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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] |
Substantia Nigra
The substantia nigra (SN) is a basal ganglia structure located in the midbrain that plays an important role in reward and movement. ''Substantia nigra'' is Latin for "black substance", reflecting the fact that parts of the substantia nigra appear darker than neighboring areas due to high levels of neuromelanin in dopaminergic neurons. Parkinson's disease is characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta. Although the substantia nigra appears as a continuous band in brain sections, anatomical studies have found that it actually consists of two parts with very different connections and functions: the pars compacta (SNpc) and the pars reticulata (SNpr). The pars compacta serves mainly as a projection to the basal ganglia circuit, supplying the striatum with dopamine. The pars reticulata conveys signals from the basal ganglia to numerous other brain structures. Structure The substantia nigra, along with four other nuclei, i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parkinsonism
Parkinsonism is a clinical syndrome characterized by tremor, bradykinesia (slowed movements), rigidity, and postural instability. These are the four motor symptoms found in Parkinson's disease (PD), after which it is named, dementia with Lewy bodies (DLB), Parkinson's disease dementia (PDD), and many other conditions. This set of symptoms occurs in a wide range of conditions and may have many causes, including neurodegenerative conditions, drugs, toxins, metabolic diseases, and neurological conditions other than PD. Signs and symptoms Parkinsonism is a clinical syndrome characterized by the four motor symptoms found in Parkinson's disease: tremor, bradykinesia (slowed movements), rigidity, and postural instability. Parkinsonism gait problems can lead to falls and serious physical injuries. Other common symptoms include: * Tremors when resting (mostly in the hands) * Short, shuffling gait * Slow movements (bradykinesia) * Loss of sound perception leading to low, soft spee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Encephalitis Lethargica
Encephalitis lethargica is an atypical form of encephalitis. Also known as "sleeping sickness" or "sleepy sickness" (distinct from tsetse fly-transmitted sleeping sickness), it was first described in 1917 by neurologist Constantin von Economo and pathologist Jean-René Cruchet. The disease attacks the brain, leaving some victims in a statue-like condition, speechless and motionless. Between 1915 and 1926, an epidemic of encephalitis lethargica spread around the world. The exact number of people infected is unknown, but it is estimated that more than one million people contracted the disease during the epidemic, which directly caused more than 500,000 deaths. Most of those who survived never returned to their pre-morbid vigour. Signs and symptoms Encephalitis lethargica is characterized by high fever, sore throat, headache, lethargy, double vision, delayed physical and mental response, sleep inversion and catatonia. In severe cases, patients may enter a coma-like state ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spanish Flu
The 1918–1920 influenza pandemic, commonly known by the misnomer Spanish flu or as the Great Influenza epidemic, was an exceptionally deadly global influenza pandemic caused by the H1N1 influenza A virus. The earliest documented case was March 1918 in Kansas, United States, with further cases recorded in France, Germany and the United Kingdom in April. Two years later, nearly a third of the global population, or an estimated 500 million people, had been infected in four successive waves. Estimates of deaths range from 17 million to 50 million, and possibly as high as 100 million, making it one of the deadliest pandemics in history. The pandemic broke out near the end of World War I, when wartime censors suppressed bad news in the belligerent countries to maintain morale, but newspapers freely reported the outbreak in neutral Spain, creating a false impression of Spain as the epicenter and leading to the "Spanish flu" misnomer. Limited historical epidemiologic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurofibrillary Tangles
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] |
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] |
