the above-mentioned points; 4) The time and the state of the excitation passing through a particular neuron in a group of neurons.
Brain↗
A new therapy of post-trauma brain oedema based on haemodynamic principles for brain volume regulation.
OBJECTIVE: To evaluate a new therapy of posttraumatic brain oedema, with the main concept that opening of the blood-brain barrier upsets the normal brain volume regulation, inducing oedema formation. This means that transcapillary fluid fluxes will be controlled by hydrostatic capillary and colloid osmotic pressures, rather than by crystalloid osmotic pressure. If so, brain oedema therapy should include reduction of hydrostatic capillary pressure and preservation of normal colloid osmotic pressure. PATIENTS: 11 severely head injured comatose patients with brain swelling, raised intracranial pressure (ICP), and impaired cerebrovascular response to hyperventilation. INTERVENTIONS: To reduce capillary hydrostatic pressure the patients were given hypotensive therapy (beta 1-antagonist, metoprolol and alpha 2-agonist, clonidine) and a potential precapillary vasoconstrictor (dihydroergotamine). The latter may also decrease cerebral blood volume through venous capacitance constriction. Colloid osmotic pressure was maintained by albumin infusions. The concept implies the need of a negative fluid balance with preserved normovolaemia. RESULTS: ICP decreased significantly within a few hours of treatment with unaltered perfusion pressure in spite of lowered blood pressure. Of 11 patients 9 survived with good recovery/moderate disability, 2 died. This was compared to outcome in a historical control group with identical entry criteria, given conventional brain oedema therapy, where mortality/vegetativity/severe disability was 100%. CONCLUSION: The results indicate that the therapy should focus on extracellular rather than intracellular oedema and that ischemia is not the main triggering mechanism behind oedema formation. We suggest that our therapy is superior to conventional therapy by preventing herniation during the healing period of the blood-brain barrier.
Adolescent↗
Electroencephalographic changes caused by tumours of the brain; notes based on 158 cases of brain tumour treated operatively at the Finnish Red Cross Hospital during the period 1956-1957.
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Brain↗
Diphtheria toxin effects on brain-tumor xenografts. Implications for protein-based brain-tumor chemotherapy.
A model was developed to determine whether protein-based chemotherapeutic agents can cross the blood-brain barrier and successfully treat brain tumors. The human small-cell lung carcinoma N417D was grown as a solid tumor in the nude rat brain, and diphtheria toxin (DT) was administered intravenously as therapy. Because rat cells lack functional DT receptors and are 1000 to 10,000 times less sensitive to DT than human cells, a therapeutic window exists between the implanted human tumor and the nude rat host. The pharmacokinetic and pharmacodynamic characteristics of DT were defined. Within 6 hours, more than 90% of the initial DT concentration was removed from the blood. The blood-to-tumor transfer constant Ki for DT in small N417D tumors was 0.49 microliters/gm-min, one-fourth to one-fifth the reported values for permeability to proteins in other experimental tumor models. Despite the toxin's short plasma half-life and the relatively intact blood-tumor barrier, DT administered intravenously as a single dose significantly extended animal survival. Untreated nude rats developed solid parenchymal tumors and died in 11 to 16 days (median 15 days). When administered at 0.1 micrograms/animal, DT increased the median survival time to 19 days (p less than 0.0016) while 1.0-microgram doses extended median survival times to 26.5 days (p less than 0.0002). A higher dose of DT (3.0 micrograms) had no further beneficial effect on survival (26.1 days). Blood-brain barrier constraints to successful monoclonal antibody-based therapies of brain tumors may have been overestimated since antibody conjugates have plasma half-lives longer than DT, and the permeability of N417D tumors to DT is equal to or less than the permeability of other experimental tumors to large proteins. Recently developed immunotoxins that have the higher potency of DT and a therapeutic window as wide as DT has in this nude rat/human tumor paradigm may be effective in treating brain tumors despite limited blood-tumor permeability.
Animals↗
Modeling the route of administration-based enhancement in the brain delivery of EAB 515, studied by microdialysis.
