Understanding Lewy Body Dementia: Symptoms and Their Impact

Lewy body dementia (LBD) is one of the most complex and misunderstood forms of dementia, affecting thinking, movement, sleep, and behaviour. It is the second most common type of progressive dementia after Alzheimer’s disease, yet it remains widely under-diagnosed and often confused with other neurological conditions.

Among the key symptoms of LBD are visual hallucinations, REM sleep behaviour disorder (RBD), and parkinsonism. These symptoms can emerge at different stages of the disease, sometimes even years before a diagnosis is made. Understanding these symptoms is crucial for early recognition, appropriate support, and improved quality of life for those living with LBD and their carers.

Visual Hallucinations in LBD

One of the hallmark symptoms of Lewy body dementia is recurrent visual hallucinations. Unlike hallucinations in other conditions, such as schizophrenia, those associated with LBD are often detailed and well-formed. People with LBD may see people, animals, or objects that are not there.

How do visual hallucinations affect daily life?

• Some individuals find their hallucinations comforting, such as seeing a deceased loved one or a friendly animal.
• Others experience them as distressing, particularly if they involve threatening or unfamiliar figures.
• Carers often struggle with how to respond—correcting the person can cause agitation, while going along with the hallucination may reinforce confusion.

Why do hallucinations occur in LBD?

These hallucinations are linked to the abnormal build-up of Lewy bodies (protein deposits) in the brain, which disrupt normal neural functioning. The visual processing areas of the brain are affected, leading to misinterpretations of reality.

Hallucinations are more common in LBD than in other types of dementia and often occur early in the disease. In contrast, hallucinations in Alzheimer’s typically appear in the later stages.

How can hallucinations be managed?

• Non-drug approaches: Ensuring good lighting, reducing visual clutter, and offering reassurance can help.
• Medication: Some medications used for Alzheimer’s disease, such as cholinesterase inhibitors, may help reduce hallucinations. However, antipsychotic medications should be used with caution, as people with LBD are highly sensitive to them and may experience severe side effects.

REM Sleep Behaviour Disorder (RBD) in LBD

REM sleep behaviour disorder (RBD) is a sleep disturbance where people physically act out their dreams, often involving kicking, punching, or talking in their sleep. This occurs because the brain fails to suppress muscle activity during REM (rapid eye movement) sleep.

How does RBD present in LBD?

• People may shout, talk, or swear while asleep.
• They might kick, punch, or thrash about, which can lead to injury for themselves or their bed partner.
• Many individuals with RBD in LBD report having vivid, intense dreams, often with aggressive or action-packed themes.

Why is RBD significant?

RBD can appear years or even decades before other symptoms of LBD, making it an early warning sign. Studies suggest that up to 80% of people with RBD go on to develop LBD or another neurodegenerative condition like Parkinson’s disease.

How can RBD be managed?

• Creating a safe sleeping environment: Removing sharp objects, using padded bedrails, or placing a mattress on the floor can help prevent injuries.
• Medication: Clonazepam (a type of benzodiazepine) and melatonin are often prescribed to reduce episodes of RBD.
• Good sleep hygiene: Avoiding alcohol, caffeine, and heavy meals before bed can help regulate sleep patterns.

Parkinsonism in LBD

Parkinsonism refers to the movement symptoms associated with Parkinson’s disease, which are also present in Lewy body dementia. These symptoms occur due to the loss of dopamine-producing cells in the brain.

Common parkinsonian symptoms in LBD:

• Slowness of movement (bradykinesia) – Tasks such as dressing or eating take much longer.
• Muscle stiffness (rigidity) – Movements become stiff, and flexibility decreases.
• Tremors – While less common in LBD than in Parkinson’s disease, some people experience hand tremors.
• Shuffling gait and balance issues – Increased risk of falls due to poor coordination.

How does parkinsonism in LBD differ from Parkinson’s disease?

• In Parkinson’s disease, motor symptoms typically appear years before cognitive changes. In LBD, cognitive symptoms and motor symptoms often appear together or within a short time frame.
• People with LBD are more likely to experience severe fluctuations in attention and hallucinations, which are less common in early Parkinson’s disease.

Managing Parkinsonism in LBD

• Physiotherapy and exercise: Movement-based therapies like gentle stretching, walking, and balance exercises can help maintain mobility.
• Medication: Levodopa, a common Parkinson’s drug, can sometimes help but may also worsen hallucinations.
• Fall prevention: Occupational therapy can provide strategies to improve safety in the home.

Conclusion

Lewy body dementia presents a unique combination of symptoms that can be challenging for individuals and carers alike. Visual hallucinations, REM sleep behaviour disorder, and parkinsonism are among the most distinctive signs of the condition. Recognising and understanding these symptoms can lead to earlier diagnosis, better management, and improved support.

If you or a loved one are experiencing any of these symptoms, speak to a healthcare professional for further assessment. While there is currently no cure for LBD, a combination of medication, therapy, and lifestyle adaptations can help maintain quality of life for as long as possible.

Further Reading & Sources

• Alzheimer’s Society UK: Lewy body dementia
• Parkinson’s UK: Parkinsonism and Lewy body dementia
• Lewy Body Society: Understanding LBD
• Mayo Clinic: REM Sleep Behaviour Disorder
• National Institute on Aging: What is Lewy Body Dementia?