The Movement Disorder Society-UPDRS (MDS-UPDRS) was published in 2008, showing satisfactory clinimetric results and has been proposed as the official benchmark scale for Parkinson's disease. The present study, based on the official MDS-UPDRS Spanish version, performed the first independent testing of the scale and adds information on its clinimetric properties. The cross-culturally adapted MDS-UPDRS Spanish version showed a comparative fit index ≥ 0.90 for each part (I-IV) relative to the English-language version and was accepted as the Official MDS-UPDRS Spanish version. Data from this scale, applied with other assessments to Spanish-speaking Parkinson's disease patients in five countries, were analyzed for an independent and complementary clinimetric evaluation. In total, 435 patients were included. Missing data were negligible and moderate floor effect (30 %) was found for Part IV. Cronbach's α index ranged between 0.79 and 0.93 and only five items did not reach the 0.30 threshold value of item-total correlation. Test-retest reliability was adequate with only two sub-scores of the item 3.17, Rest tremor amplitude, reaching κ values lower than 0.60. The intraclass correlation coefficient was higher than 0.85 for the total score of each part. Correlation of the MDS-UPDRS parts with other measures for related constructs was high (≥ 0.60) and the standard error of measurement lower than one-third baseline standard deviation for all subscales. Results confirm those of the original study and add information on scale reliability, construct validity, and precision. The MDS-UPDRS Spanish version shows satisfactory clinimetric characteristics.

To date, there are no definitive biomarkers for Parkinson's disease (PD) diagnosis. The detection of cerebrospinal fluid (CSF) alpha (α)-synuclein in PD patients has yielded promising but inconclusive results. To determine the performance of CSF α-synuclein as a diagnostic biomarker of PD and whether CSF α-synuclein can discriminate PD from other neurodegenerative diseases, a systematic search of all relevant studies investigating reproducible CSF α-synuclein quantification methods was conducted in electronic databases. A total of 17 studies that included 3311 patients were included in this systemic review and meta-analysis. The mean CSF α-synuclein concentration was significantly lower in PD patients compared to normal/neurological controls [weighted mean difference (WMD) -0.31; 95% CI, -0.45, -0.16; p < 0.0001] and patients with Alzheimer's disease (AD) [WMD -0.15; 95% CI, -0.26, -0.04; p < 0.0001]. There was no significant difference between PD patients and dementia with Lewy bodies (DLB) patients [WMD -0.03; 95% CI, -0.16, 0.09; p = 0.58] or patients with multiple system atrophy (MSA) [WMD 0.05; 95% CI, -0.04, 0.13; p = 0.25]. Sensitivity and specificity of CSF α-synuclein in the diagnosis of PD was 0.88 (95% CI, 0.84-0.91) and 0.40 (95% CI, 0.35-0.45), respectively. The positive and negative likelihood ratios of CSF α-synuclein in the diagnosis of PD were 1.41 (95% CI, 1.24-1.60), and 0.29 (95% CI, 0.15-0.56), respectively. The corresponding summary receiver operating characteristic (SROC) curve showed an area under the curve (AUC) of 0.73. The concentration of CSF α-synuclein may be a biomarker for the diagnosis of PD. The use of α-synuclein alone however is not sufficient as a single biomarker and it must therefore be used in conjunction with other documented and reliable biomarkers.

The Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) has been available in English since 2008. As part of this process, the MDS-UPDRS organizing team developed guidelines for development of official non-English translations. We present here the formal process for completing officially approved non-English versions of the MDS-UPDRS and specifically focus on the first of these versions in Italian. The MDS-UPDRS was translated into Italian and tested in 377 nativeItalian speaking PD patients. Confirmatory and exploratory factor analyses determined whether the factor structure for the English-language MDS-UPDRS could be confirmed in data collected using the Italian translation. To be designated an 'Official MDS translation,' the Comparative Fit Index (CFI) had to be ≥0.90 relative to the English-language version. For all four parts of the Italian MDS-UPDRS, the CFI, in comparison with the English-language data, was ≥0.94. Exploratory factor analyses revealed some differences between the two datasets, however these differences were considered to be within an acceptable range. The Italian version of the MDS-UPDRS reaches the criterion to be designated as an Official Translation and is now available for use. This protocol will serve as outline for further validation of this in multiple languages.2

(i) MDS-UPDRS Part I (nM-EDL) and NMSS showed a strong convergent validity; (ii) however, transformed scores using the equations from weighted regression models showed that for patients with the most severe NMS they are not concordant.