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Tauopathy
Tauopathy belongs to a class of neurodegenerative diseases involving the aggregation of tau protein into neurofibrillary or gliofibrillary tangles in the human brain. Tangles are formed by hyperphosphorylation of the microtubule protein known as tau, causing the protein to dissociate from microtubules and form insoluble aggregates. (These aggregations are also called paired helical filaments.) The mechanism of tangle formation is not well understood, and whether tangles are a primary cause of Alzheimer's disease or play a peripheral role is unknown. Detection and imaging ;Post-mortem: Tau tangles are seen microscopically in stained brain samples. ;Pre-mortem: In living patients tau tangle locations can be imaged with a PET scan using a suitable radio-emissive agent. Alzheimer's disease Neurofibrillary tangles were first described by Alois Alzheimer in one of his patients with Alzheimer's disease (AD). The tangles are considered a secondary tauopathy. AD is also classi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tauopathy In Alzheimer's Disease
Tauopathy belongs to a class of neurodegenerative diseases involving the aggregation of tau protein into neurofibrillary or gliofibrillary Neurofibrillary tangle, tangles in the human brain. Tangles are formed by phosphorylation, hyperphosphorylation of the microtubule protein known as tau, causing the protein to dissociate from microtubules and form insoluble aggregates. (These aggregations are also called paired helical filaments.) The mechanism of tangle formation is not well understood, and whether tangles are a primary cause of Alzheimer's disease or play a peripheral role is unknown. Detection and imaging ;Post-mortem: Tau tangles are seen microscopically in stained brain samples. ;Pre-mortem: In living patients tau tangle locations can be imaged with a PET scan using a suitable radio-emissive agent. Alzheimer's disease Neurofibrillary tangles were first described by Alois Alzheimer in one of his patients with Alzheimer's disease (AD). The tangles are considered a sec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tau Protein
The tau proteins (abbreviated from tubulin associated unit) are a group of six highly soluble protein isoforms produced by alternative splicing from the gene ''MAPT'' (microtubule-associated protein tau). They have roles primarily in maintaining the stability of microtubules in axons and are abundant in the neurons of the central nervous system (CNS), where the cerebral cortex has the highest abundance. They are less common elsewhere but are also expressed at very low levels in CNS astrocytes and oligodendrocytes. Pathologies and dementias of the nervous system such as Alzheimer's disease and Parkinson's disease are associated with tau proteins that have become hyperphosphorylated insoluble aggregates called neurofibrillary tangles. The tau proteins were identified in 1975 as heat-stable proteins essential for microtubule assembly, and since then they have been characterized as intrinsically disordered proteins. Function Microtubule stabilization Tau proteins are found mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurofibrillary Tangle
Neurofibrillary tangles (NFTs) are aggregates of hyperphosphorylated tau protein that are most commonly known as a primary biomarker of Alzheimer's disease. Their presence is also found in numerous other diseases known as tauopathies. Little is known about their exact relationship to the different pathologies. Formation Neurofibrillary tangles are formed by hyperphosphorylation of a microtubule-associated protein known as tau, causing it to aggregate, or group, in an insoluble form. (These aggregations of hyperphosphorylated tau protein are also referred to as PHF, or "paired helical filaments"). The precise mechanism of tangle formation is not completely understood, and it is still controversial whether tangles are a primary causative factor in disease or play a more peripheral role. Cytoskeletal changes Three different maturation states of NFT have been defined using anti-tau and anti-ubiquitin immunostaining. At stage 0 there are morphologically normal pyramidal cells sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Braak Staging
Braak staging refers to two methods used to classify the degree of pathology in Parkinson's disease and Alzheimer's disease. These methods are used both in research and for the clinical diagnosis of these diseases and are obtained by performing an autopsy of the brain. Parkinson's disease The main pathological characteristic of Parkinson's disease is cell death in the substantia nigra. In particular, this death occurs in the ventral part of the pars compacta, with up to 70% of the cells affected by the time the patient dies. The mechanisms by which the brain cells are lost are varied. One mechanism consists of an abnormal accumulation of the protein alpha-synuclein bound to ubiquitin in the damaged cells. This protein accumulation forms inclusions called Lewy bodies. Braak's theory The staging in Parkinson's disease was described by Heiko Braak in 2003. Braak and colleagues state that Parkinson's disease begins when a foreign agent enters the body via the nose or gastrointes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corticobasal Degeneration
Corticobasal degeneration (CBD) is a rare neurodegenerative disease involving the cerebral cortex and the basal ganglia. CBD symptoms typically begin in people from 50 to 70 years of age, and the average disease duration is six years. It is characterized by marked disorders in movement and cognition, and is classified as one of the Parkinson plus syndromes. Diagnosis is difficult, as symptoms are often similar to those of other disorders, such as Parkinson's disease, progressive supranuclear palsy, and dementia with Lewy bodies, and a definitive diagnosis of CBD can only be made upon neuropathologic examination. Signs and symptoms Because CBD is progressive, a standard set of diagnostic criteria can be used, which is centered on the disease's evolution. Included in these fundamental features are problems with cortical processing, dysfunction of the basal ganglia, and a sudden and detrimental onset. Psychiatric and cognitive dysfunctions, although present in CBD, are much l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microtubule
