Alzheimer’s Disease

What is Alzheimer’s Disease? Alzheimer’s disease is a neurodegenerative disorder that destroys memory and other important mental functions. It is a leading cause of dementia worldwide. It affects approximately 6.5 million Americans over 65, and the incidence is projected to increase to 13.8 million by 2060.

Signs and Symptoms of Alzheimer’s Disease

Common Symptoms of Alzheimer’s Disease Include:

  • Impairment in short-term memory
  • Difficulties in word finding
  • Disorientation and getting lost in familiar places
  • Trouble with performing everyday tasks like handling money. 
  • Poor judgment
  • Changes in mood or behavior, such as depression or agitation 

As the disease progresses, these may worsen. More severe symptoms may also manifest, such as problems recognizing family and friends, hallucinations, delusions, paranoia, inability to communicate, anorexia, loss of bowel and bladder control, and seizures.


What Causes Alzheimer’s Disease?

The pathophysiology of Alzheimer’s disease involves damage and death of neurons in the brain. It is characterized by the accumulation of insoluble proteins, such as extracellular plaques of beta-amyloid and intracellular neurofibrillary tangles composed of tau proteins, that interfere with the normal functioning of the cells.

The high level of these abnormal proteins in the brain of those diagnosed with Alzheimer’s is thought to be influenced by several factors and has been observed to spread from the initial site to healthy parts of the brain. This further increase contributes to the progression of the disease and its symptoms.


Risk factors include:

  • Increasing age
  • Genetics- the presence of APOE e4 allele and family history of Alzheimer’s disease. Mutations in genes associated with the amyloid beta protein, such as amyloid beta precursor protein (APP), presenilin 1 (PSEN1), and presenilin 2 (PSEN2), are associated with early-onset Alzheimer’s disease.
  • Increased homocysteine levels
  • Trisomy 21
  • History of traumatic brain injury
  • Depression
  • Cardiovascular and cerebrovascular disease
  • Smoking
  • Family History of dementia

Source: Scheltens, P., De Strooper, B., Kivipelto, M., Holstege, H., Chételat, G., Teunissen, C. E., Cummings, J. L., & Van Der Flier, W. M. (2021). Alzheimer’s disease. The Lancet, 397(10284), 1577–1590.