Outcome
Type |
Measure |
Description |
Time frame |
Safety issue |
Primary |
The extent of secondary hyperalgesia on the forearm in the proximo-distal direction 45 minutes after HFS |
The area of secondary hyperalgesia (cm square) will be assessed with a calibrated 128 millinewton pinprick probe. Pokes of 1-second duration will be provided at a frequency of 0.5 Hz, starting well outside and approaching the stimulation site with steps of 0,5 cm from 4 different directions towards the application site. Participants will be asked to keep their eyes closed during the entire mapping procedure |
After HFS and the assessment of pain resulting from pinprick stimulation and allodynia (time 7). This outcome is taken at day 1 at time 7. |
|
Secondary |
Age |
Self-declared age of the subject |
During the initial evaluation (time 1). This outcome is taken at day 1 at time 1. |
|
Secondary |
Weight |
Self-declared weight of the subject |
At baseline (time 1). This outcome is taken at day 1 at time 1. |
|
Secondary |
Height |
Self-declared height of the subject |
At baseline (time 1). This outcome is taken at day 1 at time 1. |
|
Secondary |
The TMD diagnosis according to the diagnostic criteria for temporomandibular disorders (DC/TMD) |
TMD subgroup based on the DC/TMD: Myalgia, Arthralgia, Headache attributed to TMD, degenerative joint disease, disc displacement with reduction, disc displacement with reduction with intermittent locking, disc displacement with reduction with limited opening, disc displacement with reduction without limited opening, or subluxation. |
At baseline (time 1). This outcome is taken at day 1 at time 1. |
|
Secondary |
Graded chronic pain scale |
questionnaire assessing TMD-related pain intensity and disability: The score will range from grade 0 (no TMD pain in prior 6 months) to grade IV (High disability, severly limiting) |
At baseline (time 1) and 6 months after the initial assessment (time 10). This outcome is taken at day 1 at time 1 and day 180 at time 10. |
|
Secondary |
Jaw functional limitation scale |
Questionnaire assessing limitations across mastication, jaw mobility, and verbal and emotional expression often accompanying TMD. The score will range from 0 (law functional limitation) to 10 (high functional limitation) |
At baseline (time 1) and 6 months after the initial assessment (time 10). This outcome is taken at day 1 at time 1 and day 180 at time 10. |
|
Secondary |
Generalized anxiety disorder-7 |
Questionnaire assessing anxiety. The score will range from 0 (no anxiety) to 27 (severe anxiety) |
At baseline (time 1) and 6 months after the initial assessment (time 10). This outcome is taken at day 1 at time 1 and day 180 at time 10. |
|
Secondary |
Patient health questionnaire-9 |
Questionnaire assessing depression symptoms. The score will range from 1 (minimal depression) to 27 (severe depression) |
At baseline (time 1) and 6 months after the initial assessment (time 10). This outcome is taken at day 1 at time 1 and day 180 at time 10. |
|
Secondary |
Patient health questionnaire-15 |
Questionnaire assessing overall physical symptoms commonly associated with TMD. The score will range from 0 (minimal physical symptoms) to 30 (high physical symptoms) |
At baseline (time 1) and 6 months after the initial assessment (time 10). This outcome is taken at day 1 at time 1 and day 180 at time 10. |
|
Secondary |
Oral Behaviors Checklist |
Questionnaire assesses the frequency of oral parafunctional behaviors. The score will range from 0 (no oral parafunctional behaviors) to 84 (high oral parafunctional behavior frequency) |
At baseline (time 1) and 6 months after the initial assessment (time 10). This outcome is taken at day 1 at time 1 and day 180 at time 10. |
|
Secondary |
Central sensitization inventory |
Questionnaire assessing symptoms and comorbidities that are presumed to be associated with central sensitization. The score will range from 0 (no symptoms and comorbidities presumed to be associated with central sensitization) to 100 (extreme symptoms and comorbidities presumed to be associated with central sensitization). |
At baseline (time 1) and 6 months after the initial assessment (time 10). This outcome is taken at day 1 at time 1 and day 180 at time 10. |
|
Secondary |
Symptom severity scale |
Questionnaire assessing the severity of symptoms associated with fibromyalgia, a condition frequently associated with TMD. The score will range from 0 (low severity) to 12 (high severity). |
At baseline (time 1) and 6 months after the initial assessment (time 10). This outcome is taken at day 1 at time 1 and day 180 at time 10. |
|
Secondary |
The distribution of pain |
Pain felt during the past 7 days drawn on a digital table |
At baseline (time 1) and 6 months after the initial assessment (time 10). This outcome is taken at day 1 at time 1 and day 180 at time 10. |
|
Secondary |
The Widespread pain index |
Questionnaire assessing the extent of bodily pain. The score will range from 1 (no painful body region) to 19 (19 painful body regions) |
At baseline (time 1) and 6 months after the initial assessment (time 10). This outcome is taken at day 1 at time 1 and day 180 at time 10. |
|
Secondary |
Average pain during the last 24h before HFS |
Pain during the last 24h on a numerical rating scale. The score will range from 0 (no pain) to 100 (worst imaginable pain) |
During the initial evaluation (time 1). This outcome is taken at day 1 at time 1. |
|
Secondary |
Average pain at present time before HFS: score |
Current pain on a numerical rating. The score will range from 0 (no pain) to 100 (worst imaginable pain) |
During the initial evaluation (time 2). This outcome is taken at day 1 at time 2. |
|
Secondary |
Pressure pain thresholds on the temporalis muscle, trapezius muscle and tibialis anterior |
Pressure pain will be assessed 3 times on each muscle, with a 30-second interstimulus interval, and the arithmetic mean of the 3 repeated measures will be used for analysis |
During the initial evaluation (time 3)]. This outcome is taken at day 1 at time 3. |
|
Secondary |
Baseline pain resulting from pinprick stimulation in the area surrounding the electrode ("test area") and on the homologous site of the contralateral control arm |
Participants will rate the pain induced by pin-prick stimulation in the area surrounding the electrode on a numerical rating scale ranging from 0 (no perception) to 100 (maximal pain), with 50 representing the transition from nonpainful to painful domains of sensation |
Just before HFS (time 4)]. This outcome is taken at day 1 at time 4. |
|
Secondary |
Allodynia in the area surrounding the electrode ("test area") and on the homologous site of the contralateral control arm |
The investigators will assess allodynia with a Cotton wisp exerting a force of 3 millinewton, a cotton wool tip fixed to an elastic strip exerting a force of 100 millinewton when slightly bent, and a standardized brush exerting a force of 200-400 millinewton |
Just before HFS (time 4) and after HFS (time 6). This outcome is taken at day 1 at time 4 and time 6. |
|
Secondary |
The long term persistence of secondary hyperalgesia after HFS |
Participants will assess the persistence of secondary hyperalgesia with calibrated neurological examination pins (Neuropen, Owen-Mumford Ltd, Oxford, UK). The score will range from 0 (no hyperalgesia) to 1 (hyperalgesia is present) |
24 hours (time 8) and 48 hours after HFS (time 9). This outcome is taken at day 2 at time 8, and at day 3 at time 9. |
|
Secondary |
The intensity of pain resulting from pinprick stimulation 30 min after HFS |
Participants will rate the pain induced by pin-prick stimulation in the area surrounding the electrode on a numerical rating scale ranging from 0 (no perception) to 100 (maximal pain), with 50 representing the transition from nonpainful to painful domains of sensation |
Time Frame: At baseline (time 6). This outcome is taken at day 1 at time 6. |
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