Chronische pijnsyndromen Hyperalgesia / chronic pain
Conditions
Interventions
Transcutaneous vagal nerve stimulation.
There are 4 main sub-interventions of this:
i) Auricular fixed-frequency tVNS
ii) Cervical fixed-frequency tVNS
iii) Auricular variable-frequency tVNS and
iv) Cervical variable-frequency tVNS.
Subjects will be randomised to receive either fixed or variable-frequency
first, however subjects will always receiv
Sponsors
Medisch Universitair Ziekenhuis Maastricht
Eligibility
Age
18 Years to 99 Years
Inclusion criteria
Inclusion criteria: * Of female sex; * Healthy participants (defined as those without a pre-existing medical comorbidity) * Age between 18 and 40 years; * BMI between 18 and 30 kg/m2; * All subjects should be on oral contraceptives * All subjects should be right-handed. * Inclusion will be determined on the basis of availability. They should be able to attend for 2 scanning sessions.
Exclusion criteria
Exclusion criteria: * Presence of metallic prostheses, pacemakers, metal clips on blood vessels, metal parts in the eye, an intrauterine device, metal braces, tattoos and/or other metal objects; * History of major head trauma or head/brain surgery; * History of claustrophobia; * History of severe or chronic cardiovascular, respiratory, urogenital, gastrointestinal/ hepatic, hematological/immunologic, HEENT (head, ears, eyes, nose, throat), dermatological/connective tissue, musculoskeletal, metabolic/nutritional, endocrine, neurological/psychiatric diseases, major surgery and/or laboratory assessments which might limit participation in or completion of the study protocol; * Use of regular medication, including vitamin and iron supplementation, except oral contraceptives, within 14 days prior to start of the study; * Pregnancy, lactation, wish to become pregnant; * High alcohol consumption (>15 alcoholic units consumed per week); * Using drugs of abuse; * Administration of investigational drugs or participation in any scientific intervention study which may interfere with this study (to be decided by the principle investigator), in the 180 days prior to the study; * Any evidence of structural brain abnormalities examined by anatomical MRI will lead to exclusion * Participants unable to provide informed consent * Participants with any systemic disease or medications that may influence the autonomic nervous system (e.g. beta-agonists or Parkinson*s disease) * Current smokers or current use of nicotine in any other way (including E-cigarettes and patches) * History of clinical anxiety or depression, or a hospital anxiety or depression score >8 * Patient whom have cardiovascular conduction problems * Patient with cochlear implants * Not meeting any of the inclusion criteria above * Participants whom score 8 or more on the HADS-questionnaire at study commencement
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Blood oxygenation level dependent (BOLD) signal activity in the central autonomic network (CAN) during tVNS. | — |
Secondary
| Measure | Time frame |
|---|---|
| * Voxel-wise dependent BOLD signal activity in the NTS of the brainstem; insula cortex; ACC hypothalamus; thalamus and amygdala during auricular tVNS (parameter set 1). * Voxel-wise dependent BOLD signal activity in the NTS of the brainstem; insula cortex; ACC; hypothalamus; thalamus and amygdala during cervical tVNS (parameter set 1). * Voxel-wise dependent BOLD signal activity in the NTS of the brainstem; insula cortex; ACC; hypothalamus; thalamus and amygdala during auricular tVNS (parameter set 2). * Voxel-wise dependent BOLD signal activity in the NTS of the brainstem; insula cortex; ACC; hypothalamus; thalamus and amygdala during cervical tVNS (parameter set 2). Voxel-wise dependent BOLD signal activity in the NTS of the brainstem; insula cortex; ACC; hypothalamus; thalamus and amygdala during subliminal auricular tVNS. * Functional connectivity / Network Connectivity of CAN regions during "active tVNS" block [to all 5 points as identified above] * Graph theory measures of brain connectivity during "active tVNS" block [to all 5 points as identified above], including modularity, efficiency and small-world properties. | — |
Countries
Netherlands
Outcome results
None listed