A review of the assessment of dyskinesias

Dyskinesias are most prevalent in patients with Huntington's disease (HD), patients with Parkinson's disease (PD) who have received chronic levodopa t herapy, and in patients who have been treated with neuroleptics (tardive dy skinesia [TD]). Recent therapeutic developments have fueled a growing inter est in the clinimetrics of dyskinesias. For dyskinesias in HD, few rating s cales are available, but data on validity, reliability, and responsiveness are scarce. Only the interrater reliability of facial dyskinesias has been evaluated and found to be low. Many subjective rating scales for dyskinesia s in PD exist, but only the Dyskinesia Rating Scale has undergone sufficien t clinimetric evaluation. For TD, numerous rating scales are available, man y of them with ample data on reliability and validity. Objective assessment of dyskinesias has been attempted with a number of techniques. All these m ethods require a laboratory setting, rendering them susceptible to influenc e of stress. Moreover, they provide only a momentary assessment of dyskines ia severity and fail to take into account diurnal fluctuations. In view of the methodologic shortcomings in the assessment of dyskinesias, more effort needs to be put into strengthening currently available modes of assessment or designing new ones. In the future ambulatory accelerometry might prove to be of value in this field.