Brain Iron Levels Associated With Disability, Disease Progression in MS

A recent study published in Radiology found that evaluating the differences in iron accumulation in the deep gray matter of the brain using a magnetic resonance imaging (MRI) technique may help to identify patients with multiple sclerosis (MS) that are at greater risk for disease progression and disability.

Currently, physicians use brain atrophy measurements as a predictor of cognitive and physical disability in MS, but it has limitations. “Brain atrophy takes a long time to see. We need an earlier measure of who will develop MS-related disability,” said lead study author Robert Zivadinov, MD, PhD professor of neurology at the Jacobs School of Medicine and Biomedical Sciences at the University of Buffalo in a statement.

Researchers used quantitative susceptibility mapping (QSM) to assess the relationship between susceptibility and clinical disability in a prospective study that took place between March 2009 and November 2013. The study included 600 patients with MS, 452 with relapsing-remitting MS and 148 with secondary progressive MS. In addition, the study included 250 age- and sex-matched healthy control participants imaged with a 3.0-T MRI to calculate magnetic susceptibility.

The study found that compared with control participants, patients with MS presented with lower thalamic susceptibility (-7.5 ppb vs -1.1 ppb; P <.001) and a higher susceptibility of basal ganglia (62 ppb vs 54.8 ppb; P <.001). Lower iron content in the thalamus and high iron content in other deep gray matter structures of patients with MS were associated with longer disease duration, higher disability degree and disease progression.

“In this large cohort of MS patients and healthy controls, we have reported, for the first time, iron increasing in the basal ganglia but decreasing in thalamic structures. Iron depletion or increase in several structures of the brain is an independent predictor of disability related to MS,” said Zivadinov.

The researchers concluded that monitoring iron accumulation in the brain may be able to better identify patients with MS that are at greater risk for developing physical disability. In addition, the study authors also suggested that iron levels may be applicable as a potential readout in clinical trials testing experimental MS therapies.

Reference

Zivadinov R, Tavazzi E, Bergsland N, et al. Brain iron at quantitative MRI is associated with disability in multiple sclerosis [published online July 17, 2018]. Radiology. doi.org/10.1148/radiol.2018180136.