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Content and Contagion in Yawning Sarnecki
Mise à jour le
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Yawning in diseases :
consequences and signifiance
O. Walusinski
Yawning is a physiological behavior, an emotional stereotypy that indicates the homeostatic process of the mechanisms regulating rhythms such as sleeping-waking, hunger-satiety or mating-relaxation, generated by the diencephalon. As with all physiological behaviors, its deregulation reveals disorders. However, a property unique to yawning, which is nevertheless physiological, is its ability to trigger certain disorders, and conversely, to cure others !
this text becomes a chapter of the book :
 The Mystery of Yawning in Physiology and Disease
Frontiers of Neurology and Neuroscience tome 28
Karger, Basel 2010
see European Neulogy website
2009 Yawning in diseases
Walusinski O
European Neurology 2009;62(3):180-187
Frustration due to an incomplete or inharmonious development of a yawn is a frequent complaint. Yawning is a stretching of respiratory muscles and muscles of the face, and is sometimes associated with a generalized muscular stretching of the trunk and limbs. The yawner perceives differences in muscle tonus, a veritable and conscious extraction of the progress of the phenomenon, of its stimulus and its contextual valence, through interoceptive pathways (projections by the lateral spinothalamic tract onto the insular cortex), leading to a hedonistic perception. The dissatisfaction felt seems to be linked to an unconscious inhibition of the "letting go" that underlies a complete yawn. Therapeutic interventions for anxiety states or for insomnia, such as relaxation or sophrology, do in fact use the control of yawning as a means of relaxation or an anti-stress aid, a veritable proprioceptive rehabilitation of the body scheme (Craig, 2003; Craig, 2009).

Drug-induced yawning: A review of the french pharmacovigilance database
Sommet A, Desplas M, Lapeyre-Mestre M, Montastruc JL.
The French Network of Pharmacovigilance Centers. Drug Saf. 2007;30(4):327-331.
Le bâillement: de la physiologie à la iatrogénie.
Philibert C, Sauveplane K, Pinzani-Harter V et al.
La lettre du pneumologue. 2011;14(5):168-172
Drug-induced yawning: a review
Patatanian E, Williams NT.
Ann Pharmacother.

André-Thomas, de Ajuriaguerra J. Etude sémiologique du tonus musculaire. Flammarion Ed. Paris 1949. 844p.
Adamantidis A, de Lecea L. Sleep and metabolism: shared circuits, new connections. Trends Endocrinol Metab. 2008;19(10):362-370.
Andy OJ, Jurko M. Diencephalic seizures. Appl Neurophysiol. 1983;46(1-4):62-67.
Arai K, Kita K, Komiyama A et al. Progressive dysautonomia in hemangioblastoma in the region of the fourth ventricle. No To Shinkei. 1986;38(2):195-200.
Avidan A. Dislocation of the temporomandibular joint due to forceful yawning during induction with propofol. J Clin Anesth. 2002;14(2):159-160.
Bateman DE. Neurological assessment of coma. JNNP. 2001;71(suppl I);113-117.
Bauer G, Gerstenbrand F, Hengl W. Involuntary motor phenomena in the locked-in syndrome. J Neurol. 1980;223(3):191-198.
Bauer G, Prugger M, Rumpl E. Stimulus evoked oral automatismsin the locked-in syndrome. Arch Neurol. 1982;39(7):435-436.
Beale MD. Murphree TM.Excessive yawning and SSRI therapy. Int. J. Neuropsycho pharmacol. 2000;3:275-276.
Beckmann H, Zimmer R. An ethological interpretation of stereotypy induced by environmental stimulus. Arch Psychiatr Nervenkr. 1981;230(1):81-89.
Benoit, A. Caplier, A.  Hypovigilence analysis: open or closed eye or mouth? Blinking or yawning frequency? Advanced Video and Signal Based Surveillance. AVSS 2005:207-212.
Bidat E, Sznajder M, Fermanian C, al. A diagnostic questionnaire for the hyperventilation syndrome in children. Rev Mal Respir. 2008;25(7):829-838.
Billeth R, Jorgler E, Baumhackl U. Bilateral anterior operculum syndrome. Nervenarzt. 2000;71(8):651-654.
