Lewy body dementia (dementia with Lewy bodies): symptoms, diagnosis and treatment

The NHS says people with dementia with Lewy bodies may have hallucinations and hearing voices (seeing, hearing or smelling things that are not there), problems with understanding, thinking, memory and judgement (similar to Alzheimer's disease, although memory may be less affected), confusion or sleepiness that can change over minutes or hours, slow movement, stiff limbs and tremors, disturbed sleep with violent movements and shouting out, fainting spells, unsteadiness and falls, and depression and anxiety.

Alzheimer's Society says both DLB and Alzheimer's disease can cause problems with staying focused, making decisions, memory loss and the way the person sees things, while DLB also causes symptoms not usually seen in Alzheimer's: hallucinations, problems staying fully awake, difficulties with movement and very disturbed sleep. Everyone experiences dementia differently.

Dementia is the name for problems with mental abilities caused by gradual changes and damage in the brain, according to the NHS. Dementia with Lewy bodies is one cause. Lewy bodies are tiny clumps of protein that appear in nerve cells of the brain; Alzheimer's Society says they are named after the German doctor FH Lewy who first identified them.

The NHS says DLB is rare in people under 65, tends to develop slowly and gets gradually worse over several years. Alzheimer's Society explains that Lewy bodies cause a range of symptoms, some shared with Alzheimer's disease and some with Parkinson's disease, so DLB is often wrongly diagnosed.

The NHS says it is caused by clumps of protein, called Lewy bodies, forming inside brain cells in areas responsible for thinking, visual perception and muscle movement. It is not clear why the deposits develop and exactly how they damage the brain, but it is thought that the proteins interfere with the signals sent between brain cells. These deposits are also found in people with Parkinson's disease.

Alzheimer's Society says Lewy bodies can be developing for a long time before any symptoms show, and that many people with DLB also have a build-up of the proteins that cause Alzheimer's disease, which is common in people over about 80 and often makes symptoms more severe and faster to progress. The NHS says DLB usually occurs in people with no family history, although very rare cases seem to run in families.

Both are caused by a build-up of Lewy bodies and share problems with thinking, movement, mood and how the body works. Alzheimer's Society explains the difference by timing: in DLB, the symptoms of dementia begin before, or around the same time as, the movement problems, while in Parkinson's disease symptoms of dementia often develop many years after the movement problems begin.

The NHS says to see a GP if you think you have early symptoms of dementia, especially if you are over 65, and to encourage a worried relative to make an appointment and perhaps go with them. The GP can do simple checks and refer you to a memory clinic or another specialist for further tests.

The NHS says there is no single test for DLB. Tests that may be needed are an assessment of symptoms, an assessment of mental abilities involving tasks and questions, blood tests to rule out conditions with similar symptoms, and brain scans such as MRI, CT or SPECT.

Alzheimer's Society explains that the doctor will talk to the person and someone who knows them well, may check eyesight, hearing and medicines (some used for depression, allergies or incontinence can cause confusion), and may refer to a neurologist for movement problems. Because how well someone functions varies day to day, tests can miss symptoms on a good day. It says CT or MRI can rule out other brain conditions, and if the diagnosis is still unclear a more specialised brain scan, or a scan of the nerve cells in the heart, may help confirm DLB.

The NHS says there is currently no cure for dementia with Lewy bodies or any treatment that will slow it down, but there are treatments that can help control some of the symptoms, possibly for several years. These include medicines to reduce hallucinations, confusion, drowsiness, movement problems and disturbed sleep, therapies such as physiotherapy, occupational therapy and speech and language therapy, psychological therapies such as cognitive stimulation, and activities such as memory cafes.

Alzheimer's Society says drug treatment of DLB symptoms often takes some trial and error because everyone responds differently and there is not much evidence about what works well. It lists donepezil, rivastigmine and memantine as drugs that may help attention, alertness and slowed thinking for a while, and says rivastigmine and, less often, donepezil may also reduce hallucinations.

The charity also describes non-drug approaches: routines, talking therapies, cognitive stimulation therapy, life story work, music and art, help from an occupational therapist or physiotherapist with movement, a speech and language therapist for swallowing and speaking, and sleep measures such as regular bedtimes, less daytime napping and making the area around the bed safe.

Alzheimer's Society says people with DLB can have a serious reaction to antipsychotic medication that is usually safe for people with other types of dementia. It says the drugs used to treat hallucinations and delusions in other types of dementia can cause a bad reaction in a person with DLB. Non-drug approaches should always be tried first.

It advises that if a person goes into hospital or sees a new doctor, the person or their family should check that medical staff know that the person has DLB, not just "dementia", and that the diagnosis should be clearly recorded in the notes. DLB may also be mistaken for delirium when first seen during an emergency admission.

The NHS says how quickly DLB gets worse varies from person to person. Home-based help will usually be needed and some people will eventually need care in a care home. The average survival time after diagnosis is around 5 to 7 years, but this is highly variable and some people live much longer.

Alzheimer's Society says DLB generally progresses over a period of several years, and describes later-stage changes including more problems with day-to-day memory, agitation, slower and less steady walking with a higher risk of falls, and speech and swallowing problems that may lead to chest infections.

See a GP if you or someone you know has early symptoms of dementia, especially over 65. Alzheimer's Society says any physical health problem, such as dehydration, an infection or constipation, can make someone with DLB more confused and disorientated, so a sudden worsening in confusion should be assessed promptly.

If someone is hurting themselves or others, or there is a medical emergency such as a fall with injury, call 999.

On the NHS, assessment usually runs from the GP to a memory clinic or another specialist service, and ongoing support such as community nursing, social care and day services is arranged through local NHS and council services. The NHS and Alzheimer's Society both point to voluntary organisations for advice for families and carers.

A private consultant assessment can be quicker or offer a second opinion, particularly where hallucinations, Parkinson-like symptoms or sleep problems make the picture unclear. Whichever route you take, make sure the diagnosis is recorded wherever the person receives care.