FACTOID # 112: A three-minute local phone call in Ecuador costs 60 U.S. cents, 60 times as much as in Ukraine, Macedonia, Saudi Arabia, Nepal, or Uzbekistan.
 
 Home   Encyclopedia   Statistics   Countries A-Z   Flags   Maps   Education   Forum   FAQ   About 
 
WHAT'S NEW
RECENT ARTICLES
More Recent Articles »
 

Encyclopedia > Photic sneeze reflex
ACHOO syndrome is inherited in an autosomal dominant fashion.
ACHOO syndrome is inherited in an autosomal dominant fashion.

Photic sneeze reflex is a medical condition by which people sneeze with sudden exposure to bright light, and possibly also to sneeze many times consecutively. It is also referred to as photic sneeze response, sun sneezing, photogenic sneezing, the photosternutatory reflex, or even whimsically as ACHOO syndrome with its related backronym Autosomal dominant Compelling Helio-Ophthalmic Outburst syndrome. The condition occurs in 17% to 35% of humans. The condition is passed along genetically as an autosomal dominant trait. Image File history File links Autosomal_Dominant_Pedigree_Chart. ... Image File history File links Autosomal_Dominant_Pedigree_Chart. ... For other uses, see Sneeze (disambiguation). ... A backronym (or bacronym) is a phrase that is constructed after the fact from a previously existing abbreviation, the abbreviation being an initialism or an acronym. ... This article is about modern humans. ... This article is about the general scientific term. ... It has been suggested that this article or section be merged into Dominance relationship. ...


The first mention of the phenomenon is probably in the later work attributed to Aristotle (Problems, book XXXIII). This article is about the philosopher. ...


The probable cause is a congenital malfunction in nerve signals in the trigeminal nerve nuclei. The fifth cranial nerve, called the trigeminal nerve, is apparently responsible for sneezes. Research suggests that some people have an association between this nerve and the nerve that transmits visual impulses to the brain. Overstimulation of the optic nerve triggers the trigeminal nerve, and this causes the photic sneeze reflex. Another theory suggests that tears leaking into the nose through the nasolacrimal duct are a cause of the photic sneeze reflex. The speed of the reflex seems to favour the first theory, as it happens much too quickly for tears to be generated and drain into the nose. In addition this sneeze reflex can be brought on by a sudden inhaling of cold air or a strong flavour such as a strong mint gum. This implies an overstimulation of any nerve close to the trigeminal nerve can cause the sneeze reflex. Nerves (yellow) Nerves redirects here. ... The sensory trigeminal nerve nucleus is the largest of the cranial nerve nuclei, and extends through the whole of the brainstem, midbrain to medulla. ... Cranial nerves are nerves which start directly from the brainstem instead of the spinal cord. ... This article is about the anatomical structure. ... The trigeminal nerve is the fifth (V) cranial nerve, and carries sensory information from most of the face, as well as motor supply to the muscles of mastication (the muscles enabling chewing), tensor tympani (in the middle ear), and other muscles in the floor of the mouth, such as the... The nasolacrimal duct carries tears from the lacrimal sac into the nasal cavity. ...


References

  • Beckman L, Nordenson I. "Individual differences with respect to the sneezing reflex: an inherited physiological trait in man?" Hum Hered. 1983, 33(6):390-1, PMID 6674114.
  • Benbow EW: Practical hazards of photic sneezing. Brit. J. Ophthal. 75: 447, 1991.
  • Breitenbach RA, "The photic sneeze reflex as a risk factor to combat pilots." Mil Med. Dec 1993, 158:806-9, PMID 8108024.
  • Collie WR, Pagon RA, Hall JG, Shokeir MH. "ACHOO syndrome (autosomal dominant compelling helio-ophthalmic outburst syndrome)." Birth Defects Orig Artic Ser. 1978, 14(6B):361-3, PMID 728575.
  • Deshmukh N. "Sneezing response to bright light. Is it a cause of accidents?" The Guthrie Journal. 1995, 64(3):104-5.
  • Everett HC. "Sneezing in response to light." Neurology. 1964, 14:483-90, PMID 14144120.
  • Forrester JM. "Sneezing on exposure to bright light as an inherited response." Hum Hered. 1985, 35:113-4, PMID 3988295.
  • Morris HH 3rd. "ACHOO syndrome: prevalence and inheritance." Clev Clin J Med. 1987, 54:431-3, PMID 3665024.
  • Peroutka SJ, Peroutka LA. "Autosomal dominant transmission of the 'photic sneeze reflex.'" N Engl J Med. Mar 1 1984, 310(9):599-600, PMID 6694722.
  • Semes LP, Amos JF, Waterbor JW. "The photic sneeze response: descriptive report of a clinic population." J Am Optom Assoc. June 1995, 66(6):372-7, PMID 7673597.
  • Whitman BW, Packer RJ. "The photic sneeze reflex: literature review and discussion." Neurology. May 1993, 43(5):868-71, PMID 8492938.

External links


  Results from FactBites:
 
Photic sneeze reflex (305 words)
Photic sneeze reflex is a medical condition by which people exposed to bright light involuntarily sneeze.
Overstimulation of the optic nerve triggers the trigeminal nerve, and this causes the photic sneezing reflex.
The photic sneeze reflex is considered a risk factor to combat pilots: people suffering from photic sneeze reflex may not fly combat aircraft.
Photic index by Martin (886 words)
PSR was observed during ophthalmoscopic examination in 5 out of 19 patients with cystinosis, an autosomnal recessive inborn error of the metabolism in which nonprotein cystine accumulates within lysosomes, depositing crystals in the cornea.
The relationship between PSR and epilepsy are investigated in the case of one epileptic patient who regularly exhibited PSR during a 15 Hs photic stimulation phase of an EEG study.
The authors discuss the genetic component of PSR and suggest it should be treated as a threshold phenomenon, depending on light intensties, photic frequencies and electromagnetic wavelengths in the subjects.
  More results at FactBites »

 

COMMENTARY     

There are 1 more (non-authoritative) comments on this page

Share your thoughts, questions and commentary here
Your name
Your location
Your comments
Please enter the 5-letter protection code


Lesson Plans | Student Area | Student FAQ | Reviews | Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms.