Expectation modulates the effect of deep brain stimulation on motor and cognitive function in tremor-dominant Parkinson's disease

Introduction: Expectation is one of the main factors mediating placebo and nocebo responses. In Parkinson's disease (PD) there is evidence for expectation-induced modulations of bradykinesia. Yet, little is known about the impact of expectation on resting tremor. Subthalamic nucleus (STN) deep brain stimulation (DBS) improves cardinal motor symptoms including tremor whereas impairment in verbal fluency (VF) has been observed as a potential side-effect. In the present study we investigated how expectation modulates the effect of STN-DBS on resting tremor and its interaction with VF [1]. Methods: In a within-subje…