Abstract
I read the study by Pazzaglia and colleagues with great interest [1]. While I believe the authors have made a considerable contribution with this work, there are some concerns that I would like to address.
Firstly, the authors of the study stated that they used “Disabilities of the Arm, Shoulder and Hand (DASH)” scale to measure the performance of the upper limb. It has already been noted in the study that the DASH scale is designed to measure physical function and symptoms in people with upper limb musculoskeletal disorders. However, there is no validation study of DASH for Parkinson's disease (PD). Also, in a comprehensive systematic review study, it has been stated that, some of the DASH scale items evaluate the symptoms specific to musculoskeletal dysfunctions that are not related to upper limb functions in individuals with PD, thus affecting their likelihood of responding in the evaluation of patients [2].
Secondly, I looked up the study protocol (Identifier: NCT02807740) which was registered by the authors in order to get information about whether conventional rehabilitation (CR) exercises are applied in the clinical setting or at home. I noticed that one of the elimination criteria (“no changes in drug therapy for PD during the rehabilitation program”) was not available in the registered study protocol. Also, there was not an evaluation with “spirometry” in the clinical trial record. However, the authors stated that electrocardiography and spirometry were used in order to exclude heart or respiratory contraindications, in the article. Besides, in the clinical trial record, it is stated that “the aim of this study is to compare a virtual reality (VR) rehabilitation program versus a conventional one in a sample of patients affected by mild to moderate Parkinson and to collect data on cardiological effects.” However, electrocardiography was only used for the exclusion of cases.
Last but not least, it is stated that KNGF recommendations were used for CR exercises Nevertheless, detailed information was not given both in the article and trial recording. The importance of “rhythmic recurring cues” was also mentioned by KNGF in CR by simple methods [3]. A detailed description of the CR program will make the results of the study more understandable, whether to claim the effectiveness of VR or external stimuli.