MS Speaks

CMSC: When It's Not MS

One-third of referred MS cases turn out to be misdiagnosed

 by Ed Susman, Contributing Writer, MedPage Today

NEW ORLEANS – More than 30% of patients sent to a tertiary clinic with a diagnosis of multiple sclerosis (MS) turn out to have something other than the disease, researchers reported here at the annual meeting of the Consortium of Multiple Sclerosis Centers.
Of 93 consecutive patients referred to an MS specialty clinic, re-evaluation found that 31 of these individuals did not have MS after all, said Marwa Kaisey, MD, of UCLA and Cedars-Sinai Medical Center in Los Angeles.

"Neurologists and multiple sclerosis specialists especially should re-evaluate an existing multiple sclerosis diagnosis rather than taking it at face value given the high rate of misdiagnoses," Kaisey said at her poster presentation.

She and her colleagues evaluated patients who were sent to her specialty center to confirm a diagnosis of MS so the patient could begin disease-modifying therapy. "These were all patients who visited a neurologist who thought the patients had multiple sclerosis," Kaisey told MedPage Today. "We found that 33% had a misdiagnosis."

The results showed that 16% of the suspected MS patients turned out to have migraines, 13% had spine spondylosis, and 13% had white matter ischemic disease.

There were also MS diagnoses that turned out to be cerebral palsy, scleroderma complicated by neuropathy, hereditary muscular disease, fibromyalgia, optic neuritis, uveitis, headache, and anxiety. The patients ranged in age from 22 to 69.

"There were no cases of purely psychiatric disease without underlying neurology," Kaisey said, adding that recent imaging studies and lumbar puncture-related tests were most likely the examinations that were able to differentiate the MS patients from those with misdiagnoses.

"The really disturbing part is that 10% of the patients with the wrong diagnosis had been started on disease-modifying agents for multiple sclerosis. I tell patients who are referred to us that there is no one test that can determine if you have multiple sclerosis. It's not like a pregnancy test where you either are or are not. The diagnosis of multiple sclerosis involves evaluation of the patient history, examination, imaging, and ancillary testing. Many diseases mimic too often vague symptoms of multiple sclerosis and cause white matter lesions in the central nervous system. We have to put together the whole picture and come up with the best diagnosis."

Kaisey said that one survey of MS specialists found that 94% of these specialists had found at least one misdiagnosis in the past year: "Every time I see a new patient or even patients I have seen before, I try to re-evaluate that diagnosis because, as we have shown, misdiagnosis happens a lot. I tell these patients that I am going to re-evaluate them again before we start discussing possible treatments."

One of the first steps Kaisey takes with a referred patient, she said, is to redo an MRI: "Some of the patients we have bring us MRIs that are 4 years old or more."

David Brandes, MD, who is in private practice with Hope Neurology/MS Center in Knoxville, Tenn., and was not involved with the study, told MedPage Today that the findings by the Los Angeles group are similar to what he sees in clinical practice: "I work in a multiple sclerosis specialty center and I am referred cases from other neurologists or physicians who are not sure if the patient has multiple sclerosis -- and it turns out that about 60% of these referrals do not have multiple sclerosis.

"Dr. Kaisey's work is not the only study to show that the diagnosis of multiple sclerosis is often incorrect," Brandes continued. "It is more common to find misdiagnosis referred from a neurologist, but it even occurs in patients referred from other multiple sclerosis specialists. We have to continually re-evaluate the patient. Each time I see one of my patients, in my mind I am thinking, 'Is this really multiple sclerosis? Am I going to change my mind based on what I am seeing?'"

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Kaisey and Brandes disclosed no relevant relationships with industry.