In a retrospective, real-world cohort study, the factors complicating the diagnosis of primary progressive forms of multiple sclerosis (PPMS) were explored.
In a study published in the European Journal of Neurology, researchers gave a second glance at the obstacles impacting the diagnosis of primary progressive forms of multiple sclerosis (PPMS). Upon reevaluation of these cases, it was determined that over one-third of these PPMS diagnoses could be questioned.
One of the crucial components for diagnosing multiple sclerosis (MS) is evidence of dissemination. In the last 2 decades, multiple revisions have been made to help establish reliable criteria for accurate diagnoses of MS because, although treatments for PPMS are limited, earlier disease detection can improve patient outcomes. Many different factors can affect the imaging results and observed disease course in patients. However, and this obstacle has made diagnosing PPMS particularly challenging.
Given that the underlying mechanisms of MS progression are not fully understood, the authors saw patients with PPMS as an important group to consider. Therefore, they conducted a retrospective, real-world study to investigate which aspects of PPMS diagnosis cause complications and see how effective the 2010 and 2017 McDonald criteria are in the midst of these challenges.
Medical files from patients diagnosed with PPMS were gathered between January 1, 2000, and February 21, 2019, from 2 MS centers located in The Netherlands. The 2010 and 2017 McDonald criteria were applied to these cases and necessitated: at least 1 year of disease progression with suspicion of demyelination and ruling decisions stemming from magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) results. In the first requirement, the authors identified signs of alternative diagnoses that were insufficiently investigated, comorbidities, and patients’ medical histories as the main complicating factors. To address the second requirement, MRI and CSF results were analyzed at the time of diagnosis to determine whether a patient met the decision rules for diagnosis.
Throughout their study period, 322 patients diagnosed with PPMS were included. In total, 240 (74.5%) met the MRI and CSF criteria for the 2010 McDonald PPMS diagnosis and 228 (70.8%) met criteria for the 2017 requirements.
In their review of patient charts, 28 patients showed signs of alternative or concomitant disease. In 22 of these cases, the authors believed confounding for comorbidities could have impacted clinical interpretations of MS disease course. Of the group of 28, significantly fewer spinal cord MRIs were also performed compared to the definite PPMS group (87.5% vs 100%).
In the remaining 294 patients, 103 were lacking assured progressive disease courses. Forty of these patients had conflicting or incomplete medical reports in their files that gave cause for concern. Of the remaining 191 patients, 73 displayed incomplete diagnostic workups.
As researchers applied the 2010 and 2017 McDonald criteria to the 191 patients with a primary progressive disease course, only 118 received full diagnostic workups. Applying the diagnostic criteria showed that 104/118 (88.1%) and 98/118 (83.1%) met the 2010 and 2017 standards, respectively (P = .15).
The findings of this study demonstrate the importance of interpreting clinical disease course, considering alternative diagnoses, and completing entire diagnostic workups. Researchers found that when diagnostic conditions were met for PPMS, the 2010 and 2017 McDonald criteria executed similarly. Given these results, the authors believe the application of these criteria should be routinely considered in clinical settings moving forward.
Blok KM, Smolders J, Rosmalen J, Jarnalo COM, Wokke B, de Beukelaar J. Real-world challenges in the diagnosis of primary progressive multiple sclerosis. Eur J Neurol. Published online August 14, 2023. doi:10.1111/ene.16042