New MR Technique May Allow Earlier Diagnosis Of MS

A new method to measure the virulence of multiple sclerosis (MS) can help physicians be more exact and aggressive in treating a disease that robs people of their youth and vitality, according to research presented at the 2003 Annual Meeting of the Radiological Society of North America (RSNA).

Using magnetic resonance (MR) spectroscopy, researchers developed a method called whole brain N-acetylaspartate (WBNAA) to measure the severity of a patient's MS and gauge how well the drugs used to treat the disease are working. The new procedure is performed at the same time the patient undergoes clinical MR imaging. The radiologist adds MR spectroscopy, which provides chemical information at the cellular level.

Multiple sclerosis is an autoimmune disease affecting approximately 400,000 people in the United States, according to the National Multiple Sclerosis Society. Over 10,000 new cases of MS are diagnosed each year, mostly among people between the ages of 20 and 50. Women are two to three times more likely than men to develop MS.

MS attacks the central nervous system, resulting in a loss of myelin, the protective layer around nerve fibers. With damaged or lost myelin, the nerves' ability to conduct electrical impulses to and from the brain is disrupted, resulting in various symptoms that can include memory loss, depression, fatigue, pain or numbness, dizziness, difficulty in walking or maintaining balance, sexual dysfunction, and bladder and bowel dysfunction.

Symptoms vary widely in severity among individuals. Therefore, it is imperative to closely tailor therapy to an individual's needs. Early diagnosis and proper treatment are key to minimizing the symptoms and damaging effects of MS.

The researchers studied 42 patients (30 women, 12 men, median age 38 years) with 0-12 years of relapsing-remitting MS. Relapsing-remitting is the most common form of MS-accounting for 85 percent of cases at initial diagnosis-and is characterized by flare-ups of symptoms followed by partial or complete recovery periods lasting months to years.

The researchers found that both the rate of brain atrophy, which is a currently accepted radiological marker of disease progression, and NAA exhibited significant decline with disease duration, at a rate of 0.5 percent and 1.8 percent, respectively, per year. Based on this disparity in loss rate, they determined that neuronal cell injury occurs before atrophy, not as a result. Because these changes are occurring even before symptoms become noticeable, it is evident that WBNAA is an earlier, more sensitive and more specific measure of ongoing disease activity. Therefore, the researchers concluded that early treatment monitoring and drug development should focus on WBNAA in addition to previous markers.

Created: 1/20/2004  -  Donnica Moore, M.D.