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Biology of Mood & Anxiety Disorders 2014It has long been suggested that feedback signals from facial muscles influence emotional experience. The recent surge in use of botulinum toxin (BTX) to induce temporary...
BACKGROUND
It has long been suggested that feedback signals from facial muscles influence emotional experience. The recent surge in use of botulinum toxin (BTX) to induce temporary muscle paralysis offers a unique opportunity to directly test this "facial feedback hypothesis." Previous research shows that the lack of facial muscle feedback due to BTX-induced paralysis influences subjective reports of emotional experience, as well as brain activity associated with the imitation of emotional facial expressions. However, it remains to be seen whether facial muscle paralysis affects brain activity, especially the amygdala, which is known to be responsive to the perception of emotion in others. Further, it is unknown whether these neural changes are permanent or whether they revert to their original state after the effects of BTX have subsided. The present study sought to address these questions by using functional magnetic resonance imaging to measure neural responses to angry and happy facial expressions in the presence or absence of facial paralysis.
RESULTS
Consistent with previous research, amygdala activity was greater in response to angry compared to happy faces before BTX treatment. As predicted, amygdala activity in response to angry faces was attenuated when the corrugator/procerus muscles were paralyzed via BTX injection but then returned to its original state after the effects of BTX subsided. This preliminary study comprises a small sample size and no placebo condition; however, the A-B-A design affords the present sample to serve as its own control.
CONCLUSIONS
The current demonstration that amygdala responses to facial expressions were influenced by facial muscle paralysis offers direct neural support for the facial feedback hypothesis. Specifically, the present findings offer preliminary causal evidence that amygdala activity is sensitive to facial feedback during the perception of the facial expressions of others. More broadly, these data confirm the utility of using BTX to address the effect of facial feedback on neural responses associated with the perception, in addition to the experience or expression of emotion.
PubMed: 25694806
DOI: 10.1186/2045-5380-4-11 -
Zhurnal Nevrologii I Psikhiatrii Imeni... 2015To determine the efficacy of type A botulinum toxin (lantox) in the treatment of chronic migraine.
OBJECTIVE
To determine the efficacy of type A botulinum toxin (lantox) in the treatment of chronic migraine.
MATERIAL AND METHODS
Authors examined 22 patients with chronic migraine at baseline and 4 and 12 weeks after the introduction of 150 U of lantox in head and cervical muscles using "follow the pain method". The drug was introduced into the following muscles: m. corrugator, m. procerus, m. frontalis, m. temporalis and m. оccipitalis. Clinical/neurological examinations, a study of the emotional sphere (anxiety and depression), daily activities, quality-of-life, patient's completion of questionnaires on the subjective satisfaction with treatment were carried out.
RESULTS AND CONCLUSION
There was a significant positive effect of treatment on the frequency of headache attacks that was important for reverse transformation of chronic pain to episodic headache. Barriers in compliance may be overcome by solving psychological problems, in particular, overcoming depression. The prescription of the drug with no side-effects and fast results allows to support the adherence of the patient to treatment.
Topics: Activities of Daily Living; Botulinum Toxins, Type A; Chronic Pain; Depression; Drug Prescriptions; Humans; Migraine Disorders; Patient Compliance; Quality of Life; Surveys and Questionnaires; Treatment Outcome
PubMed: 26978496
DOI: 10.17116/jnevro201511511270-73