Superior oblique myokymia
Encyclopedia
Superior oblique myokymia is a neurological disorder affecting vision
and was named by Hoyt and Keane in 1970.
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.
(fourth cranial nerve), which controls the action of the superior oblique muscle
in the eye. By 1998, there had been only one reported case of compression of the trochlear nerve by vessels.
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.
(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.
Samii et al. and Scharwey and Samii 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.
Visual perception
Visual perception is the ability to interpret information and surroundings from the effects of visible light reaching the eye. The resulting perception is also known as eyesight, sight, or vision...
and was named by Hoyt and Keane in 1970.
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 nerveTrochlear nerve
The trochlear nerve is a motor nerve that innervates a single muscle: the superior oblique muscle of the eye....
(fourth cranial nerve), which controls the action of the superior oblique muscle
Superior oblique muscle
For the abdominal muscle see: Abdominal external oblique muscleThe superior oblique muscle, or obliquus oculi superior, is a fusiform muscle originating in the upper, medial side of the orbit which abducts, depresses and internally rotates the eye...
in the eye. By 1998, there had been only one reported case of compression of the trochlear nerve by vessels.
More recently, magnetic resonance imaging
Magnetic resonance imaging
Magnetic resonance imaging , nuclear magnetic resonance imaging , or magnetic resonance tomography is a medical imaging technique used in radiology to visualize detailed internal structures...
experiments have shown that neurovascular compression at the root exit zone of the trochlear nerve can result in superior oblique myokymia.
Treatment
Treatment can include pharmaceutical or surgical means. The drug carbamazepineCarbamazepine
Carbamazepine is an anticonvulsant and mood-stabilizing drug used primarily in the treatment of epilepsy and bipolar disorder, as well as trigeminal neuralgia...
(Tegretol) has been used successfully. Other drugs used with variable success include gabapentin
Gabapentin
Gabapentin is a pharmaceutical drug, specifically a GABA analogue. It was originally developed for the treatment of epilepsy, and currently is also used to relieve neuropathic pain...
and, recently, memantine. Successful surgery options include superior oblique tenectomy accompanied by inferior oblique myectomy.
Samii et al. and Scharwey and Samii described a patient who had superior oblique myokymia for 17 years. The interposition of a Teflon pad between the trochlear nerve
Trochlear nerve
The trochlear nerve is a motor nerve that innervates a single muscle: the superior oblique muscle of the eye....
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.