| 词条 | Marcus Gunn phenomenon |
| 释义 |
| name = Marcus Gunn phenomenon | synonyms = | image = Gray777.png | caption = Nerves of the orbit, and the ciliary ganglion. Side view. (Trigeminal nerve and oculomotor nerve both visible) | pronounce = | field = | symptoms = | complications = | onset = | duration = | types = | causes = | risks = | diagnosis = | differential = | prevention = | treatment = | medication = | prognosis = | frequency = | deaths = }}Marcus Gunn phenomenon, also known as Marcus Gunn jaw-winking or trigemino-oculomotor synkinesis, is an autosomal dominant condition with incomplete penetrance, in which nursing infants will have rhythmic upward jerking of their upper eyelid. This condition is characterized as a synkinesis: when two or more muscles that are independently innervated have either simultaneous or coordinated movements.[1][2] Common physiologic examples of synkineses occur during sucking, chewing, or conjugate eye movements. There are also several abnormal cranial nerve synkineses, both acquired and congenital. Marcus Gunn jaw-winking is an example of a pathologic congenital synkinesis. First described by the ophthalmologist Marcus Gunn in 1883,[3] this condition presents in approximately 5% of neonates with congenital ptosis. This condition has been associated with amblyopia (in 54% of cases), anisometropia (26%), and strabismus (56%). PathophysiologyIt has been postulated that the synkinesis is due to damage to cranial nerve nuclei, caused by peripheral nerve injury and the nuclear lesion releases evolutionarily older [neural] mechanisms with their tendency toward associated movements, and so primitive reflexes are not inhibited. Marcus Gunn jaw-winking is an exaggeration of a very weak physiologic co-contraction that has been disinhibited secondary to a congenital brain stem lesion. The stimulation of the trigeminal nerve by contraction of the pterygoid muscles of jaw results in the excitation of the branch of the oculomotor nerve that innervates the levator palpebrae superioris ipsilaterally (on the same side of the face), so the patient will have rhythmic upward jerking of their upper eyelid. There are two major groups of trigemino-oculomotor synkineses: 1) External pterygoid-levator synkinesis is when the eyelid raises upon:
2) Internal pterygoid-levator synkinesis is when the eyelid raises upon teeth clenching External pterygoid-levator synkinesis is the more common group. TreatmentTreatment is usually unnecessary. In severe cases, surgery with a bilateral levator excision and frontalis brow suspension may be used.[4] Behavioral and social implicationsAlthough treatment may be unnecessary, there may be social implications, especially in young children when venturing from a supportive home environment to a public environment (e.g., starting school). Continued support, including monitoring behavior and educating the child about his or her appearance as seen by others, is encouraged. Gradual or sudden withdrawal from interaction with others is a sign that may or may not be related to such behavior. Studies are being conducted to elucidate these implications.{{cn|date=March 2019}} Inverse Marcus Gunn phenomenonInverse Marcus Gunn phenomenon is a rare condition[5] that causes the eyelid to fall upon opening of the mouth. In this case, trigeminal innervation to the pterygoid muscles of the jaw is associated with an inhibition of the branch of the oculomotor nerve to the levator palpebrae superioris, as opposed to stimulation in Marcus Gunn jaw-winking. References1. ^{{cite journal |vauthors=Yamada K, Hunter DG, Andrews C, Engle EC |title=A novel KIF21A mutation in a patient with congenital fibrosis of the extraocular muscles and Marcus Gunn jaw-winking phenomenon |journal=Arch. Ophthalmol. |volume=123 |issue=9 |pages=1254–9 |date=September 2005 |pmid=16157808 |doi=10.1001/archopht.123.9.1254 |url=http://archopht.ama-assn.org/cgi/pmidlookup?view=long&pmid=16157808 }}{{dead link|date=January 2018 |bot=InternetArchiveBot |fix-attempted=yes }} 2. ^{{cite journal |vauthors=Cates CA, Tyers AG |title=Results of levator excision followed by fascia lata brow suspension in patients with congenital and jaw-winking ptosis |journal=Orbit |volume=27 |issue=2 |pages=83–9 |year=2008 |pmid=18415867 |doi=10.1080/01676830701376072 |url=http://www.informaworld.com/openurl?genre=article&doi=10.1080/01676830701376072&magic=pubmed||1B69BA326FFE69C3F0A8F227DF8201D0}} 3. ^Gunn RM. Congenital ptosis with peculiar associated movements of the affected lid. Trans Ophthal Soc UK. 1883;3:283-7. 4. ^{{cite journal |author=Ibrahim HA |title=Use of the levator muscle as a frontalis sling |journal=Ophthal Plast Reconstr Surg |volume=23 |issue=5 |pages=376–80 |year=2007 |pmid=17881988 |doi=10.1097/IOP.0b013e3181379e20 |url=http://meta.wkhealth.com/pt/pt-core/template-journal/lwwgateway/media/landingpage.htm?issn=0740-9303&volume=23&issue=5&spage=376}} 5. ^{{cite journal |vauthors=Prakash MV, Radhakrishnan M, Yogeshwari A, Nazir W, Maragatham K, Natarajan K |title=Inverse Marcus Gunn phenomenon |journal=Indian J Ophthalmol |volume=50 |issue=2 |pages=142–4 |date=June 2002 |pmid=12194575 |doi= |url=http://www.ijo.in/article.asp?issn=0301-4738;year=2002;volume=50;issue=2;spage=142;epage=144;aulast=Prakash}} External links{{Medical resources| DiseasesDB = | ICD10 = {{ICD10|Q|07|8|q|00}} | ICD9 = | ICDO = | OMIM = 154600 | MedlinePlus = | eMedicineSubj = article | eMedicineTopic = 1213228 | MeshID = }}{{Congenital malformations and deformations of eye}}{{DEFAULTSORT:Marcus Gunn Phenomenon}} 2 : Congenital disorders of eyes|Congenital disorders of nervous system |
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