New Delhi, Aug 2 : Multiple sclerosis (MS) may begin far earlier than previously thought. Canadian researchers have decoded that the earliest warning signs of the immune system disorder may emerge more than a decade before the first classical neurological symptoms occur.

The findings, published in JAMA Network Open, 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 health care providers in the years leading up to a diagnosis as they search for answers to ill-defined medical challenges.

"MS can be difficult to recognise as many of the earliest signs -- like fatigue, headache, pain and mental health concerns -- can be quite general and easily mistaken for other conditions," said senior author Dr. Helen Tremlett, Professor of neurology at the University of British Columbia.

"Our findings dramatically shift the timeline for when these early warning signs are thought to begin, potentially opening the door to opportunities for earlier detection and intervention," she added.

The study analysed the health records of more than 12,000 people in British Columbia and found that those with MS began using health care services at elevated rates 15 years before their first MS symptoms appeared.

The team utilised linked clinical and administrative provincial health data to track physician visits in the 25 years preceding the onset of a patient's MS symptoms, as determined by a neurologist through a detailed medical history and clinical assessments.

The findings revealed that when compared to the general population, people with MS had 15 years before symptom onset made several visits to physicians for symptoms like fatigue, pain, dizziness, and mental health conditions, including anxiety and depression. Their visits to a psychiatrist increased about 12 years before, while visits to neurologists and ophthalmologists increased for issues like blurry vision or eye pain about eight to nine years before.

Further, three to five years before, their visits to emergency medicine and radiology increased, and one year before, visits across multiple specialties peaked, including neurology, emergency medicine, and radiology.

These patterns suggest that MS has a long and complex history, said the team.

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

/IANS