REFLEXES THE CODES OF NEUROLOGY

reflexesneurologytaskindumankapak21432

SUPERFICIAL REFLEXES INDUCED BY STIMULATION OF MUCOSAL SURFACES

Burç Esra Şahin

Kırşehir Ahi Evran University, Faculty of Medicine, Department of Neurology, Kırşehir, Türkiye

Şahin BE. Superficial Reflexes Induced by Stimulation of Mucosal Surfaces. In: Duman T, editor. Reflexes The Codes of Neurology. 1st ed. Ankara: Türkiye Klinikleri; 2025. p.89-102.

ABSTRACT

This chapter delves into the physiology, anatomy, and clinical significance of superficial reflexes elicited by mucosal surface stimulation, including corneal, blink, gag, palatal, sneeze, and cough reflexes. These reflexes are common in their protective role, neural complexity and diagnostic significance and are important tools for the assessment of cranial nerve function and systemic health.

The corneal and blink reflexes, essential for maintaining ocular integrity, involve intricate pathways mediated by the trigeminal and facial nerves. The corneal reflex, characterized by bilateral blinking in response to stimuli, is a diagnostic marker for trigeminal and facial nerve lesions. Similarly, the blink reflex, which can be triggered by mechanical, visual, or auditory stimuli, is an indicator of central and peripheral nervous system integrity. Both reflexes exhibit pathophysiological variations in response to supranuclear, nuclear or peripheral nerve deficits.

gag and palatal reflexes, primarily mediated by the glossopharyngeal and vagus nerves, function as evolutionary safeguards against choking and swallowing hazards. These reflexes, elicited by pharyngeal and palatal stimulation, are invaluable in assessing brainstem function and cranial nerve integrity, with clinical implications in stroke, neurodegenerative diseases, and trauma.

The sneeze reflex, triggered by irritants in the nasal mucosa, showcases a distinct two-phase mechanism involving trigeminal and vagus nerves. variants such as the photic and snatiation reflexes underline the very different excitability of the reflex. Similarly, the cough reflex, a critical airway defense, is mediated by the vagus nerve and involves a coordinated sensory-motor response to expel irritants. variations in reflex sensitivity can signal neurological, metabolic, or systemic pathologies.

Their diagnostic utility extends to identifying cranial nerve lesions, brainstem dysfunction, and systemic conditions, reinforcing their significance in clinical practice. This chapter aims to provide a comprehensive understanding of superficial reflexes, emphasising the interplay between anatomical structures, neural pathways and clinical implications.

Keywords: Corneal reflex; Blink reflex; gag reflex; Pharyngeal reflex; Palatal reflex; Sneeze reflex; Cough reflex

