山中 義崇

Multiple system atrophy with predominant parkinsonism (MSA-P) can hardly be distinguished from Parkinson’s disease (PD) clinically in the early stages. This study investigated whether a standardized T1-weighted/T2-weighted ratio (sT1w/T2w ratio) can effectively detect degenerative changes in the middle cerebellar peduncle (MCP) associated with MSA-P and PD and evaluated its potential to distinguish between these two diseases. We included 35 patients with MSA-P, 32 patients with PD, and 17 controls. T1w and T2w scans were acquired using a 1.5-T MR system. The MCP sT1w/T2w ratio was analyzed via SPM12 using a region-of-interest approach in a normalized space. The diagnostic performance of the MCP sT1w/T2w ratio was compared between the MSA-P, PD, and controls. Patients with MSA-P had significantly lower MCP sT1w/T2w ratios than patients with PD and controls. Furthermore, MCP sT1w/T2w ratios were lower in patients with PD than in the controls. The MCP sT1w/T2w ratio showed excellent or good accuracy for differentiating MSA-P or PD from the control (area under the curve (AUC) = 0.919 and 0.814, respectively) and substantial power for differentiating MSA-P from PD (AUC = 0.724). Therefore, the MCP sT1w/T2w ratio is sensitive in detecting degenerative changes in the MCP associated with MSA-P and PD and is useful in distinguishing MSA-P from PD.

Background: Multiple system atrophy (MSA) is a neurodegenerative disorder characterized by autonomic failure and various motor symptoms. While MSA-C (cerebellar type) predominates in East Asia, MSA-P (parkinsonian type) predominates in Europe and North America. This nationwide patient registry aimed to (1) conduct a prospective natural history study of MSA in Japan, (2) facilitate patient recruitment for clinical trials, and (3) deposit bioresources and clinical information in a biobank. Methods: Thirteen institutions participated in this study. Clinical information was obtained by neurologists from the patients visiting the hospital every 12 months to assess the UMSARS Part 2 scores and by telephone interviews by nurses every 6 months to assess UMSARS Part 1 scores and to determine whether clinical events had occurred. Results: Demographic data from 329 MSA patients (216 MSA-C and 113 MSA-P) were analyzed. The mean age at symptom onset was 58.2 years (standard deviation, 8.9); the mean duration of symptoms at enrollment was 3.5 years (standard deviation, 2.2). The mean 12-month changes in the UMSARS Part 1 and Part 2 scores were 7.9 (standard deviation, 5.6) and 6.4 (standard deviation, 5.9), respectively. The patient registry proved useful in recruiting participants for clinical trials, including those with gene variants. Clinical information and biospecimens were deposited in a biobank. Discussion: The study highlighted the importance of telephone interviews in minimizing drop-out rates in natural history studies and demonstrated similar MSA progression rates across populations. The deposited bioresources are available to researchers upon request, aiming to contribute to future MSA researches.