Dementia – know what’s what

Major neurocognitive disorder (formerly known as Dementia) is a widebroadm that refers to an impairment in one or more cognitive abilities that is severe enough to impede daily activities. It can be thought of as an umbrella that covers a variety of areas, including learning and memory, language, executive function, complex attention, perceptual-motor, and social cognition, and its deficits impair daily functions and independence, resulting in loss of coordination, loss of bladder control, weakness, stiffness, imbalance, mood swings, or behavioural changes. [1] [2] [3]

There are many different types of dementia, each with its cause. Starting with the most common in elderlies, here are some types of dementia:

• ?Alzheimer’s disease (AD), comprises over 60 % of cases;
• Vascular dementia;
• Frontotemporal dementia;
• Lewy body dementia;
• Mixed dementia;
• some conditions like Korsakoff syndrome, Huntington's disease, Creutzfeldt-Jakob disease, Parkinson’s disease, HIV and multiple sclerosis have been linked to dementia.

Mild cognitive impairment (MCI) is an intermediate clinical state between normal cognition and dementia. While small changes in cognition are natural with ageing, MCI may increase the chance of developing dementia. However, it may also be a reversible condition in the context of depression, as a side effect of some drugs, or while recovering from an acute illness. Mild cognitive impairment causes impairments with memory, language, reasoning, or judgement that are usually not severe enough to interfere with a person's daily life or independence. As the term implies, the problems encountered are considered mild, as opposed to the symptoms experienced by a person impacted by a major neurocognitive disorder. [1] [2] [3]

Fig 1. Understanding the Umbrella of Dementia [7]

Globally, the prevalence of dementia is rising as the population ages. Given that dementia is the most common form of neurodegenerative condition worldwide and is predicted to rise in prevalence over the next 30 years in Canada, it will continue to be a serious medical concern. By 2050, it is expected that more than 1.7 million Canadians will have dementia, with 685 new cases on average being identified every day. [3]

Fig.2.??Number of people living with dementia and the number of new cases of dementia per year in Canada, 2020 to 2050 [3]

Fig.3. Number of people in Canada with dementia by age group, 2020 and 2050 [3]

Fig. 4. Number of people with dementia in Canada by sex, 2020 to 2050 [3]

In oToperly recognize and manage cases of Alzheimer's disease (AD) and related dementias, physicians should be prepared to perform tests for cognitive impairment and ask about functional decline whenever they feel like it. [3]

It is important to be aware of dementia because the population is ageing and the average age is growing. Following that, this article will focus on Alzheimer's disease, the most common type of dementia in the elderly.[3]

Alzheimer's disease?is a neurodegenerative disease with insidious onset and?progressive impairment of memory, comprehension, language, attention, reasoning, and judgement among other behavioural and cognitive functions. Less than 10% of Alzheimer's patients have early onset, before age 65. This type of dementia cannot be cured, although there are therapies that may improve some of the symptoms. [3] [4]

Fig. 5. Alzheimer’s disease [8]

Epidemiology

Amyloid beta plaques and neurofibrillary tau tangles, which are thought to contribute to the decrease in cognition, function, and behaviour, are the hallmarks of AD. Both early-onset Alzheimer's disease and late-onset Alzheimer's disease have also a genetic component. Early-onset dementia is associated with trisomy 21 (Down syndrome). Intestinal inflammation is also linked to older age, dementia, and a higher amyloid burden. [3] [8]

Other risk factors have been associated with?AD:

-???????increasing age is the most important risk factor for?Alzheimer's disease;

-???????family history of dementia (having a first-degree relative with?AD?increases the risk of developing?AD?by 10% to 30%)

-????????traumatic head injury;

-???????depression;

-???????cardiovascular?and cerebrovascular disease;

-???????higher parental age;

-???????smoking;

-???????increased homocysteine levels and the presence of APOE e4 allele.

The risk of Alzheimer's disease is known to be reduced by higher education, estrogen use by women, anti-inflammatory drug use, recreational activities like reading or playing an instrument, a healthy diet, and regular aerobic exercise.?Weekly n-3 fatty acid intake and fish consumption may reduce the risk of Alzheimer's disease, and α-linolenic acid intake may reduce the risk of Alzheimer's disease in people with the APOE-4 genotype. [4] [10]

Fig.6. Select risk factors for dementia [3]

Diagnosis

Fig. 7. Criteria for dementia [5]

*DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, fifth edition)

• history and physical examination are the keys to diagnosis;
• collateral history from the family and caregivers is crucial as some patients may lack insight into their disease;?
• assess the functional abilities like basic and individual activities of daily living;
• neurological exexam and mental status examination are needed to evaluate the disease stage and rule out other conditions. [4]

Alzheimer's disease symptoms can range from mild to severe depending on the disease's stage. The initial and most common presenting symptom, however, is episodic short-term memory impairment, which may be evoked in the majority of patients even when it is not the presenting symptom and includes forgetting new information and having trouble finishing familiar tasks.

