Ambroxol as a Treatment for Parkinson's Disease Dementia

The present study will test the hypothesis that the medication Ambroxol is safe and well tolerated and will improve cognitive and motor symptoms of Parkinson's Disease Dementia (PDD). Ambroxol has been shown to raise the levels of the enzyme beta-glucocerebrosidase resulting in lower the levels of the protein alpha-synuclein, both of which have been shown to improve cognition in mouse models. This will be a 52 week trial of Ambroxol in 75 individuals with PDD. Participants will undergo clinical, neuropsychological and neuroimaging assessment throughout the study to assess changes.