Blau JN. Migraine postdromes: symptoms after attacks. Cephalalgia. 1991;11(5):229-231.
Blau JN, Engel HO. Premonitory and prodromal symptoms in cluster headache. Cephalalgia. 1998;18(2):91-93
Blin O, Masson G, Azulay JP, Fondarai J, Serratrice G. Apomorphine-induced blinking and yawning in healthy volunteers. Br J Clin Pharmacol. 1990;30(5):769-773.
Blin O, Azulay JP, Masson G, Aubrespy G, et al. Apomorphine-induced yawning in migraine patients: enhanced responsiveness. Clin Neuropharmacol. 1991;14(1):91-95.
Boeve BF, Wijdicks EF, Benarroch EE, et al. Paroxysmal sympathetic storms ("diencephalic seizures") after severe diffuse axonal head injury. Mayo Clin Proc. 1998;73(2):148-152.
Brown RP, Gerbarg PL. Sudarshan Kriya Yogic Breating in the treatment of stress, anxiety and depression. J Alternat Complement Med. 2005;11(1):189-201.
Bullard DE. Diencephalic seizures: responsiveness to bromocriptine and morphine. Ann Neurol. 1987;21(6):609-611.
Cameron OG. Visceral sensory neuroscience, interoception. Oxford University Press. 2002. 359p.
Cattaneo L, Cucurachi L, Chierici E, et al. Pathological yawning as a presenting symptom of brainstem ischaemia in two patients. JNNP. 2006;77(1):98-100.
Cerbo R, Barbanti P, Buzzi MG, et al. Dopamine hypersensitivity in migraine: role of the apomorphine test. Clin Neuropharmacol. 1997;20(1):36-44.
Chan TC, Harrigan RA, Ufberg J, et al. Mandibular reduction. J Emerg Med. 2008;34(4):435-440.
Charcot JM. Leçons du mardi à La Salpêtrière. Paris. Lecrosnier & Babé. 1889. 578p.
Chen CH, Lu ML. Venlafaxine-induced excessive yawning. Prog Neuro-Psycho Pharmacol Biol Psychiatry. 2009;33:156-157.
Collins GT, Newman AH, Grundt P, et al. Yawning and hypothermia in rats: effects of dopamine D3 and D2 agonists and antagonists. Psychopharmacology (Berl). 2007;193(2):159-170.
Colosimo C, Francesco E, Pontieri V, et al. Yawning in Parkinson's disease. Neurology. 1999;52(2):428.
Cooper SJ, Dourish CT. Neural basis of drug induced yawning in neurobiology of stereotyped behaviour. Clarendon Press. Oxford Ed. 1990:91-116.
Craig AD. Interoception: the sense of the physiological condition of the body. Curr Opin Neurobiol. 2003;13(4):500-505.
Craig AD. How do you feel - now ? The anterior insula and human awareness. Nature Rev Neurosci. 2009;10(1):59-70.
Crosby L, Parsons LC. Clinical neurologic assessment tool: development and testing of an instrument to index neurologic status.  Heart Lung. 1989;18(2):121-129.
Cronin TG. Yawning : an early manifestation of vasovagal reflex. Am J Roentgenology. 1988;150:209.
d'Andréa C, Méliet JL, Staikowski F. Peripheral facial palsy secondary to middle-ear overpressure Presse Med. 2008;37(4 Pt 2):643-647. (French).
De Las Cuevas C, Sanz EJ. Duloxetine-induced excessive disturbing and disabling yawning. J Clin Psychopharmacol. 2007;27(1):106-107.
Del Bene E, Poggioni M. Video assessment of yawning induced by sublingual apomorphine in migraine. Headache. 1994;34(9):536-538.
Dewey RB, Hutton JT, Lewitt PA, Factor SA. A randomized, double-blind, placebo-controlled trial of subcutaneously injected apomorphine for parkinsonian of state events. Arch Neurol. 2001;58(9):1385-1392.
de Wied D. Behavioral pharmacology of neuropeptides related to melanocortins and the neurohypophyseal hormones. Eur J Pharmacol. 1999;375(1-3):1-11.
D'Mello DA, Vincent FM, Lerner MP. Yawning as a complication of electroconvulsive therapy and concurrent neuroleptic withdrawal. J Nerv Ment Dis. 1988;176(3):188-189.