Referanslar

  1. Shaheen BS, Bakir M, Jain S. Corneal nerves in health and disease. Surv Ophthalmol. May-Jun 2014;59(3):263-85. [Crossref]  [PubMed]
  2. Beuerman RW, Schimmelpfennig B. Sensory denervation of the rabbit cornea affects epithelial properties. Exp Neurol. Jul 1980;69(1):196-201.5. [Crossref]  [PubMed]
  3. Heigle TJ, Pflugfelder SC. Aqueous tear production in patients with neurotrophic keratitis. Cornea. Mar 1996;15(2):135-8. [Crossref]  [PubMed]
  4. Nishida T, Chikama T, Sawa M, Miyata K, Matsui T, Shigeta K. Differential contributions of impaired corneal sensitivity and reduced tear secretion to corneal epithelial disorders. Jpn J Ophthalmol. Jan 2012;56(1):20-5. [Crossref]  [PubMed]
  5. Muller LJ, Marfurt CF, Kruse F, Tervo TM. Corneal nerves: structure, contents and function. Exp Eye Res. May 2003;76(5):521-42.
  6. Roszkowska AM, Colosi P, Ferreri FM, Galasso S. Age-related modifications of corneal sensitivity. Ophthalmologica. Sep-Oct 2004;218(5):350-5. [Crossref]  [PubMed]
  7. Standring S. Brainstem. Gray’s Anatomy E-Book. Elsevier Health Sciences. 42nd ed. 2021:442-464.
  8. Khan ZA. Revisiting the Corneal and Blink Reflexes for Primary and Secondary Trigeminal Facial Pain Differentiation. Pain Res Manag. 2021;2021:6664736. [Crossref]  [PubMed]
  9. Parker HL. Tumors of the Nervus Acusticus: Signs of Involvement of the Fifth Cranial Nerve. Archives of Neurology & Psychiatry. 1928;20(2):309-318. [Crossref]  [PubMed]
  10. Larner AJ. A Dictionary of Neurological Signs. Springer International Publishing. 2nd ed. 2016:54,82:137,235. [Crossref]  [PubMed]
  11. Truini A, Galeotti F, Cruccu G. New insight into trigeminal neuralgia. J Headache Pain. Sep 2005;6(4):237-9. [Crossref]  [PubMed]
  12. Maciel CB, Youn TS, Barden MM, Dhakar MB, Zhou SE, Pontes-Neto OM, et al. Corneal Reflex Testing in the Evaluation of a Comatose Patient: An Ode to Precise Semiology and Examination Skills. Neurocrit Care. Oct 2020;33(2):399-404. [Crossref]  [PubMed]
  13. Yang AY, Chow J, Liu J. Corneal Innervation and Sensation: The Eye and Beyond. Yale J Biol Med. Mar 2018;91(1):13-21.
  14. Vanbever R, Langers G, Montmayeur S, Preat V. Transdermal delivery of fentanyl: rapid onset of analgesia using skin electroporation. J Control Release. Jan 2 1998;50(1-3):225-35. [Crossref]  [PubMed]
  15. Greer DM, Shemie SD, Lewis A, Torrance S, Varelas P, Goldenberg FD, et al. Determination of Brain Death/Death by Neurologic Criteria: The World Brain Death Project. JAMA. Sep 15 2020;324(11):1078-1097. [Crossref]  [PubMed]
  16. Trontelj MA, Trontelj JV. Reflex arc of the first component of the human blink reflex: a single motoneurone study. J Neurol Neurosurg Psychiatry. Jun 1978;41(6):538-47. [Crossref]  [PubMed]
  17. Bologna M, Paparella G, Valls-Sole J, Hallett M, Berardelli A. Neural control of blinking. Clin Neurophysiol. May 2024;161:59-68. [Crossref]  [PubMed]
  18. van Ballegoij WJ, Koehler PJ, Meulen BC. The menace reflex. Pract Neurol. Jun 2015;15(3):233-5. [Crossref]  [PubMed]
  19. Preston DC, Shapiro BE. Fundamentals of nerve conduction studies. Electromyography and Neuromuscular Disorders E-Book: Clinical-Electrophysiologic-Ultrasound Correlations. Elsevier. 4th ed. 2020:52-56. [Crossref]  [PubMed]
  20. Fernández-Conejero I, Deletis V. Blink reflex. Deletis V, Shils JL, Sala F, Seidel K, eds. Neurophysiology in Neurosurgery: A Modern Approach. Academic Press. 2nd ed. 2020:229-237. [Crossref]  [PubMed]
