Lewy body dementia assessment (Dementia with Lewy bodies assessment)
An assessment to find out whether symptoms such as fluctuating alertness, visual hallucinations and movement problems are caused by dementia with Lewy bodies, a type with an important medication safety warning.
✓ Medically reviewed by a GMC-registered consultant · last reviewed September 2026 · next review September 2027 · how we review
In short
- Dementia with Lewy bodies often causes fluctuating alertness, visual hallucinations, movement problems and acting out dreams — memory may be relatively preserved at first.
- Getting the diagnosis right matters for safety: people with DLB can have severe reactions to antipsychotic medicines, so these must be used with great caution and specialist oversight.
- There is no cure, but some symptoms may be eased; a special scan (DaTscan) is sometimes used to help confirm it.
- DLB is closely related to Parkinson's disease, and assessment may involve a neurologist as well as old age psychiatry.
A plain-English summary. The detail — including risks and recovery — is below.
At a glance
A general guide. Your psychiatrist will give you advice for your situation.
Clarifies whether DLB is behind fluctuating alertness, hallucinations and movement problems
Sudden confusion over hours or days — this points to delirium from illness and needs urgent medical assessment, not a routine clinic.
You may feel tired after testing, and your scores may reflect how alert you were that day. A first impression may be shared, but a full answer often...
A clear, compassionate explanation of the diagnosis, with the antipsychotic safety warning given prominently and in writing.
You may feel tired after testing, and your scores may reflect how alert you were that day. A first impression may...
Results are reviewed together and a diagnosis is usually given, with a letter to your GP that should clearly flag...
Careful treatment may be started for some symptoms, falls risk is addressed, and any medicines that could worsen...
The team and family watch how symptoms change, including alertness, hallucinations and movement. Support is...
What is a Lewy body dementia assessment?
Dementia with Lewy bodies (DLB) is one of the more common types of dementia. It is caused by tiny clumps of a protein, called Lewy bodies, building up in brain cells. It is closely related to Parkinson's disease.
Its pattern can be different from Alzheimer's disease. People may have alertness that comes and goes — sharp at some times, very confused or drowsy at others — together with detailed visual hallucinations (seeing things that are not there), movement problems like those of Parkinson's, and acting out dreams in sleep. Falls are more common. Memory may be relatively preserved at first.
Assessment means finding out whether DLB is the cause. A memory clinic team builds a picture from your history, an account from someone who knows you well, tests of thinking, blood tests, and a brain scan. A special scan called a DaTscan is sometimes used, as it can help show the changes linked to Lewy body disease.
There is one safety point that makes getting this diagnosis right especially important: people with DLB can react very badly to antipsychotic medicines that are usually given for hallucinations or agitation. These can cause severe stiffness, worsening confusion and serious harm. Knowing the diagnosis helps everyone avoid this danger.
Types, options & approaches
There may be different ways to do this. The right approach depends on the clinical question and your circumstances.
Options at a glance
These are the main approaches described in this guide. The right option depends on the diagnosis, your goals and what your clinician thinks is safe.
History and collateral history
Central to the diagnosis. An account from someone close — about fluctuating alertness, hallucinations, movement changes, falls and acting out dreams — is essential, as these...
Cognitive (pen-and-paper) tests
Tests of thinking that look at attention, visual and spatial skills and alertness, which are often affected in DLB. Because alertness fluctuates, scores can vary from day to...
Movement and physical check
The clinician looks for Parkinson's-like features such as stiffness, slowness or tremor, and assesses falls risk. Blood tests look for treatable causes that can add to...
Brain scan and DaTscan
A CT or MRI scan helps rule out other causes. A DaTscan — a special scan of brain chemistry — is sometimes used because it can support a diagnosis of Lewy body disease when...
Preparing for your test
- Bring someone who knows you well; their account of fluctuating alertness, hallucinations, movements, falls and sleep is essential.
- Note whether alertness or confusion comes and goes, and keep examples of any hallucinations or movement changes.
- Mention any acting out of dreams during sleep, and any falls.