Staging

• Preclinical or Presymptomatic - asymptomatic with?definite laboratory evidence (biomarkers in the cerebral spinal fluid);
• Mild Cognitive Impairment?– memory or nonmemory (problem-solving, judgment, executive functioning, lack of motivation and disorganization) impairment, but still function independently. Neuropsychiatric symptoms like apathy, social withdrawal, disinhibition, agitation, psychosis, and wandering are also common in the mid to late stages;
• Major neurocognitive disorder/Dementia - memory loss that is incapacitating, along with language, and visuospatial skill impairment. Dyspraxia, olfactory dysfunction, sleep problems, and extrapyramidal motor symptoms like dystonia, akathisia, and parkinsonian symptoms appear later in the course of the condition. The need for assistance grows as the illness worsens, and finally, practically permanent surveillance becomes necessary. [4]

Management

The disease Alzheimer's has no known cure. There is only symptomatic therapy available. The treatment's anticipated advantages are not great. Treatment should be discontinued or changed if there are no noticeable benefits or intolerably significant side effects. [4]

Two categories of drugs are approved for the treatment of?Alzheimer's disease:

• cholinesterase inhibitors: increasing the level of acetylcholine - a chemical used by nerve cells to communicate with each other and important for learning, memory and cognitive functions;
• partial N-methyl D-aspartate (NMDA) antagonists – for moderate to severe disease and it can be taken in combination with cholinesterase inhibitors.

Treatment of anxiety, depression, and psychosis—common in the middle to late stages of Alzheimer's disease—is crucial in addition to symptomatic management. In particular, controlling behavioural issues benefits from environmental and behavioural methods. Maintaining a familiar environment, keeping an eye on personal comfort, providing a safe environment, refocusing attention, eliminating doorknobs, and avoiding confrontation are all straightforward methods that can be highly effective in managing behavioural disorders. Mild sleep problems can be minimized to ease the stress on caregivers by getting exposure to sunlight and engaging in daytime exercise. It has been demonstrated that regular aerobic exercise can slow the progression of Alzheimer's disease. [4] [6]

In comparison to older adults with other health conditions, who receive care for an average of 17 hours per week, care providers for those impacted by dementia give average weekly care of 26 hours (CIHI, 2018b). The severity of dementia, the qualities of the caregiver, and changes in mood, personality, and behaviour all influence the number of care hours. These elements also affect external costs and the price of medical care (Angeles et al., 2021). [3]

?Care providers frequently prassistn the following areas of care:

• daily tasks (such as cooking, cleaning, and maintaining personal hygiene);
• medical care (including scheduling, organizing, and attending appointments and dispensing medications);
• mood, personality and behaviour changes that may occur;
• companionship, support on a general level, and advocacy. [3]

Fig. 8. Types of support provided by care partners [3]

Regardless of age, take steps to actively improve your brain health and lower your risk of dementia:

• Stay physically active every day – at least 30 minutes a day, 5 days a week – including walking, running, weightlifting, gardening, yoga, tai chi, swimming, dancing, cycling, team sports and working in the garden;
• -Take care of your heart and health in general by monitoring your blood pressure, cholesterol and diabetes;
• Stay connected and be in contact with friends and family;
• Challenge your thinking by taking part in new mental activities that you enjoy;
• Sleep hygiene is crucial, aim for 6 to 8 hours of sleep per night;
• Avoid excessive alcohol consumption;
• Keep your hearing. Use hearing aids if you need them. Protect your hearing from loud noises.
• Avoid any kind of head trauma. Use appropriate protective clothing and equipment and stay away from activities that could endanger your brain;
• Adopt healthy behaviours. Make healthy food choices, reduce avoidable stress, quit or reduce smoking, and have regular checkups with your doctor. All these actions will positively affect your brain health. [3]

Fig. 9. Modifiable risk factors related to dementia risk [3]

Resources:

1.?????https://www.uptodate.com/contents/evaluation-of-cognitive-impairment-and-dementia

2.?????https://www.canada.ca/en/public-health/services/diseases/dementia.html?utm_campaign=hc-sc-dementia-22-23&utm_medium=sem&utm_source=ggl&utm_content=ad-text-en&utm_term=alzheimer%20canada&adv=2223-313201&id_campaign=18329363742&id_source=142667600633&id_content=621671849430&gclid=CjwKCAjwm8WZBhBUEiwA178UnCXxECuxqqE1X5_Vl-JJ4w1pmMR5rKURBEq83umvNpK__N7JiFu1-RoCSmcQAvD_BwE&gclsrc=aw.ds

3.?????https://alzheimer.ca/en

4.?????https://www.ncbi.nlm.nih.gov/books/NBK499922/#article-17423.s2

5.?????https://www.uptodate.com/contents/image?imageKey=NEURO%2F91276

6.?????https://canjhealthtechnol.ca/index.php/cjht/article/view/hc0027/747

7.?????https://www.summerfieldredlands.com/understanding-the-umbrella-of-dementia/

8.?????https://medlineplus.gov/ency/article/000760.htm

9.?????https://www.medrxiv.org/content/10.1101/2022.09.21.22280179v1.full-text

10.??https://jamanetwork.com/journals/jamaneurology/article-abstract/784412