The earliest warning signs of multiple sclerosis may emerge more than a decade before the first classical neurological symptoms occur, according to new research. A new study analyzed the health records of more than 12,000 people in British Columbia and found those with MS began using healthcare services at elevated rates 15 years before their first MS symptoms appear.

The findings by the University of British Columbia challenge long-held assumptions about when the disease truly begins, offering the most comprehensive picture to date of how patients engage with a range of healthcare providers in the years leading up to a diagnosis as they search for answers to ill-defined medical challenges.

The study used linked clinical and administrative provincial health data to track physician visits in the 25 years leading up to the onset of a patient’s MS symptoms, as determined by a neurologist through detailed medical history and clinical assessments.

It is the first study to examine healthcare usage this far back in a patient’s clinical history. Most previous studies only examined trends in the five to 10 years leading up to a patient’s first demyelinating event (such as vision problems) using administrative data. This is a much later benchmark compared to the neurologist-determined date of symptom onset.

The findings revealed that, when compared to the general population, people with MS had a steady build-up of healthcare engagement over 15 years with different types of doctor visits increasing at distinct points in time:

• 15 years before symptom onset: Visits to general practice physicians increased, as did visits to any physician, for symptoms such as fatigue, pain, dizziness, and mental health conditions – including anxiety and depression.
• 12 years before: Visits to a psychiatrist increased.
• Eight to nine years before: Visits to neurologists and ophthalmologists increased, which could relate to issues such as blurry vision or eye pain.
• Three to five years before: Emergency medicine and radiology visits increased.
• One year before: Physician visits across multiple specialties peaked, including neurology, emergency medicine, and radiology.

The study builds on previous work by researchers to characterize the early stages of MS, or prodromal phase, when subtle symptoms appear before the hallmark signs become recognizable. Prodromal periods are well established in other neurological disorders where mood changes, sleep disturbances, and constipation often arise years before the more familiar motor symptoms such as tremors and stiffness.

While the researchers caution the vast majority of people who experience general symptoms will not go on to develop MS, they say recognizing and characterizing the MS prodrome could one day help accelerate diagnosis and improve outcomes for patients.

The findings were published in JAMA Network Open.