Superior oblique myokymia: characteristics and treatment options.

Superior oblique myokymia (SOM) is an unusual eye movement disorder characterized by recurring episodes of vertical and torsional microtremor of an eye. Visual symptoms include vertical and torsional diplopia, monocular oscillopsia, and tremerous sensations. The disorder is caused by an abnormal firing of the superior oblique muscle in the affected eye. Three cases of SOM will be presented. One of these patients had improvement of her symptoms from the antidepressant drug mirtazapine (Remeron).