Sensory attenuation in Parkinson’s disease (P6.045)

Objective:Investigation ofSEPs suppression at the onset of movement in healthy controls and Parkinsons9s disease(PD)patients in ON and OFF medication and interaction between SEPs suppression and vibration of the limb.Background:Gating of sensory evoked potentials(SEPs)around the onset of a voluntary movement is a physiological phenomenon which may reflect sensorimotor integration required for normal movement control.Methods:10right-handed patients with PD and 10 right-handed age-matched healthy participants were studied.SEPs were elicited after electrical stimulation of the median nerve at the wrist.EEGs were recorded over the scalp at three sites on according to the International 10-20 System (F3,C3 and P3). SEPs were recorded in four conditions:at rest,at the onset of movement(a self-paced abduction movement of the right thumb), both in the absence of and in the presence of vibration of the limb.Results:SEPs amplitude at the onset of movement was significantly attenuated in the control group compared to baseline(SEPs N20(C3) amplitude (ratio=0.72).In contrast, patients with PD in OFF state did not display SEPs suppression at the onset of movement compared to baseline(SEPs N20(C3)amplitude(ratio=1.51).This difference was statistically significant (t=-4.34,df=18,p Disclosure: Dr. Macerollo has nothing to disclose. Dr. Chen has nothing to disclose. Dr. Korlipara has nothing to disclose. Dr. Kilner has nothing to disclose. Dr. Edwards has received royalty payments Oxford University Press.