Temporal Changes of Diagnostic Accuracy for Multiple System Atrophy: A 15-year Analysis from 2008 to 2022
Hiroaki Sekiya1, Philip Tipton2, Miki Kawazoe1, Shunsuke Koga1, Aya Murakami1, Ryan Uitti2, William Cheshire2, Zbigniew Wszolek2, Dennis Dickson1
1Neuroscience, 2Neurology, Mayo Clinic
Objective:
To determine if the rate of accurately diagnosing multiple system atrophy (MSA) has increased over the past 15 years.
Background:
Diagnostic accuracy of MSA is suboptimal. The second consensus diagnostic criteria have been used since 2008; however, the International Parkinson and Movement Disorder Society (MDS) recently proposed revised criteria. To understand how these revised criteria will improve current diagnostic rates, it is necessary to first know the updated diagnostic accuracy before the revised criteria become regularly implemented.
Design/Methods:
We identified 348 consecutive patients with clinically diagnosed MSA whose brains were sent to our brain bank from 2008 to 2022. After excluding 27 cases with inadequate clinical information, this study included 321 cases (136 women and 185 men). To ensure an approximately equal distribution in numbers, we divided them into two groups: 172 cases in 2008-2017 and 149 cases in 2018-2022. Diagnostic accuracy was compared between these groups and also in clinical subtypes (the parkinsonian type (MSA-P) and cerebellar type (MSA-C)).
Results:
Among 321 patients, 225 patients were pathologically MSA and the overall diagnostic accuracy was 70%. The remaining 30% had alternative pathological diagnoses including Lewy body disease (18%), progressive supranuclear palsy (3.7%), cerebrovascular disease (1.2%), corticobasal degeneration (0.9%), and others (5.9%). Diagnostic accuracy in 2018-2022 was significantly higher compared to that in 2008-2017 (78% vs. 63%, P=0.005). Brain MRI scans were significantly more frequently performed in 2018-2022 compared to 2008-2017 (91% vs. 79%, P=0.0031. Diagnostic accuracy for MSA-C was similar in both groups (87% in 2008-2017 and 93% in 2018-2022), while that for MSA-P was significantly higher in 2018-2022 compared to that in 2008-2017 (72% vs. 59%, P=0.04).
Conclusions:
This study demonstrates that diagnostic accuracy of MSA in recent years has improved over time. The increased use of brain MRI might have contributed to the improved diagnosis accuracy.