Evans EB. Yawning in pharyngeal obstruction. Br Med J. 1978;1(6110):443-444.
Evans SM, Griffiths RR. Caffeine withdrawal: a parametric analysis of caffeine dosing conditions. J Pharmacol Exp Ther. 1999;289(1):285-294.
Fanibunda K, Lovelock DJ. Calcified styloid ligament: unuusual pressure symptoms. Dentomaxillofacial Radiol. 1997;26:249-251.
Feldman VB. Eagle's syndrom: a case of symtomatic calcification of the stylhyoid ligaments. J Can Chiropr Assoc 2003;47(1):21-27.
Forté MC. Le Bâillement. Thèse pour le doctorat en médecine. Bordeaux 1982 n°117. Amicale Corporative des Etudiants en Médecine de Bordeaux. 89p.
Freye E, Levy J. Acute abstinence syndrome following abrupt cessation of long-term use of tramadol: a case study. Eur J Pain. 2000;4(3):307-311.
Freye E, Levy J. Constitutive opioid receptor activation: a prerequisite mechanism involved in acute opioid withdrawal. Addict Biol. 2005;10(2):131-137.
Furukawa T. Yawning behavior for preclinical drug evaluation. Meth Find Exp Clin Phamaco. 1996;18(2):141-155.
Gallezzo SR . Examining the connection between yawning and depression. 2006.
Ghika J, Vingerhoets F, Bogousslavsky J. Dissociated preservation of automatic-voluntary jaw movements in a patient with biopercular and unilateral pontine infarcts. Eur Neurol. 2003;50(3):185-188.
Gilles de la Tourette G, Huet E, Guinon G. Contribution à l'étude des bâillements hystériques. Nouvelle Iconographie de la Salpêtrière. Paris. Lecrosnier & Babé. 1890;3:97-119.
Giroud M, Sautreaux JL, Thierry A, et al. Diencephalic epilepsy with congenital suprasellar arachnoid cyst in an infant. Childs Nerv Syst. 1988;4(4):252-254.
Goh KY, Conway EJ, Da Rosso RC, et al. Sympathetic storms in a child with a midbrain glioma: a variant of diencephalic seizures. Pediatr Neurol. 1999;21(4):742-744.
Goldberg RL. Sustained yawning as a side effect of imipramine. Int J Psychiatry Med. 1983-84;13(4)277-280.
Goldie L, Green JM. Yawning and epilepsy. J Psychosomatic Res. 1961;5:263-268.
Goren J, Friedman J. Yawning : an aura for an L-Dopa induced "of" in Parkinson's disease. Neurology. 1998;50(3):823.
Gowers WR. Epilepsy and other chronic convulsive diseases:their causes, symptoms & treatment. New York, Willam Wood and Co. 1885. 255p.
Gowing L, Ali R, White J. Buprenorphine for the management of opioid withdrawal. Cochrane Database Syst Rev. 2004;(4):CD002025.
Graybiel A, Knepton J. Sopite syndrome: a sometimes sole manifestation of motion sickness. Aviat Space Environ Med. 1976;47(8):873-882.
Greco M, Baenninger R. On the context of yawning: when, where and why? The Psychological Recod. 1993;43:175-183. (
Grönqvist J, Häggman-Henrikson B, Eriksson PO. Impaired jaw function and eating difficulties in whiplash-associated disorders. Swed Dent J. 2008;32(4):171-177.
Grover M, Drossman DA. Psychopharmacologic and behavioral treatments for functional gastrointestinal disorders. Gastrointest Endosc Clin N Am. 2009;19(1):151-170.
Gschwend J. Yawning in a case with transsecting glioma of the pons. Fortschritte Neurol Psychiat und ihrer Grenzgebiete. 1977;45(12):652-655.
Gugle MM. Etiology, pathogenesis and treatment of habitual dislocations of the T.M. Joints . Indian J Dent Res. 2002;13(2):88-94.
Gutierrez-Alvarez AM. Do your patients suffer from excessive yawning? Acta Psychiat Scandinavica. 2007;115(1):80-81.
