Lewy body dementia and its prognosis

I attended the funeral of a friend on Tuesday. More accurately, Shane was a friend of a friend, really. I had met Shane several times over the years, so I knew him well enough for a chat. Shane died at 59 – my age – of dementia. More  specifically, Lewy body dementia.

Despite taking a fairly active interest in dementia in recent years, Shane’s funeral taught me that I had more to learn. Much more. I’ve known for some time to differentiate Alzheimer’s disease from dementia. The terms are not interchangeable. Alzheimer’s is indeed a form of dementia, but not all dementias are Alzheimer’s.

That said, until Shane’s moving farewell on Tuesday, my limited knowledge extended to Alzheimer’s disease and ‘other dementias’. I probably knew ‘other dementias’ encompassed a number of types, but I had no idea of their names, let alone what characterised each one.

The funeral celebrant mentioned Shane’s condition only once. In fact, I did not fully catch the phrase ‘Lewy body dementia’ immediately. But I knew it had registered somewhere in my brain. When I got home later, I turned to ‘Dr Google’, typing ‘types of dementia’ into the search engine. 

Up came a list, a longer one than I expected. Not surprisingly, Alzheimer’s headed the list. It is the most common form of dementia. However, the list included dementias I’d not previously encountered: vascular dementia and frontotemporal dementia to name a couple.

In amongst that list was the one that had brought about Shane’s tragically premature end: Lewy body dementia.

What defines Lewy body dementia?

The first thing I learnt is that the more accurate term is ‘Lewy body dementias’ – plural. According to Dementia Australia, Lewy body dementias is an umbrella term describing two forms of dementia: dementia with Lewy bodies and Parkinson’s disease dementia.

My immediate follow-up question was, ‘What are Lewy bodies?’ Fortunately, Dementia Australia’s excellent website provided a clear explanation in laypersons’ terms: “A Lewy body is a tiny tangle of protein called alpha-synuclein inside brain cells. These tangled proteins cause damage that affects your movement, thinking and behaviour.” (Lewy bodies were named after the German-born American neurologist who first identified them, F. H. Lewy.)

Lewy body dementia, sadly, has the characteristics that plague most other forms. As it develops over time, it affects your memory, thinking and behaviour. While there is no known cure for Lewy body dementia, there is medication, treatment and support available to sufferers. This helps patients to live the best life they can, but the longer-term prognosis is generally not favourable.

The difference between the two

While the two types of Lewy body dementias are very similar, there are key differences. One is the order of diagnosis. 

If you’ve already been diagnosed with Parkinson’s disease, and at least a year later you start experiencing symptoms of dementia, you’ll likely be given a diagnosis of Parkinson’s disease dementia. But if you have a diagnosis of dementia, and then at least 12 months later you begin to experience symptoms of Parkinson’s disease, you’re likely to receive a diagnosis of dementia with Lewy bodies.

The two dementias also display a difference in the speed of progression. Parkinson’s disease dementia can be quite slow compared to other forms of dementia, while the progress of dementia with Lewy bodies tends to be faster.

Symptoms are also likely to be different, albeit most are quite subtle. The most common movement symptoms of Parkinson’s disease are:

• tremors, typically when you’re at rest
• rigidity, or muscle stiffness
• slow movement (also called bradykinesia)
• trouble maintaining your posture and balance.

Dementia with Lewy bodies can cause the same symptoms, but with these differences:

• less tremor, or tremors when you’re at rest or when using your hands
• more stiffness in your torso
• earlier balance problems
• symptoms on both sides of your body.

The long-term prognosis for Lewy body dementia

You might have guessed from Shane’s story that the long-term prognosis for Lewy body dementia is not good. The range from diagnosis to death can be anywhere from two to 20 years, but the average is five to eight years.

Shane was diagnosed in 2018, making the six-year struggle for him and his family and friends very much ‘average’. But Shane was no average person, and neither is his wider circle of family and friends. That much became very clear in Tuesday’s celebration of his life.

As a result of Shane’s passing, I now have a greater understanding of dementia overall, and of Lewy body dementia in particular. That’s important. More important is the greater understanding of the effect Lewy body dementia has on everyone involved. And how important the support of loved ones is through the Lewy body dementia journey.

If such a fate should ever befall me, I will be very lucky to receive the love, care and support shown to Shane by his close circle.

Were you aware of Lewy body dementias? Do you know anyone who has been diagnosed with the disease? Let us know via the comments section below.

Also read: Dementia on the rise in Australia: report

Disclaimer: This article contains general information about health issues and is not advice. For health advice, consult your medical practitioner.