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Alteration of Deep Brain Stimulation Parameters for Dystonia

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified September 2009 by University of Oxford.
Recruitment status was:  Recruiting
Information provided by:
University of Oxford Identifier:
First received: September 3, 2009
Last updated: October 12, 2009
Last verified: September 2009

Deep brain stimulation (DBS) involves placing electrodes into the brain. Through these electrodes, artificial electrical signals are chronically delivered into deep brain regions in order to alter abnormal brain activity. The artificial electrical signals are generated by a battery that is inserted under the skin of the chest. DBS is used to treat several disorders of movement, including dystonia. In dystonia, the electrodes are inserted into a brain region called the globus pallidus.

Globus pallidus stimulation can be very effective therapy for dystonia. However not all patients are equally responsive and therapeutic outcomes can be frustratingly variable. The reason for this variability is unclear. Such variability in response may need to be met by tailoring stimulation to individual patients.

Another issue with deep brain stimulation is battery life. Eventually, batteries become depleted and need to be replaced. Such battery replacements require an operation, hospital stay and the risk of introducing infection. The high electrical energy that has been used to treat dystonia means that batteries are typically replaced every year or two.

The artificial electrical signals of deep brain stimulation are delivered with three parameters; frequency (Hertz - Hz), voltage (volts) and pulse width (microseconds). It has recently been reported that lower frequency stimulation, at 60Hz rather than 130Hz, can be used effectively to treat dystonia. Such 60Hz stimulation may be more effective for some patients than others. The lower energy demands of 60Hz stimulation would also greatly improve battery life (potentially doubling battery life).

The aim of this study is to assess if 60Hz stimulation is more effective in ameliorating the dystonia of patients who have responded poorly to 130Hz pallidal stimulation. The current status of the evidence is one of clinical equipoise (uncertainty) and therefore suits a double blinded randomised trial.

Condition Intervention
Procedure: Alteration of deep brain stimulator settings

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Alteration of Deep Brain Stimulation Parameters for Dystonia- A Double Blinded Randomised Controlled Trial

Resource links provided by NLM:

Further study details as provided by University of Oxford:

Primary Outcome Measures:
  • To assess if the stimulation frequency of 60 Hz is superior to 130 Hz for patients with primary dystonia who have responded poorly to standard 130 Hz pallidal stimulation [ Time Frame: 6 months ]

Secondary Outcome Measures:
  • Assess any potential changes in anxiety, mood, cognition [ Time Frame: 6 months ]

Estimated Enrollment: 20
Study Start Date: September 2009
Estimated Study Completion Date: February 2010
Estimated Primary Completion Date: January 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 60 Hz stimulation
Experimental reduced frequency pallidal stimulation
Procedure: Alteration of deep brain stimulator settings
From 130Hz to 60Hz pallidal stimulation
No Intervention: 130 Hz stimulation
Current standard pallidal stimulation setting
Procedure: Alteration of deep brain stimulator settings
From 130Hz to 60Hz pallidal stimulation


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Primary dystonia (focal cervical or generalised dystonia) who are receiving chronic (>1 year) bilateral pallidal stimulation but have had poor therapeutic responses (< 50% improvement in relevant dystonia severity rating scale*) despite confirmation of accurate electrode position.
  • Able to understand study requirements - able to provide consent.

    • Relevant dystonia rating scales: Cervical dystonia - severity subsection of the Toronto Western Hospital spasmodic torticollis rating scale; Generalised dystonia - severity section of the Burke Fahn Marsden rating scale.

Exclusion Criteria:

  Contacts and Locations
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Please refer to this study by its identifier: NCT00971854

Contact: Wesley Thevathasan, MBBS FRACP 07748729186
Contact: Julian Woollard, MMBS BSc 07779 654 944

United Kingdom
University of Oxford, Nuffield Department of Surgery Recruiting
Oxford, Oxfordshire, United Kingdom, OX3 9DU
Contact: Wesley Thevathasan, MBBS FRACP    07748729186   
Contact: Julian Woollard, MBBS BSc    07779 654 944   
Sub-Investigator: Carole Joint         
Sub-Investigator: Beth Furrow         
Sub-Investigator: Julian Woollard         
Sponsors and Collaborators
University of Oxford
Principal Investigator: Tipu Aziz, Professor University of Oxford, Nuffield Department of Surgery
  More Information

Responsible Party: Heather House, University of Oxford Identifier: NCT00971854     History of Changes
Other Study ID Numbers: 09/H0603/11
R&D Study - 5898
Study First Received: September 3, 2009
Last Updated: October 12, 2009

Keywords provided by University of Oxford:

Additional relevant MeSH terms:
Dystonic Disorders
Neurologic Manifestations
Nervous System Diseases
Signs and Symptoms
Movement Disorders
Central Nervous System Diseases processed this record on May 25, 2017