Harada KI. Paroxetine-induced excessive yawning. Psychiat Clin Neurosci. 2006;60:260.
Helöe B, Helöe LA. Frequency and distribution of myofascial pain-dysfunction syndrome in a population of 25-year-olds. Community Dent Oral Epidemiol. 1979;7(6):357-360.
Jackson JH. Selected Writings of John Hughlings Jackson. Edited by James Taylor On Epilepsy and Epileptiform Convulsions. London, 1931.
Jacome DE. Compulsive yawning as migraine premonitary symptom. Cephalalgia. 2001;21(5):623-625.
Jacome DE. Primary yawning headache. Cephalalgia. 2001;21(6)697-699.
Jacome DE. Extracephalic yawning pain. Cephalalgia. 2004;24(5):411-413.
Jurko MF, Andy OJ. Post-lesion yawning and thalamotomy site. Appl Neurophysiol. 1975;38:(1):73-79.
Klécha A, Hafian H, Devauchelle B et al. A Report of Post-Traumatic Eagle's Syndrome. Int J Oral Maxillofac Surg. 2008;37(10):970-972.
Klein DF. False suffocation alarms, spontaneous panics, and related conditions, an integrative hypothesis. Arch Gen Psychiatry. 1993;50(4):306-317.
Kolls BJ, Stacy M. Apomorphine: A Rapid Rescue Agent for the Management of Motor Fluctuations in Advanced Parkinson Disease. Clinical Neuropharmacology. 2006;29(5):292-301.
Krasnianski M, Gaul C, Neudecker S, et al. Yawning despite trismus in a patient with locked-in syndrome caused by a thrombosed megadolichobasilar artery. Clin Neurol Neurosurg. 2003;106(1):44-46.
Lafleur J, Reiher J. Pseudo-absences. EEG Clin neurophysiol. 1977;43:279-280.
Lagares A, Gomez P, Perez-Nunez A, et al. Short-lasting unilateral neuralgiform headache with conjonctival injection and tearing syndrome. Neurosurgery. 2005;56(2):E413.
Lal S. Apomorphine in the evaluation of dopaminergic function in man. Progr Neuro-psychopharmacol Biol Psych. 1988;12(2-3):117-164.
Lal S, Tesfaye Y, Thavundayil JX. et al. Effect of time-of-day on yawning response to apomorphine in normal subjects. Neuropsychobiology. 2000;44(4):178-180.
Lane JD, Phillips-Bute BG. Caffeine deprivation affects vigilance performance and mood. Physiol Behav. 1998;65(1):171-175.
Laskiewicz A. Yawning with regard to the respiratory organs and the ear. Acta Oto laryngologica (Stockholm). 1953;43(2-3):267-270.
Laurent-Vannier A, Fadda G, Laigle P, et al. Syndrome de Foix Chavany Marie d'origine traumtaique. Rev Neurol. 1999;155(5):387-390.
Lepp FH. Remarques sur la signification physiologique du bâillement. Bull Group Int Rech Sci Stomtol Odontol. 1982;25:251-290.
Lewitt PA, Ondo WG, Van Lunen B, et al. Open-Label Study Assessment of Safety and Adverse Effects of Subcutaneous Apomorphine Injections in Treating "Off" Episodes in Advanced Parkinson Disease. Clin Neuropharmacol. 2009. In press.
Louwerse E. Forced yawning as a pseudobulbar sign in amyotrophic lateral sclerosis. J Neurosci Res. 1998;sup:392.
Lum LM, Connolly MB, Farrell K, et al. Hyperventilation-induced high-amplitude rhythmic slowing with altered awareness: a video-EEG comparison with absence seizures. Epilepsia. 2002;43(11):1372-1378.
Manish M, Veenu S. Persistent vegetative state. Neurology. 2007;68(19):1635.
Marcus N. Yawning : analytic and therapeutic considerations. Int J Child Psychotherapy. 1973;2(4):406-418.
McCorkell SJ. Fractures of the styloid process and stylohyoid ligament: an uncommon injury. J Trauma. 1985;25(10):1010-1012. 
McGinnis JM Jr. Fracture of an ossified stylohyoid bone. Arch Otolaryngol. 1981;107(7):460.
