Written by Sara Bozyel
The more we age, the more we become vulnerable. Getting old is an unavoidable part of life. Some believe it is restful and peaceful, some believe that it is intimidating and depressing. Well, it is possible to say that it contains a bit of each.
It is a part of nature, getting old, a reservoir of a lifetime experience. However, no matter how much we would like to deny it, aging brings its troubles within it. Aging causes changes in brain size, vasculature, and cognition (4). The brain shrinks with increasing age and there are changes at all levels from molecules to morphology (4). Besides dementia, the incidence of stroke, white matter lesions, and the level of memory impairment also rise with age (4). There are changes in levels of neurotransmitters and hormones. Protective factors that reduce cardiovascular risk, namely regular exercise, a healthy diet, and low to moderate alcohol intake, seem to aid the aging brain as does increased cognitive effort in the form of education or occupational attainment (4). A healthy life both physically and mentally may be the best defense against the changes of an aging brain. These age-related changes –atrophy (shrinking) of certain parts of the brain, inflammation, vascular damage, production of unstable molecules called free radicals, and breakdown of energy production within cells– simply increase dementia which is the term that includes many different memory loss disorders (6). Well, what is dementia?
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Dementia is not a disease itself. It's a collection of symptoms that result from damage to the brain caused by different diseases, such as Alzheimer's (6). Dementia is a loss of normal cognitive functions that is severe enough to interfere with daily life (3). It shows a group of symptoms affecting memory, thinking, and social abilities severely enough to interfere with your daily life (2). It isn't a specific disease, but several diseases can cause dementia, it is not a normal part of aging. Though dementia generally involves memory loss, memory loss has different causes (2). Having memory loss alone doesn't mean you have dementia, although it's often one of the early signs of the condition Alzheimer's disease is the most common cause of progressive dementia in older adults, there are several other causes of dementia (2). Depending on the cause, some dementia symptoms might be reversible.
Symptoms:
Symptoms mostly include memory problems, difficulty finding words or understanding language, difficulty with attention and focusing on the task at hand, forgetting where things are or how to perform certain tasks, problems with visual perception, reasoning, and judgment, and sometimes personality changes (3). These symptoms can vary according to the type of dementia. Most dementias are due to the gradual loss of brain cells (neurons) called neurodegeneration and are slowly progressive (3). An exception is vascular dementia which results from multiple strokes and can present with sudden, stepwise declines in cognitive function (3). These symptoms are often mild and may get worse only very gradually. It's often termed "mild cognitive impairment" (MCI) as the symptoms are not severe enough to be diagnosed as dementia (5). You might not notice these symptoms if you have them, and family and friends may not notice or take them seriously for some time. In some people, these symptoms will remain the same and not worsen. But some people with MCI will go on to develop dementia (5). Dementia is not a natural part of aging. This is why it's important to talk to a GP sooner rather than later if you're worried about memory problems or other symptoms (5).
Causes:
Dementia is caused by damage or loss of nerve cells and their connections in the brain (2). Depending on the area of the brain that is damaged, dementia can affect people differently and cause different symptoms. Dementias are often grouped according to what they have in common, such as the protein or proteins deposited in the brain or the part of the brain that is affected (2). Some diseases, such as those caused by a response to medications or vitamin deficiencies, appear as dementia and may improve with treatment.
Types of Dementias:
Alzheimer's disease: This is the most common cause of dementia. While not all causes of Alzheimer's disease are known, experts know that a small percentage are associated with mutations in three genes that can be passed on from parent to child (2). While several genes are probably involved in Alzheimer's disease, an important gene that increases the risk is apolipoprotein E4 (APOE) (2). Patients with Alzheimer's disease have plaques and tangles in their brains. The plaques are clumps of a protein called beta-amyloid, and the tangles are fibrous tangles made up of tau protein. These clumps are thought to damage healthy neurons and the fibers that connect them (2).
Vascular dementia: This type of dementia results from damage to the blood vessels that supply blood to your brain (2). Blood vessel problems can cause strokes or affect the brain in other ways, such as by damaging the fibers in the brain's white matter (2). The most common symptoms of vascular dementia include difficulties in problem-solving, slow thinking, and loss of focus and organization (2). These tend to be more pronounced than memory loss.
Lewy body dementia: Lewy bodies are abnormal balloon-like clumps of proteins found in the brains of people with Lewy body dementia, Alzheimer's disease, and Parkinson's disease (2). This is one of the most common types of progressive dementia. Common signs and symptoms include re-enacting one's dreams during sleep, seeing things that are not there (visual hallucinations), and problems with focus and attention (2). Other symptoms include uncoordinated or slow movement, tremors, and rigidity (parkinsonism) (2).
Frontotemporal dementia: This is a group of diseases characterized by the breakdown of nerve cells and their connections in the frontal and temporal lobes of the brain (2). These are the areas generally associated with personality, behavior, and language (2). Common symptoms affect behavior, personality, thinking, judgment, language, and movement (2).
Mixed dementia: Autopsy studies of the brains of people aged 80 and over with dementia show that many have a combination of several causes, including Alzheimer's disease, vascular dementia, and dementia with Lewy bodies (2). Studies to determine how having mixed dementia affects symptoms and treatments are continuing (2).
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Our brains change as we age, but Alzheimer's disease and related dementia are not an inevitable part of aging. Up to 40% of dementia cases can be prevented or delayed (1). It helps to understand what is normal and what is not when it comes to brain health.
References:
Cognitive neurology and dementia. (2021, June 28). St George's University Hospitals NHS Foundation Trust. https://www.stgeorges.nhs.uk/service/neuro/neurology/cognitive-neurology-dementia/.
Dementia - Symptoms and causes. (2022, October 12). Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/dementia/symptoms-causes/syc-20352013.
Dementia | Neurology. (2016, October 24). UConn Health. https://health.uconn.edu/neurology/clinical-services/dementia.
Peters, R. (2006, February). Ageing and the brain. PubMed Central (PMC). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2596698.
Symptoms of dementia. (2017, December 21). nhs.uk. https://www.nhs.uk/conditions/dementia/symptoms/.
What causes Alzheimer's disease? (n.d.). National Institute on Aging. https://www.nia.nih.gov/health/what-causes-alzheimers-disease.
What is dementia? (n.d.). Alzheimer's Disease and Dementia. https://www.alz.org/alzheimers-dementia/what-is-dementia.
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