Assessment of Generalized Alterations in Nociceptive Processing Among Patients Presenting With Temporo-mandibular Disorders

Brief Summary

Detailed Description

This control study is designed to compare the development of secondary hyperalgesia following high frequency electrical stimulation (HFS) of skin nociceptors in the forearms in individuals with chronic TMD (as a main complain) and in healthy controls. During the first part of the experiment (time1, day 1), all potential participants will fill a basic demographic questionnaire concerning their age, weight, height, and current medications (appendix 2). Participants with TMD will be diagnosed according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). The DC/TMD includes the following questionnaires: the Graded Chronic Pain Scale, the Jaw Functional Limitation scale, the Generalized Anxiety Disorder-7, the Patient Health Questionnaire-9 and -15 and the Oral Behaviors Checklist. In addition, participants will be asked to fill the Central sensitization inventory questionnaire, as well as the symptom Severity Scale. Lastly, the investigators will evaluate the distribution of pain by asking participants to draw the pain that they felt during the past 7 days on a digital tablet. This will allow us to determine the total area of pain of each participant, as well as the Widespread Pain Index. Subjects will also be asked to provide a rating of their average pain for the last 24h The psychophysical evaluation will be conducted later on the same day (day1). Subjects will be asked to provide a rating of their average pain at present time (time 2). Then, participants will be familiarized with the different procedures involved in the experiment. Pressure pain thresholds will be assessed on the temporalis muscle, the trapezius muscle, and tibialis anterior (time 3). The intensity of pain resulting from pinprick stimulation and allodynia in the area surrounding the electrode ("test area") will be assessed, as well as on the homologous site of the contralateral control arm before HFS (time 4). Then HFS will be applied (time 5) on the left or right volar forearm (10 cm distal to the cubital fossa). HFS will consist in trains of transcutaneous electrical stimuli consisting of 42 Hz trains (pulse width: 2 ms) lasting 1 s each. The trains will be repeated 12 times. Each train will be separated by several 10 seconds of rest. The intensity of each stimulus will be set to 5 milliampere. The of pain resulting from pinprick stimulation and allodynia in the area surrounding the electrode ("test area") will be assessed 30 min after HFS (in a counterbalanced order) on the homologous site of the contralateral control arm (time 6). The extent of secondary hyperalgesia will be assessed approximately 45 min following HFS (time 7). Then, they will be asked assess the presence of secondary hyperalgesia in the test-site 24 (time 8, day 2) and 48 hours (time 9, day 3) following HFS with with calibrated neurological examination pins (Neuropen, Owen-Mumford Ltd, Oxford, UK). 6 months after their initial assessment (time 10, day 180), if they gave their consent for long-term follow-up, patients will be asked to fill the following questionnaires again

Primary Outcomes

Secondary Outcomes

• Jaw functional limitation scale(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.)
• Weight(At baseline (time 1). This outcome is taken at day 1 at time 1.)
• Patient health questionnaire-9(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.)
• Patient health questionnaire-15(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.)
• Age(During the initial evaluation (time 1). This outcome is taken at day 1 at time 1.)
• Generalized anxiety disorder-7(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.)
• Height(At baseline (time 1). This outcome is taken at day 1 at time 1.)
• The TMD diagnosis according to the diagnostic criteria for temporomandibular disorders (DC/TMD)(At baseline (time 1). This outcome is taken at day 1 at time 1.)
• Graded chronic pain scale(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.)
• Oral Behaviors Checklist(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.)
• Central sensitization inventory(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.)
• Average pain at present time before HFS: score(During the initial evaluation (time 2). This outcome is taken at day 1 at time 2.)
• The Widespread pain index(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.)
• Symptom severity scale(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.)
• The distribution of pain(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.)
• Average pain during the last 24h before HFS(During the initial evaluation (time 1). This outcome is taken at day 1 at time 1.)
• Pressure pain thresholds on the temporalis muscle, trapezius muscle and tibialis anterior(During the initial evaluation (time 3)]. This outcome is taken at day 1 at time 3.)
• The long term persistence of secondary hyperalgesia after HFS(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.)
• Baseline pain resulting from pinprick stimulation in the area surrounding the electrode ("test area") and on the homologous site of the contralateral control arm(Just before HFS (time 4)]. This outcome is taken at day 1 at time 4.)
• The intensity of pain resulting from pinprick stimulation 30 min after HFS(Time Frame: At baseline (time 6). This outcome is taken at day 1 at time 6.)
• Allodynia in the area surrounding the electrode ("test area") and on the homologous site of the contralateral control arm(Just before HFS (time 4) and after HFS (time 6). This outcome is taken at day 1 at time 4 and time 6.)