Brain structural and functional changes after action observation therapy addressed to freezing of gait of subjects with Parkinson's disease. (May 2015) - Gatti, R.; Agosta, F.; Sarasso, E.; Gemma, M.; Meani, A.; Volonté, M.A.; Cattrysse, E.; Kerckhofs, E.; Falini, A.; Comi, G.; Filippi, M.