File
Chimenti S.1, Mouraux D.1, Cheron G.2, Debeir O.3, Penelle B.3
1Université Libre de Bruxelles, Faculty of Motricity Sciences, Brussels, Belgium, 2Université Libre de Bruxelles, Neurophysiology Laboratory (Faculty of Motricity Sciences), Brussels, Belgium, 3Université Libre de Bruxelles, LISA (Laboratories of Image, Signal processing and Acoustics), Bruxelles, Belgium
Background: Unilateral facial pain can be divided into two sub-categories: trigeminal (TP) and persistent idiopathic facial pain (PIFP). TP is a neuropathic unilateral facial pathology that normally presents itself with short pain attacks during the day, limited to the innervation territory of facial nerve V. Conversely, pain in PIFP is near constant with attacks often intensifying throughout the day. Pain can be felt beyond the territory of trigeminal nerve. In both pathologies, pain can be elicited or increased by cold stimulation. Numerous treatments exist, surgical and medical, but subsequent pain relief is too often insufficient or temporary. The inefficiency of treatments is a cause of psychological distress for the majority of patients.
Purpose: The trial tested whether or not a special mirror therapy combining visual illusion and cutaneous stimulation on the unaffected side was likely to change skin sensitivity and/or reduce pain (temporarily or permanently) in patients suffering from these pathologies.
Methods: Six patients suffering from neuropathic unilateral facial pain underwent a 3D augmented reality trial during four weeks. Special equipment for mirror therapy facial application was developed using a Kinect® and a specially designed computer software. Patients received cutaneous stimulations on the unaffected side while watching the tridimensional reflection of their reversed face on a computer screen using 3D glasses. This reversed reflection created the illusion of touching the painful side while in reality, the therapist brushed the patients unaffected side. Patients completed different questionnaires evaluating neuropathic pain (DN4: Neuropathic Pain 4 Questions; NPSI: Neuropathic Pain Symptom Inventory), pain intensity (VAS: Visual Analogue Scale), pain character (MPQ: McGill Pain Questionnaire), the way facial pain influenced everyday life (BPIF: Brief Pain Inventory Facial), and depression and anxiety level (HAD: Hospital Anxiety and Depression Scale). Cutaneous sensitivity was tested by QST (Quantitative Sensory Testing). Results obtained were compared at three different moments: before treatment (t0), after four weeks of treatment (t1) and four weeks after the end of the treatment (t2).
Results: A positive evolution was observed after four weeks of treatment (between t0 and t1) for the DN4 (p-value: 0,036), VAS at the moment of testing (p-value: 0,028), and for the number of chosen words in the MPQ (p-value: 0,001). There was a global reduction for the cold pain threshold between the three tests (decreasing by 42,11% between t0 and t2) which seems to indicate a better cold tolerance.
Conclusion(s): 3D augmented reality could provide an improvement of clinical symptomatology in patients suffering from neuropathic unilateral facial pain. It is true that some patients (apparently those affected by PIFP) seemed to have a better evolution in comparison to others. A wider study would be appropriate to clearly define the effect of this treatment on pain intensity, quality of life, and skin sensitivity (especially cold pain tolerance).
Implications: Our study suggests that new physiotherapic treatments, including electronic devices to adjust the concept of mirror therapy to a special zone of the body, could be helpful and may be an effective complementary therapy in the classical clinical management of these pathologies, which includes surgical, medical, and psychological follow-up.
Funding acknowledgements: None
Topic: Pain & pain management
Ethics approval: This study was approved by the Ethics Commitee of Erasme Hospital, Brussels (BE).
All authors, affiliations and abstracts have been published as submitted.
