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Short Pulse Width DBS in Parkinson's Disease

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT03417271
Recruitment Status : Completed
First Posted : January 31, 2018
Last Update Posted : April 17, 2019
Information provided by (Responsible Party):
University College, London

Brief Summary:
The aim of this investigation is to explore the effect of reducing conventional pulse width of stimulation on known adverse effects of Subthalamic nucleus Deep Brain Stimulation (STN DBS) treatment such as; slurring of speech, gait impairment, and unsteadiness. This investigation is designed such that each of 16 patients (who have all had chronically implanted DBS systems), will be assessed using conventional (DBS-60µs) and short (DBS-30µs) pulse width DBS, in a randomised order.

Condition or disease Intervention/treatment Phase
Parkinson's Disease Device: Deep brain stimulation Phase 2

Detailed Description:

Conventional DBS most commonly uses 60µs pulse width stimulation. Higher pulse widths are less well tolerated by patients as a result of adverse effects. The ability to use short pulse width (30µs) DBS in chronically implanted STN-DBS patients has been made possible as a result of the provision of a novel software flashcard (8870 XBP application card) developed by Medtronic, compatible with the routine Medtronic N'Vision 8870 Clinician Programmer. The Medtronic 8870-XBP flashcard will enable shorter pulse width (30µs) to be used with previously implanted conventional Medtronic DBS hardware, however this is not licensed at present.

The aim of this clinical investigation is to confirm the longevity of response and the clinical relevance of DBS-30µs versus DBS-60µs in DBS patients using "optimized" stimulation amplitudes for each pulse-width. This project will be conducted in patients with Parkinson's disease who have had long term bilateral sub thalamic nucleus Deep Brain Stimulation implants. As such, they will be regular attenders at the Unit of Functional Neurosurgery, National Hospital for Neurology & Neurosurgery, and will have had frequent previous attempts at adjusting their DBS parameters including overnight stays, and off- medication assessments to optimize motor function and minimize adverse effects. They will be familiar with all procedures to be used in this study. They will be aware that the objective of the study is to identify whether additional improvements in dysarthric speech can be achieved by the use of a short pulse width setting and therefore will be highly motivated to participate.

This investigation is designed such that each patient will be assessed under the DBS-30µs and DBS-60µs pulse width condition, in a randomised order. The patients and rating clinicians will be blinded to randomisation order. An unblinded clinician will be responsible for programming the stimulation. The use of a crossover design allows each patient to essentially act as their own control subject, and will maximise the ability to judge using paired statistical tests whether there is a consistent advantage in speech intelligibility using the shorter pulse width (DBS-30µs).

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 16 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double (Participant, Outcomes Assessor)
Masking Description: Neither participants nor outcomes assessors will be aware whether the patient is receiving stimulation at 30us or 60us pulse widths.
Primary Purpose: Treatment
Official Title: A Double-blind Randomized Crossover Comparison of Short Pulse Width Versus Conventional Pulse Width Deep Brain Stimulation (DBS) in Parkinson's Disease Patients With Previously Implanted DBS Systems- a Pilot Trial
Actual Study Start Date : May 2, 2018
Actual Primary Completion Date : October 24, 2018
Actual Study Completion Date : October 24, 2018

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Active Comparator: 30us stimulation then 60us stimulation
All patients will receive both types of stimulation in a randomised crossover design. This arm will receive 30us stimulation for 4 weeks then will be switched to 60us stimulation for 4 weeks.
Device: Deep brain stimulation
The different stimulation pulse widths are made possible by the use of a Medtronic XBP flashcard used with the conventional Medtronic 8840 programmer.

Active Comparator: 60us stimulation then 30us stimulation
All patients will receive both types of stimulation in a randomised crossover design.This arm will receive 60us stimulation for 4 weeks then will be switched to 30us stimulation for 4 weeks.
Device: Deep brain stimulation
The different stimulation pulse widths are made possible by the use of a Medtronic XBP flashcard used with the conventional Medtronic 8840 programmer.

Primary Outcome Measures :
  1. Speech Intelligibility test [ Time Frame: 4 weeks ]
    Percentage of intelligible words spoken during formal speech assessment

Secondary Outcome Measures :
  1. Movement Disorders Society Unified Parkinson's Disease Rating Scale [ Time Frame: 4 weeks ]
    Validated movement scale for Parkinson's disease. Range 0-132. Higher scores indicate worse disability.

  2. Dyskinesia Rating Scale [ Time Frame: 4 weeks ]
    Validated dyskinesia rating scale. Range 0-104. Higher scores indicate worse disability.

  3. Verbal Fluency [ Time Frame: 4 weeks ]
    Number of words produced in 1 minute

  4. Timed Motor tests [ Time Frame: 4 weeks ]
    Walking and hand tapping

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   Child, Adult, Older Adult
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Diagnosis of Parkinson's disease - PD is a clinical diagnosis and is based on the opinion of the PI on site after review of the clinical history, examination findings and response to PD medication. The Queen Square brain bank criteria MAY be used to help assist in the diagnosis although this need not be a formal inclusion criteria, and the relevance of a positive family history of PD, or a confirmed genetic basis for an individual's symptoms will be evaluated in the context of other clinical features in determining diagnosis and eligibility.
  • Male or Female.
  • Treatment with subthalamic deep brain stimulation using Medtronic Activa PC hardware for at least 12 months.
  • Experiencing stimulation-induced slurring of speech defined as scoring 50-80% speech intelligibility on the Assessment of Intelligibility of Speech scale.
  • All patients will be ≥ 25 and ≤ 75 years of age.
  • Documented informed consent to participate.

Exclusion Criteria:

  • Patients unable to provide documented informed consent.
  • Already actively participating in an investigation of a drug, device or surgical treatment for Parkinson's disease.
  • Potential participants who lack the capacity to give informed consent.
  • Any medical, psychiatric or other condition which in the investigator's opinion compromises the potential participant's ability to participate fully.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03417271

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United Kingdom
UCL Institute of Neurology
London, United Kingdom, WC1N 3BG
Sponsors and Collaborators
University College, London
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Principal Investigator: Thomas Foltynie, MRCP PhD UCL Institute of Neurology
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Responsible Party: University College, London Identifier: NCT03417271    
Other Study ID Numbers: 16/0772
First Posted: January 31, 2018    Key Record Dates
Last Update Posted: April 17, 2019
Last Verified: April 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Product Manufactured in and Exported from the U.S.: No
Additional relevant MeSH terms:
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Parkinson Disease
Parkinsonian Disorders
Basal Ganglia Diseases
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Movement Disorders
Neurodegenerative Diseases