Functional MRI Reveals Distinct Patterns of Disease Progression in Parkinsonian Disorders

Neurology Reviews. 2016 October   

David Vaillancourt, PhD

A new way to track the progression of Parkinson’s disease could help evaluate experimental treatments aimed at slowing or stopping the disease’s progression. “We provide evidence using task-based functional MRI (fMRI) for cortical and striatal functional deterioration in Parkinson’s disease over a one-year period,” researchers reported in the August 16 issue of Neurology.

Study results also describe unique patterns of functional changes in patients with multiple system atrophy (MSA) and progressive supranuclear palsy (PSP) that are more widespread, compared with those in Parkinson’s disease, suggesting that distinctive rates of disease progression in parkinsonian disorders may assist in future clinical studies of disease-modifying therapies.

While current treatments focus on controlling symptoms, biomarkers provide a quantifiable way to measure how medications address not just symptoms, but the neurologic changes behind them. Previous studies have used imaging techniques that require the injection of a drug that crosses the blood–brain barrier. “Our technique does not rely upon the injection of a drug. Not only is it noninvasive, it is much less expensive,” said senior study author David Vaillancourt, PhD, a Professor in the Department of Applied Physiology and Kinesiology at the University of Florida, Gainesville.

Dr. Vaillancourt and research colleagues used fMRI to evaluate five areas of the brain that are key to movement and balance—the putamen, primary motor cortex, supplementary motor area, and superior motor regions of the cerebellum (lobules V and VI).

A total of 112 individuals were scanned at baseline and at one year while preforming a unimanual grip force task. The study cohort included 46 patients with Parkinson’s disease, 13 patients with MSA, 19 patients with PSP, and 34 healthy controls. The outcome measure was percent signal change in the prespecified brain regions.

A year after the baseline study, the 46 patients with Parkinson’s disease showed declining function in the primary motor cortex and putamen, compared with controls. Changes after one year in patients with MSA were exclusively extrastriatal and included a reduction in functional activity in the primary motor cortex, supplementary motor area, and superior cerebellum. In patients with PSP, all regions of interest were less active at one year, compared with baseline. Functional activity of the brain regions in the control group did not change during the study.

“Collectively, these findings point to disease-specific noninvasive progression markers of sensorimotor brain regions in parkinsonian disorders,” the researchers said.

The present findings build on two 2015 studies that used fMRI to document progressive deterioration from Parkinson’s disease, MSA, and PSP.

Suggested Reading

Burciu RG, Chung JW, Shukla P, et al. Functional MRI of disease progression in Parkinson disease and atypical parksonian syndromes. Neurology. 2016;87(7):709-717.

Burciu RG, Ofori E, Shukla P, et al. Distinct patters of brain activity in progressive supranuclear palsy and Parkinson’s disease. Mov Disord. 2015;30(9):1248-1258.

Oh M, Kim JS, Kim JY, et al. Subregional patterns of preferential striatal dopamine transporter loss differ in Parkinson disease, progressive supranuclear palsy, and multiple system atrophy. J Nucl Med. 2012;53(3):399-406.

Planetta PJ, Kurani AS, Shukla P, et al. Distinct functional and macrostructural brain changes in Parkinson’s disease and multiple system atrophy. Human Brain Mapp. 2015;36(3):1165-1179.

http://www.mdedge.com/neurologyreviews/article/114182/movement-disorders/functional-mri-reveals-distinct-patterns-disease