Parkinson’s disease dementia can progress quite slowly compared to other forms of dementia.
Parkinson’s disease dementia is characterised by a cognitive decline that goes beyond the mild cognitive impairment often seen in early Parkinson’s.
What is Parkinson’s disease dementia?
Parkinson’s disease dementia (PDD) might be used interchangeably with dementia with Lewy bodies (DLB), but they refer to different stages and presentations of Lewy body dementia.
They differ in the presentation of motor symptoms, with PDD movement symptoms appear first, followed by dementia symptoms more than a year later. In DLB, cognitive symptoms including problems with planning, memory, and visual-spatial abilities, appear within a year of, or even before, the motor symptoms.
PDD is characterised by the presence of Parkinson’s disease symptoms such as the classic tremors, stiffness, and slow movement before the onset of dementia. DLB may present with motor symptoms, but these are not always as prominent as in Parkinson’s disease and may differ slightly in how they present.
Both conditions are caused by the abnormal accumulation of alpha-synuclein protein in the brain, known as Lewy bodies and fall under the umbrealla term Lewy body dementia.
PDD is a type of dementia that occurs in people who have been living with Parkinson’s for some time. It is estimated that around 50-80% of people with Parkinson’s disease will eventually develop dementia. PDD
What is Parkinson’s disease dementia?
Some people 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).
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 symptoms 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.
Treatments:
While there is no cure for PDD, treatments focus on managing symptoms:
- Medications: Cholinesterase inhibitors (e.g., rivastigmine) to improve cognition, and carbidopa-levodopa for movement symptoms3.
- Therapies: Physical and occupational therapy and speech pathology to maintain function and independence.
- Non-drug treatments: Cognitive beahvioural therapy and social interaction to support mental wellbeing.
Carer needs:
Caring for someone with PDD requires a comprehensive approach:
- A multidisciplinary care team to treat all aspects of the condition.
- Personalised care plan that is tailored to your loved one’s needs and symptoms.
- Support for caregivers including dementia education, respite care, and emotional support.
- Safety measures that include adaptations in the home to prevent falls and accidents as advised by an occupational therapist.
- Regular monitoring and frequent medical check-ups to manage symptoms and medications.
How do I access dementia support?
Accessing dementia-specific services can make a significant difference in managing the symptoms of Parkinson’s disease dementia, improving quality of life and maintaining independence.
It’s advisable to explore all available pathways to find the support that best suits your individual needs. Look to:
- getting a GP referral to a care team with Parkinson‘s experience
- your state-based Parkinson’s organisation for advice on services to access
- private health to see what is covered in relation to consultations and expenses
- NDIS or My Aged Care plan supports
- Dementia Australia, the peak body for dementia in Australia.
Infosheet under review
References:
- Dementia Australia. (2024). Lewy body dementias. Retrieved from
- 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
- 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
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