A whole new imaging technique developed at MIT supplies the first peek at the degeneration of two brain structures impacted by Parkinson’s disease.
The technique, which combines several types of MRI (MRI), could allow doctors to better monitor patients’ progression and track the potency of potential new treatments, says Suzanne Corkin, MIT professor emerita of neuroscience and leader on the research team. The initial author from the paper is David Ziegler, who received his PhD in brain and cognitive sciences from MIT in 2011.
Case study, appearing inside the Nov. 26 online edition on the Archives of Neurology, is additionally the first to provide clinical evidence with the theory that Parkinson’s neurodegeneration begins deep in the brain and advances upward.
“This progression has not been proven in living people, and that’s that which was special with this study. With his new imaging methods, we could see these structures more clearly than anyone had seen them before,” Corkin says.
Parkinson’s disease currently affects one or two percent of people over 65, totaling five million people worldwide. The illness gradually destroys as their pharmicudical counterpart cells that control movement, leaving most sufferers wheelchair-bound and completely determined by caregivers. “A major obstacle to analyze around the causes and progression of this disease has become a 2010 lack of effective brain imaging strategies to areas afflicted with the disease,” Ziegler says.
In 2004, Heiko Braak, an anatomist at Johann Wolfgang Goethe University in Frankfurt, Germany, classified Parkinson’s disease into six stages, in line with the appearances in the affected brain structures. He proposed that through the earliest stages, a structure deep inside the brain, the nucleus niger, sets out to degenerate. This structure is critical for movement and as well plays important roles in reward and addiction.
Later, Braak proposed, degeneration spreads outward with a brain region called the basal forebrain. El born area, located behind the eyes, includes several structures that produce acetylcholine, a neurotransmitter necessary for learning and memory.
Neuropathologists (scientists who study the brains of deceased patients) had found evidence due to this sequence of events, nonetheless it had never been witnessed in living patients for the reason that substantia nigra, deep within the brain, is indeed challenging image with conventional MRI.
To beat that, the MIT team used four forms of MRI scans, because both versions uses slightly different magnetic fields, generating different images. By combining these scans, they created composite images of every patient’s brain that clearly show the substantia nigra and basal forebrain. “Our new MRI methods offer an unparalleled view these two structures, allowing us to calculate may volumes of each and every structure,” Ziegler says.
After scanning normal brains, they studied 29 early-stage Parkinson’s patients. They found significant lack of volume inside the substantia nigra early on, as well as decrease of basal forebrain volume later inside disease, as predicted by Braak.
In the future studies, this MRI technique could possibly be employed to follow patients after some time and measure whether degeneration of these two areas is correlated or should they deteriorate independently of one another, Corkin says.
This strategy could also give doctors an alternative way to monitor how their patients are answering and adjusting treatment, she says. (Most patients are addressed with dopamine, which assists to beat the loss of dopamine-producing neurons in the nucleus niger.) Researchers could also utilize the new imaging tools to discover the effects of potential new treatments.