People newly diagnosed with Parkinson's disease who have minor thinking
problems may be on the way to early dementia, according to a new Norwegian
Some people with Parkinson's go on to develop dementia, but whether it is
possible to predict who will fall into this group hasn't been clear. In this new
study, researchers wanted to see if early signs of thinking problems would
indicate who these patients might be.
"Mild thinking problems seem to be an important clinical concept for early
detection of patients with Parkinson's disease who are at risk to develop
dementia," said lead researcher Dr Kenn Freddy Pedersen, from the Norwegian
Center for Movement Disorders at Stavanger University Hospital.
"Specifically, we found that more than 27% of patients with thinking problems
at diagnosis progressed to dementia during the first three years of follow-up,"
he said. "Even more interesting, almost half of the patients with persistent
thinking problems one year after diagnosis developed dementia during the next
Importance of findings
One result was more encouraging: For some patients, thinking ability returned
to normal over the course of the study.
Although there is no immediate clinical implication to the new findings, they
may be important for trials of drugs that might slow or reverse the process
leading to dementia, and the findings may also help in managing patients,
Dr Brian Copeland, a movement disorder fellow at the University of Texas
Medical School at Houston and co-author of an accompanying journal editorial,
said the study indicates that patients with ongoing evidence of thinking
problems are at higher risk of getting dementia.
Although identifying patients with thinking problems is easy to do when
Parkinson's disease is diagnosed, there isn't a way to accurately classify
patients, so it isn't clear whether early thinking problems really predict
dementia, he said.
"[The finding's] value in predicting Parkinson's disease dementia is less
clear and needs further research," Copeland said.
The study and what was
To map the course of thinking problems in Parkinson's patients, Pedersen's
team followed 182 patients for three years. Participants completed a battery of
screening exams, including tests of their memory, verbal fluency and
During the study, 27% of patients who had thinking problems at diagnosis went
on to develop dementia, compared with 0.7% of those who didn't have thinking
problems, the researchers said.
For some patients, however, normal thinking returned. Among those with
thinking problems, about 19% saw their thinking problems clear up, Pedersen's
The progression to dementia was also dependent on how severe the patient's
thinking problems were, the researchers noted.
Among patients with the most severe thinking problems at the start of the
study and one year later, 45.5% went on to develop dementia while only about 9%
saw their thinking restored to normal, the researchers said.
Although the study found an association between mild thinking problems in
patients newly diagnosed with Parkinson's disease and later dementia, it did not
establish a cause-and-effect relationship.
To learn more about Parkinson's disease, visit the US
National Institute of Neurological Disorders and Stroke.