When someone is diagnosed with a serious disease, they often ask how their life and lifespan will be affected. A recent study by the Mayo Clinic analyzed survival and cause of death for individuals with Parkinson’s disease or Parkinson’s-like symptoms from synucleinopathy as compared to the general population.
Synucleinopathies are neurogenerative diseases associated with abnormal deposits of alpha-synuclein proteins in neurons and nerve fibers. There are three main types of synucleinopathy: Parkinson’s disease, dementia with Lewy bodies (clumps of alpha-synuclein proteins in the brain), and multiple system atrophy. Although each has its own distinct set of symptoms and prognosis, all are associated with shorter lifespans.
In a 2017 article published in JAMA Neurology, researchers from the Mayo Clinic in Rochester, Minnesota conducted a large-scale population-based study to compare survival and causes of death amongst patients diagnosed with the three types of synucleinopathy.
The Mayo Clinic researchers examined medical records from 1991 through 2010 from the Rochester Epidemiology Project, a database of Olmsted, Minnesota’s general population. They identified 461 individuals who had been diagnosed with synucleinopathies and Parkinson’s-like symptoms (rest tremor, slowness of movement, rigidity, and impaired postural reflexes) which they refer to as parkinsonism:
- Parkinson’s disease (N=309)
- Parkinson’s disease with dementia (N=55)
- dementia with Lewy bodies and with parkinsonism (N=81), or
- multiple system atrophy with parkinsonism (N=16).
Each individual was matched by sex and age to another Olmsted resident without parkinsonism. Approximately 60% of each group were men.
Over the course of 19 years, 68.6% of the patients and 48.7% of the matched residents passed away. By analyzing death certificates and using Kaplan-Meier survival curves, researchers found that individuals with multiple system atrophy and Parkinson’s-like symptoms had the greatest mortality risk compared to the general population, living, on average, 6 years less. People with dementia with Lewy bodies died an average of 4 years earlier. People with Parkinson’s disease with dementia died an average of 3.5 years earlier, while people with Parkinson’s alone typically lived 1.75 fewer years. The difference in lifespan amongst the different disorders may reflect different severities of the disease, as well as different rates of accumulation and location of alpha-synuclein protein deposits.
Amongst those with synucleinopathy, neurodegeneration was the most commonly listed cause of death (31.5%), followed by cardiovascular disease (15.7%). Among the comparison group, the most commonly listed cause of death was a cardiovascular event (25.5%), followed by cancer (18.1%). In both groups, women lived 2 years longer than men.
This study is one of the first to examine survival rates and cause of death among people with synucleinopathies compared to the general population. As such, the authors believe that their study can help clinicians better inform patients and their caregivers about what they can expect once diagnosed.
However, this study does not shed light on how treatment and lifestyle impact these lifespan outcomes. People with Parkinson’s and Parkinson’s-related diseases live many years with the disease. As such, healthcare professionals should still take an individualized approach to prognosis, treatment, and financial counseling.
Written by Debra A. Kellen, PhD