Italian Validation of the Revised MDS-Unified Parkinson's Disease Rating Scale

The present study is part of an international program and deals with the translation and validation program for the Italian version of the MDS-UPDRS. The program will be articulated in three steps: * Phase I: translation and back-translation of the MDS-UPDRS in Italian (completed) * Phase II: Cognitive testing. This step is aimed at a preliminary testing of a subset of potentially culturally sensitive items in a limited set of PD patients (approximately 10). Should this phase identify issues in the understanding and ease of use of some items a revised translation of some individual items might be envisaged. * Phase III: large validation testing: this phase will involve 350 PD patients from 12-14 Italian PD centres. The IRIS protocol deals with phase II and III of the program.