Dr. Paty and the news from MRI's about MS.
The technicians and nurses who conduct this examination do what they can to make the procedure comfortable. Someone can stand by and talk to the person inside the scanner, a pillow or blanket can relieve the stress of the hard table, some facilities are equipped with piped-in music, and people who are very uneasy or claustrophobic may be given a tranquilizer or muscle relaxer.
The meaning of MRI studies
For physicians and researchers, the procedure is exciting. MRI uses magnetism, radio waves, and a computer to obtain extremely detailed pictures. It is noninvasive, safe, and has no aftereffects other than a patient's well-earned feeling of relief that the scan is over.
MRI has contributed so much to the difficult task of diagnosing MS that the average time between first reporting symptoms and receiving a definitive diagnosis is shorter by years. As for progress in MS research, MRI offers eye-opening information about the dynamics of MS activity in the brain--critical details that were never seen before.
Dr. Donald W. Paty, director of the MS Research Program at the University of British Columbia and chief of the combined neurology divisions of Vancouver General Hospital and the University of B.C. Hospital, has been pursuing the nature of MS since the late 1960s. His studies of the natural history of MS, based on a large group of people with MS whose medical histories he has followed for many years, have been essential groundwork for designing sound clinical trials. This work alone is cause for recognition by his peers in research.
By the end of the 1980s, Dr. Paty, along with other investigators around the world, was using MRI to better understand what happens during MS relapses and remissions. Dr. Paty's MRI work helped establish procedures for obtaining a series of images of the same individual over time so the scans can be exactly compared to one another.
This kind of study can show if -- and by how much-- changes within the brain correlate with the use of specific treatments.
Quality MRI data and the FDA
In 1993, the FDA's speedy approval of interferon beta-1b, better known by its brand name Betaseron, was spurred by the MRI data analyzed by Dr. Paty and his colleagues during the multicenter clinical trial. Without the MRI data, Betaseron's approval would almost certainly have been delayed.
The MRI results showed the drug caused marked differences in the brain over a period of two years. The MRI's of people who were receiving the active drug showed only small increases in the number and size of lesions (or damaged areas) in the brain as compared with their baseline MRI at the start of the trial. The people in the placebo or control arm of the trial had a 10 percent increase in their lesions per year.
These MRI data appeared additionally powerful because Dr. Paty had done similar MRI studies of people in clinical trials of alpha interferon and cyclosporine several years earlier. In those studies, neither drug had prevented new MS activity within the brain.
The FDA was willing to approve Betaseron with record speed, while still requiring that data be produced demonstrating that MRI can be a true predictor of clinical benefits--such as slowing or stopping progressive problems with gait, strength, balance and the like.
What MRI's say about MS
Studies by Dr. Paty and other investigators have uncovered dramatic differences between the level of MS activity in the brain and what is seen in conventional neurological exams.
MRI not only documents chronic MS lesions that tend to increase in size over time but also reveals lesions that appear, grow, shrink, disappear, and sometimes reappear later in the same site. This activity continues even when the individual is in an outwardly quiet clinical period, not having an attack or experiencing any new symptoms.
When a contrast material called gadolinium is injected just before an MRI, active areas of "silent" MS activity can be detected. These areas are characterized by edema or swelling, a sign of inflammation. Gadolinium-enhanced MRI's have added to the understanding that hidden processes are at work--processes that differ in various forms of MS.
In one recent study, people who had primary chronic-progressive MS had the lowest rate of new lesions over a year's time. The rate was notably lower than that in people with benign MS. Primary chronic-progressive is distinguished from secondary chronic-progressive MS which develops after a period of relapses and remissions. In the study, people with primary chronic-progressive MS had very few of the kind of inflammatory lesion picked up by gadolinium enhancement. This research adds to a growing body of data suggesting this form of MS may require differently designed treatment.
More come-and-go changes
Dr. Paty's MRI research has also documented come-and-go changes affecting the integrity of the blood-brain barrier in MS. The blood-brain barrier is important because this layer of closely packed cells, which lines blood vessels in the brain, normally blocks many substances in the blood-stream from entering the central nervous system. Among the substances normally blocked are key T cells that have been implicated in the MS attack on myelin.
What happens next?
"MRI is at least five times more sensitive to disease activity than clinical tests and measurements--and it will become even more precise in the future," Dr. Paty said recently.
For now, MS lesions seen on MRI do not correlate well with an individual's level of disability, but Dr. Paty thinks that additional studies, over longer periods of time, might uncover better correlations. The number of attacks or relapses a person goes through doesn't neatly predict an increase in disability either. MS is holding onto its reputation for being highly variable from person to person.
For researchers, the existence of symptomless lesions that come and go, sometimes in rapid bursts, in so many people with MS, has stimulated much new thinking. For physicians treating people with MS, the information underscores the fact that their patients may have active MS even when they have no active symptoms.
RELATED ARTICLE: New Foundation for the Underinsured
Berlex Laboratories has created the Betaseron Foundation to address the predicament of people who are good candidates for Betaseron but are underinsured--whether by private insurers or by Medicare.
Berlex Laboratories is giving the foundation enough Betaseron to assist 4-5,000 people. The Betaseron Foundation is governed by an independent board which is solely responsible for evaluating applications.
"The needs of the underinsured cannot be solved by a single company," said Dr. Jeffrey Latts, vice president of Clinical Research and Development at Berlex. "But we've made a beginning."
Applications to the Betaseron Foundation are being accepted from people with MS who live in the U.S. and have
* a diagnosis of MS confirmed by a neurologist
* a Social Security number
* medical insurance
* a prescription for Betaseron or notice of a physician's intent to prescribe.
Call 1-800-948-5777 Monday-Friday 9AM-5PM, Eastern Time, for the required application form or additional information.
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|Title Annotation:||Donald W. Paty, multiple sclerosis|
|Date:||Jun 22, 1995|
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