Dementia series part 2 — Basics of Dementia: Types, Symptoms, and Risk Factors
Looxid Labs has developed the technology that analyzes EEG signals and eye-tracking data to assess cognitive performance. We are currently applying this technology to our in-home cognitive care solution, LUCY, designed to prevent dementia and spot the early signs of dementia in daily life. This dementia series aims to provide information on the basics of dementia and the latest digital technologies applied for early diagnosis, and last but not least, our technology and its use for early diagnosis of dementia through our cognitive care solution, LUCY.
Written by Shannon H. Jeon
hyungsin.jeon@looxidlabs.com
1. Normal Aging and Dementia
As we get older, we start to notice changes in our bodies. Our cells and tissues begin to degenerate once we reach adulthood, and those changes affect the functioning of all body systems, including our brain function. However, dementia is not a normal part of aging. Since age is the strongest known risk factor for Alzheimer’s and other dementia, the normal physiologic changes with aging may be mistaken and cause worry to some individuals as they get older. This may be due to the lack of understanding about dementia, which can produce significant confusion and misconception about the condition. With the lack of knowledge, some people become indifferent to notice the crucial changes in their body functions, possibly due to pathological causes, and neglect the symptoms of dementia until it is too late to be treated. This can happen especially in the early stage of dementia when its symptoms are difficult to tell apart from the normal age-related changes. The current article aims to impart knowledge of normal aging and dementia: the differences between the two, types of dementia, and common symptoms and risk factors of the condition.
Memory loss is the most manifested and known sign of dementia. However, when it is the early stage of dementia, the symptoms may be too subtle and mistaken as mere forgetfulness that one can expect and experience as a normal part of the aging process. The crucial difference between benign forgetfulness and pathological memory impairment due to dementia is whether the person is able to recall the lost memory of a particular event when a piece of information on the event is given. If the person is given the full description of the event and still not able to recall the memory, it is not a simple sign of forgetfulness or normal aging.
Dementia affects more than just memory. When not treated properly at an earlier stage, the damage to the person’s brain and its consequences will be more difficult to handle and may worsen over time. The consequences can affect various functions, such as problems with language skills, attention, visuospatial abilities, personality changes, and mental or physical functioning decline. Once the changes in cognitive functions are prominent and severe enough to disrupt one’s usual lifestyle, habits, and daily activities, it may indicate a developing pathological cognitive problem, possibly dementia.
2. Different Types of Dementia
Alzheimer’s disease (AD) is the most known dementia, but there are other types of dementia as well. The classifications of dementia, primary or secondary, are defined based on whether the diagnosis of impairment is resulted from other diseases or injuries. AD is considered primary dementia since brain damage is the primary condition. Whereas secondary dementia, vascular dementia (VD) for example, refers to dementia developed as a peripheral condition to a pre-existing disease or physical condition, such as stroke. There are other types of dementia like Lewy body dementia (LBD), frontotemporal dementia (FTD), or mixed dementia, but AD is the most common.
2.1 Alzheimer’s Disease (AD)
Worldwide, Alzheimer’s disease contributes to the most cases of dementia. In South Korea, about 75% of patients with dementia have a diagnosis of AD, and for those aged 85 or older, the percentage goes up to 90%. Although the exact causes of AD are not fully understood, emerging evidence shows that the accumulation of the toxic amyloid-beta (Aβ) protein and the abnormal form of the tau protein may result in brain damage. The damage and destruction of the brain cells worsen as the proteins spread throughout the brain, causing the decline in many cognitive domains like memory, attention, or perception, more significant.
2.2 Vascular dementia (VD)
Vascular dementia is the second most common dementia due to brain hemorrhages, stroke, or cerebrovascular diseases leading to brain cell death. Since VD is caused by cerebrovascular damage, the clinical course patterns can differ depending on the brain regions impacted and their severity. One stroke may cause a sudden, aggressive decline in cognitive functions, and recurrent strokes may gradually develop symptoms of cognitive impairment. Some evidence shows that VD is preventable and potentially treatable by treating the underlying cerebrovascular disease and taking care of its risk factors.
2.3 Mixed dementia
Mixed dementia refers to the condition of having more than one cause of dementia, such as co-existing pathologies of AD and VD. One may have a diagnosis of one specific dementia at a particular time, but as the brain damage worsens, the person may develop another type of dementia later in life, unbeknown to the clinicians. Researchers believe that mixed dementia is more common than it is believed to be, since many autopsies of a specific dementia actually indicate mixed dementia.
2.4 Other dementias
Other types of dementia include Lewy body dementia (LBD), frontotemporal dementia (FTD), and dementias due to alcohol abuse, vitamin B12 deficiency, brain tumor, or hypothyroidism. If the pre-existing condition contributing to dementia gets treated, the symptoms of dementia may improve.