McLean JD, Forsythe RG, Kapkin IA. Unusual side effects of clomipramine associated with yawning. Can J Psychiatry. 1983;28(7):569-570.
Marcos MM, Velicia MR, Aguirre JJ. Primary stabbing headache with buccal triggers. Eur Neurol. 2005;53(2):91-92.
Marsden CD Blepharospasm-oromandibular dystonia syndrom. JNNP. 1976;39(12):1204-1209.
Medrano V, Selles-Galiana MF, Fernandez-Izquierdo S, et al. Yawning and temporal lobe epilepsy. Rev Neurol (Spain). 2005;41(1):63-64.
Meige H, Feindel G. Les tics et leur traitement. Paris. Masson. 1902. 633p.
Minagar A, Sheremata W. Glossopharyngeal neuralgia and multiple sclerosis. Neurology. 2000; 54(6):1368-1370.
Mogilnicka E, Klimek V. Drugs affecting dopamine neurons and yawning behavior. Pharmacol Biochem Behav. 1977;7(4):303-305.
Muchnik S, Finkielman S, Semeniuk G, de Aguirre MI. Yawning and temporal lobe epilepsy. Medicina (B Aires). 2003;63(2):137-139.
Muchnik S, Finkielman S, Semeniuk G, de Aguirre MI. Yawning. Medicina (B Aires). 2003;63(3):229-232.
Mupparapu M, Robinson MD. The mineralized and elongated styloid process: a review of current diagnostic criteria and evaluation strategies. Gen Dent. 2005;53(1):54-59.
Myrhaug H. Luxation of the mandible in yawning. Tidsskr Nor Laegeforen. 1961;81:362-365. (Norwegian).
Nardi AE, Freire RC, Zin WA. Panic disorder and control of breathing. Respir Physiol Neurobiol. 2009. in press.
Nassif NJ, Talic YF. Classic symptoms in temporomandibular disorder patients: a comparative study. Cranio. 2001;19(1):33-34.
Ndiokwelu E. Bilateral dislocation of the mandible. 2 cases in a nuclear family. Odontostomatol Trop. 2005;28(112):27-30.
Oh JY, Kim JE, Park KD et al. A case of familial inverse Marcus Gunn phenomenon. JNNP. 2003;74(2):277-282.
Ostrea EM Jr, Chavez CJ, Strauss ME. A study of factors that influence the severity of neonatal narcotic withdrawal. Addict Dis. 1975;2(1-2):187-199.
Pae CU, Kim JJ, Lee CU, Lee SJ, et al. Injured temporomandibular joint associated with fluoxetine-monotherapy-induced repeated yawning. Gen Hosp Psychiatry. 2003;25(3):217-218.
Penfields W, Jasper H. Epilepsy and the functionnal anatomy of the human brain. Little, Brown & Comp. Boston. 1954. 896p.
Philippot P, Chapelle G, Blairy S. Respiratory feedback in the generation of emotion. Cognition Emotion. 2002;16(5):605-627.
Phillips-Bute BG, Lane JD. Caffeine withdrawal symptoms following brief caffeine deprivation Physiol Behav. 1997;63(1):35-39.
Postert T, Pöhlau D, Meves S, et al. Pathological yawning as a symptom of multiple sclerosis. J Neurol. 1996;243(3):300-301.
Quessard A, Barrière P, Levy F, et al. Delayed diagnosis of a postanaesthesia temporomandibular joint dislocation. Ann Fr Anesth Reanim. 2008;27(10):846-849.
Quintela E, Castillo J, Munoz P, et al. Premonitory and resolution symptoms in migraine: a prospective study in 100 unselected patients.Cephalalgia. 2006;26(9):1051-1060.
Riley DE. Paroxysmal kinesigenic dystonia associated with a medullary lesion. Mov Disord. 1996;11(6):738-740.
Robe LB, Gromisch DS, Iosub S. Symptoms of neonatal ethanol withdrawal. Curr Alcohol. 1981;8:485-493.
Sandyk R. Excessive yawning and progressive supranuclear palsy. Int J Neurosci. 1987;34(1-2):123-124.
Saper CB. The central autonomic Nervous System: conscious visceral perception and autonomic pattern generation. Annu Rev Neurosci. 2002;25:433-469.