  21. Sivakumar S, Prabhu A. Physiology, Gag Reflex. StatPearls. StatPearls Publishing Copyright © 2024, StatPearls Publishing LLC.; 2025. [Crossref]  [PubMed]
  22. Howlett WP. Neurology in Africa. Cambridge University Press. 2015. p. 27. [Crossref]  [PubMed]
  23. Drake RL, Vogl AW, Mitchell AWM. Head and Neck. Gray’s Anatomy for Students E-Book. Elsevier. 5th ed. 2023:817-1114. [Crossref]  [PubMed]
  24. Ramsey D, Smithard D, Donaldson N, Kalra L. Is the gag reflex useful in the management of swallowing problems in acute stroke? Dysphagia. Spring 2005;20(2):105-7. [Crossref]  [PubMed]
  25. Valbuza JS, de Oliveira MM, Conti CF, Prado LB, Carvalho LB, do Prado GF. Oropharyngeal examination as a predictor of obstructive sleep apnea: pilot study of gag reflex and palatal reflex. Arq Neuropsiquiatr. Oct 2011;69(5):805-8. [Crossref]  [PubMed]
  26. Askenasy JJ. The history of sneezing. Postgrad Med J. Jul 1990;66(777):549-50. [Crossref]  [PubMed]
  27. Songu M, Cingi C. Sneeze reflex: facts and fiction. Ther Adv Respir Dis. Jun 2009;3(3):131-41. [Crossref]  [PubMed]
  28. Seijo-Martinez M, Varela-Freijanes A, Grandes J, Vazquez F. Sneeze related area in the medulla: localisation of the human sneezing centre? J Neurol Neurosurg Psychiatry. Apr 2006;77(4):559-61. [Crossref]  [PubMed]
  29. Nishino T. Physiological and pathophysiological implications of upper airway reflexes in humans. Jpn J Physiol. Feb 2000;50(1):3-14. [Crossref]  [PubMed]
  30. Wallois F, Macron JM, Jounieaux V, Duron B. Trigeminal afferences implied in the triggering or inhibition of sneezing in cats. Neurosci Lett. Jan 28 1991;122(2):145-7. [Crossref]  [PubMed]
  31. Martin RA, Handel SF, Aldama AE. Inability to sneeze as a manifestation of medullary neoplasm. Neurology. Oct 1991;41(10):1675-6. [Crossref]  [PubMed]
  32. Hersch M. Loss of ability to sneeze in lateral medullary syndrome. Neurology. Jan 25 2000;54(2):520-1. [Crossref]  [PubMed]
  33. Langer N, Beeli G, Jancke L. When the sun prickles your nose: an EEG study identifying neural bases of photic sneezing. PLoS One. Feb 15 2010;5(2):e9208. [Crossref]  [PubMed]
  34. Sekizawa SI, Ishikawa T, Sant’Ambrogio G. Asymmetry in reflex responses of nasal muscles in anesthetized guinea pigs. J Appl Physiol (1985). Jul 1998;85(1):123-8. [Crossref]  [PubMed]
  35. Wallois F, Bodineau L, Macron JM, Marlot D, Duron B. Role of respiratory and non-respiratory neurones in the region of the NTS in the elaboration of the sneeze reflex in cat. Brain Res. Sep 12 1997;768(1-2):71-85. [Crossref]  [PubMed]
  36. Kofman O. Paroxysmal Sneezing. Can Med Assoc J. 1964 Jul 25;91(4):154-7. [Crossref]  [PubMed]
  37. Nonaka S, Unno T, Ohta Y, Mori S. Sneeze-evoking region within the brainstem. Brain Res. Mar 19 1990;511(2):265-70. [Crossref]  [PubMed]
  38. Teebi AS, al-Saleh QA. Autosomal dominant sneezing disorder provoked by fullness of stomach. J Med Genet. Aug 1989;26(8):539-40. [Crossref]  [PubMed]
  39. Setzen S, Platt M. The Dangers of Sneezing: A Review of Injuries. Am J Rhinol Allergy. May 2019;33(3):331-337. [Crossref]  [PubMed]
  40. Baydin A, Nural MS, Guven H, Deniz T, Bildik F, Karaduman A. Acute aortic dissection provoked by sneeze: a case report. Emerg Med J. Oct 2005;22(10):756-7. [Crossref]  [PubMed]
