- Brain Abnormalities: The hallmark of Alzheimer's disease is the presence of amyloid plaques (abnormal clumps of beta-amyloid protein) and neurofibrillary tangles (twisted strands of tau protein) in the brain. These abnormal proteins are believed to disrupt cell function and lead to widespread brain cell death.
- Genetics: Genetics play a role, particularly in early-onset Alzheimer's (which is rare). Specific genes (e.g., APOE-e4 allele) increase the risk of late-onset Alzheimer's, but inheriting them does not guarantee development of the disease.
- Age: Advancing age is the greatest known risk factor. Most people with Alzheimer's are 65 and older.
- Sex: Women appear to be more likely to develop Alzheimer's than men, possibly because they live longer on average.
- Down Syndrome: Many people with Down syndrome develop Alzheimer's due to having an extra copy of chromosome 21, which carries the gene for amyloid precursor protein.
- Head Trauma: A history of moderate or severe head injury increases the risk.
- Lifestyle and Heart Health: Factors linked to heart disease and stroke, such as high blood pressure, high cholesterol, diabetes, obesity, and smoking, also increase the risk of Alzheimer's.
- Memory Loss: Forgetting recently learned information, important dates or events, asking for the same information repeatedly, increasing reliance on memory aids or family members.
- Challenges in Planning or Solving Problems: Difficulty following a familiar recipe, managing finances, or concentrating.
- Difficulty Completing Familiar Tasks: Trouble driving to a familiar location, managing a budget, or remembering rules of a favorite game.
- Confusion with Time or Place: Losing track of dates, seasons, and the passage of time; difficulty understanding something if it's not happening immediately.
- Trouble Understanding Visual Images and Spatial Relationships: Difficulty reading, judging distance, or determining color or contrast (beyond age-related vision changes).
- New Problems with Words in Speaking or Writing: Difficulty following or joining a conversation, stopping in the middle of a conversation with no idea how to continue, repeating themselves, or struggling to find the right word.
- Misplacing Things and Losing the Ability to Retrace Steps: Putting things in unusual places; accusing others of stealing.
- Decreased or Poor Judgment: Making poor decisions with money or personal hygiene.
- Withdrawal from Work or Social Activities: Losing interest in hobbies, sports, or social engagements.
- Changes in Mood and Personality: Becoming confused, suspicious, depressed, fearful, or anxious, especially when out of their comfort zone.
- Medical History and Physical Exam: The doctor will gather detailed information from the individual and family about cognitive changes, medical history, medications, and lifestyle. A physical and neurological exam is performed.
- Cognitive and Neuropsychological Tests:
- Screening tests: Such as the Mini-Mental State Examination (MMSE) or Montreal Cognitive Assessment (MoCA), assess memory, thinking, and reasoning.
- More extensive neuropsychological testing: Provides a detailed profile of cognitive strengths and weaknesses.
- Brain Imaging:
- MRI (Magnetic Resonance Imaging) or CT scan: To rule out other causes of memory impairment (e.g., stroke, tumors, hydrocephalus, bleeding). They can show brain shrinkage (atrophy) but not definitively diagnose Alzheimer's.
- PET (Positron Emission Tomography) scans: Can detect amyloid plaques (amyloid PET) or tau tangles (tau PET) in the brain, which are characteristic of Alzheimer's. Fludeoxyglucose (FDG-PET) can show patterns of reduced brain metabolism associated with Alzheimer's.
- Cerebrospinal Fluid (CSF) Analysis: Measuring levels of amyloid-beta and tau proteins in CSF obtained via a spinal tap can support an Alzheimer's diagnosis.
- Blood Tests: To rule out other reversible causes of memory loss (e.g., thyroid problems, vitamin B12 deficiency, infections). Newer blood tests for amyloid are emerging to aid diagnosis.
- Medications:
- Cholinesterase Inhibitors: (e.g., donepezil, rivastigmine, galantamine) increase levels of acetylcholine, a neurotransmitter important for memory. They can help with memory, thinking, and behavior for a limited time.
- Memantine: (Namenda) Works differently to improve memory, reasoning, language, and the ability to perform daily activities. Often used in moderate to severe Alzheimer's, sometimes in combination with a cholinesterase inhibitor.
- Lecanemab: (Leqembi) A newer monoclonal antibody approved for early Alzheimer's that targets amyloid plaques, aiming to slow cognitive decline. Requires careful patient selection and monitoring for side effects.
- Medications for Associated Symptoms: Antidepressants for depression, anxiolytics for anxiety, or antipsychotics (used cautiously due to risks) for severe behavioral issues or psychosis.
- Non-Pharmacological Approaches:
- Cognitive Stimulation Therapy (CST): Engaging in activities to stimulate thinking and memory.
- Behavioral Interventions: Strategies to manage behavioral symptoms (e.g., agitation, wandering) by addressing triggers and creating a supportive environment.
- Supportive Environment: Establishing consistent routines, simplifying tasks, ensuring safety, and providing appropriate supervision.
- Lifestyle Management:
- Healthy Diet: A Mediterranean-style diet may support brain health.
- Regular Physical Activity: Can help maintain cognitive function and overall health.
- Cognitive Engagement: Keeping the brain active with puzzles, reading, and learning new skills.
- Social Engagement: Maintaining social connections.
- Sleep Hygiene: Addressing sleep disturbances.
- Caregiver Support: Education, resources, and support groups for family caregivers are vital, as Alzheimer's significantly impacts caregivers.