Almost one in five patients diagnosed with multiple sclerosis (MS) and referred to one of two MS-specialized centers in the U.S. were found to not have the disease, a study at those two centers reported. Migraine was the most common correct diagnosis eventually given these people.
The retrospective study “Incidence of multiple sclerosis misdiagnosis in referrals to two academic centers” was published in the journal Multiple Sclerosis and Related Disorders.
No single test can directly identify MS, and a diagnosis can be difficult. To rule out MS-mimicking conditions during clinical assessments, physicians perform a set of evaluations that include lab tests, a patient’s medical history, and magnetic resonance imaging (MRI) scans of the brain.
To better establish clinical recommendations, speed-up diagnosis, and avoid misdiagnosis, an international panel established the McDonald criteria for MS in 2001 in association with the National Multiple Sclerosis Society. The panel further revised the criteria in 2005, 2010, and 2017.
But misdiagnosis can still be prevalent, raising a risk of improper treatment for the person and needlessly higher healthcare costs to the society.
A clinical team at the Cedars-Sinai Medical Center in Los Angeles performed a retrospective (backward-looking) study, investigating the rates and types of MS misdiagnoses at two local MS-specialized centers.
Out of 364 patients evaluated for MS at Cedars-Sinai and at the University of California, Los Angeles (UCLA), 241 were referred for treatment between July 1, 2016, and June 30, 2017.
Results showed that 19 (17%) of these patients at Cedars-Sinai and 24 (19%) at UCLA had been misdiagnosed. These people spent an average of four years under specialized MS care before being correctly diagnosed, with one wrongly treated for MS for 20 years.
Most of these patients showed clinical symptoms uncharacteristic for MS, including headache — 74% in Cedars-Sinai group, and 67% in UCLA group.
Most were given an MS diagnosis after an MRI or a cerebrospinal fluid assessment.
The most common correct diagnoses finally given were migraine (16%), radiologically isolated syndrome (9%), spondylopathy (7%; a disorder affecting the vertebrae), and neuropathy (7%; a disorder affecting peripheral nerves).
Researchers then analyzed the types of treatment used by misdiagnosed patients. They found that 72 percent had been prescribed disease-modifying MS treatments, with 48 percent of patients receiving therapies with a known risk of progressive multifocal leukoencephalopathy, a serious viral brain infection.
About $10 million was the estimated cost to U.S. healthcare system due to the unnecessary use of MS disease-modifying treatments.
“In our combined cohort, almost 1 in 5 patients who carried an established diagnosis of MS did not fulfill contemporary McDonald Criteria and had a more likely alternate diagnosis,” the researchers wrote.
“Misdiagnosis appeared to be associated with misapplication of MS diagnostic criteria, specifically overreliance on – or misinterpretation of – radiographic findings in patients with syndromes atypical for MS,” they added.
Given these findings, the team emphasized the need for MS-specific biomarkers to help more accurately diagnose MS.