P7.17 Gait impairment following subthalamic deep brain stimulation in Parkinson's disease: multi-center prospective trial of parameter adjustments - Fasano, A.; Morgante, F.; Modugno, N.; Zibetti, M.; Lena, F.; Lopiano, L.; Piano, C.; Bentivoglio, A.R. (Clinical Neurophysiology, 2011)