5:09 p.m. ET (2220 GMT) November 12, 1999
NEW YORK, Nov 12 (Reuters Health) - Early diagnosis and treatment of multiple sclerosis (MS) may slow the gradual ''shrinking'' of the brain associated with the disease, new research suggests.
Even before symptoms of the central nervous system disease appear, there may be progressive brain tissue loss, according to researchers led by Dr. Lawrence Jacobs, a professor of neurology at the State University of New York at Buffalo.
In this month's issue of the journal Neurology, the researchers report study results showing that MS patients treated with the drug interferon beta-1a experienced less brain shrinkage over 2 years than did those on a placebo (inactive) pill.
"This study has a bad part and a good part,'' Jacobs told Reuters Health in an interview. "The bad part is that (in many MS patients) there is a relentless progression in brain shrinkage. The good news is that we have a medication that seems to slow it.''
Jacobs and colleagues reviewed the magnetic resonance imaging (MRI) scans of 140 MS patients who had participated in a 2-year clinical trial of interferon beta-1a, marketed as Avonex since its approval for MS treatment in 1996. All of the patients had relapsing-remitting MS, an earlier stage of the disease marked by recurrent, damaging inflammation in the brain and spinal cord. Episodic symptoms of memory loss, slurred speech, and loss of muscle control grow more severe as the MS progresses.
Despite being in the early stages of MS, the patients showed brain shrinkage, or atrophy, when compared with healthy control subjects, Jacobs' team reported. Brain scans of the 68 patients who received Avonex and the 72 who did not reveal that during the first year of treatment, both groups had comparable brain atrophy.
During the second year, however, Avonex patients experienced 55% less shrinkage than placebo patients. The study was not designed to track whether reduced brain shrinkage led to reduced disability, Jacobs said. However, he noted that in the original study analysis that led to Avonex's approval, the drug was found to slow the progression of disability. "For example,'' he said, "it reduced the number of patients who required a cane.''
Previous research, Jacobs noted, has shown that MS attacks not only the sheath that insulates nerve fibers, but also the nerve fibers themselves. "We presume,'' he said, "that brain atrophy occurs because brain fibers have died.'' Early treatment of MS, according to Jacobs and his colleagues, may help preserve this brain tissue.
Still, Avonex's long-term effects on brain volume remain to be seen, Jacobs said. Also unknown is whether patients' degree of brain atrophy early on predicts the severity of their disability later. In a statement, the National Multiple Sclerosis Society (NMSS) noted that further studies are needed to answer several questions, including what brain atrophy means in the progression of MS and whether the MRI scans captured actual brain shrinkage or some other occurrence, such as fluid loss.
According to the NMSS, about 350,000 Americans have MS, a disease that
can strike at any age, but usually appears during the 20s or 30s.
SOURCE: Neurology 1999;53:1698-1704.