Diagnosing multiple sclerosis is not a simple process, and even experienced doctors make mistakes. Even with improved testing tools and more detailed diagnostic criteria, MS misdiagnosis remains an important problem in neurology, with significant consequences.
Misdiagnosis is too common in MS
Rates of MS misdiagnosis range from 6 percent to 35 percent, based on a number of studies published between 1985 and 2005. There are several possible diseases that a person misdiagnosed with MS might have instead. Two of the most common missed diagnoses in these studies were psychiatric disease (23-27 percent) and migraine (9-10 percent).
In a more recent study (Solomon 2012), 95.1 percent of neurologists surveyed (n=122) had evaluated a patient, previously diagnosed with MS by another provider, who they “strongly felt did NOT in fact have MS.” Within the preceding year 39.7 percent of respondents estimated that they had seen three to five such patients. More than one-third (34.4 percent) reported seeing six or more misdiagnosed patients in the last year, including 20 (17.2 percent) respondents who had seen 10 or more such patients.
At this year’s Consortium of MS Centers conference, Andrew J. Solomon, MD, Assistant Professor of Neurology at the University of Vermont, confessed: “I have misdiagnosed MS.” Even neurologists with special training in multiple sclerosis can make an inaccurate diagnosis. As much as patients want answers to explain our symptoms, it is important to consider that the answer may not come easily or quickly. No matter how many symptoms you have that seem to point to MS, it might not be MS.
Potential causes of misdiagnosis
There is no highly specific biomarker for MS, so diagnosis continues to rely upon the interpretation of clinical and radiographic data with healthy doses of critical thinking and clinical skills.
Basically, neurologists must rely upon their skilled expertise, knowledge, and the correct application of diagnostic criteria and testing to make an accurate diagnosis. During his session at CMSC, Dr. Solomon stressed that MRI criteria weren’t specifically developed to differentiate MS from other conditions, but instead to identify patients at high risk for MS after initial typical presentations of MS-like symptoms. MS diagnostic criteria were also not rigorously validated in clinically atypical presentations.
The problem of misdiagnosis is not confined to non-specialists, however. Out of 110 misdiagnosed patients identified in the 2012 survey, a surprising twenty-four percent had been misdiagnosed by a neurologist with MS fellowship training or who worked in an MS-focused medical practice. Thirty-two percent had been misdiagnosed by a neurologist without MS training; three percent were diagnosed by a non-neurologist; and forty-two percent had been diagnosed by a physician for whom their training was unknown.
Dangers of misdiagnosis
Thirty-three percent of the patients had been living with their misdiagnosis for more than 10 years; 29 percent for three to nine years; and 38 percent for less than three years. Neurologists surveyed indicated that patients misdiagnosed with MS actually suffered from several other conditions, including: nonspecific white matter abnormalities (NWMA), small vessel ischemic disease (SVID), migraine, psychiatric disease, neuromyelitis optica spectrum disorder (NMOSD), and fibromyalgia.
A misdiagnosis of MS means the patient is suffering from an undiagnosed, untreated condition that could lead to unnecessary risk and even death. Patients may be exposed to potentially harmful therapies that carry a risk of progressive multifocal leukoencephalopathy (PML) or may be burdened with the financial risk of expensive DMTs, routine imaging, and clinical care they don’t need.
More than 70 percent of the misdiagnosed patients identified in the 2012 survey had received disease-modifying therapy (DMT) for MS, including 36 percent who had used two or more DMTs. Twenty-nine percent of the patients had been using a DMT for more than 10 years; 29 percent for three to nine years; and 42 percent for less than three years. The most commonly used medications were interferon beta (53 percent), glatiramer acetate (40 percent), or natalizumab (13 percent). Four percent of the misdiagnosed patients had even participated in clinical trials of disease-modifying therapies.
Challenges of un-diagnosing MS
Dr. Solomon says that neurologists tend to take the prior or established diagnoses of new patients at face value when care is transferred. Instead, they ought to step back and question whether it is truly a case of MS. Atypical clinical presentations or nonspecific MRI abnormalities warrant further evaluation, further radiographic monitoring, and further clinical monitoring.
If you are an MS patient who has seen a new neurologist who expressed an interest in reevaluating your diagnosis, please know the doctor has your best interests in mind. It’s not that the doctor doubts your symptoms, but simply wants to make sure that you are receiving the most appropriate care and treatment for your condition. And be aware that without a biomarker, a misdiagnosis of MS can be understandable. MS isn’t called the “great mimicker” for no reason.
While the process may be emotionally challenging, un-diagnosing a patient is not easy for the doctor either.
Solomon says that doctors often worry that they’re going to harm patients when they un-diagnose MS. Perhaps the patient is invested in the diagnosis and it has become part of their identity. There is the potential loss of a built-in support system among the MS community and advocacy organizations. The patient may fear abandonment by their medical team. But none of these risks justify the withholding of information from the misdiagnosed patient as maintenance of a trustworthy doctor-patient relationship with open shared decision making is vital.
See more helpful articles:
5 Hidden Symptoms of MS
Invisible MS Symptoms Can Cause Frustration and Mask Disability
How is MS Diagnosed?
Solomon AJ. Misdiagnosis of Multiple Sclerosis: Frequency, Causes, Effects and Prevention [presentation]. Consortium of MS Centers Conference, June 1-4, 2016, National Harbor, MD.
Solomon AJ, Klein EP, Bourdette D. "Undiagnosing" multiple sclerosis: the challenge of misdiagnosis in MS. Neurology. 2012 Jun 12;78(24):1986-91. doi: 10.1212/WNL.0b013e318259e1b2. Epub 2012 May 11.