Neurodegenerative
Disorders
Dementia itself is not a disease, rather it is the symptom of various neurodegenerative disorders, which result in a loss of brain functions due to the loss of neurons. Dementias can be categorized into two groups based on which part of the brain it is affecting. The two groups are cortical and subcortical dementias. According to WebMD, “Cortical dementias happen because of problems in the cerebral cortex (the outer layer of the brain). They play a critical role in memory and language. People with these types of dementias usually have severe memory loss. Subcortical dementias happen because of problems in the parts of the brain beneath the cortex. People with subcortical dementias tend to show changes in their speed of thinking and ability to start activities”. All types of neurodegenerative disorders can be put into one of (or both of) the two categories. The different types of disorders include:
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Alzheimer’s Dementia: The most common cause of dementia among the elderly, as it is the sixth leading cause of death in the U.S. It is a disorder that slowly destroys memory and eventually the ability to execute daily tasks. Initially, Alzheimer’s develops in the hippocampus (the part of the brain where memories are formed). As neurons die and lose connections with each other in the hippocampus, the disorder eventually spreads to other parts of the brain.
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Vascular Dementia: Second most common cause of dementia after Alzheimer’s Dementia. It refers to the loss of brain function due to a vascular injury, or a disease in the brain. The risk factors for Vascular Dementia are the same for stroke, including high blood pressure, high cholesterol, diabetes, and an abnormal heartbeat. Problems with organization, attention, and problem solving are prevalent in this disorder. Symptoms of Vascular Dementia are often confused with Alzheimer’s.
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Dementia with Lewy Bodies (DLB): Third most common cause of dementia after Alzheimer’s Dementia and Vascular Dementia. Abnormal amounts of a protein called alpha-synuclein(collectively known as Lewy Bodies) alter the chemicals in many different parts of the brain. The changes in the chemicals lead to problems with thinking, behavior, and mood. Early symptoms of DLB are often confused with Alzheimer’s Dementia.
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Mixed Dementia: A combination of any two types of dementia or more.
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Parkinson’s Disease: A disorder that happens when neurons in the area of the brain that controls movement die. This disorder leads to shaking, stiffness, and difficulty with balance and coordination. Affects 50 percent more men as compared to women.
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Frontotemporal Dementia: This disorder is caused by the damage to neurons in the brain’s frontal and temporal lobes, causing them to shrink. The damage to these parts of the brain can cause emotional problems, problems with communication, and at work. This neurodegenerative disorder causes 10 percent of dementia.
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Creutzfeldt-Jakob Disease: A rare neurodegenerative disorder which researchers believe to be caused by an abnormal form of prions (a cellular protein which is largely present in the nervous system). The infectious form of prion leads to nerve cell loss and other brain damage which is fatal. Patients may have failing memory, changes in behavior, and lack of coordination. As the illness develops, patients may encounter blindness and enter into a coma.
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Normal Pressure Hydrocephalus: This disorder is caused by the abnormal buildup of cerebrospinal fluid (CSF) in brain cavities, putting pressure on the brain. It can result from complications in a surgery, a tumor, or even an infection. Problems with walking and bladder control may occur as well. Symptoms for this disorder are often confused with Alzheimer’s, Parkinson's and Creudzefeltd-Jakob Disease.
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Huntington’s Disease: An inherited disorder that causes neurons to die in many different areas of the brain. This disorder causes three of the building blocks of DNA to repeat more times than it is normal. Patients develop abnormal body postures and involuntary movements.
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Wernicke-Korsakoff Syndrome: This disorder is caused by a lack of vitamin B12. Symptoms include lack of muscle coordination, cognitive decline, and vision changes.
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