Dyskinesia Rating Scales in Parkinson’s Disease

Abstract

Drug-induced dyskinesia is a common phenomenon in Parkinson’s disease and may be socially as well as physically disabling for patients. Because of the impact of dyskinesia on activities of daily living, quality of life, and consequent global disability of PD patients, the Movement Disorder Society (MDS) organized a systematic review of the clinimetric properties of the scales used to measure dyskinesia in this disease. This chapter is mainly based on the published review,1 but includes also part of the supplementary materials produced by the task force and initially published online on the Movement Disorders journal website. A scale was designated “Recommended” if the scale had been used in clinical studies beyond the group that developed it, had been specifically used in PD reports, and if clinimetric studies had established that it was valid, reliable, and sensitive. “Suggested” scales met two of the above criteria; and those meeting one were “Listed.” Eight rating scales for dyskinesia that have either been validated or used in PD were identified: Abnormal Involuntary Movement Scale (AIMS), the Unified Parkinson’s Disease Rating Scale (UPDRS) part IV, the Obeso Dyskinesia Rating Scale, the Rush Dyskinesia Rating Scale, the Clinical Dyskinesia Rating Scale (CDRS), the Lang-Fahn Activities of Daily Living Dyskinesia Scale, the Parkinson Disease Dyskinesia Scale (PDYS-26), and the Unified Dyskinesia Rating Scale (UDysRS). Based on this review and rating system, four of the reviewed dyskinesia scales (AIMS, Rush Dyskinesia Rating Scale, PDYS-26, and the UDysRS) can be recommended for use in PD populations; all of the remaining met criteria to be suggested. However, some of the recommended scales have significant weaknesses (AIMS does not allow differentiation among the different forms of dyskinesia, and the Rush scale “actual” intra- and inter-rater reliability is not really known). Conversely, the two most recent scales (PDYS-26 and UDysRS) have excellent clinimetric properties and appear to provide a reliable and valid assessment tool of dyskinesia in PD. Since further testing of these newer scales in PD is warranted, no new scales are needed until the available scales are fully analyzed clinimetrically.