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Updated: Aug 15, 2026
Magnetic Resonance Imaging of Multiple Sclerosis at 7.0 Tesla
Published on: February 19, 2021
Changes in the ascertainment of multiple sclerosis
1Department of Neurology, Cleveland Clinic Foundation, Cleveland, OH 44195, USA. marrier@ccf.org
Objective:
With diagnostic criteria alterations, increased MRI availability, and awareness of therapies, temporal changes in incidence and prevalence rates may occur, with an increase in the proportion of mildly affected persons diagnosed with multiple sclerosis (MS). The authors assessed temporal trends in the delay from symptom onset to diagnosis (DONDX), and determined whether the degree of disability at diagnosis differs by year of symptom onset (YONSET), using the NARCOMS Registry.
Methods:
The authors selected US participants with an age at symptom onset of 10 to 60 years, and YONSET > or = 1980 (n = 16,581). The authors divided YONSET into 5-year groups and compared DONDX between groups using multivariate Cox regression. The authors classified participants enrolled within 2 years of diagnosis (n = 5,548) as having mild, moderate, or severe disability using Patient Determined Disease Steps, and assessed the association of disability with YONSET using polytomous logistic regression.
Results:
DONDX decreased with later YONSET (r = -0.43, p < 0.0001). This association remained after adjustment for demographic factors in a multivariate Cox model. Later YONSET was associated with increased odds of having mild disability at diagnosis as compared to severe disability (OR = 1.10 per year; 1.09 to 1.11).
Conclusion:
The delay from symptom onset to diagnosis is steadily decreasing in MS. An increasing proportion of patients with MS have mild disability at diagnosis after accounting for confounders. As the effectiveness of therapies is influenced by disease duration, this has implications for comparison of treatment effects in modern clinical trials to earlier study results.
Insights
The time to diagnose multiple sclerosis (MS) is decreasing, with more patients diagnosed at an earlier, milder disease stage. This trend impacts how treatment effectiveness is compared across studies.
Area of Science:
- Neurology
- Epidemiology
- Clinical Research
Background:
- Diagnostic criteria for multiple sclerosis (MS) have evolved, MRI availability has increased, and therapeutic options are more widely known.
- These factors may influence temporal trends in MS incidence and prevalence, potentially leading to earlier diagnosis and a higher proportion of mildly affected individuals being identified.
Purpose of the Study:
- To assess temporal trends in the delay from symptom onset to diagnosis (DONDX) in multiple sclerosis (MS).
- To determine if the degree of disability at diagnosis differs based on the year of symptom onset (YONSET).
Main Methods:
- Analysis of data from 16,581 US participants in the NARCOMS Registry with symptom onset between 1980 and age 60.
- Comparison of DONDX across 5-year YONSET groups using multivariate Cox regression.
- Assessment of disability (mild, moderate, severe) at diagnosis for 5,548 participants using Patient Determined Disease Steps and polytomous logistic regression.
Main Results:
- A significant decrease in DONDX was observed with later YONSET (r = -0.43, p < 0.0001), persisting after demographic adjustment.
- Later YONSET was associated with a higher likelihood of being diagnosed with mild disability compared to severe disability (OR = 1.10 per year).
Conclusions:
- The delay from symptom onset to diagnosis in MS is progressively shortening.
- An increasing proportion of MS patients are diagnosed with mild disability, even after accounting for confounding factors.
- These findings have implications for comparing treatment effects in contemporary clinical trials with historical data, given the influence of disease duration on therapy effectiveness.
