Condition category
Nervous System Diseases
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Plain English Summary

Background and study aims
Patients with advanced Parkinson's disease often do not respond well to medication. When this is the case, deep brain stimulation (DBS) is a treatment option to improve stiffness, shaking and slowness. DBS is a type of surgery in which two electrodes are placed deep in the brain: one on each side of the brain. These electrodes transmit a current that relieves symptoms. This can be done in a brain area called the subthalamic nucleus (STN) or in an area called the globus pallidus (GPi). This study compares the effects of DBS of the STN with DBS of the GPi.

Who can participate?
Patients with Parkinson's disease suffering from uncontrollable involuntary movements, pain, or severe slowness can participate.

What does the study involve?
Patients are randomly allocated to receive DBS of either the STN or the GPi. Afterwards, they are followed extensively, for up to 5 years, to monitor the effects on motor symptoms, mental status, and behavior.

What are the possible benefits and risks of participating?
Both STN DBS and GPi DBS are already established treatment options for advanced PD. Risks of surgery include hemorrhage (bleeding), infection and malfunctioning of the equipment.

Where is the study run from?
The study is run from the Academic Medical Center, Amsterdam, The Netherlands. Four other centers in the Netherlands have participated

When is the study starting and how long is it expected to run for?
Patient recruitment ran from January 2007 until May 2012

Who is funding the study?
Stichting Internationaal Parkinson Fonds, Prinses Beatrix Fonds, and Parkinson Vereniging (Netherlands)

Who is the main contact?
Rob M A de Bie

Trial website

Contact information



Primary contact

Dr Rob M A de Bie


Contact details

Academic Medical Center (AMC)
Department of Neurology
PO Box 22660
1100 DD

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Randomised double-blind multicentre trial comparing bilateral subthalamic nucleus deep brain stimulation and bilateral globus pallidus deep brain stimulation for advanced Parkinson's disease



Study hypothesis

Assuming that the effects on Parkinson's disease symptoms and dyskinesias, and the rates of procedure-related and device-related complications are almost equal, then continuous bilateral Globus Pallidus Deep Brain Stimulation (GPi DBS) may produce greater functional improvement than bilateral SubThalamic Nucleus (STN) stimulation in Parkinson's disease, because the latter is associated with long-term cognitive, mood, and behavioural problems.

Ethics approval

Medisch Ethische Commissie AMC, 17/05/2006, ref: MEC 06/084 # 07.17.0069. Last amendment approval received on 11/01/2007.

Study design

Randomised controlled parallel-group double-blinded multicentre trial

Primary study design


Secondary study design

Randomised parallel trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Parkinson's disease


Stereotactic bilateral implantation of DBS electrodes in the globus pallidus internus or the nucleus subthalamicus.

Intervention type



Drug names

Primary outcome measure

The number of patients with significant cognitive, mood, and behavioural adverse effects and the off-on phase weighted Academic Medical Centre (AMC) Linear Disability Scale (functional improvement).

Significant cognitive, mood, and behavioural adverse effects are defined as worsening on three or more cognitive tests (based on the reliable change index), or the loss of professional activity/work/job, or the loss of an important relationship (e.g. marriage), or psychosis/depression/anxiety for a period of three months or longer.

Outcome measurements will be performed at baseline and 12 months after surgery.

Secondary outcome measures

Secondary outcome consists of:
1. Symptom scales (Unified Parkinson's Disease Rating Scale [UPDRS] motor, Clinical Dyskinesia Rating Scale [CDRS])
2. Activities of daily living scales (ADLS) and UPDRS Activity of Daily Living (ADL) scale
3. A quality of life questionnaire (Parkinsons Disease Quality of Life [PDQL])
4. Adverse effects
5. Medication use

Additionally, patients will undergo extensive neuropsychological and standardised psychiatric assessment.

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

Idiopathic Parkinson's disease and - despite optimal pharmacological treatment - at least one of the following symptoms: severe response fluctuations, dyskinesias, painful dystonias, or bradykinesia

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Age below 18 years
2. Previous functional stereotactic neurosurgery
3. Hoehn and Yahr stage five at the best moment during the day
4. A Mattis dementia rating scale score of less than 120
5. Psychosis, and contraindications for stereotactic neurosurgery such as a physical disorder making surgery hazardous (severe hypertension, blood coagulation disorder, severe dysphagia, or dysphasia)

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

Academic Medical Center (AMC)
1100 DD

Sponsor information


Academic Medical Centre (AMC) (Netherlands)

Sponsor details

PO Box 22660
1100 DD

Sponsor type

Hospital/treatment centre



Funder type

Research organisation

Funder name

Prinses Beatrix Fonds (Netherlands)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Funder name

Internationaal Parkinson Fonds (Netherlands)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

2012 results in:
2016 results in:

Publication citations

  1. Results

    Odekerken VJ, van Laar T, Staal MJ, Mosch A, Hoffmann CF, Nijssen PC, Beute GN, van Vugt JP, Lenders MW, Contarino MF, Mink MS, Bour LJ, van den Munckhof P, Schmand BA, de Haan RJ, Schuurman PR, de Bie RM, Subthalamic nucleus versus globus pallidus bilateral deep brain stimulation for advanced Parkinson's disease (NSTAPS study): a randomised controlled trial., Lancet Neurol, 2013, 12, 1, 37-44, doi: 10.1016/S1474-4422(12)70264-8.

  2. Results

    Odekerken VJ, Boel JA, Schmand BA, de Haan RJ, Figee M, van den Munckhof P, Schuurman PR, de Bie RM; NSTAPS study group, GPi vs STN deep brain stimulation for Parkinson disease: Three-year follow-up, Neurology, 2016 , 86, 8, 755-761, doi: 10.1212/WNL.0000000000002401.

Additional files

Editorial Notes

04/07/2016: Publication reference added. 15/03/2010: this record was updated to include a second funder (details in the relevant section below). The overall trial end date was changed from 31/12/2009 to 01/07/2012.