Sato F, Aoki H, Nakamura K, T, et al. Suppressive effects of chronic hyperprolactinemia on penile erection and yawning following administration of apomorphine to pituitary-transplanted rats. J Androl. 1997;18(1):21-25.
Sato-Suzuki I, Kita I, Seki Y, et al. Cortical arousal induced by microinjection of orexins into the paraventricular nucleus of the rat. Behav Brain Res. 2002;128(2):169-177.
Shilkret H. Psychogenic sneezing and yawning. Psychosom Med. 1949;11(2):127-128.
Schoonman GG, Evers DJ, Terwindt GM, et al.The prevalence of premonitory symptoms in migraine: a questionnaire study in 461 patients. Cephalalgia. 2006;26(10):1209-1213.
Sicard JA et Paraff A. Fou rire syncopal et bâillements au cours de l'encéphalite épidémique. Bull Mém Soc Méd Hôp Paris. 1921;45:232.
Skelton A, Fried R. Headphone neuralgia. N Engl J Med. 1995;333(26):1786-1787.
Sommet A, Desplas M, Lapeyre-Mestre M, Montastruc JL. Drug-induced yawning: a review of the French pharmacovigilance database. Drug Saf. 2007;30(4):327-331.
Symonds CP. Discussion on faints and fits. Proc Royal Soc. Med. 1950;43(7):507-518.
Tassinari CA, Gardella E, Meletti S et al. The neuro-ethological interpretation of motor behaviours in 'nocturnal-hyperkinetic-frontalseizures': emergence of 'innate' motor behaviours and role of cental pattern generators. In Frontal Seizures and Epilepsies in Children. Beaumanoir A, Andermann F, Chauvel P et al. Montrouge. J. Libbey Eurotext. 2003;43-48.
Tesfaye Y, Lal S. Hazard of yawning. CMAJ. 1990;142(1):15.
Tjakkes GH, Rijnvis DJ, Timmenga NM, Stegenga B. A patient with glossopharyngeal neuralgia: a (un)known trap. Ned Tijdschr Tandheelkd. 2008;115(5):263-265. (Dutch).
Urba-Holmgren R, Holmgren B, Rodriguez R, et al. Serotoninergic modulation of yawning. Pharmacol Biochem Behav. 1979;11:371-372.
Ugboko VI, Oginni FO, Ajike SO, et al. A survey of temporomandibular joint dislocation: aetiology, demographics, risk factors and management in 96 Nigerian cases. Int J Oral Maxillofac Surg. 2005;34(5):499-502.
Unnikrishnan KP, Sinha PK, Rao S. Mandibular dislocation from yawning during induction of anesthesia. Can J Anaesth. 2006;53(11):1164-1165.
von Economo C. Encephalitis Lethargica, its sequellae and treatment. Oxford Univ Press. London. 1931. 200p.
Walusinski O. Yawning and stroke. Editorial Commentaries. JNNP. 2007;78(11):1166.
Wicks P. Excessive yawning is common in the bulbar-onset form of ALS. Acta Psychiatr Scand. 2007;116(1):76.
Williams DR. The yawning reflex: an upper motor neuron sign in amyotrophic lateral sclerosis. Neurology. 2000;55(10):1592-1593.
Winther B, Gwaltney JM Jr, Phillips CD, et al. Radiopaque contrast dye in nasopharynx reaches the middle ear during swallowing and/or yawning. Acta Otolaryngol. 2005;125(6):625-628.
Wong KY, Ngan KC, Sin VC et al. Sphenoidal sinus mucocoele and yawning after radiation treatment for nasopharyngeal carcinoma. Clinical Oncol. 1997;9(6):415-417.
Yankovsky AE, Andermann F, Dubeau F. Post-ictal forceful yawning in a patient with nondominant hemisphere epilepsy. Epileptic Disord. 2006;8(1):65-69.
Yap AU, Chua EK, Hoe JK. Clinical TMD, pain-related disability and psychological status of TMD patients. J Oral Rehabil. 2002;29(4):374-80.
Zafar H, Nordh E, Eriksson PO. Temporal coordination between mandibular and head-neck movements during jaw opening-closing tasks in man. Arch Oral Biol. 2000;45(8):675-682.
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