Background: Bradykinesia is the clinical feature of Huntington's disease most closely related to functional discapacity and stage, probably as a consequence of spreading of neuronal injury. The aim of the present article is to verify whether a choice reaction time could be considered an estimate measurement of clinical bradykinesia, and its possible relationships with other evolutive parameters such as functional discapacity, clinical stage and prefrontal executive dysfunction.
Methods: Fifteen patients were studied (9 in advanced stage and 6 initials), equal number of controls and 3 asymptomatic gene carriers. We used clinical bradykinesia and functional capacity scales, an extensive prefrontal battery and a computerized paradigm of reaction time.
Results: Clinical bradykinesia and reaction time are closely related. The associations between reaction time with those parameters indicatives of prefrontal dysfunction, functional discapacity and clinical stage are closer and more significatives than those that could be established with clinical bradykinesia.
Conclusions: Reaction time is an objective measurement of global motor slowness that allow us assigning each subject to a specific stage, and avoid possible errors derived from interobserver bias in clinical scales.