Functional changes in brain activity after hypnosis in patients with dental phobia

• Published in: Journal of physiology, Paris Vol. 109; no. 4-6; pp. 131 - 142
• Main Authors: Halsband, Ulrike, Wolf, Thomas Gerhard
• Format: Journal Article
• Language: English
• Published: France Elsevier Ltd 01.12.2015
• Subjects: Adult; Amygdala; Anterior cingulate cortex; Brain - diagnostic imaging; Dental Anxiety - diagnostic imaging; Dental Anxiety - therapy; Dental phobia; Fear; Female; fMRI; Functional brain activity changes; Hippocampus; Humans; Hypnosis; Insula; Magnetic Resonance Imaging; Male; Middle Aged; Treatment Outcome; Young Adult; Dental phobia; Fear; fMRI; Amygdala; Anterior cingulate cortex; Functional brain activity changes; Insula; Hypnosis; Hippocampus
• ISSN: 0928-4257; 1769-7115
• DOI: 10.1016/j.jphysparis.2016.10.001

•First study of hypnosis on brain plasticity changes in patients with dental phobia.•Using fMRI, phobic videos/neutral stimuli under hypnosis and awake state were applied.•Significantly reduced activation in dental phobics under hypnosis (left amygdala/bilateral ACC/insula/hippocampus).•Hypnosis: Powerful method inhibiting reaction of fear circuitry structures in dental phobics. Visiting the dentist is often accompanied by apprehension or anxiety. People, who suffer from specific dental phobia (a disproportional fear of dental) procedures show psychological and physiological symptoms which make dental treatments difficult or impossible. For such purposes, hypnosis is often used in dental practice as an alternative for a number of treatments adjuvant or instead of sedation or general anaesthetics, as medication is often associated with risks and side effects. This is the first study to address the effects of a brief dental hypnosis on the fear processing structures of the brain in dental phobics using functional magnetic resonance imaging (fMRI). 12 dental phobics (DP; mean 34.9years) and 12 healthy controls (CO; mean 33.2years) were scanned with a 3T MRI whole body-scanner observing brain activity changes after a brief hypnotic invervention. An fMRI event-related design symptom provocation task applying animated audio-visual pseudorandomized strong phobic stimuli was presented in order to maximize the fearful reactions during scanning. Control videos showed the use of familiar electronic household equipment. In DP group, main effects of fear condition were found in the left amygdala and bilaterally in the anterior cingulate cortex (ACC), insula and hippocampu (R<L). During hypnosis DP showed a significantly reduced activation in all of these areas. Reduced neural activity patterns were also found in the control group. No amygdala activation was detected in healthy subjects in the two experimental conditions. Compared to DP, CO showed less bilateral activation in the insula and ACC in the awake condition. Findings show that anxiety-provoking stimuli such as undergoing dental surgery, endodontic treatments or insufficient anaesthetics, can be effectively reduced under hypnosis. The present study gives scientific evidence that hypnosis is a powerful and successful method for inhibiting the reaction of the fear circuitry structures.