EAB 515 (S-alpha-amino-5-phosphonomethyl[1,1'biphenyl]-3-propanoic acid) is an extremely hydrophilic N-methyl-D-aspartate antagonist. It shows marked CNS activity, in that it is a potent neuroprotector in models of cerebral ischemia, and also demonstrates social and non-social behavioral alteration following systemic administration in animals. Because of its high degree of ionization at physiologic pH, one would not expect appreciable brain uptake of EAB 515 across tight junctions of the blood-brain barrier. This is in contrast to its pharmacologic effect as well as brain/plasma ratios measured during systemic administration in rats. These observations lead us to investigate other transport pathways that might account for its brain uptake. Such mechanistic information is imperative in rational drug delivery and drug design strategies. Upon intracerebroventricular administration, the observed steady-state cortical extracellular fluid concentrations of EAB 515 were over 100-fold higher than those observed following intravenous administration, when normalized for the dosing rate. This increased distribution into the brain, based upon the route of administration, suggests the transport of drug directly between the cerebrospinal fluid and the brain extracellular space. The parameters of the model that adequately describes the data obtained from the two routes of administration in individual animals were estimated. The clinical significance of these results is in the use of intracerebroventricular administration for enhanced brain delivery of hydrophilic drugs that poorly cross the blood-brain barrier.
Animals↗
Brain-computer communication based on the dynamics of brain oscillations.
This chapter presents a review of brain-computer communication based on motor imagery and the dynamics of brain oscillations. The concept of motor imagery as experimental strategy and the two different modes of operation a brain-computer interface can have are explained. An EEG based brain switch that can control a FES-induced hand grasp of a tetraplegic and an approach towards an ECoG based brain switch are presented.
Brain↗
Estimating the mutual information of an EEG-based Brain-Computer Interface.
An EEG-based Brain-Computer Interface (BCI) could be used as an additional communication channel between human thoughts and the environment. The efficacy of such a BCI depends mainly on the transmitted information rate. Shannon's communication theory was used to quantify the information rate of BCI data. For this purpose, experimental EEG data from four BCI experiments was analyzed off-line. Subjects imaginated left and right hand movements during EEG recording from the sensorimotor area. Adaptive autoregressive (AAR) parameters were used as features of single trial EEG and classified with linear discriminant analysis. The intra-trial variation as well as the inter-trial variability, the signal-to-noise ratio, the entropy of information, and the information rate were estimated. The entropy difference was used as a measure of the separability of two classes of EEG patterns.
Attention↗
Detection, visualization and animation of abnormal anatomic structure with a deformable probabilistic brain atlas based on random vector field transformations.
This paper describes the design, implementation and preliminary results of a technique for creating a comprehensive probabilistic atlas of the human brain based on high-dimensional vector field transformations. The goal of the atlas is to detect and quantify distributed patterns of deviation from normal anatomy, in a 3-D brain image from any given subject. The algorithm analyzes a reference population of normal scans and automatically generates color-coded probability maps of the anatomy of new subjects. Given a 3-D brain image of a new subject, the algorithm calculates a set of high-dimensional volumetric maps (with typically 384(2) x 256 x 3 approximately 10(8) degrees of freedom) elastically deforming this scan into structural correspondence with other scans, selected one by one from an anatomic image database. The family of volumetric warps thus constructed encodes statistical properties and directional biases of local anatomical variation throughout the architecture of the brain. A probability space of random transformations, based on the theory of anisotropic Gaussian random fields, is then developed to reflect the observed variability in stereotaxic space of the points whose correspondences are found by the warping algorithm. A complete system of 384(2) x 256 probability density functions is computed, yielding confidence limits in stereotaxic space for the location of every point represented in the 3-D image lattice of the new subject's brain. Color-coded probability maps are generated, densely defined throughout the anatomy of the new subject. These indicate locally the probability of each anatomic point being unusually situated, given the distributions of corresponding points in the scans of normal subjects. 3-D MRI and high-resolution cryosection volumes are analyzed from subjects with metastatic tumors and Alzheimer's disease. Gradual variations and continuous deformations of the underlying anatomy are simulated and their dynamic effects on regional probability maps are animated in video format (on the accompanying CD-ROM). Applications of the deformable probabilistic atlas include the transfer of multi-subject 3-D functional, vascular and histologic maps onto a single anatomic template, the mapping of 3-D atlases onto the scans of new subjects, and the rapid detection, quantification and mapping of local shape changes in 3-D medical images in disease and during normal or abnormal growth and development.
Anatomy, Cross-Sectional↗
Cranial imaging in autosomal recessive osteopetrosis. Part II. Skull base and brain.
