(HealthDay News) – Use of sodium 23 (23Na) magnetic resonance imaging (MRI) has identified dramatic increases in total sodium concentration (TSC) in the brain of patients with advanced relapsing-remitting multiple sclerosis (RR MS), with increased sodium in gray matter correlating with disability.

In an effort to examine sodium abnormalities at different stages of RR MS, Wafaa Zaaraoui, PhD, of Aix-Marseille University in France, and colleagues conducted a three-dimensional 23Na MRI study involving 14 patients with early RR MS (disease duration of less than five years), 12 patients with advanced RR MS (disease duration of more than five years), and 15 control subjects.

The researchers found that all patients with RR MS exhibited increased TSC in demyelinating lesions, and patients with advanced RR MS had increased TSC in normal-appearing white matter and gray matter. Increased TSC in the gray matter correlated with disability (measured with the Expanded Disability Status Scale [EDSS]) and lesion load at T2-weighted imaging, but did not correlate with disease duration. Those with early-stage RR MS displayed TSC increases confined to the brainstem, cerebellum, and temporal poles, while in advanced RR MS there were widespread increases affecting the entire brain. The EDSS score correlated with elevated TSC in the motor networks.

“In conclusion, 23Na MRI showed that brain sodium accumulation is present at the early stage of RR MS and is dramatically widespread at the advanced stage of the disease concomitant to disability,” the authors write. “Brain sodium MRI may help monitor the occurrence of tissue injury and disability.”

One author disclosed financial ties to the medical device industry.

Full Text (subscription or payment may be required)