According to research published in JAMA Neurology, people with Parkinson disease (PD), who show symptoms of mild cognitive impairment, are at an increased risk of early dementia.
As part of the Norwegian ParkWest study – which is analyzing the incidence and prognosis of PD in Norway – researchers analyzed the extent of mild cognitive impairment in PD patients and its progression to full blown dementia.
Dementia is a progressive deterioration in cognitive function – intelligence. As the condition is progressive, symptoms gradually get worse. It can be caused by either damage (such as stroke) or disease (such as Alzheimer’s). According to the World Alzheimer Report, there are around 35 million people in the world living with dementia.
A total of 182 patients with PD were included in the study. The research, led by Kenn Freddy Pedersen, M.D., Ph.D., of Stavanger University Hospital, Norway, involved monitoring these patients for three years to identify any trends in dementia progression.
Mild cognitive impairment (MCI) progression to dementia was far more common among patients with initial MCI at baseline compared to those without (27 percent versus 0.7 percent).
21.6 percent of patients with MCI at baseline had normal cognition by the end of the follow up period.
MCI at the one-year follow up was also associated with increased risk of dementia, with 27.8 percent of patients with MCI at the one-year visit eventually progressing to dementia.
Nearly half of patients (45.5 percent) who had MCI at baseline, as well as the one-year visit, went on to develop dementia. Only 9 percent of these patients had MCI that recovered back to normal cognition.
According to the study authors:
“This prospective population-based study of an incident PD cohort demonstrates that MCI within the first year of PD diagnosis signals a highly increased risk for early incident dementia. More than 25 percent of patients with MCI at diagnosis of PD developed dementia within three years of follow-up compared with less than 1 percent of patients without MCI at PD diagnosis.
Among patients with MCI at baseline and one year of follow-up, almost half progressed to dementia. These findings support the validity of the MCI concept in patients with early PD.”
In addition, according to previous research published in Archives of Neurology, not only are PD patients at an increased risk of dementia, but the relatives of the patient are as well – due to families sharing susceptibility genetic variants.
Written by Joseph Nordqvist