Alteration of Deep Brain Stimulation Parameters for Dystonia

Dystonia Clinical Trial

Official title:

Alteration of Deep Brain Stimulation Parameters for Dystonia- A Double Blinded Randomised Controlled Trial

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT00971854
• Other study ID #: 09/H0603/11
• Secondary ID: R&D Study - 5898
• Status: Recruiting
• Phase: N/A
• First received: September 3, 2009
• Last updated: October 12, 2009
• Start date: September 2009
• Est. completion date: February 2010

Study information

• Verified date: September 2009
• Source: University of Oxford
• Contact: Wesley Thevathasan, MBBS FRACP
• Phone: 07748729186
• Email: wesley.thevathasan[@]nds.ox.ac.uk
• Is FDA regulated: No
• Health authority: United Kingdom: Research Ethics Committee
• Study type: Interventional

Clinical Trial Summary

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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 20
• Est. completion date: February 2010
• Est. primary completion date: January 2010
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 18 Years and older

Eligibility

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:

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Dystonia
• Dystonic Disorders

Intervention

Procedure:
• Alteration of deep brain stimulator settings
From 130Hz to 60Hz pallidal stimulation

Locations

Country	Name	City	State
United Kingdom	University of Oxford, Nuffield Department of Surgery	Oxford	Oxfordshire

Sponsors (1)

Lead Sponsor	Collaborator
University of Oxford

Country where clinical trial is conducted

United Kingdom, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	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		6 months	No
Secondary	Assess any potential changes in anxiety, mood, cognition		6 months	No