- Bring a full list of your medicines; tell the team about any bad reaction to medicines, especially antipsychotics or some anti-sickness drugs.
- Bring glasses and hearing aids and use them during testing.
- Write down your questions and any medical words used, so you can look them up later.
- If a scan is planned, mention any pacemaker, metal implants, or difficulty with enclosed spaces.
What happens
At the assessment, the clinician talks with you and, importantly, the person who came with you, about your thinking, alertness, any hallucinations, movement and sleep, and your physical health. Because key features like fluctuating alertness and acting out dreams may not be obvious to the person, this account is central.
You will do tests of thinking, with particular attention to attention, alertness and visual and spatial skills. The clinician will check for Parkinson's-like movement changes and assess your risk of falls. Most people have blood tests and a brain scan, and a DaTscan may be arranged to help confirm Lewy body disease if the picture is unclear.
Because DLB is closely related to Parkinson's disease, a neurologist may be involved. A clear answer can take time, and the diagnosis may become clearer as symptoms develop.
If DLB is diagnosed, the team explains what this means, including the important warning about antipsychotic medicines. Some symptoms may be eased with careful treatment, and support, falls prevention and planning are arranged.
Is this test right for me?
A good consultation should explore whether it's the right choice for you now — including reasons to wait or consider something else.
May not be suitable if…
- Sudden confusion over hours or days — this points to delirium from illness and needs urgent medical assessment, not a routine clinic.
- Someone acutely unwell or having frequent falls with injury — the immediate problem needs addressing first.
- Where the picture clearly fits established Parkinson's disease, the right route may be a Parkinson's or neurology service.
- Starting an antipsychotic in primary care when DLB is suspected — this should be avoided because of the risk of a severe reaction.
Delay or rearrange if…
- There is a current infection, delirium or other acute illness affecting alertness.
- The person is in crisis or too distressed by hallucinations to take part safely.
- Key information is missing — without a collateral history, the fluctuating features are hard to assess.
- A medicine that could be worsening symptoms needs reviewing first.
- Eyesight or hearing problems would make test scores unreliable until corrected.
Alternatives to discuss
- Neurology or a Parkinson's service where movement problems predominate.
- Treatment of reversible causes such as delirium, low mood or medication effects first.
- A DaTscan to help clarify the diagnosis where the picture is uncertain.
- Watchful waiting with planned review, as DLB can become clearer over time.
- The NHS pathway rather than private assessment if speed is not the main concern.
Before you decide
Use this as a shared-decision checklist. The aim is not just “can this be done?”, but whether it is right for you, now, with the risks and alternatives clearly understood.
What matters most to me?
Think about symptoms, daily life, work, caring responsibilities, sport, fertility, travel, appearance and anxiety — the right choice depends on your priorities, not just the medical facts.
What are all my options?
Ask about waiting, monitoring, medicines, rehabilitation, a smaller or larger procedure, a different test, NHS referral, or a second opinion where that would help.
What would make me pause?
Active infection, pregnancy, unstable medical problems, smoking, medicines that increase bleeding, poor support at home, or feeling pressured are all reasons to slow down and get tailored advice.
What happens if I do nothing today?
For some problems, waiting is safe; for others, delay can make treatment harder. A good consultation should explain the trade-off in plain English.
Benefits
- Clarifies whether DLB is behind fluctuating alertness, hallucinations and movement problems
- Critically, flags the antipsychotic sensitivity warning so dangerous medicines can be avoided
- Guides treatment of symptoms that may respond to careful management
- Identifies falls risk so it can be reduced
- Opens access to support for the person and family, and to Parkinson's-related services where relevant
- Allows planning ahead while the person can take part in decisions
Risks & complications
- Finding the assessment tiring or upsetting
- Worry while waiting for results or a DaTscan
- Scores that vary because alertness fluctuates, making the picture harder to read
- Distress on hearing the diagnosis
- An unclear diagnosis at first, needing a DaTscan or a later review
- DLB initially mistaken for Alzheimer's disease, Parkinson's disease or a psychiatric illness
- Effects on driving, work and insurance that need to be thought through
- Falls causing injury, which are more common in DLB
- A wrong or incomplete first diagnosis that is later revised
- A severe reaction to an antipsychotic medicine if the diagnosis is not recognised — a key reason to get it right
The most important safety point is antipsychotic sensitivity: people with DLB can react severely to antipsychotic medicines, with marked stiffness, worsening confusion and serious harm, and the Alzheimer's Society notes up to around half of those given these drugs can have severe reactions. These medicines should be avoided unless truly necessary, and only ever used in low doses under specialist supervision with close monitoring. A sudden worsening of confusion is more likely to be delirium from illness than the dementia itself.
