View source for Superior oblique myokymia

{{Infobox disease |
 Name = Superior oblique myokymia |
 Image = Eyemuscles.png |
 Caption = 6 = [[Superior oblique muscle]]|
 DiseasesDB = |
 ICD10 = {{ICD10|G|51|4|g|50}} |
 ICD9 = |
 ICDO = |
 OMIM = |
 MedlinePlus = |
 eMedicineSubj = |
 eMedicineTopic = |
 MeshID = |
}}
'''Superior oblique myokymia''' is a [[neurological]] disorder affecting [[Visual perception|vision]] and was named by Hoyt and Keane in 1970.<ref>{{cite journal
| author = Hoyt WF, Keane JR
| title = Superior oblique myokymia. Report and discussion on five cases of benign intermittent uniocular microtremor
| journal = Arch. Ophthalmol.
| volume = 84
| issue = 4
| pages = 461–7
| year = 1970
| month = October
| pmid = 5492451
| accessdate = 2009-07-13
}}</ref>

It is a condition that presents as repeated, brief episodes of movement, shimmering or shaking of the vision of one eye, a feeling of the eye trembling, or vertical/tilted vision. It can present as one or more of these symptoms. Diagnosis is most often made by the elimination of other conditions, disorders or diseases.

Onset usually occurs in adulthood, and the course is benign and is not commonly associated with other disorders.

==Causes==
In 1983, Bringewald postulated that superior oblique myokymia resulted from [[vascular compression]] of the [[trochlear nerve]] (fourth cranial nerve), which controls the action of the [[superior oblique muscle]] in the eye.<ref>{{cite journal
| author = Bringewald PR
| title = Superior oblique myokymia
| journal = Arch. Neurol.
| volume = 40
| issue = 8
| pages = 526
| year = 1983
| month = August
| pmid = 6870617
| accessdate = 2009-07-13
}}</ref> By 1998, there had been only one reported case of compression of the trochlear nerve by vessels.<ref name="Sam">{{cite journal |author=Samii M, Rosahl SK, Carvalho GA, Krzizok T |title=Microvascular decompression for superior oblique myokymia: first experience. Case report |journal=J. Neurosurg. |volume=89 |issue=6 |pages=1020&ndash;4 |year=1998 |pmid=9833830 |doi=10.3171/jns.1998.89.6.1020}}</ref><ref name="Rem">{{cite journal |author=Scharwey K, Krzizok T, Samii M, Rosahl SK, Kaufmann H |title=Remission of superior oblique myokymia after microvascular decompression |journal=Ophthalmologica |volume=214 |issue=6 |pages=426&ndash;8 |year=2000 |pmid=11054004 |doi=10.1159/000027537}} </ref>
More recently, [[magnetic resonance imaging]] experiments have shown that neurovascular compression at the root exit zone of the trochlear nerve can result in superior oblique myokymia.<ref>{{cite journal
| author = Yousry I, Dieterich M, Naidich TP, Schmid UD, Yousry TA
| title = Superior oblique myokymia: magnetic resonance imaging support for the neurovascular compression hypothesis
| journal = Ann. Neurol.
| volume = 51
| issue = 3
| pages = 361–8
| year = 2002
| month = March
| pmid = 11891831
| doi = 10.1002/ana.10118
| accessdate = 2009-07-13
}}</ref>

==Treatment==
Treatment can include pharmaceutical or surgical means. The drug carbamazepine (Tegretol) has been used successfully. Other drugs used with variable success include gabapentin and, recently, memantine. Successful surgery options include superior oblique tenectomy accompanied by inferior oblique myectomy.<ref>{{cite web |url=http://telemedicine.orbis.org/bins/volume_page.asp?cid=735-954-1328-1350&lang=1 |title=Superior Oblique Myokymia 379.58 |accessdate=2007-06-25 |format= |work=}}</ref>

Samii et al.<ref name="Sam"/> and Scharwey and Samii<ref name="Rem"/> described a patient who had superior oblique myokymia for 17 years. The interposition of a [[Teflon]] pad between the [[trochlear nerve]] and a compressing artery and vein at the nerve's exit from the midbrain led to a remission lasting for a follow-up of 22 months.

==References==
{{Reflist|2}}

==External links==
* [http://SOMPeople.org/ Information] from SOMPeople

{{PNS diseases of the nervous system}}
[[Category:Ophthalmology]]

[[de:Obliquus-superior-Myokymie]]
[[Category:2Fix]]