Causes Of Dementia

What is dementia?

Dementia is a group of conditions that progressively cause deterioration in various areas of the brain.1 This condition is most prevalent in the ages of 65 and over.1  The ‘Dementia UK’ states that there are around 200 subtypes of dementia which include Alzeheimer’s, amongst others.1  In each subtype symptoms, which will be discussed below worsen with time. Cognitive functioning of thinking, calculating and judgment are most affected due to the damage in the brain ( neural pathways) caused by this condition.2 


The ten early signs/symptoms to look out for in dementia according to ‘Alzheimer's Association’  are:

  • Daily life disrupted by memory loss 3
  • Finding it challenging to plan or solve problems 3
  • Having a difficulty in completing day-to-day tasks e.g writing a shopping list 3
  • Getting confused over the time or place 3
  • Issues with spatial awareness ( balance) and judging distance or colour 3
  • A new issue with speech and language both written and orally  - using the wrong vocabulary to name objects e.g a watch becomes a hand-clock 3
  • Objects getting misplaced and unable to locate them 3
  • A decrease in judgment level 3
  • Withdrawal from social/ work activities 3
  • Personality and mood changes 3  

Above are the most common warning signs of dementia. There are also psychological symptoms (neuropsychiatric) that can range from joyful moods and apathy to anxiety and having delusional ideas (delusional disorder).4 Neuropsychiatric symptoms have a frequency of 35-85% amongst patients, even in the early stages of the disorder.4 

If you or someone you know are suffering from any of the above, then a GP or doctor should be contacted in order to take relevant action.  

Dementia is caused by damage to brain cells

The damage to the cells in the brain (nerve cells) is the main cause of dementia. The disease destroys neurons and their connective pathway which causes a  loss of  function in certain brain regions.The onset of dementia can be triggered by traumatic brain injury  or in older age due to internal changes within the brain.6 It’s important to note that there isn’t one specific cause as autoimmune diseases and lifestyle factors such as stress and alcohol can increase the risk of developing the disease. 

Alzheimer's disease

Dementia is an umbrella term for brain disorders that are degenerative, meaning that they get progressively worse with time. Alzheimer's is a more specific condition that falls under this umbrella, and the risk of development increases with age. As the disease progresses, memory loss and forgetfulness get worse. 7 The ‘Alzheimer Society’ states that 1 in 10 people suffer from a mixture of both Alzheimer’s and Vascular Dementia, which causes varying symptoms combined.7 Currently, there is no cure for this; however, several treatment options are available, including the medication Aducanumab to prevent the deterioration of the disease and medications to aid with memory loss. A doctor will be able to prescribe the relevant course of treatment in line with your symptoms. 

Parkinson’s disease

Parkinson’s disease occurs when there isn’t enough dopamine in the brain due to the nerve cells which fabricate this hormone dying.8 According to the ‘Parkinson’s society’, there are around 40 symptoms of this condition with the most noteworthy being tremors, slowness in movement and muscle stiffness.8 As more nerve cells die and not enough dopamine is produced, the condition and symptoms worsen, and it is then classified as dementia. Treatment options include both drug treatments to manage symptoms and therapy in the form of physiotherapy, speech and occupational. Risk factors for Parkinson’s involve rural lifestyle, pesticide use, family history of neurological disease and history of depression.9 

Dementia with Lewy bodies 

Lewy bodies, which are clumps of proteins inside of the nerve cell, prevent the cells from communicating properly, and this can lead to difficulties with movement, concentration, hallucinations and problems with alertness.10 As more nerve cells get damaged, the symptoms worsen, and memory loss can become more affected.10  Research has yet to uncover why these clumps of protein form and cause the nerve cells to perish. 

Vascular dementia 

Vascular dementia arises in ages typically over 65 due to damaged blood vessels in the brain, and this provokes a lack of oxygen and nutrients to be supplied.11 The brain can’t function optimally without the correct amount of oxygen which typically in this organ is 3.5ml of Oxygen per 100g of brain tissue per minute.12  Damaged blood vessels can lead to lesions forming, and the location of these determines the type of symptoms which typically are the slowing of cognitive processing and impairments to memory. 11 A study concludes that the prevalence of this type of dementia increases with age as worldwide for people aged between 60-64 it is 0.4%, whereas by 85 it rises to 4.2%.11 Age plays a massive factor in the development of this degenerative disease.  

Multiple system atrophy

According to the ‘Multiple System Atrophy Trust’, this is not a common condition as research proposes that it affects 4.4 people out of 100,000. 13 Multiple system atrophy arises due to nerve cells shrinking in varying areas of the brain, and this can provoke issues with balance as well as issues controlling blood pressure.13  In most cases, there is no correlation between MSA and dementia unless cognitive issues that affect both the thought processes and behaviour commence.13 

Trauma to the brain

A traumatic brain injury can be caused by a vehicle crash, a fall or being struck by an object.14   The risk of developing dementia is increased by this trauma. A study conducted in Denmark found that the risk of dementia was at its highest six months after sustaining a brain trauma and if the person incurred more traumatic events to the brain that this would increase their risk of developing dementia.15 Frequent symptoms can include depression, agitation and parkinsonism.16 It should be noted that not all TBIs lead to dementia and that you should be in constant contact with a doctor if you have any new symptoms. 


Leukoencephalopathy, caused by an infection in the nerve cells (oligodendrocytes), occurs most predominantly in individuals who are immunodeficient.17 This progressive disease has symptoms of clumsiness, speech impairment and personal changes. 18  

Treatment options include immune-deficient reversal that entails plasma exchange to treat underlying symptoms.18 


To conclude, this article examined the different risk factors for dementia which are Alzheimer’s, and Parkinson’s, caused by a traumatic brain injury, multiple system atrophy and leukoencephalopathies. The disorder is classified as ‘Dementia’ as it progressively worsens with time and notable symptoms include memory loss and loss in cognitive functions. 


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  4. Behavioral and psychological symptoms of dementia. Frontiers in Neurology [Internet]. 2012 [cited 26 September 2022];. Available from: 
  5. What happens to the brain in alzheimer’s disease? [Internet]. National Institute on Aging. [cited 2022 Sep 25]. Available from: 
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  8. What is Parkinson's? [Internet]. Parkinson's UK. [cited 30 September 2022]. Available from: 
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  13. Brief Guide to MSA – Multiple System Atrophy Trust [Internet]. Multiple System Atrophy Trust. [cited 29 September 2022]. Available from:  
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  15. Fann J, Ribe A, Pedersen H, Fenger-Grøn M, Christensen J, Benros M et al. Long-term risk of dementia among people with traumatic brain injury in Denmark: a population-based observational cohort study. The Lancet Psychiatry [Internet]. 2018 [cited 29 September 2022];5(5):424-431. Available from:  
  16. Shively S, Scher A, Perl D, Diaz-Arrastia R. Dementia Resulting From Traumatic Brain Injury. Archives of Neurology [Internet]. 2012 [cited 29 September 2022];69(10). Available from:  
  17. Das S, Daimary P, Chatterjee S, Krishnapillai R. Rapidly progressive dementia in a case of progressive multifocal leukoencephalopathy. Indian Journal of Psychiatry [Internet]. 2019 [cited 29 September 2022];61(3):315. Available from:  
  18. Progressive Multifocal Leukoencephalopathy | National Institute of Neurological Disorders and Stroke [Internet]. [cited 29 September 2022]. Available from: 

Rebecca Dion

Master of Public Health - MPH Student, Lund University, Sweden

Interested in health promotion for children and young adults. I have been working and studying in the multicultural environments of London , Paris and more recently in Lund. presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
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