Published figures to discuss
The assessment itself is not a procedure with complication rates. The most important figure relates to treatment safety, not to the assessment: the Alzheimer's Society reports that up to around half of people with DLB given antipsychotic medicines can have severe reactions. This is why recognising DLB matters. Diagnostic uncertainty is also a feature, because alertness fluctuates and DLB overlaps with Parkinson's and Alzheimer's disease.
| Figure | Reported range | How to interpret it | Source / confidence |
|---|---|---|---|
| Severe reaction to antipsychotic medicines in DLB | Up to around half of those given antipsychotics, per the Alzheimer's Society | Marked stiffness, worsening confusion and serious harm can occur. Antipsychotics should be avoided unless truly necessary, and only used in low doses under specialist supervision with close monitoring. This describes the condition, not a risk of the assessment. | NHS — Dementia with Lewy bodiesnhs.ukSource-linked context |
| Falls, fainting and sleep disturbance | Common DLB management issues | Parkinsonism, autonomic symptoms and REM sleep behaviour disorder can increase injury risk. | NHS — Dementia with Lewy bodiesnhs.ukSource-linked context |
| Misdiagnosed as Alzheimer's disease, delirium or primary psychosis | Recognised | Fluctuating cognition, visual hallucinations and parkinsonism should prompt consideration of DLB. | Guide sourcesClinical context |
| Cholinesterase inhibitor side effects | Common enough to monitor | Nausea, diarrhoea, vivid dreams, slow pulse and dizziness should be reviewed after starting treatment. | Guide sourcesClinical context |
These are literature figures, not a personalised prediction. Your own risks and likely benefits depend on your circumstances, your health, and how your care is carried out and followed up.
What happens afterwards
There is no physical recovery from the assessment. What matters afterwards is understanding the diagnosis — including the medication safety warning — getting support, reducing falls and planning ahead.
- Feeling tired after a long assessment, with alertness that naturally varies
- Needing time to take in the diagnosis and the safety information
- Careful, gradual changes to medicines, with close monitoring
- A diagnosis that becomes clearer with a DaTscan or over time
- Mixed emotions in the person and family — all understandable
Aftercare
- Make sure you and your family understand the diagnosis and, especially, the antipsychotic sensitivity warning.
- Carry a note of the diagnosis and of any medicines to avoid, in case of emergency or hospital admission.
- Take any prescribed medicine exactly as directed, and report new stiffness, drowsiness or worsening confusion promptly.
- Take steps to reduce falls at home, as falls are more common in DLB.
- Look into support such as an Admiral Nurse or local dementia adviser, and Parkinson's-related services where relevant.
- Tell the driving licence authority and your insurer if you are advised this affects driving — this is a legal duty. The authority is the DVLA in England, Scotland and Wales, or the DVA in Northern Ireland.
- Plan ahead while decisions can be made: lasting power of attorney, finances and future wishes.
- Bring the person who knows you best to appointments
- Notes on fluctuating alertness, hallucinations, movement changes and falls
- Any history of acting out dreams in sleep
- Full list of current medicines and any bad medicine reactions
- Glasses and hearing aids
- Questions written down in advance
- A way to record what you are told, including the medication safety advice
⚠ Get urgent help if…
- Sudden severe stiffness, marked drowsiness or rapidly worsening confusion, especially after a new medicine — seek urgent medical advice, as this may be a reaction to an antipsychotic
- A fall with a head injury or a suspected fracture — seek urgent help
- Sudden confusion or a clear change over hours or days — this may be delirium from illness and needs urgent medical attention
- Distressing hallucinations or fear that cannot be settled
- Thoughts of harming yourself, or feeling unable to go on — contact your GP urgently or call Samaritans on 116 123; call 999 if there is immediate danger
- Difficulty swallowing or choking, which can occur as the condition advances
- Becoming unsafe alone — for example frequent falls or getting lost
Who to contact: your clinician, clinic or test provider first (keep their number to hand). For urgent advice when you can't reach them, call NHS 111. In an emergency, call 999.
