Types of Dementia and Their Characteristics

Understanding the various forms of dementia helps patients and families better prepare for the journey ahead and seek appropriate support and resources. Here, we provide a comprehensive guide to the main types of dementia affecting people in the UK and their key characteristics.

Alzheimer’s Disease

Alzheimer’s disease is the most common form of dementia, accounting for roughly 60-80% of cases. This progressive neurological disorder gradually destroys brain cells, leading to decline in thinking skills, behavioural changes, and eventually, loss of ability to carry out simple and every-day tasks.

Key characteristics:

• Caused by amyloid plaques and tau tangles in the brain
• Typically begins with memory loss and confusion
• Progresses to affect language, reasoning, and daily functioning
• Usually affects people over 65, but early-onset can occur from age 40

The first signs usually involve minor memory problems like forgetting names of places and objects or recent events. As Alzheimer’s progresses, individuals may experience confusion, disorientation, difficulty planning or making decisions, as well as problems with speech and language. Personality changes, such as aggression, demanding behaviours, or paranoia can occur, as well as hallucinations.

Although there’s currently no cure for Alzheimer’s disease, medications and psychological treatments can relieve common symptoms related to memory function and problem-solving skills and language use.

Vascular Dementia

Vascular dementia is caused by reduced blood flow to the brain, often after a stroke or series of mini-strokes. It’s the second most common type of dementia after Alzheimer’s. People may experience confusion, trouble focusing, or memory problems that appear suddenly or get worse in steps

Key features:

• Symptoms may appear suddenly following a stroke or develop gradually
• Characterised by problems with planning, decision-making and thinking speed
• Often co-occurs with Alzheimer’s disease as mixed dementia

Common risk factors include smoking, being overweight, high blood pressure and diabetes, with symptoms including slowness of thought, difficulty planning and understanding, problems with concentration, mood changes, difficulty walking and keeping balance, and confusion.

There’s no cure, but treatment can sometimes slow progression. Keeping your heart healthy is crucial – eat well, maintain healthy weight, stop smoking, exercise regularly, reduce alcohol and take prescribed medications.

Lewy Body Dementia

Lewy body dementia (LBD) is caused by abnormal deposits of the alpha-synuclein protein (Lewy bodies) forming inside brain cells. These protein deposits interfere with normal brain function and communication between cells.

Distinctive features include:

• Visual hallucinations and fluctuating alertness
• Movement problems similar to Parkinson’s disease
• Sleep disturbances and acting out dreams
• May respond differently to medications than other dementia types

People with LBD often experience periods of alertness that fluctuate dramatically throughout the day. They may seem fully engaged one moment and confused the next. Movement can be slow and stiff with tremors, and many experience vivid dreams they physically act out during sleep.

Frontotemporal Dementia

Frontotemporal dementia affects the frontal and temporal lobes of the brain affecting personality, language and behaviour, and often begins at a younger age (45-65).

Characteristics include:

• Primarily affects behaviour, personality and language
• Memory may remain relatively intact in early stages
• Several variants exist, including behavioural variant and primary progressive aphasia

This type can be particularly challenging as personality changes may be dramatic – someone previously considerate might become inappropriate or lose empathy.

Mixed Dementia

Mixed dementia involves a combination of two or more types of dementia occurring simultaneously. Most commonly, this involves Alzheimer’s disease with vascular dementia, affecting around 10% of people with dementia.

Important points:

• Symptoms reflect the brain regions affected by each type
• Becomes more common with advancing age
• May require complex management approaches

Less Common Types of Dementia

Parkinson’s Disease Dementia

• Develops in people with established Parkinson’s disease
• Typically occurs at least a year after movement symptoms begin
• Affects thinking, reasoning and memory
• Visual hallucinations and sleep disturbances are common

Creutzfeldt-Jakob Disease

• Rare, rapidly progressing form of dementia
• Caused by abnormal prion proteins in the brain
• Symptoms progress quickly over months rather than years
• May include muscle stiffness, twitches and coordination problems
• No effective treatments currently available

Huntington’s Disease

• Inherited genetic condition causing dementia symptoms
• Usually appears between ages 30 and 50
• Causes movement disorders alongside cognitive decline
• Can be identified through genetic testing

Normal Pressure Hydrocephalus

• Caused by buildup of cerebrospinal fluid in the brain
• Presents with walking difficulties, urinary incontinence and dementia
• One of the few potentially reversible causes of dementia
• May be treated with surgical shunt placement

Wernicke-Korsakoff Syndrome

• Primarily caused by severe thiamine (vitamin B1) deficiency
• Often associated with chronic alcohol misuse
• Characterised by confusion and gaps in memory
• May improve with thiamine supplementation if caught early
• Preventable with proper nutrition and reduced alcohol consumption

Getting Help and Support

Whatever type of dementia is affecting your loved one, support is available throughout the UK. Early diagnosis is crucial for accessing treatments and planning for the future.

Key resources:

• Alzheimer’s Society – Information and local support services
• Dementia UK – Admiral Nurses provide specialist support
• NHS Dementia Guide – Comprehensive medical information
• British Heart Foundation – Vascular dementia resources
• The Lewy Body Society – Specialist LBD support
• Rare Dementia Support – For frontotemporal and other rare types
• Age UK – Practical support and advice