The authors reviewed cranial imaging studies (radiographs, computed tomographic scans, and magnetic resonance [MR] images) in 13 infants and children with the autosomal recessive form of osteopetrosis to characterize patterns of skull base, brain, and cranial nerve involvement at presentation and with progression of disease. Marked sclerosis and deposition of osteopetrotic bone was noted along the anterior (but not posterior) occipitomastoid suture (n = 8), at the basioccipital-exoccipital synchondrosis (n = 9), and along the sphenooccipital synchondrosis (n = 8). Endobones, presumably representing unresorbed primitive ossification centers, were seen in the sphenoidal body and basioccipital bone in 11 of the 13 patients. Marked cupping at the basioccipital-exoccipital synchondrosis was observed in three. Neurologic deficits included blindness (n = 11), conductive hearing loss (n = 11), and facial nerve palsies (n = 4). Delayed myelination was seen with MR imaging in two of five retarded infants, including one with a documented coexisting neuronal storage defect. Prominent extracerebral cerebrospinal fluid spaces were present over the frontal lobes in five of the eight developmentally normal patients, representing either subclinical parenchymal disease or a phenomenon related to discordant growth rates between skull and brain.
Brain↗
Personalized functional topography-based multisite brain age prediction modeling reveals divergent neurodevelopment in major depression.
Major depressive disorder (MDD) is associated with widespread alterations in functional brain networks across the lifespan. However, heterogeneity in atypical brain development among patients with MDD remains largely uncharacterized. Using a multisite resting-state functional MRI dataset consisting of 1,105 MDD patients and 1,065 healthy controls, we constructed a harmonized multicenter brain age prediction model based on individualized functional topography and identified two patient subgroups with positive or negative brain age gaps (BAGs). In patients with a positive BAG (BAG+), expansion of the salience network (SAL) into the dorsolateral prefrontal and ventrolateral prefrontal cortices, in addition to contraction of the sensorimotor and dorsal attention networks (DAN), contributes to accelerated brain aging. Conversely, in the negative BAG (BAG-) group, SAL expansion into the orbitofrontal cortex (OFC) and contraction of the visual and sensorimotor networks (SMN) were linked to delayed brain development. These subgroups also exhibited distinct neurodevelopmental trajectories. Clinically, BAG+ patients showed stronger associations between higher-order network topography and mood symptoms, whereas BAG- patients exhibited links between visual/default mode network topography and insomnia. At the molecular level, both groups showed enrichment of genes related to synaptic signaling but displayed distinct expression patterns and divergent expression trajectories in key neurodevelopmental gene sets. Notably, antidepressant treatment modulated the brain in ways that were specific to each subgroup. These findings reveal heterogeneous neurodevelopmental profiles in MDD with distinct biological and clinical signatures, offering insights into personalized precision medicine for this disorder.
Humans↗
The pathogenesis of climacteric syndrome and principle of acupuncture treatment based on TCM theory about brain.
The brain is the sea of marrow, stores the cerebral spirit and dominates all the life activities of the human body, which are the basic TCM knowledge about the brain. Based on this knowledge, the pathogenesis of climacteric syndrome is considered as consumption and deficiency of kidney-essence, and incoordination between the brain and kidney. The principle of acupuncture treatment should be soothing the mind and tonifying the kidney.
Acupuncture Therapy↗
Cloning of the cDNA for a novel receptor tyrosine kinase, Sky, predominantly expressed in brain.
Based on homology to the tyrosine kinase domain of the chick erythroblastosis virus oncogene v-sea, we cloned a cDNA encoding a novel receptor tyrosine kinase from a human hepatoma HepG2 cDNA library. The encoded protein, which we termed 'Sky', contains an intracellular tyrosine kinase domain and a unique extracellular domain with two immunoglobulin (Ig)-like domains and two fibronectin type III (FN III) domains. The overall structure of Sky is homologous to the reported sequence of the oncogenic Axl/Ufo receptor tyrosine kinase. Phylogenetic analysis in the tyrosine kinase domain shows that Sky, Axl/Ufo, Ark, and v-Ryk form a sub-family distinct from other tyrosine kinases. Northern blot analysis revealed that sky mRNA is expressed predominantly in brain and faintly in tissues of other organs. As the combination of Ig-like and FN III domains is often observed in neural cell adhesion molecules and receptor protein tyrosine phosphatases, Sky may be involved in cell adhesion processes, particularly in the central nervous system.
Amino Acid Sequence↗
The relationship between certain forms of potentials and the variations in brain excitability (based on EEG, recorded during photic stimuli triggered by rhythmic brain potentials).
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Brain↗