General guidance — it doesn't replace the specific advice your psychiatrist gives you.
Results & realistic expectations
A good outcome from assessment is a clear, honest explanation that the symptoms are due to DLB, a plan to ease symptoms where possible, attention to falls, and — crucially — clear safety information about medicines to avoid. Recognising DLB helps protect the person from a dangerous reaction to antipsychotic drugs.
The limits matter. There is no cure, treatment eases some symptoms rather than stopping the disease, and the diagnosis can be hard to make because alertness fluctuates and it overlaps with Parkinson's and Alzheimer's. The picture may need review over time.
DLB is progressive, and over time alertness, movement, swallowing and physical health can all be affected, with falls an ongoing risk. The plan is reviewed over time and support needs usually increase. As the condition advances, the focus shifts towards comfort, dignity, support and planning, always keeping the medication safety warning in mind.
Related tests, treatments or support
A Lewy body dementia assessment often combines old age psychiatry with neurology, because of the close link with Parkinson's disease. Falls assessment, a medication review and, where the picture is unclear, a DaTscan are commonly done together. A careful look for delirium and other treatable causes is part of the picture.
Follow-up & long-term care
After diagnosis, a letter usually goes to your GP and should clearly state the antipsychotic sensitivity warning. The clinic agrees who will follow you up. Reviews check symptoms, falls risk, medicines and support needs. You should be told who to contact between appointments and how to get support.
- Regular review of alertness, hallucinations, movement, mood and falls risk
- Careful review of all medicines, avoiding those that worsen DLB unless specialist-led
- Ongoing falls prevention at home and in daily life
- Support for the person and family, including Parkinson's-related services where relevant
- Revisiting plans for care, finances and future wishes over time
Repeat, follow-on and what comes next
- The diagnosis may be revised once a DaTscan or neurology input is available.
- DLB is sometimes only recognised after a period of being labelled as Alzheimer's, Parkinson's or a psychiatric illness.
- Because alertness fluctuates, a single visit may not capture the picture, and review over time helps.
- Treatment is adjusted carefully over time, always mindful of medication sensitivity.
Ask what happens if the result is unclear or needs repeating, and what is included if further tests or follow-up are needed.
What good aftercare looks like
- A clear, compassionate explanation of the diagnosis, with the antipsychotic safety warning given prominently and in writing.
- A named point of contact, and the diagnosis and medicines-to-avoid recorded for emergencies and hospital admissions.
- A plan to ease symptoms carefully, reduce falls, and review all medicines with specialist oversight.
- Signposting to support for the person and family, including Parkinson's-related services where relevant.
- Support with planning ahead and honest, kind advice on driving and legal matters.
What affects the cost
Costs vary a great deal between people and providers, and we don't publish prices. What matters is understanding what drives the cost and making sure your quote is complete. The main things that affect it:
- Length and number of appointments, and whether a consultant leads the assessment
- The cognitive tests used and any detailed psychological testing
- Blood tests, a movement assessment and a falls-risk assessment
- Whether a brain scan (CT or MRI) is arranged, and who reports it
- Whether a DaTscan is needed to help confirm the diagnosis
- Neurology input, follow-up appointments, and reports or letters
- The consultant or clinician's fee for assessment and follow-up
- Cognitive testing and any psychology input
- Blood tests and who arranges and interprets them
- Any scan fee, including a DaTscan, and the reporting fee
- Whether neurology input is included
- Reports, letters and communication with your GP, clearly stating the medication safety warning
- What happens, and what it costs, if the diagnosis is unclear or a DaTscan is needed
On the NHS? Assessment for dementia with Lewy bodies is available on the NHS when clinically indicated, sometimes with neurology input; private routes are mostly used for speed, choice or a second opinion.
