Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT02231645 |
| Other study ID # |
DBS-Parkinson |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
May 2013 |
| Est. completion date |
September 2014 |
Study information
| Verified date |
October 2020 |
| Source |
Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
The purpose of this study is to evaluate whether subthalamic deep brain stimulation (STN DBS)
can affect moral and economic decisions in patients with Parkinson's disease (PD).
Description:
Sample
A group of patients with idiopathic PD and with bilateral STN DBS implant (experimental
group) and a control group including patients with idiopathic PD and without DBS implant who
are treated with dopaminergic medications will be recruited from the IRCCS Fondazione Ca'
Granda Ospedale Maggiore Policlinico of Milan and from the Istituto Neurologico Nazionale
IRCCS Casimiro Mondino of Pavia. Patients will be selected in order to balance groups for
gender, age, disease duration, cognitive and motor functions.
Decision-making computerized tasks
Moral task. The task consisted of 38 sentences divided into 13 neutral, 10 moral conflictual
and 15 moral non conflictual statements. Each statement was presented in a random order for a
maximum of 10 s. During this period, participants were instructed to read each sentence and
to respond if they agreed or disagreed with it by pressing the "A" (agreement) or the "L"
(disagreement) keys with the left or the right finger. After the key was pressed, a black
screen was displayed for 1 s before the next statement appeared on the screen (Fumagalli et
al., 2011).
Economics task. Pairs of stimuli (four letters from the Latin alphabet) are presented on the
screen in white on a black background. To maximize gains, subjects are asked to choose a
letter by pressing one of the two keyboard keys, corresponding to the stimulus on the left or
right of the screen. Each choice prompts two visual feedbacks, the first displaying the money
won or lost and the second indicating the total sum of money the subject was gaining. Each
stimulus pair is preceded by a black screen. Six different stimulus pairs (AB, AC, AD, BC,
BD, CD) are presented. Stimulus pairs comprised stimuli with the same probability to win
(conflictual trials) and different probability to win (non conflictual trials). The letters
"A" and "D" led to positive feedback (+60 Euros) 80% of the times and to negative feedback
(-30 Euros) 20% of the times (non risky letters). "B" and "C" letters led to high positive
feedback (+100 Euros) only 20% of the times and to a high negative feedback (-70 Euros) 80%
(risky letters). The task is designed to reward non risky choices, so that the larger the
number of non risky choices, the higher is the amount of money earned. The task comprises 102
trials, 68 non conflictual and 34 conflictual (Rosa et al., 2013).
Experimental protocol
All patients will be tested with the moral and the economics tasks during the best ON-drug
medication condition. The experimental group performed the tasks in the STN DBS ON condition
and in the STN DBS OFF condition. Following the end of the STN DBS ON session, the DBS
devices will be turned off by the physician 30 minutes prior to the STN DBS OFF session. The
order of stimulation conditions and of the versions of the task will be randomized and
counterbalanced.
The control group will similarly perform the moral and the economics tasks twice with the
same time intervals, without the STN DBS manipulation.
Motor, cognitive and psychological assessment. Patients will perform a short motor, cognitive
and psychological assessment using the UPDRS III, the MMSE and VASs for subjective evaluation
of mood, anxiety, movement difficulty and motor fatigue. VASs will be performed twice: in STN
DBS ON and OFF conditions for experimental group, and in the first and the second session for
the control group. UPDRS III and MMSE will be evaluated when patients from the experimental
group are in STN DBS ON condition and when control patients are in the first session.
Statistical Analysis
Normality tests will be performed on behavioural data (reaction times and responses at
computerized tasks, scores obtained at MMSE, UPDRS III, VASs) with One-Sample
Kolmogorov-Smirnov Test.
Behavioural data obtained by the experimental group in STN DBS ON and STN DBS OFF conditions
will be compared with analysis of variance (ANOVA). Also data obtained by patients from the
experimental group will be compared to data obtained by the control groups.
