Dementia

Why Do We Grow Older?

  • Genetic Clock

    • Limited number of times a cell can divide.

    • Hayflick Limit: Refers to the maximum number of times a normal somatic mammalian cells can divide before cell division stops.

    • Telomeres:

    • Caps at the ends of chromosomes.

    • They get clipped a little bit every time the cell divides.

  • Senescence and Primary Aging

    • Processes of biological aging characterized by a gradual decline in physiological function.

  • Wear and Tear Theory:

    • Suggested that aging occurs due to accumulated damage over time from use.

    • Use It or Lose It:

    • Vital to maintain brain health through activity.

    • Involves various factors such as habits, illness, injury, and pollutants leading to cell death and secondary aging.

  • Effects on Brain Development:

    • Built-in aging processes vs. plasticity.

    • Level of activity has significant impacts.

    • Exercise:

    • Known to release Brain-Derived Neurotrophic Factor (BDNF), which plays a crucial role in maintaining and supporting neuronal plasticity.

    • Avoiding Disease: Importance of a healthy lifestyle for prevention.

Alzheimer's Disease

A. Characteristics

  1. Memory Loss:

    • Recognition troubles (agnosias): difficulty in recognizing familiar faces or objects.

    • Loss of ability to remember new information.

  2. Judgment and Planning Suffers:

    • Challenges in reasoning and abstract thought.

  3. Mood Swings and Confusion:

    • Symptoms include wandering behavior and sundowning (confusion or agitation that occurs in the late afternoon and evening).

  4. Paranoia, Hallucinations, Delusions:

    • Increased social withdrawal and alterations in behavior.

  5. Difficulty Learning:

    • This includes deficits in language (aphasias) and poor impulse control.

  6. Physical Decline:

    • Occurs particularly in the middle and late stages of the disease.

B. Prevalence, Onset, and Progression

  1. Onset:

    • Typically begins in mid to late 60s.

    • Early onset Alzheimer's can occur before the age of 65.

  2. Progression:

    • Average duration of 3-5 years, but can range from 10 to 20 years depending on various factors.

  3. Demographics:

    • Women account for 2/3 of cases.

  4. 2024 Prevalence Estimates:

    • Estimated 7 million patients in the U.S. aged 65 and older.

    • Prevalence rates:

    • Overall: 10.9%

    • Ages 75-84: 13.8%

    • Ages 85 and above: 34.6%.

C. Diagnosis

  1. Autopsy

    • Plaques and tangles are key indicators:

    • Plaques: Consist of beta-amyloid protein.

    • Tangles: Composed of tau protein, causing a mixed-up appearance of brain cells.

  2. Mental Status Exam:

    • Approximately 80% accurate for diagnosing Alzheimer's.

  3. APOE-4:

    • Protein associated with an increased risk of developing dementia.

  4. Spinal Fluid and Eye Exams:

    • These may provide new avenues for diagnostic testing.

  5. PET and MRI Scans:

    • Used to observe changes in brain mass and overall structure.

  6. Blood Test:

    • Utilizes biomarkers and family history to assist in diagnosis.

Causes

  1. Diseased Brain:

    • Key characteristic features:

    • Beta-Amyloid Plaque and Neurofibrillary Tangles.

    • Affected areas often include the hippocampus crucial for memory.

    • Acetylcholine levels drop significantly in dementia (90% drop in concentration).

    • Reduction of connections (40% drop in number).

    • Down Syndrome patients have a 2-3x increased risk.

  2. Genetic Factors:

    • Risk increases with age; earlier onset correlates with hereditary factors.

    • Known gene mutations that confer risk include APP, PS1, PS2.

  3. Other Risk Factors:

    • Possible connections to aluminum exposure.

    • Previous head trauma, heart disease, high cholesterol, and pollution exposure may increase risk.

    • Other factors include sleep quality, level of activity, education level, social interaction, and personality traits.

E. Prevention and Treatment

  1. Current Status:

    • No known cures exist.

  2. Medication Options:

    • Ibuprofen, estrogen therapy, and vitamin E may provide some benefits.

  3. Mental Fitness:

    • Engaging in cognitive exercises is critical for cognitive health.

  4. Lifestyle Modifications:

    • Emphasizes the importance of diet, exercise, and adequate sleep.

  5. Assisted Living:

    • Therapeutic practices to support patients, including validation theory approaches.

  6. Validation Theory:

    • Incorporates therapeutic fibbing to support patients emotionally and mentally, providing comfort as they deal with cognitive decline.