Stages of Lewy Body Dementia

Lewy body dementia (LBD) is caused by abnormal clumps of a protein called alpha-synuclein, known as Lewy bodies, building up inside brain cells. It covers two closely related conditions:

• Dementia with Lewy bodies (DLB), where problems with thinking come first or at the same time as movement problems
• Parkinson's disease dementia, where dementia develops in someone who has had Parkinson's disease for some time

It usually starts at age 50 or over, and slightly more men than women are affected. Early on it is often mistaken for Alzheimer's disease, but it has a distinctive set of symptoms that set it apart.

What makes Lewy body dementia different

Compared with Alzheimer's disease, DLB is more likely to cause:

• visual hallucinations early on: seeing detailed, realistic things that aren't there, often people or animals
• fluctuating alertness and confusion: being clear one hour and very confused or drowsy the next, sometimes changing over minutes or hours
• movement problems similar to Parkinson's: slowness, stiffness, shuffling, tremor, falls
• REM sleep behaviour disorder: acting out dreams by shouting, punching or kicking in sleep, which often starts years before diagnosis
• problems with attention, planning and judging distances, with memory often less affected at first
• changes in automatic body functions: dizziness or fainting on standing (from low blood pressure), constipation, bladder problems and loss of smell

How quickly does it progress?

LBD is progressive: symptoms start slowly and worsen over several years. How fast varies a great deal from person to person, and many people have good days and bad days because of the fluctuations. It is generally described in three stages.

Early stage

• Can often manage everyday tasks but struggles with complex activities, such as handling money or driving
• Visual hallucinations and misinterpreting what they see, often with insight that these aren't real
• Fluctuations in attention and alertness: staring into space, seeming "switched off", or sleeping a lot in the day
• Difficulty judging distances and depth, for example the edge of a step
• Disturbed sleep. Up to 90% of people have sleep problems before diagnosis
• Movement symptoms in many people: up to two-thirds have them by the time they are diagnosed
• Depression, anxiety or apathy

Visual hallucinations and perception problems can make driving unsafe even in the early stage.

Middle stage

• Needs more help with dressing, washing and preparing meals
• Difficulty recognising familiar places or people
• Delusions, such as believing someone is watching them, or that a family member has been replaced by an impostor (Capgras syndrome)
• Increasing movement problems and a high risk of falls, which may mean needing supervision
• Communication becomes harder
• More anxiety, low mood and fluctuating awareness

Late stage

• Marked decline in thinking and physical abilities
• More problems with day-to-day memory
• Difficulty speaking and understanding, and may not recognise surroundings or loved ones
• Agitation, restlessness or shouting out
• Very slow, unsteady walking, and eventually may be unable to get out of bed
• Swallowing problems, raising the risk of choking and chest infections
• Hallucinations may continue even if the person can't describe them

For what to expect in the final months, see end stage dementia.

Life expectancy

On average, people live about five to seven years after a diagnosis of Lewy body dementia, but it can range from two to twenty years depending on age, overall health and how severe the symptoms are. The Alzheimer's Society gives an average of about six years for DLB. Falls and infections are common causes of decline. See dementia life expectancy to compare types.

Treatment

There is no cure, but treatment can help some symptoms for a time.

• Cholinesterase inhibitors (donepezil, rivastigmine) are offered to people with DLB. They can help with thinking, alertness and motivation, and may reduce hallucinations and delusions. Memantine may be used if these aren't tolerated.
• Levodopa (a Parkinson's medicine) can help movement problems in some people, but it can also increase confusion and hallucinations, so it needs careful monitoring.
• Melatonin or clonazepam may help with REM sleep behaviour disorder.

Important: sensitivity to antipsychotic medicines

People with Lewy body dementia can have severe, sometimes life-threatening reactions to antipsychotic medicines, including worsening movement problems, extreme sleepiness, confusion and falls. Older ("typical") antipsychotics such as haloperidol should generally be avoided. If an antipsychotic is ever considered for distressing hallucinations or agitation, it should be done by a specialist, at the lowest dose, for the shortest time, with close monitoring.

Make sure every doctor, hospital and care home knows about the diagnosis, especially before any operation or hospital stay, as some anaesthetics and medicines can cause sudden confusion.

Non-drug support

• a calm routine, simple tasks and regular exercise
• making the home safer to reduce falls (good lighting, removing trip hazards)
• physiotherapy, occupational therapy, and speech and language therapy
• cognitive stimulation therapy and social contact
• support for carers, as hallucinations, fluctuations and night-time disturbance can be exhausting

Lewy body dementia compared with other types

See also stages of Alzheimer's disease, stages of vascular dementia and the 7 stages of frontotemporal dementia.