July 17, 2012

Sodium Buildup In Brain Linked To MS

(Ivanhoe Newswire) — A new study marks the beginning of important research that could potentially help develop and assess treatments for multiple sclerosis (MS).

Researchers found that patients with early-stage MS revealed a sodium accumulation in certain regions of the brain, and patients with a more advanced stage of the disease showed sodium accumulation throughout the whole brain. There was a direct correlation between sodium buildup in motor areas of the brain and the degree of disability in the advanced stage patients.

"A major challenge with multiple sclerosis is providing patients with a prognosis of disease progression," Patrick Cozzone, Ph.D., director emeritus of the Center for Magnetic Resonance in Biology and Medicine, a joint unit of National Center for Scientific Research (CNRS) and Aix-Marseille University in Marseille, France, was quoted as saying. "It's very hard to predict the course of the disease."

MS causes the body´s immune system to attack the protective myelin sheath covering nerve cells in the brain and spinal cord. This results in scarring which affects the neurons´ ability to conduct signals, thus causing neurological and physical disability. The type and severity of symptoms differ from one patient to another.

Dr. Cozzone, Wafaa Zaaraoui, Ph.D., research officer at CNRS, Jean-Philippe Ranjeva, Ph.D., professor in neuroscience at Aix-Marseille University and a European team of interdisciplinary researchers used 3 Tesla (3T) sodium MRI to study relapsing-remitting multiple sclerosis (RRMS), the most common form of MS where clearly defined attacks of worsening neurologic function are followed by recovery periods. Sodium MRI delivers images and information on the sodium content of cells in the body.

"We collaborated for two years with chemists and physicists to develop techniques to perform 3T sodium MRI on patients," Dr. Zaaraoui was quoted as saying. "To better understand this disease, we need to probe new molecules. The time has come for probing brain sodium concentrations."

Researchers used specially developed hardware and software to conduct sodium MRI on 26 MS patients, including 14 with early stage RRMS (less than five years in duration) and 12 with advanced disease (longer than five years), and 15 age- and sex-matched control participants.

Early-stage RRMS patients had abnormally high concentrations of sodium in specific brain regions, including the brainstem, cerebellum, and temporal pole. Advanced-stage RRMS patients had abnormally high sodium accumulation widespread and throughout the whole brain, even in normal appearing brain tissue.

"In RRMS patients, the amount of sodium accumulation in gray matter associated with the motor system was directly correlated to the degree of patient disability," Dr. Zaaraoui was quoted as saying.

Current MS treatments can only slow disease progress, but this study shows how sodium accumulation can be used as a biomarker of neuron degeneration to assist pharmaceutical companies in assessing and developing potential treatments.

"Brain sodium MR imaging can help us to better understand the disease and to monitor the occurrence of neuronal injury in MS patients and possibly in patients with other brain disorders," Dr. Ranjeva was quoted as saying.

Source: Radiology. July 2012