Pain and Perceptual Distortion of Face

August 30, 2024 updated by: University of Aarhus

From Pain in the Face to Perceptual Distortion: Exploring Mechanisms and Novel Treatment Strategies

Post-traumatic trigeminal neuropathic pain (PTNP) is "a unilateral or bilateral facial or oral pain following and caused by trauma to the trigeminal nerve(s), with other symptoms and/or clinical signs of trigeminal nerve dysfunction, and persisting or recurring for more than 3 months". PTNP may result from a major craniofacial/oral trauma or may be subsequent to relatively minor dental treatments such as teeth extractions, surgeries, root canal treatment. Patients suffering from this condition have a significantly reduced quality of life. Unfortunately, the currently available management modalities are associated with limited success and side effects.

Repetitive transcranial magnetic stimulation (rTMS), which is a safe, non-invasive brain stimulation technique has emerged as a potential treatment for chronic pain. In this study, the purpose is to explore the potential of rTMS in treating the persistent neuropathic pain by providing individualized treatment for the sufferers.

Study Overview

Detailed Description

In addition to pain, a curious observation in people with PTNP is that they report that the painful facial area is "swollen" or "feels differently". There are often no clinical signs or physical differences present, hence such self-reported "illusions" may represent a kind of disrupted body image or a "perceptual distortion" of the face and can be speculated to contribute to the maintenance of facial pain. rTMS paradigms are being widely applied in both therapeutic and investigative studies.In this project, the aim is to employ continuous theta-burst stimulation (cTBS), an inhibitory rTMS paradigm, to evaluate its effect on pain perception and PD in people with PTNP.

In this project, people with PTNP (N=9) received a rTMS (50 Hz, 600 pulses for 40s) session/week as intervention for four consecutive weeks at the primary somatosensory cortex (face area) in a "n-of-1" single-blinded randomized controlled cross-over design: (A) active-sham-active-sham or (B) sham-active-sham-active. That is the same participant received both active and sham either in the (A) order or (B). Pain intensity and perceptual distortion (PD) as perceived size changes of the affected face area were measured at baseline, immediately, 60 mins after rTMS in each session and end of the session (a week after rTMS), one and three months after rTMS. Questionnaires on quality of life, jaw function, sleep quality were also assessed. Changes in pain and PD after each intervention were evaluated.

Study Type

Interventional

Enrollment (Actual)

12

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Aarhus C, Denmark, 8000
        • Department of Dentistry and Oral Health

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Persistent Post-traumatic trigeminal neuropathic pain patients for 6 months or longer
  • Stable on analgesic medication

Exclusion Criteria:

  • past history of TMS therapy or TMS-related contraindications (pacemaker, epilepsy etc.).
  • Major stroke
  • Pregnancy
  • Severe organic brain damage

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Active group
Continuous theta burst stimulation
cTBS (50 Hz, 600 pulses, 80% resting motor threshold) for 40s was applied continuously as active rTMS at the face representation area of primary somatosensory cortex (S1)
Sham Comparator: Sham group
Sham repetitive transcranial magnetic stimulation (rTMS)
A sham rTMS was applied using the same stimulation parameters as with cTBS, but using a placebo coil, which produced similar sound as the real coil.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Changes in pain intensity
Time Frame: Prior to intervention at each session (baseline) to the end of that session (7 days after intervention).
Changes in pain intensity from baseline to end of each session measured using self-reported pain dairy using a 0-10 visual analog scale (VAS; 0=no pain and 10=worst pain imaginable). The intervention (active and sham rTMS) were each given in 2 sessions. In total, the participant received 4 sessions of intervention.
Prior to intervention at each session (baseline) to the end of that session (7 days after intervention).
Changes in perceptual distortion
Time Frame: Prior to intervention at each session (baseline) to the end of that session (7 days after intervention).
Perceptual distortion defined as perceived change in the size/shape of the affected face area will be measured using Numerical Rating Scale ranging from -100% through 0% to +100%, where 0% = no size change, -100% = half the size and +100% = double the size in comparison with non-affected side of face and drawings of the affected area. The changes will be measured from baseline to the end of each session as done for pain intensity.
Prior to intervention at each session (baseline) to the end of that session (7 days after intervention).

