|
Uncinate Fasciculus
The uncinate fasciculus is a white matter association tract in the human brain that connects parts of the limbic system such as the temporal pole, anterior parahippocampus, and amygdala in the temporal lobe with inferior portions of the frontal lobe such as the orbitofrontal cortex. Its function is unknown though it is affected in several psychiatric conditions. It is one of the last white matter tracts to mature in the human brain. Anatomy The uncinate fasciculus is a hook-shaped bundle of axons that links anterior portions of the temporal lobe with the inferior frontal gyrus and the lower surfaces of the frontal lobe. It arises in the anterior temporal lobe and amygdala, in the temporal lobe curving in an upward pathway behind the external capsule inward of the insular cortex and continuing up into the posterior part of the orbital gyrus. It does not appear to have cell bodies in the hippocampus proper. The average length of the uncinate fasciculus is 45 mm with a ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tractography
In neuroscience Neuroscience is the scientific study of the nervous system (the brain, spinal cord, and peripheral nervous system), its functions and disorders. It is a multidisciplinary science that combines physiology, anatomy, molecular biology, development ..., tractography is a 3D modeling technique used to visually represent nerve tracts using data collected by diffusion MRI. It uses special techniques of magnetic resonance imaging (MRI) and computer-based diffusion MRI. The results are presented in two- and three-dimensional images called tractograms. In addition to the long tracts that connect the brain to the rest of the body, there are complicated neural circuits formed by short connections among different Cerebral cortex, cortical and subcortical regions. The existence of these tracts and circuits has been revealed by histochemistry and biology, biological techniques on post-mortem specimens. Nerve tracts are not identifiable by direct exam, computed tomography, CT ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diffusion Tensor Imaging
Diffusion-weighted magnetic resonance imaging (DWI or DW-MRI) is the use of specific MRI sequences as well as software that generates images from the resulting data that uses the diffusion of water molecules to generate contrast in MR images. It allows the mapping of the diffusion process of molecules, mainly water, in biological tissues, in vivo and non-invasively. Molecular diffusion in tissues is not random, but reflects interactions with many obstacles, such as macromolecules, fibers, and membranes. Water molecule diffusion patterns can therefore reveal microscopic details about tissue architecture, either normal or in a diseased state. A special kind of DWI, diffusion tensor imaging (DTI), has been used extensively to map white matter tractography in the brain. Introduction In diffusion weighted imaging (DWI), the intensity of each image element (voxel) reflects the best estimate of the rate of water diffusion at that location. Because the mobility of water is driven by t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semantic Dementia
Semantic dementia (SD), also known as semantic variant primary progressive aphasia (svPPA), is a progressive neurodegenerative disorder characterized by loss of semantic memory in both the verbal and non-verbal domains. However, the most common presenting symptoms are in the verbal domain (with loss of word meaning). Semantic dementia is a disorder of semantic memory that causes patients to lose the ability to match words or images to their meanings. However, it is fairly rare for patients with semantic dementia to develop category specific impairments, though there have been documented cases of it occurring. Typically, a more generalized semantic impairment results from dimmed semantic representations in the brain. SD is one of the three canonical clinical syndromes associated with frontotemporal lobar degeneration (FTLD), with the other two being frontotemporal dementia and progressive nonfluent aphasia. SD is a clinically defined syndrome but is associated with predominantly t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alzheimer's Disease
Alzheimer's disease (AD) is a neurodegeneration, neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in short-term memory, remembering recent events. As the disease advances, symptoms can include primary progressive aphasia, problems with language, Orientation (mental), disorientation (including easily getting lost), mood swings, loss of motivation, self-neglect, and challenging behaviour, behavioral issues. As a person's condition declines, they often withdraw from family and society. Gradually, bodily functions are lost, ultimately leading to death. Although the speed of progression can vary, the typical life expectancy following diagnosis is three to nine years. The cause of Alzheimer's disease is poorly understood. There are many environmental and genetic risk factors associated with its development. The strongest genetic risk factor is from an alle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brodmann Area 38
Brodmann area 38, also BA38 or temporopolar area 38 (H), is part of the temporal cortex in the human brain. BA 38 is at the anterior end of the temporal lobe, known as the temporal pole. BA38 is a subdivision of the cytoarchitecturally defined temporal region of cerebral cortex. It is located primarily in the most rostral portions of the superior temporal gyrus and the middle temporal gyrus. Cytoarchitecturally it is bounded caudally by the inferior temporal area 20, the middle temporal area 21, the superior temporal area 22 and the ectorhinal area 36 (Brodmann-1909). The temporal pole is a paralimbic region involved in high level semantic representation and socio-emotional processing. The uncinate fasciculus provides a direct bidirectional path to the orbitofrontal cortex, allowing mnemonic representations stored in the temporal pole to bias decision making in the frontal lobe. The temporal pole appears to be a convergence zone where concepts (also known as semantic memori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schizophrenia
Schizophrenia is a mental disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, and disorganized thinking. Other symptoms include social withdrawal, decreased emotional expression, and apathy. Symptoms typically develop gradually, begin during young adulthood, and in many cases never become resolved. There is no objective diagnostic test; diagnosis is based on observed behavior, a history that includes the person's reported experiences, and reports of others familiar with the person. To be diagnosed with schizophrenia, symptoms and functional impairment need to be present for six months (DSM-5) or one month (ICD-11). Many people with schizophrenia have other mental disorders, especially substance use disorders, depressive disorders, anxiety disorders, and obsessive–compulsive disorder. About 0.3% to 0.7% of people are diagnosed with schizophrenia during their lifetime. In 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Social Anxiety
