Parkinson's disease is bad enough, but when it also involves dementia, the condition is particularly difficult. A recent study published online in PLoS ONE suggests that lipids involved in ceramide metabolism may serve as a biomarker for people with Parkinson's who are at increased risk for mild cognitive impairment.
"I'm excited about this," Michelle Mielke, associate professor of epidemiology and neurology at the Mayo Clinic in Rochester, MN, told Medscape Medical News. "I think it opens up a whole new avenue of research. We can look at this pathway and see if it's related to the development of (Parkinson's) as well as whether it's a specific biomarker for cognitive impairment in (Parkinson's)."
The most common genetic risk factor for sporadic Parkinson's is mutation in the gene coding for glucocerebrosidase (GBA), which metabolizes glucosylceramide, a monohexosylceramide, into glucose and ceramide, Medscape explains. Those people who carry that mutation are at an increased risk of getting Parkinson's at an earlier age and then developing cognitive impairment and dementia. That led the authors to consider that lipids involved in ceramide metabolism might also be altered in Parkinson's non-GBA mutation carriers.
In a small study, researchers found that patients with Parkinson's had significantly higher levels of nearly all ceramide, monohexosylceramide and lactosylceramide species compared with the control group. Since levels did not differ between patients with Parkinson's or mild cognitive impairment and those with dementia, the researchers combined these groups. The combined group showed much higher levels of certain ceramide and monohexosylceramide species, and the levels were highest in those patients with Parkinson's disease who also had dementia or mild cognitive impairment. Among patients with Parkinson's, the study also found a significant correlation in some cases for symptoms of depression.
Dr. Mielke told Medscape that the the researchers are seeking funding to try to replicate the results in a group of 500 patients with Parkinson's. If they are able, then the lipids could be used as a potential biomarker and this pathway could become a treatment target, she said. It might provide some insight into other neurodegenerative conditions as well.