Health care use before an initial demyelinating event suggests a measureable prodromal period in multiple sclerosis.
Symptoms of multiple sclerosis (MS) can appear 5 years before onset of the disease, according to a new study published in Lancet Neurology.
For the study, investigators used data from linked health administrative and clinical databases from British Columbia, Saskatchewan, Manitoba, and Nova Scotia, in Canada. The study authors compared physician, hospital, and prescription use data from patients with MS, as well as their general population controls in the 5 years before the first demyelinating disease claim or clinically-reported symptom onset.
The primary outcome was all-cause use of health care during each of the 5 years before the health administrative or clinical index date.
Overall, the health administrative cohort included 14,428 MS cases and 72,059 matched controls between April 1984, and April 2014.
The goal of the study was to identify prodromes for MS. Prodromes are an early set of symptoms that can indicate the onset of the disease. Thus far, they have been identified in other neurological conditions, such as Alzheimer’s disease and Parkinson’s disease.
“When other degenerative brain diseases have a prodrome, it suggests that something may be happening,” said senior author Helen Tremlett. “We hope to uncover what this might be in multiple sclerosis.”
The results of the study showed that annual health care use increased steadily between 5 years and 1 year before the first demyelinating disease claim in patients with MS compared with controls.
The investigators observed similar patterns for physician claims and prescriptions in the cohort with available clinical symptom onset. However, the differences in use in each of the 5 years mostly did not reach statistical significance, the authors noted.
“Proving that people with multiple sclerosis have already changed their behavior in the 5 years before even the earliest medical recognition of the condition is very important because it means we have to look beyond those 5 years to understand how it is caused,” Tremlett said.
The findings indicated a phase in which patients begin to show symptoms before MS is medically recognized. During this period, patients tend to visit their physicians, be admitted to a hospital, and fill prescriptions more than the general population.
“More frequent use of health care in patients with multiple sclerosis than in controls in the 5 years before a first demyelinating event, according to health administrative data, suggests the existence of a measurable multiple sclerosis prodrome,” the authors concluded. “These findings have clinical and research implications, including the establishment of an earlier window of opportunity to identify and potentially treat multiple sclerosis.”