Patients with multiple sclerosis (MS) may be developing the disease for up to five years before the first clinical diagnosis is made, a study has found. The study, "Health-care use before a first demyelinating event suggestive of a multiple sclerosis prodrome: a matched cohort study," was published in the journal The Lancet Neurology. A team of researchers from the University of British Columbia examined health records of 14,428 MS patients and compared them to the health records of 72,059 people without the disease. All health records were filled from April 1984 to April 2014 in four Canadian provinces (British Columbia, Saskatchewan, Manitoba, and Nova Scotia). Statistical analysis comparing hospital attendances between MS patients and the general population revealed that, throughout the five years prior to the occurrence of first symptoms, the number of annual visits to healthcare facilities increased steadily in people diagnosed later with MS. The findings suggest the existence of a measurable MS prodrome, an early set of signs and symptoms that can indicate the onset of demyelination occurring in MS patients. If this is the case, it may allow for the establishment of an earlier window of opportunity to identify and potentially treat MS. A better characterization of the MS prodrome may help physicians screen for the disease and start interventions earlier, as well as point scientists in a new direction for finding the initial cause of MS. “Proving that people with multiple sclerosis have already changed their behavior in the five years before even the earliest medical recognition of the condition is very important because it means we have to look beyond those five years to understand how it is caused,” said Helen Tremlett, PhD, senior author of the study, in a press release. Tremlett is a professor in the department of medicine at the Djavad Mowafaghian Centre for Brain Health. “When other degenerative brain diseases have a prodrome, it suggests that something may be happening,” said Tremlett. “We hope to uncover what this might be in multiple sclerosis.” Further studies will include the assessment of physician claims and prescriptions in the health records of the MS patients, in order to determine the existence of trends in illnesses reported and prescriptions filled to treat a specific set of symptoms. Such assessment ultimately could help diagnose MS signs at an earlier stage and improve patient care and outcomes.