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Changes in Psychological Distress
Time Frame: Prior to intervention at each session (baseline) to the end of that session (7 days after intervention), 1 and 3 months after intervention.
Will be measured using general anxiety disorder (GAD-7) scale. Total score is obtained by adding score for each question (total points). A score of 8 or greater represents a reasonable cut-point for identifying probable cases of generalized anxiety disorder.
Prior to intervention at each session (baseline) to the end of that session (7 days after intervention), 1 and 3 months after intervention.
Changes in Pain Catastrophizing
Time Frame: Prior to intervention at each session (baseline) to the end of that session (7 days after intervention), 1 and 3 months after intervention.
Will be measured using the Pain Catastrophizing Scale (PCS-DK). Consists of 13 items. Each item is ranged from 0-4. A high score corresponds to a high degree of pain catastrophizing.
Prior to intervention at each session (baseline) to the end of that session (7 days after intervention), 1 and 3 months after intervention.
Changes in patients health
Time Frame: Prior to intervention at each session (baseline) to the end of that session (7 days after intervention), 1 and 3 months after intervention.
Measured using patient health questionnaire-15 (PHQ-15).Each item on the PHQ-15 is rated on a 3-point scale (0=not bothered at all; 1=bothered a little; 2= bothered a. lot). The total score can range from 0 to 30, with higher scores indicating greater severity of somatic symptoms.
Prior to intervention at each session (baseline) to the end of that session (7 days after intervention), 1 and 3 months after intervention.
Changes in sleep quality
Time Frame: Prior to intervention at each session (baseline) to the end of that session (7 days after intervention), 1 and 3 months after intervention.
Measured using the Pittsburgh Sleep Quality Index (PSQI-DK). Seven component scores are derived, each scored 0 (no difficulty) to 3 (severe difficulty). The component scores are summed to produce a global score (range 0 to 21). Higher scores indicate worse sleep quality.
Prior to intervention at each session (baseline) to the end of that session (7 days after intervention), 1 and 3 months after intervention.
Changes in perceived health or health related quality of life
Time Frame: Prior to intervention at each session (baseline) to the end of that session (7 days after intervention), 1 and 3 months after intervention.
Will be measured using Short Form Survey-36- (SF -36).The instrument includes scales for physical functioning, social functioning, role limitations due to physical or emotional problems, mental health, energy, pain and general health perception. It consists of 36 items. Each item is graded on a scale of 0 to 100, with 0 and 100 serving as the lowest and highest possible scores respectively. A high score corresponds to better health status.
Prior to intervention at each session (baseline) to the end of that session (7 days after intervention), 1 and 3 months after intervention.
Changes in oral-health related quality of life
Time Frame: Prior to intervention at each session (baseline) to the end of that session (7 days after intervention), 1 and 3 months after intervention.
Will be measured using Oral Health Impact Profile (OHIP-14) questionnaire .The OHIP-14 scores can range from 0 to 56 and are calculated by summing the ordinal values for the 14 items. The domain scores can range from 0 to 8. Higher OHIP-14 scores indicate worse and lower scores indicate better oral health related quality of life (OHRQol).
Prior to intervention at each session (baseline) to the end of that session (7 days after intervention), 1 and 3 months after intervention.
Changes in functional limitation of the jaw.
Time Frame: Prior to intervention at each session (baseline) to the end of that session (7 days after intervention), 1 and 3 months after intervention.
Will be measured using jaw functional limitation scale (JFLS-20). The scores range from 1 to 200, with higher scores indicating deteriorating jaw function.
Prior to intervention at each session (baseline) to the end of that session (7 days after intervention), 1 and 3 months after intervention.
Changes in neuropathic pain characteristics
Time Frame: Prior to intervention at each session (baseline) to the end of that session (7 days after intervention), 1 and 3 months after intervention.
Measured using modified PainDetect questionnaire. The PainDetect questionnaire was slightly modified so that the oral components can also be added. It is scored from 0 to 38, with total scores of less than 12 considered to represent nociceptive pain, 13-18 possible neuropathic pain, and >19 representing >90% likelihood of neuropathic pain.
Prior to intervention at each session (baseline) to the end of that session (7 days after intervention), 1 and 3 months after intervention.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Simple F Kothari, BDS, PhD, University of Aarhus

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 9, 2022

Primary Completion (Actual)

May 11, 2024

Study Completion (Actual)

July 11, 2024

Study Registration Dates

First Submitted

August 27, 2024

First Submitted That Met QC Criteria

August 27, 2024

First Posted (Actual)

August 29, 2024

Study Record Updates

Last Update Posted (Estimated)

September 5, 2024

Last Update Submitted That Met QC Criteria

August 30, 2024

Last Verified

August 1, 2024

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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