Vascular dementia, which occurs after a stroke, is the second most common dementia type. But there are many other conditions that can cause symptoms of dementia, including some that are reversible, such as thyroid problems and vitamin deficiencies. In vascular dementia, changes in thinking skills sometimes occur suddenly following strokes that block major brain blood vessels. Thinking problems also may begin as mild changes that worsen gradually as a result of multiple minor strokes or other conditions that affect smaller blood vessels, leading to cumulative damage. Vascular dementia symptoms can vary widely, depending on the severity of the blood vessel damage and the part of the brain affected. Memory loss may or may not be a significant symptom depending on the specific brain areas where blood flow is reduced. Symptoms may be most obvious when they happen soon after a major stroke
Neurodegenerative disease primarily affects the neurons in the human brain. Neurons are the building blocks of the nervous system which includes the brain and spinal cord. Neurons normally don’t reproduce or replace themselves, so when they become damaged or die they cannot be replaced by the body. Neurodegenerative diseases are incurable and debilitating conditions that result in progressive degeneration and / or death of nerve cells. This causes problems with movement (called ataxias), or mental functioning (called dementias). Dementias are responsible for the greatest burden of neurodegenerative diseases, with Alzheimer’s representing approximately 60-70% of dementia cases.
In Alzheimer's disease, high levels of certain proteins inside and outside brain cells make it hard for brain cells to stay healthy and to communicate with each other. The brain region called the hippocampus is the center of learning and memory in the brain, and the brain cells in this region are often the first to be damaged. That's why memory loss is often one of the earliest symptoms of Alzheimer's. While most changes in the brain that cause dementia are permanent and worsen over time, thinking and memory problems caused by various conditions
Neuro-oncology is the study of brain and spinal cord neoplasms, many of which are very dangerous and life-threatening (astrocytoma, glioma, glioblastoma multiforme, ependymoma, pontine glioma, and brain stem tumors are among the many examples of these). Among the malignant brain cancers, gliomas of the brainstem and pons, glioblastoma multiforme, and high-grade (highly anaplastic) astrocytoma are among the worst.The CNS consists of the brain and spinal cord. The brain is protected by the skull (the cranial cavity) and the spinal cord travels from the back of the brain, down the center of the spine, stopping in the lumbar region of the lower back. The brain and spinal cord are both housed within a protective triple-layered membrane called the meninges.
Parkinson's disease (PD) is an age-related degenerative disorder of certain brain cells. It mainly affects movements of the body, but other problems, including dementia, may occur. It is not considered a hereditary disease, although a genetic link has been identified in a small number of families. Depression, anxiety, personality and behavior changes, sleep disturbances, and sexual problems are commonly associated with Parkinson's disease. In many cases, Parkinson's disease does not affect a person's ability to think, reason, learn, or remember (cognitive processes).