Brain Atrophy in MS Occurs Earlier in Disease than Previously Thought
TORONTO, April 21 /PRNewswire/ -- Researchers from the Cleveland Clinic Foundation today presented findings that show that the brains of people with multiple sclerosis (MS) atrophy, or shrink, much earlier in the course of this disease, than neurologists previously thought and demonstrating for the first time that the rate of brain shrinkage can be significantly reduced with drug treatment.
Brain shrinkage, or atrophy, is irreversible and is associated with various symptoms, such as loss of memory, inability to walk and slurred speech, that are frequently experienced by people with multiple sclerosis.
According to the study, patients receiving AVONEX(R) (Interferon beta-1 a) over a two year period experienced a 55 percent reduction in the rate of brain atrophy in the second year of treatment compared to patients who received placebo. The data were presented today by Richard Rudick, M.D., director of the Mellen Center for Multiple Sclerosis Treatment and Research at the Cleveland Clinic Foundation, at the annual meeting of the American Academy of Neurology (AAN) in Toronto.
"Our study shows MS patients continually lose brain tissue, even in the early stages of the disease, when physical symptoms are still very mild," says Dr. Rudick, principal investigator of the study. "However, those patients treated with AVONEX(R) had a significantly lower rate of cerebral atrophy -- less than half after the first treatment year -- compared with placebo patients."
In the double-blind, placebo-controlled study, the magnetic resonance image (MRI) scans of 140 MS patients who participated in the two-year AVONEX(R) Phase III study were reevaluated by Dr. Rudick and his team to determine the amount of brain atrophy that had occurred, calculated as the loss of brain tissue volume relative to the cranial volume. The MRI scans were analyzed using a new image analysis method called brain parenchymal fraction (BPF), which was developed by Dr. Elizabeth Fisher, a biomedical engineer at the Cleveland Clinic Foundation. BPF calculates the amount of brain tissue as a ratio of the total brain volume. Upon study entry, the baseline MRIs showed a significantly reduced BPF in the MS patients when compared to 16 healthy controls, indicating significant brain atrophy at entry into the study.
The placebo-controlled group showed a significant reduction in BPF -- or increased loss of brain tissue -- during the first year (-0.75%) and second year (-0.53%) of observation. AVONEX(R) treatment (30 mcg injected intramuscularly once a week) had no effect on brain atrophy during the first year of observation; however, there was a statistically significant 55 percent reduction in the rate of atrophy compared with placebo recipients during the second year.
Multiple sclerosis is a disease of the central nervous system in which
most patients suffer physical disability over time. An estimated
Americans have MS, with nearly 200 new cases diagnosed every week. The disease most often strikes people in their 20s and 30s. Women develop MS more frequently than men. MS symptoms vary widely and may include, fatigue, muscle weakness, incontinence, temporary blindness or double vision, and cognitive impairment, among others.
The study was supported in part by grants from the National Institute
of Neurological Diseases and Stroke (NINDS) of the National Institutes
of Health (NIH), the National Multiple Sclerosis Society, and Biogen, Inc.
AVONEX(R), approved by the FDA in 1996, was developed by Biogen, Inc.
SOURCE The Cleveland Clinic Foundation