Alteration of Deep Brain Stimulation Parameters for Dystonia

Study Description

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Study Description Study Design Arms and Interventions Outcome Measures Eligibility Criteria Contacts and Locations More Information

Brief 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.

Condition or disease	Intervention/treatment	Phase
Dystonia	Procedure: Alteration of deep brain stimulator settings	Not Applicable

Study Design

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Study Type :	Interventional (Clinical Trial)
Estimated Enrollment :	20 participants
Allocation:	Randomized
Intervention Model:	Parallel Assignment
Masking:	Quadruple (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
Study Start Date :	September 2009
Estimated Primary Completion Date :	January 2010
Estimated Study Completion Date :	February 2010

Arms and Interventions

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Study Description Study Design Arms and Interventions Outcome Measures Eligibility Criteria Contacts and Locations More Information

Arm	Intervention/treatment
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

Outcome Measures

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Study Description Study Design Arms and Interventions Outcome Measures Eligibility Criteria Contacts and Locations More Information

Primary Outcome Measures :

1. 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 :

1. Assess any potential changes in anxiety, mood, cognition [ Time Frame: 6 months ]

Eligibility Criteria

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Study Description Study Design Arms and Interventions Outcome Measures Eligibility Criteria Contacts and Locations More Information

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

Criteria

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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Study Description Study Design Arms and Interventions Outcome Measures Eligibility Criteria Contacts and Locations More Information

Contacts

Contact: Wesley Thevathasan, MBBS FRACP	07748729186	wesley.thevathasan@nds.ox.ac.uk
Contact: Julian Woollard, MMBS BSc	07779 654 944	julian.woollard@doctors.org.uk

Locations

United Kingdom
University of Oxford, Nuffield Department of Surgery	Recruiting
Oxford, Oxfordshire, United Kingdom, OX3 9DU
Contact: Wesley Thevathasan, MBBS FRACP 07748729186 wesley.thevathasan@nds.ox.ac.uk
Contact: Julian Woollard, MBBS BSc 07779 654 944 julian.woollard@doctors.org.uk
Sub-Investigator: Carole Joint
Sub-Investigator: Beth Furrow
Sub-Investigator: Julian Woollard

Sponsors and Collaborators

University of Oxford

Investigators

Principal Investigator:	Tipu Aziz, Professor	University of Oxford, Nuffield Department of Surgery

More Information

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Study Description Study Design Arms and Interventions Outcome Measures Eligibility Criteria Contacts and Locations More Information

Responsible Party:	Heather House, University of Oxford
ClinicalTrials.gov Identifier:	NCT00971854 History of Changes
Other Study ID Numbers:	09/H0603/11; R&D Study - 5898
First Posted:	September 4, 2009
Last Update Posted:	October 14, 2009
Last Verified:	September 2009

Keywords provided by University of Oxford:

Dystonia

Additional relevant MeSH terms:

Dystonia; Dystonic Disorders; Dyskinesias; Neurologic Manifestations	Nervous System Diseases; Signs and Symptoms; Movement Disorders; Central Nervous System Diseases