Study Results
The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.
Basic Information
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COMPLETED
NA
7 participants
INTERVENTIONAL
2014-10-31
2014-12-31
Brief Summary
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The strength of stimulation can be individually adjusted by changing the voltage of stimulation. A too high voltage will produce side effects (e.g. seizures) while a too low voltage will not provide pain control. The aim of this study is to analyze the optimal stimulation parameters in patients already implanted with a motor cortex stimulation who have received good pain relief. The actual voltage may vary widely between patients but the investigators feel that there may be an "ideal" voltage if it is measured as a percentage of motor threshold (PMT). If motor threshold is the stimulation voltage that can evoke a muscle contraction then a PMT = 80% would be a voltage that was eighty percent of that value. Although the actual voltage may be widely different between patients, the percentage needed may be very similar. The investigators therefore plan to measure the effect of different percentages of PMT in patients already being treated with motor cortex stimulation.
Systematic analysis of the findings of this study might help the individual participant and future patients to better programming and less side effects.
Detailed Description
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If motor threshold is the voltage that can evoke a muscle contraction then a PMT = 80% would be a voltage that was eighty percent of that value. Although the actual voltage may be different between patients, the effective PMT may be similar since it represents a more physiologic measure of stimulation.
Systematic analysis of the findings of this study might help the individual participant and future patients by reducing voltage to the lowest effective setting and reducing the chance of seizures.
Motor cortex stimulation is used in the treatment of neuropathic pain since 1991 but still no guidelines for programming exist and programming is therefore mainly bases on trial and error. This is mostly due to many variables influencing the choice of stimulation parameters and significant individual differences in susceptibility to stimulation. Routinely the motor threshold is determined during programming to identify the superior limit of voltage at which twitching is induced. No stimulation above the motor threshold should be performed as this is known to cause seizures. The voltage of simulation that will be effective for an individual is unknown at the beginning of the treatment.
The investigators try to find the lowest effective voltage because that will reduce the risk of stimulation-induced seizures and prolong the life of the pacemaker.
Conditions
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Keywords
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Study Design
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RANDOMIZED
CROSSOVER
TREATMENT
SINGLE
Study Groups
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-10% of effective PMT
Patients are set to a voltage 10% less than their original PMT at start of study, Changes in PMT settings
Change of PMT setting
The patients current motor threshold is determined and the patient is set to a new PMT (= new treatment arm)
former setting (+/- 0% of PMT)
Patients are set to their original PMT at start of study, Changes in PMT settings
Change of PMT setting
The patients current motor threshold is determined and the patient is set to a new PMT (= new treatment arm)
+10% of effective PMT
Patients are set to a voltage 10% more than their original PMT at start of study, Changes in PMT settings
Change of PMT setting
The patients current motor threshold is determined and the patient is set to a new PMT (= new treatment arm)
Interventions
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Change of PMT setting
The patients current motor threshold is determined and the patient is set to a new PMT (= new treatment arm)
Eligibility Criteria
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Inclusion Criteria
* Chronic neuropathic pain effectively treated with motor cortex stimulation
* Stable medication during the trial
* Willing and able to comply with the study protocol and to return per the follow-up visit schedule and able to provide informed consent.
Exclusion Criteria
* Technical malfunction of the MCS device
* History of seizures
* Unable to provide informed consent
18 Years
ALL
No
Sponsors
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University of British Columbia
OTHER
Responsible Party
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Principal Investigators
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Christopher R Honey, MD, DPhil
Role: PRINCIPAL_INVESTIGATOR
UBC
Locations
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Vancouver General Hospital
Vancouver, British Columbia, Canada
Countries
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References
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Tsubokawa T, Katayama Y, Yamamoto T, Hirayama T, Koyama S. Treatment of thalamic pain by chronic motor cortex stimulation. Pacing Clin Electrophysiol. 1991 Jan;14(1):131-4. doi: 10.1111/j.1540-8159.1991.tb04058.x.
Tsubokawa T, Katayama Y, Yamamoto T, Hirayama T, Koyama S. Chronic motor cortex stimulation for the treatment of central pain. Acta Neurochir Suppl (Wien). 1991;52:137-9. doi: 10.1007/978-3-7091-9160-6_37.
Peyron R, Garcia-Larrea L, Deiber MP, Cinotti L, Convers P, Sindou M, Mauguiere F, Laurent B. Electrical stimulation of precentral cortical area in the treatment of central pain: electrophysiological and PET study. Pain. 1995 Sep;62(3):275-286. doi: 10.1016/0304-3959(94)00211-V.
Lima MC, Fregni F. Motor cortex stimulation for chronic pain: systematic review and meta-analysis of the literature. Neurology. 2008 Jun 10;70(24):2329-37. doi: 10.1212/01.wnl.0000314649.38527.93.
Other Identifiers
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H14-01258
Identifier Type: -
Identifier Source: org_study_id