You're entitled to your total cost in writing — including reports, follow-up and what happens if the result is inconclusive — before you decide.
Consent traps and marketing red flags
These are not small details. They are often where patients lose choice, time to reflect, or realistic expectations.
Consent traps
- Not warning the person and family about antipsychotic sensitivity, or not flagging it clearly to the GP and hospitals.
- A diagnosis without a collateral history, missing the fluctuating and sleep features.
- Not discussing falls risk and how to reduce it.
- Treating DLB as ordinary Alzheimer's disease without explaining the differences.
- Not being told what the diagnosis means for driving, work and insurance, or who sees the report.
Marketing red flags
- Claims that a treatment can cure, reverse or stop dementia with Lewy bodies.
- Any suggestion that antipsychotics are a routine, low-risk treatment for hallucinations in DLB.
- A single test or scan sold as proof of DLB without a full clinical assessment.
- Supplements or unproven treatments promoted as slowing the condition.
Choosing a specialist safely
- Check the psychiatrist is on the GMC Specialist Register for this area.
- Make sure they work at a CQC-registered service, and look for membership of the relevant Royal College or professional body.
- You're entitled to time to consider and to have your questions answered before you agree — the psychiatrist who looks after you should explain it, not a salesperson.
- Be wary of pressure: time-limited offers or deposits taken before you've had time to think are red flags, not bargains.
- You're entitled to your total cost in writing — including any follow-up — before you decide.
Questions to ask your medical professional
Take this to your consultation. A good psychiatrist will welcome every one of these.
- How confident are you that this is DLB rather than Alzheimer's, Parkinson's or a psychiatric illness?
- Will I need a DaTscan, and has a neurologist been involved?
- Which medicines should I avoid, and how will this be made clear to other doctors and hospitals?
- What can be done to ease my symptoms and reduce my risk of falls?
- What support is available for me and my family, and who do I contact?
- What does this mean for driving, work and planning ahead?
- Are you on the GMC Specialist Register for this area, and which Royal College or professional body are you a member of?
- Will you be the psychiatrist who carries out my test, and who looks after me afterwards?
- What are the risks for someone like me, and how often do your own patients have a problem or need it repeated or redone?
- What does a realistic result look like — and what can this test not achieve?
- What are my options, including waiting, doing nothing for now, or choosing a different approach?
- Can I have written information, results and aftercare instructions in a format I can use, including any accessibility or communication support I need?
- What is the total cost in writing, including any follow-ups, and how much time do I have to decide?
Frequently asked questions
What makes dementia with Lewy bodies different?
Why is the warning about antipsychotic medicines so important?
What is a DaTscan?
Is there a cure?
How is it related to Parkinson's disease?
Can I get the assessment on the NHS?
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How we made this page
Medically reviewed by a GMC-registered consultant. Written in plain English, checked against NHS, NICE, GMC and relevant Royal College / specialist-society guidance, and kept under review. No clinic paid to appear on this page, and we publish no pricing. This is general information to help you prepare — it is not a substitute for advice from your own clinician. How we review our guides →
Source hierarchy: UK regulator and NHS/NICE guidance first, then relevant Royal College or specialist-society guidance, then peer-reviewed evidence for procedure-specific figures where available.
Sources & standards: NHS — Dementia with Lewy bodies Alzheimer's Society — Dementia with Lewy bodies (DLB) Alzheimer's Society — Treatments and support for DLB NICE NG97 — Dementia: assessment, management and support Dementia UK — How is dementia diagnosed? Royal College of Psychiatrists — Memory problems and dementia DVLA — Assessing fitness to drive DVA Northern Ireland — Tell DVA about a driver medical condition
Reviews reflect patients' experience of care, not clinical outcomes. For procedure volumes and outcome data see PHIN.
Last medically reviewed 2026-09-21. Spotted something wrong or out of date? Report an error in this guide.
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