PROJECT SUMMARY Parkinson’s disease dementia (PDD) is a frequent non-motor symptom in patients with Parkinson’s disease (PD). PDD is associated with cognitive decline that can increase morbidity and mortality and dramatically reduce patient quality of life. Three out of four PD patients will develop PDD, yet the only FDA-approved treatment for PDD is rivastigmine which provides effects that are short-lived and modest at best and may worsen PD motor symptoms. Furthermore, gold standard therapies for Parkinsonian motor impairments (i.e., levodopa and deep brain stimulation) can worsen PDD, yet stopping treatment is typically not recommended. To address this dire need, Scion NeuroStim, Inc has developed a novel, home-use device that non-invasively stimulates nuclei in the brainstem that send projections throughout the brain to regulate a variety of functions including cognition, memory, well-being, and mood. In a previous double-blind, randomized controlled trial, eight weeks of Device treatments dramatically improved both motor and non-motor symptoms in PD patients. Device treatments were well tolerated and safe with only infrequent, transient, and mild side effects. Importantly, a sub-analysis of data from participants with evidence of either mild cognitive impairment or dementia revealed that Device treatment was associated with significantly improved cognitive performance according to the Montreal Cognitive Assessment. Treatment adherence was excellent and study participants remained blind to their treatment allocation. Furthermore, the kinetics of the clinical responses indicate that longer treatment periods are likely to result in even greater clinical improvements. Thus, in this project, Scion will conduct a single-arm clinical trial to evaluate the safety and feasibility of non-invasive brainstem stimulation with Scion’s Device over a period of 12 weeks in PDD patients. Further, it will explore the potential for Scion’s Device to treat cognitive and other motor and non-motor symptoms associated with PDD, which, if favorable, will enable the design and powering of a pivotal trial.