Patients with a number of common conditions — some neurological and some autoimmune, but others not — are being mistakenly diagnosed with multiple sclerosis (MS) because of difficulties in correctly determining this disease and, possibly, pressure to begin treatment early in the disease’s course, according to a recent study published in the journal Neurology.
“Although many rare disorders are known to mimic MS, it appears that presently, a number of common disorders are frequently mistaken for MS,” Andrew Solomon, MD, from the University of Vermont and the study’s lead author, said in a news release.
Several factors likely contribute to this problem, such as the lack of specific disease markers or blood tests to diagnose MS, the combination of different genetic and environmental factors responsible for the development of the disease, and the wide range of symptoms associated with the nerve damage observed in MS patients.
In the study, “The Contemporary Spectrum Of Multiple Sclerosis Misdiagnosis,” Solomon and colleagues — all MS specialists working at four MS academic centers in the U.S. (University of Vermont, Mayo Clinic, Washington University, and Oregon Health & Science University) — pooled data on people they found to be wrongly diagnosed with MS.
Specifically, the neurologists identified 110 people either “definitely” (51 patients) or “probably” (59) misdiagnosed. Of these, 73 patients had one of five conditions: migraine (alone or in combination with other problems), fibromyalgia, an abnormal MRI (magnetic resonance imaging, a test widely used in MS diagnosis) with nonspecific or nonlocalizing neurologic symptoms, a psychological condition, or neuromyelitis optica spectrum disorder (a disease that induces damage to the optic nerves and spinal cord).
As a consequence of the misdiagnosis, 72% of the patients were incorrectly medicated — treated for MS — sometimes taking MS medications for “many” years. This is relevant, because some MS treatments can have serious side effects. Moreover, 33% of the patients remained misdiagnosed for at least 10 years before being informed they did not have MS by the researchers. Four patients without MS had also enrolled in clinical trials for experimental MS therapies. In addition, the researchers reported that in 79 patients (72%) there was an earlier opportunity to make a correct diagnosis.
“One drug, which 13 percent of the misdiagnosed patients took, can cause a potentially fatal brain infection,” Solomon said. “Other patients suffered from the discomfort and inconvenience of daily injections, others experienced side effects from medications, and finally, they lacked treatment for their actual correct diagnoses.”
Misinterpretation or misapplication of MS diagnostic criteria can contribute to an incorrect diagnosis, the researchers said. The criteria include the accurate interpretation of symptoms, physical examination, and radiological tests, such as MRI. However, because MRI may not always provide a clear and definite result, it is important that clinicians fully consider a patient’s entire history, symptoms, and examination results before committing to an MS diagnosis.
“There is pressure to make the diagnosis of MS early, and to start patients on MS therapies quickly,” said Solomon. “But in some patients who do not meet our diagnostic criteria, waiting longer and following them closely may help determine the correct diagnosis.”
The authors hope their study will help to increase awareness about the challenges in correctly diagnosing MS, leading to better physician education, and encourage further study into possible misdiagnoses.