Cerebral Responses During Bilateral/Unilateral Sacral Nerve Stimulation for Idiopathic Faecal Incontinence

Study Overview
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Brief Summary
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The purpose of this study is to determine whether Sacral Nerve Stimulation (SNS) for idiopathic faecal incontinence affect cortical and deep brain activity in an acute and chronically stimulation model. Furthermore the association between brain activity and unilateral/bilateral SNS will be studied in each patient. Brain activity will be studied by use of positron emission tomography.

Detailed Description
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Faecal incontinence is a devastating condition affecting daily living and quality of life. A new treatment Sacral Nerve Stimulation (SNS) has over the last decade given new hope to these patients. In Europe SNS is routinely offered to patients not archiving satisfactory continence result with standard non-surgical treatments. SNS is electrical stimulation of the sacral nerve root(s2,3 or 4). Stimulation of this nerve roots results in improved continence. The mechanism of action is at present not well described. Recent studies have shown that the effect of SNS is by means a neuromodulation in the central nervous system, whereas direct stimulation of efferent nerves to the anal sphincter and the pelvic floor has less significance. The aim of this study is to describe changes in regional cerebral blood flow (RCBF), with positron emission tomography (PET), in patients implanted bilaterally with sacral neuromodulators with the indication idiopathic faecal incontinence. RCBF in three deferent stimulations settings will be compared. PET will be performed before and one hour after changes in the activity status of the pacemakers. Four weeks prior to the first scan, patients are informed to switch both neurostimulator off. PET will be performed with the pacemaker settings: OFF/OFF (Stimulation status of left/right pacemaker), On/Off and On/On. The order of the On/OFF and On/On period will be random. Unilateral stimulation will be performed with the pacemaker there has the best efficacy, determined prior to study enrolment. The interval between these three pacemaker settings is four weeks. Four weeks prior to each PET scan the patients fill in bowel habit diaries, bowel habit questionnaires and quality of life assessments. The association between continence and changes in RCBF will be studied. Additional RCBF and quality of life will be compared.

Official Title
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Cerebral Responses During Bilateral/Unilateral Sacral Nerve Stimulation for Idiopathic Faecal Incontinence - Assessed With Positron Emission Tomography Scan (PET-scan)

Conditions
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Regional Cerebral Blood Flow, Fecal Incontinence

Intervention / Treatment
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* Device: Medtronic InterStim II - 3058


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18 years or older Informed consent Idiopathic fecal incontinence or Fecal incontinence due to small sphincter defect(≤60 o) Permanent neuromodulator (medtronic InterStim II) bilateral implanted Reduction in fecal incontinence episodes of at least 50% between baseline and latest follow up with unilateral stimulation(Bowel diary card) Willing and competent to fill out diary cards MR-cerebrum before implantatation of neuromodulator Right-handed dominant Exclusion Criteria: Colorectal/proctological surgery since IPG-implant Pregnancy Neurological diseases including spinal cord injury. Use of medication with known alternation of gastrointestinal motilitet (thyroid, diabetes, neuroleptica) Claustrofobia Latex allergy

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Off/Off<br>Pacemaker status: Bilateral Off for four weeks before first PET scann. | Device: Medtronic InterStim II - 3058<br>* Stimulation with optimal pacemaker settings unilateral and bilateral with standard pacemaker settings: Amplitude sensory treshold, frequency 14 Hz and impulsduration 210 μsec.<br>|
| Experimental: On/On<br>Pacemaker status: Bilateral On. PET scan one hour after activation and after four weeks continuous stimulation. | Device: Medtronic InterStim II - 3058<br>* Stimulation with optimal pacemaker settings unilateral and bilateral with standard pacemaker settings: Amplitude sensory treshold, frequency 14 Hz and impulsduration 210 μsec.<br>|
| Experimental: On/Off<br>Pacemaker status: Unilateral On. PET scan one hour after activation and after four weeks continuous stimulation. | Device: Medtronic InterStim II - 3058<br>* Stimulation with optimal pacemaker settings unilateral and bilateral with standard pacemaker settings: Amplitude sensory treshold, frequency 14 Hz and impulsduration 210 μsec.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in Regional Cerebral Blood Flow with different pacemaker settings | RCBF evaluated with positron emission tomography. | 12 weeks after study enrolment | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in continence and quality of life with different pacemaker activation. | Changes in incontinence episodes and quality of life will be correlated to changes in RCBF with different pacemaker activation. | 12 weeks after study enrolment | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Positron emission tomography (PET), Idiopathic Faecal Incontinence, Bilateral Sacral Nerve Stimulation, Sacral Nerve Stimulation, Sacral Nervemodulation