Dementia and Alzheimer's Disease Basics
Key Takeaways
- Dementia is an umbrella term for a group of symptoms affecting memory, thinking, and function; Alzheimer's disease is one specific disease under that umbrella
- Alzheimer's disease is progressive and irreversible, moving through early (mild), middle (moderate), and late (severe) stages with increasing dependence
- Delirium has a sudden onset and is a medical emergency that must be reported to the nurse immediately; dementia develops gradually over months to years
- Infections, dehydration, and medication side effects can cause reversible cognitive changes that mimic dementia and must be reported
- Person-centered care focuses on the resident's remaining abilities, not the losses caused by the disease
Dementia: An Umbrella Term, Not a Single Disease
Dementia is not one disease. It is an umbrella term — a general label for a group of symptoms severe enough to interfere with daily life, including memory loss, impaired judgment, language problems, and changes in behavior and personality. Think of it the way you would the word "cancer": many different diseases live underneath it.
Key facts the exam expects you to know:
- Dementia is not a normal part of aging. Occasional forgetfulness is normal; dementia is a disease process that damages brain cells.
- Most dementias are progressive (symptoms worsen over time) and irreversible (lost function does not come back).
- Dementia affects more than memory — it impairs reasoning, communication, recognition of people and objects, and the ability to perform activities of daily living (ADLs).
Alzheimer's Disease: The Most Common Dementia
Alzheimer's disease is the most common cause of dementia, accounting for the majority of cases. It is a progressive, fatal brain disease in which abnormal protein deposits (plaques and tangles) destroy nerve cells. There is currently no cure; medications may slow symptoms in some people but do not stop the disease.
Progression Through Three Stages
| Stage | Also Called | Typical Characteristics | Care Focus |
|---|---|---|---|
| Early | Mild | Forgetfulness of recent events, misplacing items, trouble with names and words, poor judgment, personality changes; may still live fairly independently | Reminders, calendars, routine, support independence |
| Middle | Moderate | Increased memory loss and confusion, may not recognize family, wandering, sleep problems, repetitive statements, delusions or accusations, needs help with ADLs such as bathing and dressing | Supervision, safety measures, calm communication, assistance with personal care |
| Late | Severe | Little or no meaningful speech, cannot recognize family, total dependence for all ADLs, difficulty swallowing, incontinence, may become bedridden; vulnerable to infection, especially pneumonia | Total care, comfort measures, skin care, safe feeding, dignity |
A classic exam point: short-term (recent) memory is lost first, while long-ago memories are often preserved until late in the disease. A resident may not remember lunch but can describe their wedding day in detail.
Other Types of Dementia
- Vascular dementia — caused by reduced blood flow to the brain, often after a stroke or series of small strokes. Symptoms may worsen in noticeable steps rather than a smooth decline.
- Lewy body dementia — abnormal protein deposits (Lewy bodies) in the brain. Hallmark features include visual hallucinations, movement problems similar to Parkinson's disease (stiffness, shuffling gait), and fluctuations in alertness.
- Frontotemporal dementia — affects the front and side lobes of the brain. Prominent early changes in personality, behavior, and language rather than memory; often begins at a younger age than Alzheimer's.
You do not need to diagnose these. You need to recognize that behavior changes have a physical cause in the brain — the resident is not being difficult on purpose.
Delirium vs. Dementia: Know the Difference Cold
This is one of the most tested distinctions in the Care Impaired domain.
| Feature | Delirium | Dementia |
|---|---|---|
| Onset | Sudden (hours to days) | Gradual (months to years) |
| Cause | Acute illness: infection, dehydration, medication reaction, low blood sugar | Progressive brain disease |
| Consciousness/alertness | Fluctuates; may be hyper-alert or drowsy | Usually normal until late stages |
| Reversibility | Often reversible if the cause is treated | Usually irreversible |
| Significance | Medical emergency — report immediately | Chronic condition managed over time |
Any sudden change in a resident's mental status — new confusion, agitation, hallucinations, or drowsiness appearing over hours or days — must be reported to the nurse right away. Untreated delirium can signal a life-threatening problem such as sepsis.
Depression vs. Dementia
Depression in older adults can look like dementia: poor concentration, apathy, slowness, withdrawal. Key differences: depression often has a more recent, identifiable onset, the person is usually aware of and distressed by their memory problems (whereas a person with dementia may be unaware or unconcerned), and depression is treatable. Report signs of depression — sadness, tearfulness, loss of interest, statements about worthlessness or death — to the nurse.
Reversible Causes of Cognitive Change
Never assume new confusion is "just dementia." Report it. Reversible causes include:
- Infection — especially urinary tract infections (UTIs) and pneumonia, which classically cause sudden confusion in older adults
- Dehydration and electrolyte imbalances
- Medication side effects or interactions — older adults process drugs more slowly
- Poor nutrition, low blood sugar, low oxygen, pain, constipation, and even sensory problems such as uncorrected hearing or vision loss
Person-Centered Care and Remaining Abilities
Person-centered care means seeing the person first and the disease second. Practical application for the aide:
- Focus on what the resident can still do, and let them do it — even slowly. Doing everything for a resident accelerates loss of function.
- Learn the person's life history, preferences, routines, and former occupation, and use them to guide care.
- Break tasks into small steps and offer simple choices ("blue shirt or red shirt?") rather than open-ended questions.
- Never talk about the resident as if they are not there, and never label behaviors as "bad" — behaviors are communication of an unmet need.
Care that protects dignity and supports remaining abilities is the standard the Montana knowledge exam expects you to apply throughout the Care Impaired questions.
A resident who was alert and oriented yesterday is suddenly confused, restless, and seeing things that are not there this morning. What should the nurse aide do first?
A resident with Alzheimer's disease can recall events from 40 years ago but cannot remember what she ate for breakfast. This pattern is best explained by which fact about Alzheimer's disease?
Which statement about dementia is correct?