(Nov. 2005 - BreakThrough Digest) An international panel of neurologists has updated the current guidelines for diagnosing multiple sclerosis (MS), strengthening the role of magnetic resonance imaging (MRI). The guidelines, published online November 10, 2005 in the Annals of Neurology, update the "McDonald criteria," created five years ago and named after the chair of the previous panel, Prof W. Ian McDonald of the Institute of Neurology in London.

 "We hope, and trust, that these revisions will allow an even earlier diagnosis of MS, without any loss of diagnostic accuracy," said Chris H. Polman, M.D., of the Free University Medical Center in Amsterdam, The Netherlands, and chair of the current panel.

Multiple sclerosis is an enigmatic disease of the nervous system and results in the loss of myelin, a substance that normally insulates nerve fibers and speeds electrical conduction through the fibers.

 Depending on which nerve fibers are hindered, patients can experience problems ranging from weakness and clumsiness to numbness, visual disturbances, and even emotional and intellectual alterations. In some patients, MS manifests itself in cycles of relapse and remission, while in others the disease progresses steadily.

 "The changes in diagnostic criteria for primary progressive multiple sclerosis is particularly helpful," said Robert P. Lisak, M.D., of Wayne State University in Detroit, Michigan, and chair of the American Neurological Association's public information committee. "The ability to make the diagnosis of multiple sclerosis early and accurately is important for both patient care and for clinical research including clinical trials of new treatments."

There is increasing evidence that MS drugs such as interferon beta and glatiramer acetate are most effective when started early in the disease course.

The original McDonald Criteria were the first to incorporate MRI testing into the traditional tool kit of neurological history and examination, along with various laboratory exams. Brain imaging can show physicians the damaged sites (termed 'lesions') in the brain and spinal cord.

"A series of studies performed during the last few years, with improved techniques for spinal cord MRI, shows that it is a powerful tool not only to demonstrate MS lesions, but also to exclude alternative diagnoses," said Polman.

 The new criteria also conclude that only two separate MRI scans, rather than three, are needed to evaluate whether the disease is progressing.