Comparative Diagnostic and Therapeutic Strategies Among General and Multiple Sclerosis (MS) Subspecialist Neurologists – Opportunities for Education

Background: Though clinicians recognize the McDonald criteria as a diagnostic standard for MS, recent literature suggests knowledge gaps or misapplication in practice. The recent influx of novel MS therapies accompanied by new data surrounding the impact of prognostic factors (e.g., brain volume [BV]) has also generated controversy concerning how to optimally choose, monitor, and adjust therapeutic approaches.

Objectives: Assess the knowledge and application of diagnostic and management approaches among neurologists who do and do not specialize in MS.

Methods: An online survey comprised of case-based and stand-alone questions on MS diagnosis and management was developed. MS experts (MSE) from the US and Canada and US general neurologists (GN) who care for 3-15 MS patients per week were invited to participate. The survey was conducted in August 2021.

Results:

26 MSE and 100 GN completed the survey. Most GN correctly classified common presentations as typical for MS but also misclassified several syndromes (e.g., bilateral optic neuritis [54%]). Most GN incorrectly selected MRI optic nerve (70%) and deep white matter lesions (61%) as part of dissemination in space (DIS) criteria. Only 14% of GN chose the correct definition of both juxtacortical (JC) and periventricular (PV) lesions. On two sample MRIs, 4% GN vs. 58% MSE and 28% GN vs. 88% MSE, respectively correctly identified JC or PV lesions. In response to a case, 63% GN (vs 8% MSE) misapplied dissemination in time (DIT) criteria.

The majority of GN and MSE recognized negative prognostic factors in MS (e.g., spinal lesions) but their influence on therapeutic decision-making in clinical scenarios varied between groups. For a newly diagnosed young female with moderate risk factors, 51% MSE prioritized high-efficacy injectable/infusion therapy (vs. 32% GN). Following a sensory relapse in a patient already on DMT, 92% MSE would recommend switching therapy vs 66% GN. There was heterogeneity in treatment approaches chosen by all participants in response to prognostic factors currently less commonly used in routine care decisions (e.g., BV loss, cognitive changes).

Conclusions: Key elements of the McDonald criteria may be misapplied in practice, particularly by GN. Therapeutic approaches in response to MS prognostic factors differed between MSE and GN. These data suggest a need for education focused on the application of MS diagnostic criteria and important prognostic factors that may influence treatment decisions.