AAN Guideline: MRIs help diagnose multiple sclerosis faster

Using MRI scans can help make the diagnosis of multiple sclerosis (MS) more quickly, according to a guideline developed by the American Academy of Neurology. The guideline is published in the September 9 issue of Neurology, the scientific journal of the American Academy of Neurology.

The point at which MS can be diagnosed has been under debate, according to guideline author Elliot Frohman, MD, PhD, of the University of Texas Southwestern Medical School in Dallas.

“Before, the criteria used to diagnosis people required neurologists to show that disease activity had occurred in the brain over time,” said Frohman. “People would have to wait for a diagnosis. Now that we have evidence showing that early treatment can reduce the entire course of the disease, we really needed to ask the question about how early the diagnosis can be made.”

To develop the guideline, the researchers evaluated all of the scientific studies on the topic. They determined that in many cases findings on a single MRI of the brain and spinal cord can be a strong indicator of whether someone will develop MS in the future. The guideline addresses cases where a young to middle-aged adult has a single occurrence of a sign or symptom of MS activity and other possible diagnoses have been ruled out.

MS involves inflammation of the brain and spinal cord. This inflammation leads to lesions, or areas of damage, on the brain and spinal cord. The guidelines outline the number and type of these lesions that, if present, are a strong predictor of the future development of clinically definite MS. For example, a patient with three or more lesions in the white matter area of the brain has a greater than 80-percent likelihood of developing MS within the next seven to 10 years.

“This guideline helps us use MRI to telescope into the future to see what’s going to happen with these patients,” Frohman said. “The evidence allows us to predict with more certainty who will develop MS, which allows us to begin helpful treatment earlier than in the past.”

Evidence shows that early treatment of MS can lessen the disease activity and severity. There is also evidence that, if untreated in the early stages, the disease can accelerate and may even become resistant to treatment, Frohman said.

“With this knowledge and the fact that the current drugs for MS have few downsides except for cost and minor side effects, there’s not much sense in waiting for more disability and more attacks to occur,” he said.

The criteria currently used for diagnosis are not sensitive enough to identify many patients who already have MS at the time of their first attack, Frohman said. The current criteria recommend waiting for additional signs of disease activity before making the diagnosis of MS.

“In some ways, that’s like waiting for the other shoe to drop,” he said. “If the majority of these patients have MS and waiting could compromise how we can affect the course of the disease, then we need to go ahead and treat them.”

The guideline notes that neurologists must consider MRI information in the context of each patient’s specific situation.

The American Academy of Neurology, an association of more than 18,000 neurologists and neuroscience professionals, is dedicated to improving patient care through education and research. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as stroke, Alzheimer’s disease, epilepsy, Parkinson’s disease, autism and multiple sclerosis.

For more information about the American Academy of Neurology, visit its web site at http://www.aan.com.