The degeneration of two brain structures affected by Parkinson’s disease can now be seen by using a new imagine technique which may also enable doctors to improve the monitoring of a patient’s progression and even detect the benefits of new therapies.

The technique combines several kinds of magnetic resonance imaging (MRI) and was created by a team at MIT led by Suzanne Corkin, MIT professor emerita of neuroscience.

The research was published in Archives of Neurology was the first to support the theory that Parkinson’s neurodegeneration starts deep in the brain and proceeds upward with clinical evidence.

“This progression has never been shown in living people, and that’s what was special about this study. With our new imaging methods, we can see these structures more clearly than anyone had seen them before,” Corkin said.

One to two percent of people older than 65 struggle with Parkinson’s disease, meaning five million people are affected with the disease around the world. The brain cells that are in charge of movement slowly become destroyed, which is why the majority of those affected need wheelchairs and are very dependent on caregivers.

“A major obstacle to research on the causes and progression of this disease has been a lack of effective brain imaging methods for the areas affected by the disease,” David Ziegler, first author and received his PhD in brain and cognitive sciences from MIT in 2011, explained.

Parkinson’s was categorized into 6 stages in 2004 by Heijo Braak, an anatomist at Johann Wolfgang Goethe University in Frankfurt, Germany, based on the appearances of the structures of the brain that become harmed.

He proposed that the substantia nigra, a structure deep inside the brain that is important for movement and plays a part in reward and addiction, starts to degenerate during the earliest stages.

Braak then proposed that degeneration extends to a part of the brain located behind the eyes called the basal forebrain, which consists of many structures that create acetylcholine – a neurotransmitter critical to learning and memory.

Neuropathologists, scientists who analyze the brains of patients who have died, found evidence for this series of events. However, since the substantial nigra is such a challenge to image with traditional MRI because it is deep within the brain, it had never been examined in living patients.

In order to fix that problem, the experts used 4 types of MRI scans which all generated different images because each used moderately different magnetic fields. The scans were then combined, which created compound images of each person’s brain that distinctly displayed the substantia nigra and basal forebrain.

“Our new MRI methods provide an unparalleled view of these two structures, allowing us to calculate the precise volumes of each structure,” Ziegler said.

The team scanned brains of healthy people and then examined the brains of 29 early-stage Parkinson’s patients. As Braak anticipated, the scientists found a considerable loss of volume in the substantia nigra early on, and then saw a loss of basal forebrain volume later in the disease.

According to Corkin, subsequent research could use this MRI technique to follow patients and determine whether the degenerate of the 2 brain areas are connected or if they worsen separately with no correlation.

Clinicians could also use this method as a new way to monitor how their patients are reacting to therapy, she added. Dopamine is often used to treat patients, which helps to conquer the loss of neurons that produce dopamine in the substantia nigra.

Scientists can even use this new imaging procedure to discover the effectiveness of new treatments, Corkin concluded.

Written by Sarah Glynn