Highlights
- •This study examines whether injections of hypertonic saline can lead to perceptual distortions of the face in healthy volunteers.
- •Injections of isotonic saline into the infraorbital nerve region and the mental nerve region can lead to perceptual distortions.
- •Perceptual distortions of the face might also be influenced by the psychological variable of dissociation, as indicated by the statistically significant correlations between perceptual distortions and dissociation measured using a set of psychological questionnaires.
Abstract
Anecdotally, orofacial pain patients sometimes report that the painful face area feels
“swollen.” Because there are no clinical signs of swelling, such illusions may represent
perceptual distortions. In this study, we examine whether nociceptive stimulation
can lead to perceptual distortion of the face in a way similar to that of local anesthesia.
Sixteen healthy participants received injections of .4 mL hypertonic saline to induce
short-term nociceptive stimulation, .4 mL mepivacaine (local anesthetic) to transiently
block nerve transduction, and .4 mL isotonic saline as a control condition. Injections
were administered in both the infraorbital and the mental nerve regions. Perceptual
distortions were conceptualized as perceived changes in magnitude of the injected
areas and the lips, and they were measured using 1) a verbal subjective rating scale
and 2) a warping procedure. Prior to the study, participants filled in several psychological
questionnaires. This study shows that both nociceptive stimulation (P < .05) and transient blocking of nerve transduction (P < .05) can lead to perceptual distortion of the face. A test-retest experiment including
9 new healthy subjects supported the results. Perceptual distortions were positively
correlated with the psychological variable of dissociation in several conditions (P < .05). Perceptual distortions may therefore be influenced by somatosensory changes
and psychological mechanisms.
Perspective
Knowledge of the factors that influence the perception of the face is important to
understand the possible implications of perceptual distortions in orofacial pain disorders
(and possibly other chronic pain states). Such information may ultimately open up
new avenues of treatment for persistent orofacial pain.
Key words
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References
- Chairside intraoral qualitative somatosensory testing: Reliability and comparison between patients with atypical odontalgia and healthy controls.J Orofac Pain. 2013; 27: 165-170
- The somatosensory amplification scale and its relationship to hypochondriasis.J Psychiatr Res. 1990; 24: 323-334
- BDI-II, Beck Depression Inventory: Manual.Psychological Corp.; Harcourt Brace, San Antonio, TX; Boston1996
- Chronic orofacial pain.Curr Pain Headache Rep. 2010; 14: 33-40
- Development, reliability, and validity of a dissociation scale.J Nerv Ment Dis. 1986; 174: 727-735
- Rapid cortical reorganisation and improved sensitivity of the hand following cutaneous anaesthesia of the forearm.Eur J Neurosci. 2009; 29: 837-844
- Survey of chronic pain in Europe: Prevalence, impact on daily life, and treatment.Eur J Pain. 2006; 10: 287-333
- C-fibres provide a source of masking inhibition to primary somatosensory cortex.Proc Biol Sci. 1991; 243: 269-275
- Immediate and chronic changes in responses of somatosensory cortex in adult flying-fox after digit amputation.Nature. 1988; 332: 446-448
- Viewing one's own face being touched modulates tactile perception: An fMRI study.J Cogn Neurosci. 2011; 23: 503-513
- It feels like it's me: Interpersonal multisensory stimulation enhances visual remapping of touch from other to self.J Exp Psychol Hum Percept Perform. 2013; 39: 630-637
- Extensive reorganization of primary somatosensory cortex in chronic back pain patients.Neurosci Lett. 1997; 224: 5-8
- Cortical reorganisation and chronic pain: Implications for rehabilitation.J Rehabil Med. 2003; 41: 66-72
- Perceptual distortions of the human body image produced by local anaesthesia, pain and cutaneous stimulation.J Physiol. 1999; 514: 609-616
- Measures of adult pain: Visual analog scale for pain (VAS pain), numeric rating scale for pain (NRS pain), McGill Pain Questionnaire (MPQ), Short-Form McGill Pain Questionnaire (SF-MPQ), Chronic Pain Grade Scale (CPGS), Short Form-36 Bodily Pain Scale (SF-36 BPS), and measure of Intermittent and Constant Osteoarthritis Pain (ICOAP).Arthritis Care Res (Hoboken). 2011; 63: S240-S252
- Review of neuroimaging studies related to pain modulation.Scand J Pain. 2011; 2: 108-120
- The sense of the body in individuals with spinal cord injury.PLoS One. 2012; 7: e50757
- Body perception disturbance: A contribution to pain in complex regional pain syndrome (CRPS).Pain (Amsterdam). 2007; 133: 111-119
- Patterns of cortical reorganization in complex regional pain syndrome.Neurology. 2003; 61: 1707-1715
- Distorted body image in complex regional pain syndrome.Neurology. 2005; 65: 773
- I can't find it! Distorted body image and tactile dysfunction in patients with chronic back pain.Pain. 2008; 140: 239-243
- Bodily illusions in health and disease: Physiological and clinical perspectives and the concept of a cortical “body matrix”.Neurosci Biobehav Rev. 2012; 36: 34-46
- Regional nerve blocks of the face.Emerg Med Clin North Am. 2013; 31: 517-527
- The phenomenology of body image distortions induced by regional anaesthesia.Brain. 2003; 126: 702-712
- Somatic motor and sensory representation in the cerebral cortex of man as studied by electrical stimulation.Brain. 1937; 60: 389-443
- Massive cortical reorganization after sensory deafferentation in adult macaques.Science. 1991; 252: 1857-1860
- Behavioral and magnetoencephalographic correlates of plasticity in the adult human brain.Proc Natl Acad Sci U S A. 1993; 90: 10413-10420
- Short-term brain “plasticity” in humans: Transient finger representation changes in sensory cortex somatotopy following ischemic anesthesia.Brain Res. 1994; 642: 169-177
- Functional reorganization of the human primary somatosensory cortex after acute pain demonstrated by magnetoencephalography.Neurosci Lett. 2001; 298: 195-198
- Manual for the State-Trait Anxiety Inventory (Form Y) (“Self-Evaluation Questionnaire”).Consulting Psychologists Press, Palo Alto, CA1983
- The Pain Catastrophizing Scale: Development and validation.Psychol Assess. 1995; 7: 524-532
- Effect of chronic and experimental jaw muscle pain on pain-pressure thresholds and stimulus-response curves.J Orofac Pain. 1995; 9: 347-356
- The other in me: Interpersonal multisensory stimulation changes the mental representation of the self.PLoS One. 2012; 7: e40682
- The person in the mirror: Using the enfacement illusion to investigate the experiential structure of self-identification.Conscious Cogn. 2012; 21: 1725-1738
- The cerebral signature for pain perception and its modulation.Neuron. 2007; 55: 377-391
- Looking for myself: Current multisensory input alters self-face recognition.PLoS One. 2008; 3: e4040
- Perceptual distortion of face deletion by local anaesthesia of the human lips and teeth.Exp Brain Res. 2005; 165: 37-43
Article info
Publication history
Published online: January 29, 2015
Accepted:
January 13,
2015
Received in revised form:
January 5,
2015
Received:
May 9,
2014
Footnotes
The work was done at the Section of Clinical Oral Physiology, Department of Dentistry, Aarhus University, Denmark.
The study was funded by a grant from Aarhus University (AU-IDEAS) of 500,000 Danish kroner. The research group was economically independent of the grant. Participants received financial compensation in terms of 100 Danish kroner/h, which was reported to the tax authorities. The authors have no conflict of interest.
Identification
Copyright
© 2015 American Pain Society. Published by Elsevier Inc. All rights reserved.
