Types of Dementia
Dementia is not a single disease. It is a group of symptoms, chiefly impairment of memory, judgment, motor skills and the general functions related to logic and thought, that can be caused by a variety of diseases.
These symptoms occur when brain cells (neurons) die or are damaged, and there are many ways that damage can happen. Because different conditions damage different parts of the brain, dementia’s effects and progression vary widely. Some dementias progress slowly and may take years to show symptoms; others cause a rapid functional decline.
This page introduces the six forms of dementia that Silverado’s resource pages cover in depth, with a short answer to the questions families ask most: what it is, how it tends to show up, and how it is diagnosed. Each section links to the full page.
What are the most common types of dementia?
Silverado’s resource pages cover six forms. Alzheimer’s disease is the most common form of dementia encountered in the world today, and Lewy body dementia is the second most prevalent.
- Alzheimer’s diseaseProgressive; interrupts thinking, memory and behavior. Symptoms begin gradually and worsen over time.
- Vascular dementiaCaused by inadequate blood flow to the brain. Can start suddenly after a stroke or build gradually.
- Lewy body dementiaAlzheimer’s-like cognitive symptoms with Parkinson’s-like motor issues. Hallmark: vivid visual hallucinations.
- Frontotemporal dementiaShrinkage in the frontal and temporal lobes of the brain. Usually presents as an early-onset dementia, with first symptoms between the ages of 55 and 65.
- Parkinson’s disease dementiaMovement symptoms come first; cognitive changes in attention, executive function and visuospatial abilities develop at least a year later.
- Chronic traumatic encephalopathyBelieved to follow repetitive brain trauma. Behavior and mood changes prominent initially; confirmatory diagnosis can be made only after death.
Alzheimer’s disease
Alzheimer’s disease is a progressive disorder that interrupts normal thinking, memory and behavior patterns. Symptoms begin gradually and worsen over time, and their severity varies among those affected. There is no cure, only treatments that help alleviate certain symptoms, alongside a growing field of prevention and management options aimed at delaying the onset and progression of cognitive symptoms.
What is happening in the brain
Researchers have found a connection between abnormal structures in the brain, plaques (deposits of a protein fragment called beta-amyloid between nerve cells) and tangles (twisted fibers of a protein called tau inside brain cells), and the cell damage that leads to Alzheimer’s symptoms. Plaques and tangles also form in normal aging, but the brains of people with Alzheimer’s show far higher levels.
How it shows up
Memory lapses that disrupt daily life, problem-solving and planning difficulties, trouble with familiar tasks, confusion about time and place, new problems with words, misplacing things, poor judgment, withdrawal from work or social activities, and changes in mood and personality. Several of these together warrant a complete examination by a physician.
Read more: Alzheimer’s Disease · Causes · Signs & Symptoms · Stages · Testing · Management
Vascular dementia
Vascular dementia is a decline in cognitive skills caused by inadequate blood flow to the brain, which deprives brain cells of oxygen and nutrients and kills small but vital areas. It is also known as multi-infarct dementia. Pure multi-infarct dementia is now known to be quite rare; vascular disease often co-exists in the brain with the plaques and tangles of Alzheimer’s disease.
How it shows up
After a stroke or blood-vessel blockage, changes can be almost instant, such as confusion, disorientation, trouble speaking or understanding speech, and loss of vision. A series of minor strokes or small-vessel problems produces subtler changes that appear as damage accumulates: diminished planning and judgment, declining focus or abstract thinking, impaired social abilities, apathy and vocabulary difficulties.
How it is diagnosed, and what is different
Mental status testing is recommended for people with high risk factors such as a previous stroke or TIA, high blood pressure, high cholesterol, circulatory disease, a history of smoking, or diabetes, followed by imaging and lab tests as indicated. Unlike other dementias, vascular dementia can be somewhat avoidable: regular exercise, treating hypertension and hyperlipidemia, not smoking and avoiding diabetes reduce the risk.
Read more: Vascular Dementia
Lewy body dementia
Lewy body dementia (LBD) combines Alzheimer’s-like cognitive symptoms with Parkinson’s-like motor issues. It is a neurodegenerative disease named for the abnormal protein deposits, Lewy body inclusions, discovered by neurologist Dr. Frederic Lewy; these are present in both Parkinson’s disease and LBD. The term covers both dementia with Lewy bodies and Parkinson’s disease dementia, which are pathologically similar.
How it shows up
The hallmark is vivid visual hallucinations. Other core features are changes in thinking and reasoning often with memory loss; a shuffling gait, hunched posture, balance problems and rigid muscles; wide fluctuations between confusion and alertness from day to day or within a day; problems processing visual information; REM sleep disorders, sometimes acting out dreams; and failures of the autonomic nervous system.
Why the diagnosis matters
LBD is often underdiagnosed. It is common for someone to be diagnosed with Parkinson’s disease first, with treatment then revealing greater cognitive deficits and hallucinations that lead to a later, more accurate LBD diagnosis. People with LBD can have severe reactions to certain medications, so symptomatic treatment is prescribed with special care.
Read more: Lewy Body Dementia
Frontotemporal dementia
Frontotemporal dementia (FTD) is a neurodegenerative disease that causes tissue shrinkage and reduced function in the brain’s frontal and temporal lobes, the areas responsible for attention, planning and motivation, and for visual memories, sensory processing, language, recent memories, emotions and meaning. It is often responsible for early-onset dementia, generally showing first symptoms between the ages of 55 and 65, and appears to affect men and women at equal rates.
