Thursday, 15 January 2015

Life Expectancy

Last year I put up a post which compared HSP with other types of Motor Neuron Disease, and in which I summarised HSP as:

"The primary features of HSP are spasticity and weakness in the legs, varying between individuals. There is progressive difficulty walking and symptoms worsen over time. Initial symptoms are typically difficulty with balance, stubbing the toe or stumbling. Changes begin gradually. As the disease progresses, canes, walkers and eventually wheelchairs may become needed, although some people never require assistive devices. A wide variety of symptoms are observed across cases and over time, including balance, fatigue, bladder and back pain. The majority of individuals with HSP have a normal life expectancy."

As mentioned, I had borrowed the text from other HSP sites. I also used this post as the basis for one of my columns in the UK HSP Support Group Newsletter, and I was asked by one reader about life expectancy. This is an interesting question, and one I'm slightly nervous about writing about given that this is a sensitive issue. My advice for any readers who are concerned about this should contact their HSP specialist to get their own answer.

Some clarity is obtained from the NINDS website: which indicates that "The majority of individuals with uncomplicated HSP have a normal life expectancy." I realise now that I should have included this important differentiation in my post (and I have now added an update accordingly). There is an increased risk with pure HSP due to falls and from infections, principally bladder.

Given that life expectancy for uncomplicated/pure HSP is usually normal this raises the question about what is the life expectancy for complex HSP. In summary, there is not much information which I can find, and this is an overview of what I have found, with links.

In my trawl of research papers there are only two papers which talk about life expectancy, both in relation to SPG11. - A Dutch study covering 18 patients - A study from France with 7 patients

The Dutch study suggests a life expectancy of 3-4 decades after the start of walking problems. The paper from France gives life expectancy of 30-40 years, but it is not clear from the abstract if this is from onset, the same as the Dutch study, or 30-40 years total. These two studies seem to have quite small sample sizes, and I dont have the benefit of the full papers to see what the uncertainty/confidence might be.

There is also a lot of information about HSP on this Washington University page which indicates that SPG11 has an onset usually before 20 but sometimes up to 50, which perhaps ties in with the Dutch study in that some people don't get SPG11 until older than 30-40. The Washington page doesn't give life expectancy for SPG11.

The Washington page also describes all of the different forms of HSP and other related conditions, although it is not clear where all the data comes from. There are references in most areas of the page, but I don't have access to full papers to check. This page indicates that SPG13 has a life expectancy of less than 2 decades after onset.

Looking for further information starts to become more of a challenge needing to use other search terms like prognosis, life span, death, morbidity. This following paper presents all the HSP types and indicates which are complex/complicated and which are pure/uncomplicated, and could form a start.

All of the other information/comments I find are not specific and I can find various answers to the question which contradict each other. Since I dont know which to believe, if any, I'll avoid any of those links here.

Originally I was quite surprised how little information there is out there on this topic. I couldn't decide if that's just because HSP is a rare condition and this aspect hasn't yet got the attention that it needs in the limited budget research world, or if it was the case that the other issues associated with complex HSP need more attention than looking at this issue. Some more thought, and discussion with others leads me to believe that life expectancy varies significantly from person to person, and perhaps that it can be varied with the level of care that is received. Which brings me back to my original observation - if this is important to you, talk to your specialist.

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