The Movement Disorder Society Criteria: Its Clinical Usefulness in Multiple System Atrophy.

Area of Science:

• Neurology
• Rare Diseases
• Diagnostic Criteria

Background:

• The 2022 Movement Disorder Society (MDS) criteria were introduced as an alternative for diagnosing Multiple System Atrophy (MSA).
• Previous diagnostic statements for MSA required evaluation and updates.
• Assessing the utility and trends of the new MDS criteria is crucial for clinical practice.

Purpose of the Study:

• To examine the diagnostic trends and patient classification changes using the 2022 MDS criteria for Multiple System Atrophy (MSA).
• To evaluate the impact of clarified imaging and supportive findings on MSA diagnosis over time.

Main Methods:

• Utilized patient data from the Hokkaido Rare Disease Consortium for Multiple System Atrophy (November 2014 - July 2022).
• Evaluated 68 patients using the MDS criteria at initial assessment, diagnosis (enrollment), and final evaluation.
• Included neurological examinations and imaging findings in the diagnostic assessment.

Main Results:

• At initial evaluation, 39.7% were clinically established, 19.1% probable, 17.6% possible prodromal, and 23.5% negative.
• By diagnosis, classifications shifted: 66.2% established, 17.6% probable, 5.9% possible prodromal, and 10.3% negative.
• At final evaluation, 76.5% were established, 13.2% probable, 2.9% possible prodromal, and 7.4% negative, indicating improved diagnostic certainty.

Conclusions:

• The MDS criteria demonstrated a dynamic patient classification, with a notable increase in 'clinically established' diagnoses over time.
• Clarification of imaging and supportive findings within the MDS criteria facilitated improved diagnostic accuracy for MSA.
• These findings highlight the evolving nature of MSA diagnosis and the utility of the updated MDS criteria.