The MRI-based technique of quantitative susceptibility mapping can monitor iron levels in the brains of multiple sclerosis (MS) patients, allowing physicians to identify those at a higher risk of developing physical disability, according to research in Radiology published online July 17.
The study, from a team at the State University of New York at Buffalo, demonstrated the technique can detect MS-related disability earlier than brain atrophy—and it has the potential to be used to test the effectiveness of MS drugs.
"[MS] can progress in many patients, leaving them severely disabled. Brain atrophy is the current gold standard for predicting cognitive and physical decline in MS, but it has limitations," said lead author Robert Zivadinov, MD, PhD, professor of neurology at the Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo in New York, in a prepared statement.
Between March 2009 and November 2013, Zivadinov and colleagues used quantitative susceptibility mapping to measure brain iron levels in 600 MS patients—452 with early-stage MS and 148 whose MS was more advanced—and compared them to the brain iron levels of 250 healthy control patients. A brain region with more iron would have higher deep gray matter magnetic susceptibility, according to the researchers.
Compared to the control group, MS patients had higher levels of iron in the basal ganglia, which are responsible for movement, but decreasing levels of iron in thalamic structures, which help process sensory input from the spinal cord, Ziavadinov et al wrote. Additionally, these findings were associated with longer duration of MS, higher disability degree and disease progression.
“Iron depletion or increase in several structures of the brain is an independent predictor of disability related to MS," Zivadinov said. “Susceptibility is an interesting imaging marker of disease severity that can predict which patients are at severe risk of progressing. To be able to act against changes in susceptibility would be extremely beneficial.”