Overview
This lecture provides an in-depth overview of Alzheimer's disease, covering its pathophysiology, stages, symptoms, risk factors, diagnosis, nursing roles, and treatments.
Introduction to Alzheimer's Disease
- Alzheimer's disease is the most common type of dementia and is a chronic, progressive brain disorder.
- It occurs when neurons in the brain lose the ability to communicate and eventually die.
- Beta-amyloid plaques (outside neurons) and neurofibrillary tangles (inside neurons, made of tau protein) are key pathological features.
- Brain atrophy (shrinkage) occurs in late-stage disease.
Epidemiology & Risk Factors
- Fifth leading cause of death in adults 65+ in the US.
- Higher prevalence in women, Hispanics, and African Americans.
- Risk factors: age, family history, female gender, smoking, diabetes, heart disease.
Pathophysiology
- Neurons communicate via neurotransmitters (notably acetylcholine and glutamate).
- Beta-amyloid plaques disrupt neuron communication and trigger inflammation, causing neuron death.
- Tau protein malfunction leads to neurofibrillary tangles, disrupting neuron structure and nutrient transport.
Brain Regions & Symptoms
- Early damage affects the hippocampus (memory, learning), entorhinal cortex (time, memory, direction), and amygdala (emotions).
- Progression impacts the cerebral cortex including the frontal, parietal, temporal, and occipital lobes, leading to diverse symptoms.
- Key symptoms: memory loss (amnesia), inability to perform tasks (apraxia), speech/language deficits (aphasia), inability to recognize objects (agnosia), inability to recall names (anomia).
Stages of Alzheimer's Disease
- Pre-clinical: brain changes, no symptoms.
- Mild Cognitive Impairment: subtle memory changes, no impact on daily life.
- Mild (Early): noticeable forgetfulness, short-term memory loss, minor functional impairment.
- Moderate (Middle): significant confusion, impaired judgment, wandering, safety issues, need for supervision.
- Severe (Late): severe cognitive/motor deficits, minimal communication, complete care dependence, swallowing difficulties.
Diagnostic Methods
- No single definitive test; diagnosis is based on history, exams, and ruling out other causes.
- Cognitive assessments, MRI/CT, amyloid PET scan, CSF analysis, and new blood tests for beta-amyloid.
- Genetic testing (APOE) more for research.
Nursing Interventions (Seven M's)
- Memory: frequent reorientation, use visual aids, patience, simple tasks.
- Movement: promote independence, daily routines, regular exercise.
- Mental health: manage mood swings, avoid rushing, maintain routines, address sundowner syndrome.
- Maintain safety: prevent wandering, remove hazards, use identification devices.
- Maximize communication: use simple, clear, step-by-step instructions; non-verbal cues; direct interaction.
- Medical needs: support hygiene, continence, skin integrity, appropriate clothing.
- Medications and nutrition: monitor hydration, weight, swallowing; serve easy-to-eat foods; adjust food consistency as needed.
Pharmacological Treatments
- Cholinesterase inhibitors (Donepezil, Rivastigmine, Galantamine): increase acetylcholine, side effects include GI upset and bradycardia.
- NMDA antagonist (Memantine): moderates glutamate activity for moderate to severe cases, side effects include headache and constipation.
- Aducanumab: IV medication to decrease beta-amyloid plaques; monitor for brain swelling/bleeding.
Key Terms & Definitions
- Beta-amyloid plaques — Protein accumulations outside neurons, disrupt communication.
- Neurofibrillary tangles — Tau protein clumps within neurons that disrupt structure.
- Hippocampus — Brain area for memory and learning.
- Apraxia — Inability to perform purposeful movements.
- Aphasia — Loss of speech comprehension or production.
- Agnosia — Inability to recognize objects/people.
- Amnesia — Memory loss.
- Anomia — Inability to recall object names.
- Sundowner syndrome — Increased confusion/agitation in the evening.
Action Items / Next Steps
- Review signs, symptoms, and staging of Alzheimer's for exams.
- Complete the associated quiz on this content.
- Study medication mechanisms and side effects.
- Practice distinguishing symptom terms (apraxia, aphasia, etc.).
- Prepare to educate caregivers using the seven M's approach.