Ambroxol as a novel disease-modifying treatment for Parkinson’s disease dementia: protocol for a single-centre, randomized, double-blind, placebo-controlled trial oleh C. R. A. Silveira, J. MacKinley, K. Coleman, Z. Li, E. Finger, R. Bartha, S. A. Morrow, J. Wells, M. Borrie, R. G. Tirona, C. A. Rupar, G. Zou, R. A. Hegele, D. Mahuran, P. MacDonald, M. E. Jenkins, M. Jog, S. H. Pasternak