Social anxiety is the anxiety and fear specifically linked to being in social settings (i.e., interacting with others). Some categories of disorders associated with social anxiety include anxiety disorders, mood disorders, autism spectrum disorders, eating disorders, and substance use disorders. Individuals with higher levels of social anxiety often avert their gazes, show fewer facial expressions, and show difficulty with initiating and maintaining a conversation. Social anxiety commonly manifests itself in the teenage years and can be persistent throughout life, however, people who experience problems in their daily functioning for an extended period of time can develop social anxiety disorder. Trait social anxiety, the stable tendency to experience this anxiety, can be distinguished from state anxiety, the momentary response to a particular social stimulus. Half of the individuals with any social fears meet the criteria for social anxiety disorder. Age, culture, and gender im ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peabody Picture Vocabulary Test
The Peabody Picture Vocabulary Test, the 2007 edition of which is known as the PPVT-IV, is an untimed test of receptive vocabulary for Standard American English and is intended to provide a quick estimate of the examinee’s receptive vocabulary ability. It can be used with the Expressive Vocabulary Test-Second Edition (EVT-2) to make a direct comparison between the examinee’s receptive and expressive vocabulary skills. The PPVT was developed in 1959 by special education specialists Lloyd M. Dunn and Leota M. Dunn. The current version lists L.M. Dunn and his son D.M. Dunn as authors. Procedure The test is given verbally and takes between twenty to thirty minutes to complete. No reading is required by the individual, and scoring is rapid. For its administration, the examiner presents a series of pictures to each person. There are four pictures to a page, and each is numbered. The examiner speaks a word describing one of the pictures and asks the individual to point to or say the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wechsler Adult Intelligence Scale
The Wechsler Adult Intelligence Scale (WAIS) is an IQ test designed to measure intelligence and cognitive ability in adults and older adolescents. The original WAIS (Form I) was published in February 1955 by David Wechsler, as a revision of the Wechsler–Bellevue Intelligence Scale, released in 1939. It is currently in its fourth edition (''WAIS-IV'') released in 2008 by Pearson, and is the most widely used IQ test, for both adults and older adolescents, in the world. History The WAIS is founded on Wechsler's definition of intelligence, which he defined as "... the global capacity of a person to act purposefully, to think rationally, and to deal effectively with his environment." He believed that intelligence was made up of specific elements that could be isolated, defined, and subsequently measured. However, these individual elements were not entirely independent, but were all interrelated. His argument, in other words, is that general intelligence is composed of various speci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Preterm
Preterm birth, also known as premature birth, is the birth of a baby at fewer than 37 weeks gestational age, as opposed to full-term delivery at approximately 40 weeks. Extreme preterm is less than 28 weeks, very early preterm birth is between 28 and 32 weeks, early preterm birth occurs between 32 and 36 weeks, late preterm birth is between 34 and 36 weeks' gestation. These babies are also known as premature babies or colloquially preemies (American English) or premmies (Australian English). Symptoms of preterm labor include uterine contractions which occur more often than every ten minutes and/or the leaking of fluid from the vagina before 37 weeks. Premature infants are at greater risk for cerebral palsy, delays in development, hearing problems and problems with their vision. The earlier a baby is born, the greater these risks will be. The cause of spontaneous preterm birth is often not known. Risk factors include diabetes, high blood pressure, multiple gestation (being pregna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conduct Disorder
Conduct disorder (CD) is a mental disorder diagnosed in childhood or adolescence that presents itself through a repetitive and persistent pattern of behavior that includes theft, lies, physical violence that may lead to destruction, and reckless breaking of rules, in which the basic rights of others or major age-appropriate norms are violated. These behaviors are often referred to as " antisocial behaviors." It is often seen as the precursor to antisocial personality disorder, which by definition cannot be diagnosed until the individual is 18 years old. Conduct disorder may result from parental rejection and neglect and can be treated with family therapy, as well as behavioral modifications and pharmacotherapy. Conduct disorder is estimated to affect 51.1 million people globally Signs and symptoms One of the symptoms of conduct disorder is a lower level of fear. Research performed on the impact of toddlers exposed to fear and distress shows that negative emotionality (fear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temporal Lobe Epilepsy
Temporal lobe epilepsy (TLE) is a chronic disorder of the nervous system which is characterized by recurrent, unprovoked focal seizures that originate in the temporal lobe of the brain and last about one or two minutes. TLE is the most common form of epilepsy with focal seizures. A focal seizure in the temporal lobe may spread to other areas in the brain when it may become a ''focal to bilateral seizure''. TLE is diagnosed by taking a medical history, blood tests, and brain imaging. It can have a number of causes such as head injury, stroke, brain infections, structural lesions in the brain, brain tumors, or it can be of ''unknown onset''. The first line of treatment is through anticonvulsants. Surgery may be an option, especially when there is an observable abnormality in the brain. Another treatment option is electrical stimulation of the brain through an implanted device called the vagus nerve stimulator (VNS). Types Over forty types of epilepsy are recognized and these ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
