While some risk factors for dementia can’t be helped, researchers have been exploring the impact of other risk factors on brain health that can potentially be reversed.
September is World Alzheimer’s Awareness month. Every year, in celebration of the international campaign, people come together from all around the world with the aim of spreading awareness and challenging the stigma around dementia.
Before the pandemic, estimates had shown that dementia cases could rise globally from 55 million to 78 million by the year 2030, according to Alzheimer’s Disease International (ADI).
Since the start of the health crisis, researchers around the world have become increasingly aware and concerned of the link between the neurological symptoms of Covid-19 and dementia.
What is dementia?
Dementia is not a specific disease, but a general term that is used to describe the impaired ability to remember, socialise, think, or make decisions to an extent that it interferes with everyday activities. It typically involves memory loss, but memory loss can have different causes. Therefore, having memory loss alone does not necessarily mean you have dementia, although it is generally considered one of the early signs of the condition.
Alzheimer’s disease is the most common cause or type of dementia, and the most well-known. However, there are many different types that exist:
- Alzheimer’s disease. Alzheimer’s disease is the most common cause of dementia. The causes of Alzheimer’s are not always known; however, experts attribute a small percentage of its onset to the mutation of three known heritable genes. Individuals with Alzheimer’s disease have plaques and tangles in their brains, and it is believed that these clumps are the reason behind the damage of healthy neurons and their connecting fibres.
- Vascular dementia. This type of dementia occurs when the vessels that supply blood to the brain are damaged. This damage in blood vessels can cause strokes or affect the brain in other ways including damaging the fibers located in the white matter of the brain. The most common symptoms and signs of this type of dementia are difficulties with problem-solving, slowed thinking and loss of overall organisation and focus.
- Lewy body dementia. Lewy bodies are clumps of proteins that are abnormal, found in the brains of people with Lewy body dementia, Alzheimer’s disease and Parkinson’s disease. This type of progressive dementia is quite common and symptoms include: acting out one’s dreams in their sleep, visual hallucinations, and difficulties with attention span and focus. Symptoms can also include uncoordinated movement, tremors and rigidity.
- Frontotemporal dementia. This type of dementia refers to a group of diseases that are characterised by the destruction of nerve cells and their associated connections in the frontal and temporal lobes of the brain. These areas of the brain are generally associated with personality, language and behaviour. Therefore, the main signs and symptoms of frontotemporal dementia affect behavior, personality, judgement, language, movement, and thinking.
- Mixed dementia. Mixed dementia occurs when individuals have a combination of different dementias such as Alzheimer’s disease, vascular dementia and Lewy body dementia.
What are the risk factors?
While some risk factors for dementia can’t be helped, such as age and genetics, researchers have been exploring the impact of other risk factors on brain health that can potentially be reversed.
Research suggests that adopting healthy lifestyle changes such as consuming a healthy diet, engaging in regular physical activity, increased cognitive stimulation, and smoking cessation, all can lead to a decrease in the risk of cognitive decline and dementia.
What are the causes?
Generally, dementia occurs as a result of damage to or loss of nerve cells and their associated connections in the brain. It affects different people based on the area of the brain that is damaged.
Although most dementias are permanent and progressive, sometimes thinking and memory problems are caused by different conditions such as depression, thyroid problems, excessive alcohol use, vitamin deficiencies and medicinal side effects. If these conditions are treated or addressed, the memory problems will improve over time.
What’s the link between Covid-19 and dementia?
There is increasing evidence that Covid-19 can lead to long-term brain damage. One study has shown a similarity in biochemical changes between patients with coronavirus and those with Alzheimer’s. These changes indicate neuronal injury and inflammation.
In addition to this, there are a number of emerging studies on long Covid that show that many long-haulers suffer from cognitive problems such as “brain fog” and difficulties with memory, concentration, and language. Although in most patients these symptoms resolve over time, the fear is that in others, these symptoms may accelerate progressive dementia.
In addition to this, increased isolation due to the restrictions brought about by the Covid-19 pandemic such as social distancing, is in itself, considered a risk factor for the development of dementia due to the lack of cognitive stimulation that helps delay the onset of symptoms.
On Wednesday, Alzheimer’s Disease International (ADI), the global federation of dementia associations, revealed a specialist working group charged with understanding the scale of the impact of Covid-19 on dementia, and coming up with recommendations on how best to mitigate the problem at hand.
Based on evidence gathered from previous coronavirus outbreaks, it would not be “unusual” for Covid-19 infections to be associated with progressive neurological disorders. In fact, this was also observed during the 1918 Spanish flu pandemic, where an infection increased the long-term risk of developing Parkinson’s disease by two to three folds.
While it is still too early to fully understand the exact impact of Covid-19 on future dementia cases, the expectation is that it will have a large impact. More research, funding and overall awareness is needed to help prepare the health system for the expected rise in prevalence of dementia due to Covid-19.
Maha El Akoum, MPH, is a public health professional currently working as Head of Content at World Innovation Summit for Health [WISH].