The second consensus criteria for the diagnosis of multiple system atrophy (MSA) are widely accepted as the gold standard for clinical research, although they are insufficiently sensitive to detect the illness in its early stages. Therefore, researchers sought to create new Movement Disorder Society (MDS) criteria for MSA diagnosis using an evidence-based and consensus-based technique.

They found flaws in the second consensus criteria for MSA diagnosis. They conducted a comprehensive literature analysis to address predetermined questions on clinical presentation and diagnostic techniques used in MSA diagnosis. The criteria were designed and later optimized through two Delphi rounds inside the MSA Criteria Revision Task Force, an MDS membership poll, and a virtual Consensus Conference.

The neuropathologically established MSA criteria remained constant. A new category of clinically established MSA was developed for clinical MSA diagnosis to achieve maximal specificity while maintaining adequate sensitivity. A clinically plausible MSA category was created to improve sensitivity while retaining specificity. A putative prodromal MSA study category was intended to identify individuals in the early phases when symptoms and indicators are present but do not reach the clinically established /clinically likely MSA criterion. Brain magnetic resonance imaging markers indicative of MSA are necessary for clinically established MSA. The number of research biomarkers supporting all clinical diagnostic categories was expected to expand.

The collection of MDS MSA diagnostic criteria attempted to improve diagnosis accuracy, especially in the early stages of the disease. However, a prospective clinical and clinicopathological investigation is required to validate it.

Reference: movementdisorders.onlinelibrary.wiley.com/doi/10.1002/mds.29005