Efficacy and Safety of Deep Brain Stimulation (DBS) of the Pallidal (GPi) in Patients With Tardive Dystonia

Sponsor

Charite University, Berlin, Germany (Other)

Overall Status

Unknown status

CT.gov ID

NCT00331669

Collaborator

Humboldt-Universität zu Berlin (Other), Ruhr University of Bochum (Other), Medical University of Cologne (Other), Heinrich-Heine University, Duesseldorf (Other), University Hospital Freiburg (Other), Medical University of Hannover (Other), Medical University Innsbruck (Other), University of Kiel (Other), Philipps University Marburg Medical Center (Other), Ludwig-Maximilians - University of Munich (Other), University of Rostock (Other), University of Regensburg (Other), University Hospital Tuebingen (Other), Medical University of Vienna (Other), Medtronic (Industry)

Enrollment

Location

Arm

Duration (Months)

0.4

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

The purpose of this randomized, double blind, multi-center study is to assess the efficacy and safety of bilateral pallidal deep brain stimulation in patients with tardive dystonia.

Condition or Disease	Intervention/Treatment	Phase
Dystonia Movement Disorder	Procedure: deep brain stimulation	Phase 2

Detailed Description

Deep brain stimulation (DBS) has been established as a new reversible, neurosurgical therapeutic option for patients suffering from disabling neurological movement disorders such as essential tremor and Parkinson´s disease. Recently, deep brain stimulation has been successfully applied in patients with primary generalized and segmental dystonia. Additionally, a number of case reports suggest that pallidal deep brain stimulation may also improve tardive dystonia, which may for instance result from the intake of neuroleptics and which is notoriously difficult to treat medically. The present study will investigate the effects of pallidal DBS using a double blind, randomized design (sham- versus verum-stimulation within a 3-months interval post implantation of the electrodes).

Initially 60 patients had been calculated in a power analysis to assess significant results based on an average improvement of dystonic symptoms of 30%. However, in a recent study (Damier et al., Archives of General Psychiatry, 2007), 10 out of 10 showed a successful outcome of approximately 50% decrease on the extrapyramidal symptoms rating scale score. The exact one- sided lower 95% confidence limit would be 0.794 for this result. If such an approach is chosen for sample size estimation with 18 verum and 18 placebo patients one would obtain a power of 82% against a placebo effect of 30% success rate. For a placebo effect of 25% one needs 16+16 patients and for the placebo effect of 20% one needs 12+12 patients. We thus decided to reduce the sample size to 36- 32- 24 patients. It is expected that the continuous primary outcome measure will preserve even higher power than the binary one used in the study mentioned above. The local ethical committee has approved this.

Study Design

Study Type:

Interventional

Anticipated Enrollment :

24 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

Triple (Participant, Care Provider, Outcomes Assessor)

Primary Purpose:

Treatment

Official Title:

Multicenter, Randomized Trial on the Effects of Pallidal Deep Brain Stimulation for Tardive Dystonia

Study Start Date :

May 1, 2006

Anticipated Study Completion Date :

Dec 1, 2010

Arms and Interventions

Arm	Intervention/Treatment
Placebo Comparator: 1 device	Procedure: deep brain stimulation high frequency stimulation

Arm

Intervention/Treatment

Placebo Comparator: 1

device

Procedure: deep brain stimulation

high frequency stimulation

Outcome Measures

Primary Outcome Measures

Improvement of the motor scale of Burke-Fahn-Marsden-Dystonia Rating Scale via blinded video assessment 3 months after starting DBS in comparison to sham-stimulated patients [3 months]

Secondary Outcome Measures

AIMS [3 months]
Non-motor subscores of BMFDRS [3 months]
Visual analogue scales for both patients and treating physicians [3 months]
Quality of life (SF-36) [3 months]
Psychiatric assessment (HADS-D and PANSS) [3 months]

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 75 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria:

Operational criteria for tardive dystonia for > 18 months after cessation of neuroleptic exposure
18-75 years
Relevant functional impairment in daily living activities
BFMDRS > 8 or AIMS > 16
Informed written consent