  41. Birkent H, Durmaz A, Hidir Y, Erdem U, Tosun F. Sneezing-related orbital emphysema and pneumocephalus treated with transnasal endoscopic surgery. J Otolaryngol Head Neck Surg. Dec 2008;37(6):E167-9.
  42. Fonseca AC, Ferreira JJ, Albuquerque L, Ferro JM. Sneeze as a precipitating factor of cerebral venous thrombosis. Eur J Neurol. Oct 2007;14(10):e7-8. [Crossref]  [PubMed]
  43. Gonzalez F, Cal V, Elhendi W. Orbital emphysema after sneezing. Ophthalmic Plast Reconstr Surg. Jul 2005;21(4):309-11. [Crossref]  [PubMed]
  44. Gupta A, Dogra PM, Singh B, Agarwal SK. Arteriovenous fistula intimal tear: think before you sneeze. Ther Apher Dial. Feb 2010;14(1):124. [Crossref]  [PubMed]
  45. Rochels R, Bleier R, Nover A. [Compression pneumatocele of the lacrimal sac]. Klin Monbl Augenheilkd. Sep 1989;195(3):174-6. Kompressionspneumatocele des Tranensacks. [Crossref]  [PubMed]
  46. Sharir M, Huntington AC, Nardin GF, Zimmerman TJ. Sneezing as a cause of acute angle-closure glaucoma. Ann Ophthalmol. Jun 1992;24(6):214-5. [Crossref]  [PubMed]
  47. Whitehead E. Sudden sensorineural hearing loss with fracture of the stapes footplate following sneezing and parturition. Clin Otolaryngol Allied Sci. Sep 1999;24(5):462-4. [Crossref]  [PubMed]
  48. Polverino M, Polverino F, Fasolino M, Ando F, Alfieri A, De Blasio F. Anatomy and neuro-pathophysiology of the cough reflex arc. Multidiscip Respir Med. Jun 18 2012;7(1):5. [Crossref]  [PubMed]
  49. Barberán A, Ladau J, Leff JW, Pollard KS, Menninger HL, Dunn RR, et al. Continental-scale distributions of dust-associated bacteria and fungi. Proc Natl Acad Sci U S A. May 5 2015;112(18):5756-61. [Crossref]  [PubMed]
  50. Prescott SL, Liberles SD. Internal senses of the vagus nerve. Neuron. Feb 16 2022;110(4):579-599. [Crossref]  [PubMed]
  51. Bradley RM. Sensory receptors of the larynx. Am J Med. Mar 6 2000;108 Suppl 4a:47S-50S. [Crossref]  [PubMed]
  52. Prescott SL, Umans BD, Williams EK, Brust RD, Liberles SD. An Airway Protection Program Revealed by Sweeping Genetic Control of Vagal Afferents. Cell. Apr 30 2020;181(3):574-589 e14. [Crossref]  [PubMed]
  53. McGarvey L. Update: the search for the human cough receptor. Lung. Aug 2014;192(4):459-65. [Crossref]  [PubMed]
  54. Marie Jetté. Chronic Cough. Scholes MA, Ramakrishnan VR, eds. ENT Secrets E-Book. Elsevier. 5th ed. 2023:440-447. [Crossref]  [PubMed]
  55. Mutolo D, Iovino L, Cinelli E, Bongianni F, Pantaleo T. Brainstem Structures Involved in the Generation of Reflex Cough. Zanasi A, Fontana GA, Mutolo D, eds. Cough: Pathophysiology, Diagnosis and Treatment. Springer International Publishing. 2020:45-72. [Crossref]  [PubMed]
  56. Canning BJ, Mazzone SB, Meeker SN, Mori N, Reynolds SM, Undem BJ. Identification of the tracheal and laryngeal afferent neurones mediating cough in anaesthetized guinea-pigs. J Physiol. Jun 1 2004;557(Pt 2):543-58. [Crossref]  [PubMed]
  57. Shingai T, Miyaoka Y, Ikarashi R, Shimada K. Swallowing reflex elicited by water and taste solutions in humans. Am J Physiol. Apr 1989;256(4 Pt 2):R822-6. [Crossref]  [PubMed]
  58. Boggs DF, Bartlett D, Jr. Chemical specificity of a laryngeal apneic reflex in puppies. J Appl Physiol Respir Environ Exerc Physiol. Aug 1982;53(2):455-62. [Crossref]  [PubMed]
  59. Al-Biltagi M, Bediwy AS, Saeed NK. Cough as a neurological sign: What a clinician should know. World J Crit Care Med. May 9 2022;11(3):115-128. [Crossref]  [PubMed]