What is Alzheimer’s Disease | Stages of AD | Causes of AD | Treatment for AD

What is Alzheimer’s Disease?

Alzheimer’s Disease is a common type of dementia [1], an overarching term for loss of cognitive functioning. Dementia can manifest as memory loss, confusion and poor reasoning. AD is a brain disorder whereby neurons decay and brain mass shrinks. The symptomlogy is progressive– around 7 to 10 years between diagnosis and end-of-life– and can be broken into mild, moderate and severe stages. [2]

Stages of Alzheimer’s Disease

  • Loss of memory
  • Poor judgement and decision-making
  • Frequently misplacing things
  • Increased anxiety and/aggression
  • Issues counting money
  • Slower reaction times
  • More severe memory loss and confusion
  • Poor language and arithmetic skills
  • Difficulty handling complicated tasks
  • Impulsivity and in-adherence to usual social norms (e.g. groping a stranger)
  • Angry outbursts 
  • Psychosis (e.g. hallucinations)
  • Severe mood swings
  • Unable to communicate
  • Seizures
  • Inability to control bodily functions (e.g. bladder problems, difficulty swallowing)
  • Weight Loss

At this stage, the patient will be unable to function by themselves. Commonly, they pass away from aspiration pneumonia (swallowing food and liquid into their lungs instead of air).

Causes of Alzheimer’s

There is no known cause of AD, but researchers have theorised there is a combination of genetic and environmental factors that exacerbate the ageing process, leading to brain degeneration. [4] Certain factors, including high alcohol consumption, a sedentary lifestyle, poor diet, decreased muscle mass, high blood pressure, type II diabetes, heart disease and atrial fibrillation, raise the risk of developing AD. [5]

Newer research has found that maintaining a healthy lifestyle that protects the brain’s infrastructure can help prevent AD development. This consists of keeping physically active and following a diet low in fat and high in fruits and vegetables. [5]

Treatment for Alzheimer’s

To make an AD diagnosis, doctors may perform brain scans or analyse a patients’ cerebrospinal fluid to investigate for the presence of amyloid deposits. [6] However, with no straightforward cure for AD, treatment focuses on mitigating symptoms. Several drugs, such as galantamine, rivastigmine and donepezil, are prescribed to control mild to moderate symptoms. [6]

The only drug to target underlying causes of AD is Aducanumab, and it aids in reducing amyloid plaques in the brain. [6] Currently, researchers are carrying out clinical trials of drugs targeting amyloid β and tau-proteins in the brain, as they have been associated with cognitive decline. [6]

References:

[1] National Institute of Aging (2021). What is Dementia? Symptoms, Types and Diagnosis. National Institute of Health. https://www.nia.nih.gov/health/what-is-dementia#:~:text=Dementia%20is%20the%20loss%20of,and%20their%20personalities%20may%20change.

[2] American Psychological Association (2022). Alzheimer’s disease. American Psychological Association. https://www.apa.org/topics/alzheimers#:~:text=Alzheimer’s%20disease%20is%20a%20chronic,learn%20and%20remember%20new%20information.

[3] National Institute of Aging (2017). What Are the Signs of Alzheimer’s Disease?. National Institute of Health. https://www.nia.nih.gov/health/what-are-signs-alzheimers-disease

[4] Munoz, D.G. & Feldman H (2000). Causes of Alzheimer’s disease. Canadian Medical Association Journal, 162 (1): 65-72.  https://www.cmaj.ca/content/162/1/65.short

[5] Adams, J. D. (2021). Probable Causes of Alzheimer’s Disease. Sci. 2021; 3(1):16. https://doi.org/10.3390/sci3010016

[6] National Institute of Aging (2021). How is Alzheimer’s Disease Treated?. National Institute of Health. https://www.nia.nih.gov/health/how-alzheimers-disease-treated#:~:text=Aducanumab%20is%20the%20only%20disease,brain%20lesions%20associated%20with%20Alzheimer’s.