Project details


Parkinson's disease, visual hallucinations and apomorphine: a randomized, placebo-controlled trial

Parkinson's disease

prof. dr. T. van Laar
R.W.K. Borgemeester

Type of project:
Stage Wetenschap / Research project

Nature of the research:
Randomized, placebo-controlled trial: collecting data - data-analysis - writing process

Fields of study:

Background / introduction
Visual hallucinations occur frequently in the course of Parkinson’s disease (PD) and are predictive for PD dementia. The incidence ranges from 22 to 38%, increasing with long-term follow-up to more than 60%. The genesis of visual hallucinations in PD is related to impaired “bottom-up” and “top-down” processing and imbalanced neurotransmitter systems including cholinergic, dopaminergic and serotonergic system. The treatment of visual hallucinations is challenging. Only clozapine has proved to be efficacious on visual hallucinations without worsening motor symptoms of PD. In a small open-label trial, apomorphine (strong dopamine agonist and serotonin 2A antagonist) had a beneficial effect on visual hallucinations. Now, the aim of this study is to investigate the superiority of apomorphine compared to a placebo in hallucinating PD patients.
Research question / problem definition
This study investigates the efficacy of apomorphine on refractory visual hallucinations compared to a placebo. Furthermore, we are interested in the effect of apomorphine on “bottom-up” and “top-down” mechanisms and quality of life.
This randomized, placebo-controlled trial will be conducted in the department of Neurology, University Medical Center Groningen. The student will participate in collecting data, data-analysis and writing process. Students may formulate a specific research question and be one of the (co)-authors when published. As this study involves patients, good proficiency of the Dutch language is mandatory. The study has already approval of the Ethics Committee and ready to start.
1. van Laar T, Postma AG, Drent M. Continuous subcutaneous infusion of apomorphine can be used safely in patients with Parkinson’s disease and pre-existing visual hallucinations. Parkinsonism Relat Disord. 2010; 16: 71-2.
2. Geerligs L, Meppelink AM, Brouwer WH, van Laar T. The effects of apomorphine on visual perception in patients with Parkinson’s disease and visual hallucinations: a pilot study. Clin Neuropharmacol. 2009; 32: 266-8.
3. Borgemeester RW, Lees AJ, van Laar T. Parkinson’s disease, visual hallucinations and apomorphine: a review of the available evidence. Parkinsonism Relat Disord. 2016; 27 :35-40.
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