Lewy body dementia

Lewy body dementia is an umbrella term describing two forms of dementia: dementia with Lewy bodies and Parkinson’s disease dementia.

While there are currently no cures for Lewy body dementias, there are treatments to help with the symptoms.

Lewy Body dementias

Lewy bodies are clumps of abnormal protein, specifically alpha-synuclein, that build up inside nerve cells in certain parts of the brain. These clumps are a key feature of Parkinson’s, Parkinson’s disease dementia (PDD), and dementia with Lewy bodies (DLB). Everyone diagnosed with Parkinson’s has Lewy bodies in their brain, but not everyone will go on to develop dementia.

When cognitive symptoms appear before movement symptoms, or within a year of them, specialists may consider a diagnosis of DLB rather than Parkinson’s with dementia. The Movement Disorder Society provides guidelines to help distinguish between these conditions. Even though PDD and DLB share similar causes, they follow different patterns and timelines.

Mild Cognitive Impairment (MCI) vs dementia

Cognitive changes are common in Parkinson’s, but they don’t always mean dementia. Mild cognitive impairment (MCI) and dementia affect thinking and memory in different ways.

MCI causes noticeable changes in memory, attention, or problem-solving. These changes go beyond what’s expected for your age, but they don’t stop you from managing your daily life. You might forget names, lose focus, or take longer to make decisions, but you can still live independently.

Dementia, on the other hand, brings more serious challenges. It affects memory, language, judgment, and behaviour. People with dementia often need help with everyday tasks and may struggle to live on their own.

Parkinson’s disease dementia

Some people living with Parkinson’s may later develop cognitive impairment and dementia. In these cases, Lewy bodies are often found in both the brainstem (where they are associated with motor symptoms) and the cerebral cortex (where they are linked to cognitive decline). It is referred to as Parkinson’s disease dementia (PDD).

Risk factors for developing PDD are:

having Parkinson’s for a long time
being elderly
being diagnosed with Parkinson’s at an older age
being non-tremor dominant.

Common features of PDD are:

Problems with planning, sequencing and decision making
Memory loss associated with free recall of recent events or new learning
Memory can improve with cueing
Visuo-spatial difficulties
Apathy
Changes in personality and mood
Visual hallucinations may occur.

Long-term use of Parkinson’s medications may also result in confusion and hallucinations.

Frequent monitoring by the treating medical specialist is essential. The decision to introduce medications used in the management of dementia must be made on an individual basis.

Dementia with Lewy bodies

Dementa with Lewy Bodies (DLB) is a progressive brain disorder that shares similarities with both Parkinson’s disease and Alzheimer’s disease. Lewy bodies are a key pathological feature in DLB, affecting multiple brain regions.

Common features of DLB are:

Fluctuating cognition early in the progression
Recurrent hallucinations early in the progression
REM (Rapid Eye Movement) sleep disorder – often acting out dreams
Severe sensitivity to medications prescribed for hallucinations
Sensitivity to medications prescribed for Parkinson’s.

Symptoms will depend on which area of the brain is affected and disease progression. However likely early symptoms include:

apathy, anxiety, depression
fainting
constipation
urinary incontinence
excessive sleepiness
poor sense of smell (hyposmia)
parkinsonism (bradykinesia, muscle rigidity, tremor, postural instability)
confusion or unresponsiveness that fluctuates
visual hallucinations
spatial disorientation or trouble with spatial perceptions
acting out dreams.

n.b. Levodopa (a drug prescribed for Parkinson’s symptoms) may worsen the cognitive and hallucination symptoms.

Later symptoms include:

inability to self-care
excessive daytime sleepiness
complete dependence.

Key Statistics

More than 100,000 Australians have Lewy body dementia. (1)
Lewy Body Dementia Is the Second Most Common Neurodegenerative Dementia: Dementia with Lewy bodies (DLB) ranks just behind Alzheimer’s disease in prevalence. It accounts for approximately 4.2% of dementia cases in community settings and up to 20% in neuropathological studies, suggesting it is often underdiagnosed.
Integrated outpatient palliative care, in addition to standard care, has improved multiple aspects of care in Parkinson’s disease dementia patients compared to standard care alone.
DLB and Parkinson’s Disease Dementia Share Genetic Risk Factors: Variants in genes such as SNCA, GBA, and APOE have been repeatedly linked to increased risk of DLB. These genes influence protein aggregation, lysosomal function, and lipid metabolism, key processes in LBD pathology.

