Researchers in the Sastry Advanced Imaging Laboratory and Movement Disorders in the Wayne State University School of Medicine's Department of Neurology have published a novel magnetic resonance imaging technique to quantify in-vivo tissue loss in the brains of patients with Parkinson's disease.

The study published in the Movement Disorders Journal, the official journal of the World Movement Disorders Society, is the first to demonstrate longitudinal loss of dopaminergic cellular loss in the substantia nigra, a pathologic hallmark of Parkinson's disease.

Omar Khan, M.D., professor and chair of WSU Neurology and the study's principal investigator, said, "The value of biomarkers in early diagnosis and development of therapeutics in Parkinson's disease and other neurodegenerative disorders is a critical need," said Omar Khan, M.D., professor and chair of WSU Neurology and the study's principal investigator. "We used proton magnetic resonance spectroscopy in a prospective, longitudinal study of patients with early Parkinson's disease, naïve to dopaminergic therapy, and compared to age-matched healthy controls to examine the temporal changes in the metabolic profile of substantia nigra over a period of three months. In 90 days from baseline, total N-acetyl aspartate (neuronal metabolic marker) had decreased by 4.4 percent, which was a significant decline compared to age-matched controls that did not demonstrate any change."

This is the first longitudinal MRS study of substantia nigra in Parkinson's disease, he said. Previous studies were either cross-sectional, lagged refined acquisition parameters or often incorporated a single voxel.

Navid Seraji-Bozorgzad, M.D., assistant professor of Neurology and associate director of the Sastry Advanced Imaging Laboratory, is the lead author of the study. He developed the novel technique of "side-to-side asymmetry" used in the study.

"Patients with early Parkinson's disease develop asymmetric loss of dopaminergic neurons in the right and left substantia nigra," he said. "This often correlates with unilateral symptoms such as tremor before patients develop symptoms bilaterally. Our results showed that the side-to-side asymmetry was 16.7 percent in patients with Parkinson's disease compared to 1.6 percent in age-matched healthy controls. This is a remarkable potential diagnostic tool that needs to be explored in large multi-center studies and has the potential to assist in the diagnosis of patients suspected with early Parkinson's disease, when making the clinical diagnosis can be challenging."

Edwin George, assistant professor of Neurology and director of the Movement Disorders Center, said, "This is an exciting discovery that has potentially significant clinical implications not only in confirming the diagnosis of Parkinson's disease but also in developing novel therapeutic agents incorporating this biomarker approach."

Dr. Khan, director of the Sastry Foundation Advanced Imaging Laboratory, said this approach "has the potential to accelerate the development of potential therapies that may alter disease course in Parkinson's disease. We are very fortunate to have the support of the Sastry Family Foundation, and are optimally poised to seek major external grants as well as develop collaborations to conduct validation studies."