New MDS Criteria for the Diagnosis of Multiple System Atrophy: How to Use in Clinical Practice and Clinical Trials

Abstract

The newly revised diagnostic criteria for multiple system atrophy (MSA) have reduced the criteria for diagnosing orthostatic hypotension compared to the conventional diagnostic criteria, but require tests such as MRI and residual urine measurement. Under the new diagnostic criteria, cases that were previously classified as possible MSA with low diagnostic accuracy may become clinically established with higher diagnostic accuracy. However, examination of the cohort treated in our establishment showed that there were cases in which the diagnostic criteria could not be applied when the symptoms and test items necessary for diagnosis were not confirmed. In clinical trials, clinically established or clinically probable MSA are targeted for interventional studies, and possible prodromal MSA are considered to be more important for observational studies. In the future, it will be necessary to confirm the diagnostic accuracy pathologically, accumulate evidence from various clinical tests that are listed as supportive biomarkers, and to develop more useful diagnostic criteria.