More science news
Researchers have identified characteristics that may help doctors to predict progression of symptoms in some people living with Parkinson’s disease (PD). In the online January 23 issue of Neurology, investigators report improvements in predicting which individuals will experience more or less severe motor symptoms and disability in the five years following a PD diagnosis.
The progression of PD symptoms varies substantially among individuals. Five years after diagnosis, some people develop severe symptoms that cause them significant disability, while others show only a slight worsening of their symptoms. But doctors have difficulty identifying which individuals will progress more quickly or more slowly.
Researchers led by Daan Velseboer, M.D., at Radboud University Nijmegen Medical Center, in the Netherlands, wanted to know if certain characteristics of people with newly diagnosed PD could help them predict who would suffer more severe disability five years down the road. So the team studied 129 people with PD at the time of diagnosis and one, two, three and five years later. Each time, the researchers assessed the participants’ motor symptoms, disability and quality of life. They looked for correlations between these levels and characteristics at the time of diagnosis, such as age, sex, cognitive dysfunction and the presence of levodopa-nonresponsive motor symptoms such as impaired speech, posture or gait.
Researchers found that two groups: people with cognitive impairment at the time of PD diagnosis and men in general, showed a more rapid progression of motor symptoms during the five-year period.
Three groups showed a more rapid increase in disability: people with cognitive impairment, people who were older when they started experiencing PD symptoms, and people with levodopa-nonresponsive motor symptoms at the time of diagnosis.
What Does It Mean?
PD progresses differently in different people. This study identified some characteristics of people who may undergo a more rapid progression of the disease.
Most of these characteristics have been identified in previous retrospective studies. The confirmation provided by this prospective study, that followed people with PD from the onset of the disease, may help doctors predict the course of disease in a given individual. This could enable people with PD and their families to better plan and prepare for the future.
The most important factor the study identified in determining progression of PD, is an individual’s responsiveness to the PD medication, levodopa. Levodopa and related drugs known as dopamine agonists can improve some motor symptoms of PD, such as tremors and stiffness. However, other symptoms do not respond to levodopa treatment and can significantly affect a person’s level of disability and quality of life.
People with cognitive impairment at the time of PD diagnosis, which also is not helped by levodopa had both a more rapid progression of motor symptoms and increase in disability. People who have cognitive problems usually have more advanced disease, which may explain why their PD progressed more rapidly. Also, this study found that people who were older at the time of PD diagnosis had a faster rate of disability. Older people also tend to more rapidly experience levodopa-nonresponsive symptoms, which could contribute to their increased disability.
For people with PD, an encouraging finding of this study is that the majority of participants experienced very little deterioration in quality of life in the five years after PD diagnosis. This finding suggests that, despite worsening motor symptoms and disability, people with PD can still maintain a satisfactory quality of life in the first few years after diagnosis.
Reference: Velseboer DC, Broeders M, Post B, van Geloven N, Speelman JD, Schmand B, de Haan RJ, de Bie RMA, CARPA Study Group (2013) Prognostic factors of motor impairment, disability, and quality of life in newly diagnosed PD. Neurology 80:627–633. DOI: 10.1212/WNL.0b013e318281cc99