Survival Rates Differ Widely in Parkinson's, MSA, Lewy Bodies

Deborah Brauser

May 24, 2017

Although patients with synucleinopathies have lower survival rates than the general population, the rates differ among various neurodegenerative diseases, new research suggests.

The population-based study of more than 900 participants showed that 69% of those who received a diagnosis of synucleinopathy died during follow-up of about 10 years compared with 49% of the matched control group, which did not have this type of diagnosis. They also died about 2 years sooner.

Compared with the control group, the risk for death was more than 10 times greater for those with multiple system atrophy with parkinsonism (MSA-p) and almost 4 times greater for those with dementia with Lewy bodies (DLB) or Parkinson's disease (PD) with dementia.

However, mortality in those with PD alone was "only moderately increased compared with the general population," write the investigators.

Lead author, Rodolfo Savica, MD, PhD, neurologist and associate professor of neurology and epidemiology at Mayo Clinic, Rochester, Minnesota, told Medscape Medical News that this particular finding corresponds to past research and that early detection and "correct treatment" were probably contributing factors.

"Our population with Parkinson's had a consistent way of being treated," said Dr Savica, adding that all of the new data on the various disease types should be helpful to clinicians.

"I think these are important messages for our patients, to keep them informed" and empowered with regard to treatment decisions, he said. "You need to know these things to plan your life."

The findings were published online May 15 in JAMA Neurology.

Trying to Answer "What's Next?"

"The first questions we're asked many times by people with Parkinson's or parkinsonism is, 'What's next?' and 'What does the future hold for me?'” said Dr Savica. “And that's why we wanted to study survival: to find information that could be used in the clinical practice to provide an estimate on what's going to happen in the future to these patients. We wanted to provide them with data on life expectancies, depending on the type of disease.”  

Synucleinopathy diseases are defined by having "ɑ-synuclein as the pathological hallmark," write the researchers.

For this analysis, they assessed medical records of individuals living in Olmsted County, Minnesota, including 461 patients who were diagnosed with a synucleinopathy between 1991 and 2010 (60.5% men; mean age at symptom onset, 75.8 years). In this group, 67% had PD, 17.6% had DLB, 11.9% had PD dementia, and 3.5% had MSA-p.

The investigators also examined records for 452 age- and sex-matched "general population referent" participants (60.2% men). This group did not have parkinsonism or any type of tremor during the year that their matched individual received their diagnosis.

The mean age at death for the overall group with synucleinopathies was 84.7 years vs 87.8 years for the referent group. The former also had a significantly greater risk for death than the latter (hazard ratio [HR], 2.26; 95% confidence interval [CI], 1.89 - 2.69).

"When stratified by synucleinopathy types, patients with MSP-p died 6 years earlier, patients with DLB died 4 years earlier, patients with PDD [PD dementia] died 3.5 years earlier, and patients with PD died 1 year earlier than the respective referent participants," write the researchers.

In addition, all of these subgroups had a higher mortality risk than the comparative group.

Table. Risk for Death Among Synucleinopathy Subgroups vs Referent Group

Cohort HR (95% CI)
MSA-p 10.51 (2.92 - 37.82)
DLB 3.94 (2.61 - 5.94)
PD dementia 3.86 (2.36 - 6.30)
PD 1.75 (1.39 - 2.20)

 

In the full patient group, the most frequent cause of death was neurodegenerative disease (31.5%), followed by cardiovascular events (15.8%) and respiratory failure/pneumonia (15.4%) — which was also true for those who had PD alone (25.6%, 16.3%, and 13.4%, respectively).

The most frequently reported cause of death in the comparative group was cardiovascular events (25.5%), followed by cancers (18.1%), respiratory failure/pneumonia (14.8%), and neurodegenerative disease (11.6%).

"Our findings contribute important new evidence about the natural history and survival of people affected by synucleinopathies of various types [and] may be helpful to guide clinicians counselling patients and caregivers," write the study authors.

Dr Savica noted that the investigators would like to look further, not only into survival rates but also next steps in the evolution of the disease. "What are the next things that are going to happen to our patients? And what is the effect from onset of one symptom versus another?"

"A Marathon Not a Sprint"

Asked to comment, James Beck, PhD, chief scientific officer at the Parkinson’s Foundation, told Medscape Medical News that this study provides new evidence that will be reassuring to patients living with different synucleinopathies.

"Particularly in those with Parkinson's, it tells them that their life span isn't dramatically shortened by their disease," said Dr Beck, who is also an adjunct professor at the New York University School of Medicine.

"We tell people with [PD] that their diagnosis isn't a death sentence. And this certainly supports that in spades," he said. "They have a long haul ahead of them, but one thing they can be confident about is that this isn't something that will dramatically shorten their life."

Dr Beck agreed with Dr Savica that getting a diagnosis such as this can be devastating and leads to a lot of questions about the future.

"Clearly we're talking about averages of a population here, but I think this is some of the best evidence we have to date that suggest that, again, this isn't going to lead to an early demise. For Parkinson's, it'll be a marathon not a sprint, and hopefully that will provide some reassurance."

The study was supported by a grant from the National Institute on Aging and by the Mayo Foundation for Medical Education and Research. Dr Savica has disclosed no relevant financial relationships. Disclosures for the coauthors are in the paper. Dr Beck noted no disclosures relevant to this study but reported that Dr Savica is working on a different study (on prevalence of PD) that is funded by the Parkinson's Disease Foundation.

JAMA Neurol. Published online May 15, 2017. Full article

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