Symptoms of dementia with Lewy bodies (DLB)

Problems with attention and mental abilities are very common symptoms in dementia with Lewy bodies. For example, a person with DLB may:

• become confused and what they say may not make sense. These problems are likely to vary a lot throughout the day, from hour to hour or even over the course of a few minutes.
• have difficulty staying alert during the day. They may become less aware of what’s going on around them and appear to ‘switch off’.
• struggle judging distances and seeing objects clearly in three dimensions. This is because the brain makes links with other information to make sense of what we see. For example, the person may not be able to recognise the edge of a step on the stairs and know to change how they approach this.
• have difficulty with planning, organising and making decisions.
• face day-to-day memory problems. This often affects people with DLB, but usually much less than in the early stages of Alzheimer’s disease, where it is the main feature.
• experience depression, anxiety or apathy. This happens for some people with DLB.

A common early symptom for people with DLB is visual hallucinations (seeing things that are not there). The person might describe seeing people or animals. For some people this is disturbing.

Hallucinations in other senses – such as hearing, smell, or touch – can also happen in DLB, although these are less common.

Visual hallucinations are one of the reasons why a person with DLB may stop driving because it is no longer safe. 

Most people with DLB also have delusions (persistently thinking things that are not true) at some stage. 

Up to two-thirds of people with DLB have movement difficulties when they are diagnosed, and this increases as DLB progresses. The movement-related symptoms of DLB are similar to those of Parkinson’s disease. These include:

• slow and stiff movement of limbs
• limited facial expressions
• posture becoming more and more stooped
• shuffled walking
• difficulty with balance
• trembling limbs.

This, combined with difficulty seeing objects properly, can make it likely for people living with DLB to fall and get hurt. 

Not sleeping well is a common symptom of DLB and can start many years before a person is diagnosed.

They may fall asleep very easily during the day, but then have restless, disturbed nights. If the person has rapid eye movement (REM) sleep behaviour disorder, they may physically act out their dreams. This kind of very disturbed sleep is a feature of DLB (and Parkinson’s). 

DLB affects the body in many ways that don’t relate to either dementia or movement. These can include the things we do automatically but don’t usually think about. For example, DLB can cause problems with:

• constipation
• problems passing urine – for example, needing to pee very often or in a hurry, or not being able to stop it coming
• erectile dysfunction (not being able to get or keep a firm erection)
• losing some sense of smell or taste (or both)
• low blood pressure when standing up – this can cause dizziness and fainting.