Microtubules are polymers of tubulin that form part of the cytoskeleton and provide structure and shape to eukaryotic cells. Microtubules can be as long as 50 micrometres, as wide as 23 to 27 nm and have an inner diameter between 11 and 15 nm. They are formed by the polymerization of a dimer of two globular proteins, alpha and beta tubulin into protofilaments that can then associate laterally to form a hollow tube, the microtubule. The most common form of a microtubule consists of 13 protofilaments in the tubular arrangement. Microtubules play an important role in a number of cellular processes. They are involved in maintaining the structure of the cell and, together with microfilaments and intermediate filaments, they form the cytoskeleton. They also make up the internal structure of cilia and flagella. They provide platforms for intracellular transport and are involved in a variety of cellular processes, including the movement of secretory vesicles, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lytico-bodig Disease
Lytico-bodig (also Lytigo-bodig) disease, Guam disease, or amyotrophic lateral sclerosis-parkinsonism-dementia (ALS-PDC) is a Neurodegeneration, neurodegenerative disease of uncertain etiology endemic to the Chamorro people of the island of Guam in Micronesia. ''Lytigo'' and ''bodig'' are Chamorro language words for two different manifestations of the same condition. ''ALS-PDC'', a term coined by Asao Hirano and colleagues in 1961, reflects its resemblance to amyotrophic lateral sclerosis (ALS), Parkinson's disease, and Alzheimer's disease. First reports of the disease surfaced in three death certificates on Guam in 1904 which made some mention of paralysis. The frequency of cases grew amongst the Chamorro until it was the leading cause of adult death between 1945 and 1956. The incidence rate was 200 per 100,000 per year and it was 100 times more prevalent than in the rest of the world. Neurologist Oliver Sacks detailed this disease in his book ''The Island of the Colorblind''. Sack ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ganglioglioma
Ganglioglioma is a rare, slow-growing primary central nervous system (CNS) tumor which most frequently occurs in the temporal lobes of children and young adults Classification Gangliogliomas are generally benign WHO grade I tumors; the presence of anaplastic changes in the glial component is considered to represent WHO grade III (anaplastic ganglioglioma). Criteria for WHO grade II have been suggested, but are not established. Malignant transformation of spinal ganglioglioma has been seen in only a select few cases. Poor prognostic factors for adults with gangliogliomas include older age at diagnosis, male sex, and malignant histologic features. Histopathology Histologically, ganglioglioma is composed of both neoplastic glial and ganglion cells which are disorganized, variably cellular, and non-infiltrative. Occasionally, it may be challenging to differentiate ganglion cell tumors from an infiltrating glioma with entrapped neurons. The presence of neoplastic ganglion cells formin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meningioangiomatosis
Meningioangiomatosis is a rare disease of the brain. It is characterized by a benign lesion of the leptomeninges usually involving the cerebral cortex, and by leptomeningeal and meningovascular proliferation. Often the patient will present with seizures. The disease may be either sporadic In mathematics, a sporadic group is one of the 26 exceptional groups found in the classification of finite simple groups. A simple group is a group ''G'' that does not have any normal subgroups except for the trivial group and ''G'' itself. Th ... or associated with neurofibromatosis type 2. The lesion is usually focused in one place, though extremely rare multifocal cases have been reported in both adults and children. Biopsy is usually necessary for diagnosis. Treatment conventionally involves surgical removal of the lesion. References Further reading * * * Brain disorders {{nervoussystem-disease-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lead Poisoning
Lead poisoning, also known as plumbism and saturnism, is a type of metal poisoning caused by lead in the body. The brain is the most sensitive. Symptoms may include abdominal pain, constipation, headaches, irritability, memory problems, infertility, and tingling in the hands and feet. It causes almost 10% of intellectual disability of otherwise unknown cause and can result in behavioral problems. Some of the effects are permanent. In severe cases, anemia, seizures, coma, or death may occur. Exposure to lead can occur by contaminated air, water, dust, food, or consumer products. Lead poisoning poses a significantly increased risk to children as they are far more likely to ingest lead indirectly by chewing on toys or other objects that are coated in lead paint. The amount of lead that can be absorbed by children is also higher than that of adults. Exposure at work is a common cause of lead poisoning in adults with certain occupations at particular risk. Diagnosis is typically ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Postencephalitic Parkinsonism
Post-encephalitic parkinsonism is a disease believed to be caused by a viral illness that triggers degeneration of the nerve cells in the substantia nigra. Overall, this degeneration leads to clinical parkinsonism. Historically, starting in 1917 an epidemic of encephalitis lethargica, also called von Economo's encephalitis or "sleepy-disease" occurred, possibly related to the 1918 Spanish flu pandemic; however, even with the use of modern molecular diagnostic tests on appropriate corpses, no firm link between encephalitis lethargica with influenza has been made. Although parkinsonism was occasionally seen during the acute encephalitic phase of encephalitis lethargica, it was often encountered in the post-encephalitic phase. The onset of post-encephalitic parkinsonism can be delayed by several years from the resolution of encephalitis lethargica. The brain regions affected contain neurofibrillary tangles, similar to those seen in Alzheimer's disease. Nevertheless, the senile plaque ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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