Researchers at Yonsei University College of Medicine said Thursday that they developed a model based on a neurocognitive test to predict the risk of dementia among patients in the early phase of Parkinson's disease.
Parkinson's disease is a degenerative brain disease in which neurons that secrete dopamine slowly disappear in the region called black matter located in the midbrain. Patients often accompany dementia. About 45 percent of the patients with the illness longer than 10 years and 80 percent of those who have it for more than 20 years could develop dementia.
It is essential to actively manage cognitive function by screening patients with a high risk of early onset of dementia, as Parkinson's disease patients are likely to develop the symptom in the future.
In Europe, which goes ahead in the research of dementia linked to Parkinson's disease, the cognitive domain related to the occipital cortex was suggested as a predictor. However, it is difficult to generalize the hypothesis due to limited research methods.
The Yonsei research team, led by Professors Lee Phil-hyu and Chung Seok-jong, followed 350 patients with early Parkinson's disease for an average of 5.6 years. They confirmed that the pattern of cognitive degrading in neurocognitive tests conducted during the diagnosis of Parkinson's disease could predict dementia in the future.
Researchers simplified the neurocognitive test data into scores for each area to identify each patient's cognitive decline patterns. The four divided cognitive functions are visual memory and space-time capability, language memory, frontal lobe and performance, concentration, working memory, and language skills.
The study results showed 78 out of 350 patients, or 22.3 percent, developed dementia during the follow-up. The research team also found that the frontal lobe and performance score had the most significant influence on the risk of dementia.
The risk of dementia fell by 47.2, 19.3, 57.2, and 7.7 percent for every 1-point increase in the four categories – visual memory/time-space ability, language-memorizing ability, frontal lobe/performing ability, and concentration/working memory, and language skills.
"We had limitations to developing drugs for controlling dementia without the means to predict Parkinson's disease dementia,” Professor Lee said. "We expect the lately developed model to play a significant role in finding modifiers for dementia in Parkinson's disease."