Clinicians and researchers have known for decades that multiple sclerosis misdiagnosis is a problem. The authors of a new study define the nature of medical conditions that lead patients to be misdiagnosed with MS and possible reasons why they are misdiagnosed. They hope the study will encourage better education of clinicians on the proper use of MS diagnostic criteria and on the problem of MS misdiagnosis, and further study of how to recognize patients incorrectly diagnosed with MS.
The study involved 24 MS subspecialist neurologists at Mayo Clinic, University of Vermont, Washington University and Oregon Health and Science University, who identified an incorrect diagnosis of MS in 110 patients. In the study, five primary diagnoses or syndromes were identified in two-thirds of participants as the actual causes of symptoms misidentified as MS: migraine, either alone or in combination with other problems; fibromyalgia; an abnormal MRI with unexplained symptoms; a psychological condition; and neuromyelitis optica spectrum disorder, a disease similar to MS that affects the optic nerves and spinal cord.
They found that 72 percent of the misdiagnosed patients took medication to treat a disease they didn't have, with some taking these medications for many years. The authors also found 33 percent remained misdiagnosed for a decade or longer before being evaluated by the physicians participating in the study, who had informed them of an incorrect misdiagnosis. Four of the patients misdiagnosed with MS had participated in clinical trials for experimental MS therapies.
The authors examined the possible causes for misdiagnosis in the 110 patients in the study. They found the initial clinicians may not have used MS diagnostic criteria appropriately. A proper clinical diagnosis relies on a rigorous evaluation that includes careful interpretation of radiological data from an MRI. However, MRI misinterpretation can complicate misdiagnosis. Abnormalities that resemble those of MS show up on a scan for reasons other than MS, and nonspecific abnormalities may lead to a faulty diagnosis. The study identified patients misdiagnosed by both MS specialist neurologists and nonspecialists.
The study was published online in the journal Neurology.