January 5, 2025
A new research paper from Mayo Clinic and the Karolinska Institutet suggests that the brain’s energy use levels decline measurably early in the course of the disease.
Among people living with dementia with Lewy bodies (DLB), a type of brain scan called FDG-PET commonly reveals low energy usage in the brain, particularly in the area of the brain associated with vision. In fact, this is so common that doctors consider it a supportive biomarker for the diagnosis of DLB. However, until now it has not been clear when this change begins.
What was done in the study?
To help answer the question of when this change begins, the researchers examined FDG-PET scans from the brains of 172 volunteers. One hundred volunteers had no cognitive impairment, thirty-seven had mild cognitive impairment due to Lewy bodies (MCI-LB), and thirty-five had DLB. MCI-LB is a condition that often progresses to DLB and can be thought of as an early form of DLB. When the researchers later re-examined the individuals with MCI-LB, they found that 49% of them had progressed to DLB.
What were the findings?
Energy use in the brain declines even in normal aging. However, the FDG-PET scans revealed that volunteers with MCI-LB had faster decline in many areas of the brain associated with dementia. And volunteers with DLB had faster decline in the same areas, along with several additional areas, indicating a further decline in brain energy use as the disease progressed. Furthermore, the researchers found that these reductions in brain energy use were associated with the rate of change in the symptoms the volunteers experienced as measured by an assessment that is commonly used in clinical trials.
Will this change medical practice?
Not yet. These results are important, but they need to be confirmed in additional studies with larger groups of volunteers.
However, taken together, these results provide critical clues to researchers, particularly when planning clinical trials that may slow or stop the progression of DLB. The results suggest that the changes begin early – in the MCI-LB stage or possibly even before – and that they correspond to changes in symptoms that can be measured in clinical trials. If the results hold up, they may point toward both a time to intervene with a drug anda method for examining the drug’s effectiveness.
Reference:
Ferreira D, Przybelski SA, Lesnick TG, Diaz-Galvan P, Schwarz CG, Murray MM, Dickson DW, Nguyen A, Reichard RR, Senjem ML, Gunter JL, Jack Jr CR, Min PH, Jain MK, Miyagawa T, Forsberg LK, Fields JA, Savica R, Graff-Radford J, Ramanan VK, Jones DT, Botha H, St Louis EK, Knopman DS, Graff-Radford NR, Day GS, Ferman TJ, Kremers W, Petersen RC, Boeve BF, Lowe VJ, and Kantarci K. 2025. Longitudinal FDG-PET Metabolic Change Along the Lewy Body Continuum. JAMA Neurology, published online January 13, 2025. doi:10.1001/jamaneurol.2024.4643