By Erin R. King
Dec. 1 (CBSHealthWatch)--A drug used to help slow the progression of multiple sclerosis (MS) can also reduce the cognitive symptoms of the disease that affect everyday life, according to a new study.
People with MS who took interferon beta-1a, sold under the brand name Avonex, for two years performed better on tests involving information processing, learning and recent memory, and visual and spatial abilities than MS patients given a placebo. Interferon beta-1a is one of several drugs approved to treat MS.
In people with MS, a fatty tissue called myelin that covers the nervous system's cells deteriorates. Myelin acts like the insulation on electrical wires, and like wires, the nervous system can't transmit messages between the brain and other parts of the body without good insulation.
This can result in neurological difficulties, vision problems or trouble walking, and can ultimately lead to severe disability.
"MS-related cognitive dysfunction can have a devastating impact on employment, social functioning, and the management of household responsibilities," write the researchers, collectively known as the Multiple Sclerosis Collaborative Research Group. Their findings are published in the December issue of the Annals of Neurology.
They found that the people who took interferon beta-1a tended to do better on tests that involved skills most often affected by MS than the people who received the placebo, but the pattern was not found on tests of skills that MS does not interfere with. "Thus, beneficial treatment effects were most apparent in cognitive domains commonly disrupted by MS," the researchers write.
Since early treatment with drugs approved to slow MS has already been shown to be beneficial in other areas affected by the disease, these newly found benefits in the area of brain functioning add to the evidence, according to one expert.
"This is important because it indicates that treatment with … Avonex can have an important impact on cognitive problems in people with MS," says Patricia O'Looney, MD, director of biomedical research at the National Multiple Sclerosis Society.
About half of all people with MS have cognitive problems, O'Looney says, such as a change in learning or memory, or difficulty processing information, such as a list of words.
The National MS Society recommends early treatment with any of the drugs approved to treat MS, O'Looney says. Treatment may be a good idea even if the patient does not feel like they are being affected.
"Disease and damage seems to be going on even when a person feels OK," O'Looney says.
The Multiple Sclerosis Collaborative Research Group's study was funded by the National Institute of Neurological Disorders and Stroke and by the Cambridge, Massachusetts-based Biogen, Inc., makers of Avonex.
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