MS Symptoms Often Apparent Years Before Diagnosis

Many people with multiple sclerosis (MS) start experiencing symptoms of the disease several years before being diagnosed, a new study suggests.

While it has long been known that people with MS tend to seek medical attention more frequently in the years before diagnosis than those without the disease, there has been debate as to whether this is a result of MS itself, or a prodromal phase of the disease. Prodromal refers to a distinct period of unspecific and mild symptoms seen prior to the onset of actual MS.

In the new study, a team of researchers at the Technical University of Munich (TUM) analyzed insurance data in an effort to address this question. Their findings were published in the journal Neurology, in the study, “Systematic Assessment of Medical Diagnoses Preceding the First Diagnosis of Multiple Sclerosis.”

Using the insurance data, researchers looked for documented medical complaints among 10,262 people with MS in the five years prior to their diagnosis. For comparison, the team looked at data for 73,430 people without any autoimmune disease. They also assessed data on 15,502 people with Crohn’s disease — an autoimmune disease that affects the gut — and 98,432 with psoriasis, an autoimmune skin disease.

Relative to the other groups, MS patients had significantly higher frequencies of certain medical issues (as identified by insurance codes). Notably, most of the issues that were more frequent among MS patients “represent symptoms suggestive of demyelinating events or other neurologic diagnoses,” the researchers wrote.

In other words, the patients appear to have been experiencing MS-like symptoms years before their diagnosis. Based on this, the researchers think patients are not experiencing a distinct prodromal disease phase, but instead are dealing with symptoms of unrecognized MS.

“We believe that many complaints that have been attributed to a prodromal phase are in fact caused by ongoing disease,” Bernhard Hemmer, MD, a professor at TUM and co-author of the study, said in a press release. “We therefore believe that, although the disease has not yet been diagnosed, it is fully active and not in a preliminary or prodromal phase.”

These findings may have important implications for MS diagnosis and treatment, the team said.

“The sooner MS is recognized, the better we can treat the disease. We now need to take a closer look at which early symptoms of MS might be overlooked. This could allow us to recognize the disease at an earlier stage and thus enable earlier treatment initiation,” said Christiane Gasperi, a physician and researcher at TUM and co-author of the study.

In addition to MS-like symptoms being more common among MS patients in the years before diagnosis, some medical issues were significantly less common among MS patients before diagnosis. In particular, there were significantly lower frequencies for several insurance codes related to upper respiratory tract infections among the MS patients before diagnosis.

This association “suggests a link between protection from infection and MS,” the researchers wrote, but they stressed a need for more research into this connection.