The main goal of this study is to investigate the influence of STN DBS on the cognitive processes of reward processing and selective visual attention.
ID
Source
Brief title
Condition
- Movement disorders (incl parkinsonism)
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
Main parameters of interest are the reaction time differences in the visual
search tasks, and alterations of perceived stimulus presentation onset. Both
can be used as a measure to indicate the degree of influence of DBS on reward
processing and selective attention. Previous and ongoing studies on healthy
observers in our groups show a beneficial effect of monetary reward on reaction
times in visual search tasks (Hickey et al. 2010) and perceived stimulus onset
in the simultaneity judgement task. In the present study we aim to test both
whether DBS changes these effects of monetary reward and whether stimulation
could actually replace the monetary reward as source for the observed influence
on selective attention.
Secondary outcome
not applicable
Background summary
Subthalamic nucleus (STN) deep brain stimulation (DBS) is an effective therapy
for the motor manifestations of Parkinson*s disease (PD; Lozano and Lipsman,
2013). In DBS procedures stimulation electrodes are surgically placed directly
inside the brain and continuous high frequency stimulation is delivered via an
implanted pulse generator that can be programmed externally. Modulating the
pathological motor circuits with DBS in PD may produce significant benefits but
the precise mechanisms underlying the beneficial effects of DBS are not well
understood. Mechanisms of action may reflect differences in the
microenvironment surrounding the DBS electrodes or more remote neural
components. DBS does not only alleviate clinical symptoms, but also probes the
function of related brain circuits. Several studies have shown non-symptomatic
beneficial effects of DBS in patients treated with DBS, such as improvements in
psychomotor functions, working memory, probabilistic learning and response
inhibition (Coulthard et al., 2012; Frank et al. 2007;van den Wildenberg et
al., 2006; van Wouwe et al. 2011; Wilkinson et al., 2011). In order to
understand these mechanisms it is important to have a better idea of the
non-symptomatic effects of stimulation.
Study objective
The main goal of this study is to investigate the influence of STN DBS on the
cognitive processes of reward processing and selective visual attention.
Study design
The study is a cross sectional, double blind study. We will use a within
subject design, in which patients will act as their own controls (DBS
ON/OFF).We will conduct the experiments in separate blocks, lasting in total
2.5 hours. All tasks that we intend to use in this patient study have already
been conducted by healthy observers, revealing clear effects of reward on the
distribution of visual attention. We will first repeat the basic experiment in
the DBS patients in the absence of stimulation to obtain a baseline measure of
the effect shown in the healthy observers. We well then move on to test the
impact of stimulation on the underlying reward-based attention mechanisms.
Study burden and risks
The burden for the patients will consist of visiting the AMC to conduct visual
search and simultaneity judgment tasks for 2.5 hours.Subjects will have to
withhold from the PD medication 12 hours (the night) prior to the experiment.
To our knowledge, there will be no additional risks associated with our
experiments. Participating patients will not benefit directly from the
experiments. They will, however, contribute to the extension of knowledge about
deep brain stimulation in future patients. In addition, they will help to
improve understanding of reward processing in the human brain.
Meibergdreef 5
Amsterdam 1105 BA
NL
Meibergdreef 5
Amsterdam 1105 BA
NL
Listed location countries
Age
Inclusion criteria
Written informed consent, Patients implanted with a DBS device for the treatment of Parkinson*s, Age > 18 years, Patients with bilateral electrode implants will only be included if the stimulation can be generated by one external pulse generator (Kinetra, ActivaPC, or ActivaRC), Therapeutic stimulation parameters should be such that the patient does not directly feel the stimulation pulses and thus can be blinded to the stimulation ON/OFF condition, Symptoms do not immediately reoccur when Stimulation is turned off, absence of dementia or major psychiatric illness, patients have to withhold from their PD medication 12 h prior to the experiment.
Exclusion criteria
I- Inability to turn off the stimulator for the duration of the experiment on clinical grounds
- Color blindness
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL44259.018.13 |