Researchers from New York University in New York City have suggested that magnetic resonance spectroscopy (MRS) could help doctors predict the course of disease in patients with multiple sclerosis (MS).
At the 2003 RSNA meeting last week, professor of radiology Oded Gonen, Ph.D., said that by studying N-acetylaspartate (NAA) levels, researchers may also be able to tell how well medications and investigative therapies are performing in controlling the progressive disease.
Because MS has such a varying course -- episodic attacks can occur weeks, months, or years apart -- doctors usually wait for the second attack before declaring that a person has MS, Gonen said.
"Patients want to know: 'What is going to happen to me?'" he explained. "We think that magnetic resonance spectroscopy to determine levels of NAA is potentially a better indicator to monitor disease progression and severity in multiple sclerosis."
By earlier diagnosis of multiple sclerosis, doctors may be able to initiate treatment sooner. Although present medications do not alter the course of the disease, the injections are proven to reduce the number of exacerbations involved in the disease process, Gonen said.
MRS measures NAA levels, with a reduced NAA correlating to the death of brain cells. Gonen said that he believes these results will resolve a controversy over whether the brain cells die in response to atrophy of the brain, or if the cells die first before the atrophy occurs.
This study of NAA levels was done in 42 patients with MS, and among a healthy control population. Cross-section macroscopic and microscopic deficits were evaluated with MRI and whole-brain NAA, non-localized 1H MRS. According to the results, NAA declined 3.6 times faster in MS patients over time, indicating that neuronal cell injury precedes brain atrophy.
Gonen said that measuring NAA levels with MRS could aid in the development of MS drugs, particularly to see if the pharmaceuticals are effectively controlling the disease.
"MS is a disease described by some as wearing an uncomfortable shoe for 50 years," Gonen said. "People with multiple sclerosis have nearly a normal longevity or about 70-75 years. That means if they are diagnosed with MS in their 20s they are looking towards 50 years of fighting a step-by-step deterioration."
Commenting on the study was Dr. David Yousem, director of neuroradiology and professor of radiology at Johns Hopkins University in Baltimore. Yousem said that Gonen's work was surprising because it indicated changes in the gray matter of people with MS. Previous evidence indicates that MS is a white matter disease, he said.
"Another novel aspect of this work is that it attempts to assess disease before clinical manifestations occur and predict how the patient will respond," Yousem said. However, "we will still diagnose this disease on the basis of clinical evidence -- the symptoms experienced by the patient," Yousem commented. In such an environment, MRS could find a niche as an affirmation test for an MS diagnosis.
By Edward SusmanAuntMinnie.com contributing writer
December 8, 2003
Related Reading
MRI may speed MS diagnosis, September 12, 2003
Brain lesion in optic neuritis linked with increased risk of MS, July 17, 2003
SPECT highlights hypoperfusion in multiple sclerosis, April 24, 2003
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