Diagnosis of Parkinson's disease is not easy or straightforward: it can often be hard to distinguish from other diseases. Currently, clinicians have to rely on medical history and neurological examination, as there are no reliable radiologic techniques to aid in diagnosis.
Now, new research suggests a special type of magnetic resonance imaging (MRI), which shows high-resolution, detailed views of the part of the brain affected by Parkinson's, may help to detect the disease earlier.
Parkinson's disease is a chronic, progressive neurological disorder that results from loss of brain cells that produce dopamine, a chemical that helps brain cells communicate and control movement.
The disease is characterized by shaking, stiffness, and impaired balance and coordination. There is currently no cure, but early diagnosis would help choose the best course of treatment quickly for many of the millions affected by the disease worldwide.
In this latest study, to be published this week in the journal Radiology, Dr. Mirco Cosottini, of Italy's University of Pisa, and colleagues examined the brains of 38 people, including 17 patients with Parkinson's disease and 21 healthy individuals who acted as controls. They also had a brain specimen from a person who had died.
The point of their study was to find out whether ultra-high-field 7-Tesla (7-T) MRI, which operates at a higher resolution than more common types of MRI, would be sufficiently accurate at identifying Parkinson's, and whether it would be useful in helping diagnose the condition.
7-T MRI achieved high level of accuracy in Parkinson's diagnosis
They found that it was. With the higher-resolution images, the researchers could better see what was going on in the part of the brain affected by Parkinson's - a crescent-shaped mass of cells in the midbrain called the substantia nigra (SN).
The researchers found the higher-resolution MRI images helped them distinguish a three-layered organization of the SN.
Loss of dopamine-producing cells in this part of the brain is a hallmark of Parkinson's. Dopamine is an important brain chemical essential for many functions that affect movement, mood, reward, stress and addiction.
Based on the abnormalities in the SN that the researchers found using 7-T MRI, they correctly classified patients with Parkinson's disease with 100% sensitivity and 96.2% specificity.
Sensitivity and specificity are used to assess the accuracy of a diagnostic tool. Simply put, sensitivity helps rule out disease when the test is negative, and specificity helps rule in the disease when the test is positive.
Results show promise for supporting Parkinson's diagnosis with a radiologic assessment
Dr. Cosottini says these figures show promise for using 7-T MRI to help detect Parkinson's earlier, and thus get patients onto the treatment they need more promptly:
"Parkinson's disease diagnosis remains clinically based, but with the introduction of 7-T MRI into clinical practice, a supporting radiologic diagnosis can be made."
The team is now exploring whether 7-T MRI may help diagnose or investigate other brain conditions such as cognitive impairment, which can lead to Alzheimer's disease.
In December 2013, Medical News Today reported how fine-tuned MRI may help MS diagnosis. Researchers writing in the Proceedings of the National Academy of Sciences described how an MRI approach called quantitative susceptibility mapping (QSM), once improved, could be used to diagnose multiple sclerosis earlier and to track its progression.
Written by Catharine Paddock PhD