Diagnosis of Parkinson’s-related dementias

A full assessment may include:

a medical history from the person
an interview with a family member
blood tests
tests of cognitive abilities
brain imaging
other medical tests as requested by a doctor or medical specialist.

Imaging techniques like SPECT and PET scans can help identify abnormal protein deposits during a person’s lifetime, aiding in the clinical diagnosis. However, the definitive diagnosis of conditions associated with Lewy bodies, such as Parkinson’s or LBD, is often confirmed through post-mortem examination of brain tissue.

Your care

Currently, there are no cures for disorders associated with Lewy bodies. Treatment focuses on managing symptoms and improving the quality of life for affected people. Medications, physiotherapy, and support services are often part of the comprehensive care approach for people with these conditions.

It’s important to note that research into Lewy bodies and associated neurodegenerative disorders is ongoing, with scientists working to better understand the underlying causes and develop targeted therapies.

Being diagnosed with DLB or PDD can lead to a range of emotions, and there’s a lot to learn. The Dementia Australia information kit helps you learn about your diagnosis, identify goals for the future, and access support and services. Go to www.dementia.org.au or call their National Dementia Helpline 1800 100 500 for support.

Care partners of people with Parkinson’s dementias should prioritise their self-care. Dementia or significant cognitive decline can seriously impact care partner burden. Respite for the carer is essential and forward planning and palliative consultations are recommended. Contact Carers Australia and register on the Carer Gateway for more information on carers’ supports. You can also reach out to the GriefLine on their Helpline 1300 845 745 8am to 8pm: 7 days (AEST)

Palliative Care Australia can also provide assistance at palliativecare.org.au

References:

Dementia Australia. (2024). Lewy body dementias. Retrieved from https://www.dementia.org.au/about-dementia/lewy-body-dementias
Aarsland D, Kurz MW. The epidemiology of dementia associated with Parkinson’s disease. Brain Pathol. 2010 May;20(3):633-9. doi: 10.1111/j.1750-3639.2009.00369.x. PMID: 20522088; PMCID: PMC8094858. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8094858/
Kiesmann, M., Chanson, J. B., Godet, J., Vogel, T., Schweiger, L., Chayer, S., & Kaltenbach, G. (2013). The Movement Disorders Society criteria for the diagnosis of Parkinson’s disease dementia: their usefulness and limitations in elderly patients. Journal of neurology, 260(10), 2569–2579. https://doi.org/10.1007/s00415-013-7018-8
Yamada, M., Komatsu, J., Nakamura, K., Sakai, K., Samuraki-Yokohama, M., Nakajima, K., & Yoshita, M. (2020). Diagnostic Criteria for Dementia with Lewy Bodies: Updates and Future Directions. Journal of movement disorders, 13(1), 1–10. https://doi.org/10.14802/jmd.19052
Yamada M, Komatsu J, Nakamura K, Sakai K, Samuraki-Yokohama M, Nakajima K, Yoshita M. Diagnostic Criteria for Dementia with Lewy Bodies: Updates and Future Directions. J Mov Disord. 2020 Jan;13(1):1-10. doi: 10.14802/jmd.19052. Epub 2019 Nov 8. PMID: 31694357; PMCID: PMC6987529.
Safarpour D, Willis AW. Clinical Epidemiology, Evaluation, and Management of Dementia in Parkinson Disease. American Journal of Alzheimer’s Disease & Other Dementias®. 2016;31(7):585-594. doi:10.1177/1533317516653823 https://journals.sagepub.com/doi/abs/10.1177/1533317516653823
Phillips, O., Ghosh, D., & Fernandez, H. H. (2023). Parkinson disease dementia management: an update of current evidence and future directions. Current Treatment Options in Neurology, 25(1), 93–119. https://doi.org/10.1007/s11940-023-00749-4
Giannakis, A., Sioka, C., Kloufetou, E., & Konitsiotis, S. (2024). Cognitive impairment in Parkinson’s disease and other parkinsonian syndromes. Journal of Neural Transmission, 31(2), 123–135. https://doi.org/10.1007/s00702-024-02865-0