Cholinesterase Inhibitors to Slow Progression of Visual Hallucinations in Parkinson&Apos;s Disease

Rationale: Visual hallucinations (VH) are the most common non-motor symptoms in Parkinson's disease (PD). As an independent predictor for cognitive decline and nursing home placement they form an important disability milestone in the course of PD. According to current clinical guidelines minor VH do not require treatment per se. But as minor VH precede the stage of major VH without insight and PD associated psychosis (PDP) they offer an opportunity for early intervention. Neuroleptic drugs delay the transition into PDP but are unsuitable for early treatment of VH due to their side effects. We hypothesize that cholinesterase inhibitors (ChEI) are a well-tolerated alternative for the early treatment of minor VH to delay the progression to PDP, and that brain network analysis is suitable to predict treatment response. Objective: Investigate whether early treatment with ChEI delays the progression of minor VH to major VH without insight or PDP. In addition, we will measure motor control, psychotic symptoms, cognitive impairment, mood disorders, daytime sleepiness, adverse events and compliance, disability, caregiver burden and care use. We assess the cost-effectiveness of early chronic treatment of VH with ChEI. Finally, we analyse changes of functional brain networks before and during treatment. Study design: A randomized, double blind, placebo-controlled, multi-center trial with an economic evaluation. Study population: 168 patients with PD and VH after fulfilling the in-and exclusion criteria. Intervention: Rivastigmine capsule 6 mg BID or placebo BID for 24 months. Main study parameters/endpoints: The primary outcome measure is the median time until PD patients with minor VH progress to major VH without insight. The clinical endpoint is defined as the start with antipsychotic treatment. Secondary outcome measures are changes in motor control, psychotic symptoms, cognitive impairment, mood disorders, daytime sleepiness, cholinergic deficiency, the number of adve