3. Stages of Alzheimer’s Disease
Since there are many types of dementia, the presentation of dementia can vary among individuals, depending on the dementia type one has. For this reason, Alzheimer’s disease is taken as an example since it is the most common dementia. AD progresses through 5 main stages of symptoms, as seen in the following table.
Preclinical Stage
- the levels of toxic proteins in the brain may have elevated, but there are no symptoms of the condition noticeable to the person or others
Mild Cognitive Impairment (MCI) Stage
- as the brain damage worsens, one or more cognitive domains start to decline; the changes in cognitive abilities can be subtle but noticeable
Mild Stage
- The symptoms in cognition impairment such as problems with attention, memory, decision-making start to appear; mood changes can also occur
Moderate Stage
- More than one cognitive domains are impacted and the symptoms become distinct, interfering with many everyday activities
Severe Stage
- The symptoms interfere with most everyday activities; individuals require help with most of the basic activities such as dressing, eating, using the bathroom, etc
4. Risk Factors of Dementia
Knowing one’s risk factors for dementia is important to prevent or manage dementia. Please refer to the common risk factors for dementia below.
Sociodemographic factors
- Age: Dementia is more common in people over the age of 65
- Gender: Worldwide, more women have impacted by dementia than men do
- Marital status: Unmarried individuals, including divorced, separated, widowed, may impact one’s likelihood of than their married counterparts
Genetic factors
- ApoE4: having ApoE4 genes increase risk for Alzheimer’s disease and is also associated with an earlier age of disease onset
- Family history of dementia: those who have first-degree relatives with dementia are more likely to develop the condition than those who don’t
Others
- Excessive use of substances: Substances like alcohol, marijuana, and prescription drugs have been found to increase a person’s chances of developing dementia
- Medical history of traumatic brain injury (TBI) and cardiovascular disease
Closing
Again, dementia is not a normal part of the aging process, and it is very challenging and complicated to cure once it has manifested. In order to successfully prevent or manage dementia, it is crucial to have proper knowledge of the differences between normal aging and dementia, including dementia’s different types, common symptoms, and risk factors. Please visit the nearest hospitals or dementia centers if you are concerned after reading this article. Dementia can only be diagnosed by qualified and experienced health professionals.
Looxid Labs is developing an in-home cognitive care solution, Lucy, using virtual reality and biosignal data to detect the early signs of cognitive impairment. With our biosignal analysis techniques, we collaborate with many prestigious hospitals and research organizations in the hope of developing an early diagnosis tool for dementia. In the following articles, we will present the new methods of detecting the early signs of dementia using various technologies. We will further explain our technology and its approach to offer the possibilities of defeating dementia in the later articles.
References
[1] https://www.nid.or.kr/info/diction_list5.aspx?gubun=0501
[2] https://www.alzheimers.org.uk/about-dementia/symptoms-and-diagnosis/how-dementia-progresses/normal-ageing-vs-dementia
[3]https://www.alz.org/alzheimers-dementia/what-is-dementia
[4] https://www.who.int/mental_health/publications/dementia_report_2012/zh/
[5] https://www.nid.or.kr/info/today_list.aspx
[6] https://www.nature.com/articles/nrn2967
[7] https://www.alz.org/alzheimers-dementia/stages
[8] https://www.sciencedirect.com/science/article/pii/S0896627313009112
[9] https://www.alz.org/alzheimers-dementia/what-is-dementia/types-of-dementia/vascular-dementia
[10] https://www.alzheimers.org.uk/blog/what-is-mixed-dementia#:~:text=Lewy%20body%20disease.-,Alzheimer's%20disease%20and%20vascular%20dementia,contribute%20to%20their%20dementia%20symptoms
[11] https://www.mdpi.com/2076-3425/9/8/187
[12] https://n.neurology.org/content/69/24/2197.short
[13] https://www.sciencedirect.com/science/article/pii/S0072975207840607
[14] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5970949/
[15] https://www.who.int/news-room/fact-sheets/detail/dementia
[16] https://www.alz.org/alzheimers-dementia/what-is-dementia/related_conditions/mild-cognitive-impairment
[17] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4592781/pdf/nihms659303.pdf
[18] https://www.nid.or.kr/notification/data_view.aspx?board_seq=91
[19] https://www.researchgate.net/publication/49702379_A_Nationwide_Survey_on_the_Prevalence_of_Dementia_and_Mild_Cognitive_Impairment_in_South_Korea
[20] https://www.acpjournals.org/doi/full/10.7326/0003-4819-144-2-200601170-00004
[21] https://www.nid.or.kr/info/diction_list3.aspx?gubun=0302
[22] https://www.alz.org/media/homeoffice/facts%20and%20figures/facts-and-figures.pdf
This information is not intended as a substitute for professional medical care. Always follow your healthcare professional’s instructions.