How it shows up
FTD has three main forms. Behavioral variant FTD mainly affects personality and behavior and is often mistaken for depression before developing into a lack of inhibition. Primary progressive aphasia affects language first, either as limited word choice and meaning (semantic dementia) or as faltering, effortful speech (progressive nonfluent aphasia). FTD movement disorders (corticobasal degeneration and progressive supranuclear palsy) affect involuntary muscle function, coordination, balance and eye movement.
How it is diagnosed
No test conclusively diagnoses FTD. MRI and PET imaging can show shrinkage in the frontal and temporal lobes, but FTD is a clinical diagnosis made from a doctor’s judgment of the evidence at hand.
Read more: Frontotemporal Dementia · Understanding Frontotemporal Dementia: Lessons from Bruce Willis’ Journey
Parkinson’s disease dementia
Parkinson’s disease affects the nerve cells that produce dopamine, a neurotransmitter nerve cells use to signal one another. Insufficient dopamine leads to muscle rigidity, tremors and changes in speech and gait that increase as the disease progresses.
With progression of Parkinson’s disease, dementia can develop. Roughly 75–80% of people living with Parkinson’s disease for 10 or more years develop dementia.
How it shows up
In Parkinson’s disease, early motor symptoms include a unilateral resting “pill rolling” type of tremor of the hand, slow movement, rigidity and difficulty with fine motor tasks. Later signs include slowed voluntary movement, diminished facial expression, a quiet voice, a shuffling “Parkinson’s gait” with stooped posture, poor balance, and swallowing and digestive problems in later stages.
If one develops dementia more than 1 year after the motor symptoms of Parkinson’s disease, it is considered Parkinson’s disease dementia (PDD). Cognitive symptoms of PDD are typically executive dysfunction, slow thinking, visuospatial impairment and attention deficits with fluctuations.
Treatment and management
While there is currently no cure for Parkinson’s disease, there are a number of medications that can relieve symptoms. Most pharmaceutical treatments for Parkinson’s work to increase and stabilize dopamine in the brain. Physical exercise and regular activity are also a vital component of treatment, as are physical, speech and occupational therapies.
In Parkinson’s disease dementia, treatment focuses on improving thinking, preventing psychosis and maintaining function.
Who it affects
Parkinson’s disease is far more common after age 50, though it can affect younger people. Men are more likely to develop Parkinson’s disease than women.
Read more: Parkinson’s Disease
Chronic traumatic encephalopathy (CTE)
CTE is a progressive degenerative disease believed to be related to repetitive brain trauma such as concussions and other head injuries. It is often observed in athletes in football, ice hockey, boxing and professional wrestling, and in soldiers who have suffered blast injuries. Clinical diagnostic criteria are being developed as confirmatory diagnosis can only be made after death currently.
How it shows up
The core features are cognitive impairment and neurobehavioral dysregulation (difficulty in controlling one’s emotions, reactions and behavior). Mood is often affected. A history of substantial repetition of multiple head impacts is required. Symptoms may appear years, even decades, after injuries. CTE has a progressive course.
Read more: Chronic Traumatic Encephalopathy
How the types differ
| Type | Usually starts with | What sets it apart |
|---|---|---|
| Alzheimer’s | Gradual memory and thinking changes | Plaques and tangles in the brain; the most common form |
| Vascular | Sudden change after a stroke, or gradual build-up | Caused by reduced blood flow; the one form where lifestyle and blood-pressure control reduce risk |
| Lewy body | Hallucinations and fluctuating alertness | Parkinson’s-like movement problems alongside thinking changes; medication sensitivity |
| Frontotemporal | Behavior, personality or language change | Often younger onset, first symptoms between 55 and 65 |
| Parkinson’s disease | Movement symptoms | Cognitive changes in attention, executive function and visuospatial abilities develop at least a year later |
| CTE | Behavior and mood changes, years after injury | Follows repeated head trauma; confirmatory diagnosis only after death |
Frequently asked questions
Is dementia a disease?
No. Dementia is a group of symptoms that can be caused by a variety of diseases, even though it is sometimes mistakenly referred to as a disease in itself.
What is the most common type of dementia?
Alzheimer’s disease is the most common form of dementia encountered in the world today. Lewy body dementia is the second most prevalent.
Which type of dementia is linked to strokes?
Vascular dementia, also called multi-infarct dementia, results from inadequate blood flow to the brain. A stroke or blood-vessel blockage can cause almost immediate changes, and a series of minor strokes can cause gradual ones.
Which type of dementia affects younger people?
Frontotemporal dementia is often responsible for early-onset cases, generally showing first symptoms between ages 55 and 65 and sometimes affecting people in their 40s and 50s.
Can more than one type be present at once?
Yes. Vascular disease often co-exists in the brain with the plaques and tangles of Alzheimer’s disease.
How do I know if it is time to seek help?
If a loved one shows several of the common warning signs, such as memory lapses that disrupt daily life, trouble with familiar tasks, confusion about time and place, or changes in mood and personality, it may be time to get support, and a physician should perform a complete examination. Silverado’s dementia care specialists are available as a resource.
Talk with a dementia care specialist
If your loved one is showing several warning signs, you can use Silverado as a resource. Our dementia care specialists can talk through what you are seeing and what the next step might be.
Explore each type
Alzheimer's Disease
The sixth leading cause of death domestically, Alzheimer's affects more than 5 million individuals in the United States alone.
Chronic Traumatic Encephalopathy
A form of dementia connected with repetitive head traumas and concussions.
Frontotemporal Dementia
Frontotemporal dementia is often responsible for early-onset dementia cases.
Parkinson's Disease
Symptoms such as muscle rigidity, tremors and changes in speech and gait are common.
Vascular Dementia
Causes a decline in cognitive skills due to brain cell damage due to circulatory problems.
Lewy Body Dementia
A common form of dementia combining Alzheimer's-like cognitive symptoms and Parkinson's-like motor issues.
