Superior Oblique Myokymia (SOM)

𝗢𝗿𝗶𝗴𝗶𝗻𝗮𝗹 𝗗𝗲𝘀𝗰𝗿𝗶𝗽𝘁𝗶𝗼𝗻: This is a patient with transient monocular oscillopsia OD and vertical diplopia noted to have many episodes of SOM in the office. There was not only myokymia OD, but also a 4 prism diopter left hypertropia during episodes (suggestive of mild depression OD from SO activation). Ocular motor and alignment examinations between attacks were normal. Routine MRI was normal, and unfortunately CISS/FIESTA images to evaluate for neurovascular compression could not be done. Symptoms gradually diminished spontaneously over time. 𝗡𝗲𝘂𝗿𝗼-𝗼𝗽𝗵𝘁𝗵𝗮𝗹𝗺𝗼𝗹𝗼𝗴𝘆 𝗮𝗻𝗱 𝗡𝗲𝘂𝗿𝗼-𝗼𝘁𝗼𝗹𝗼𝗴𝘆 𝗧𝗲𝘅𝘁𝗯𝗼𝗼𝗸 𝗟𝗲𝗴𝗲𝗻𝗱: This patient presented with episodes of monocular oscillopsia and vertical diplopia due to right SOM. The primary action of the superior oblique (SO) is incycloduction, which generated the quick phase of these movements resulting in oscillopsia OD. The secondary action of the SO is depression, which was responsible for a right hypotropia resulting in binocular vertical diplopia. https://collections.lib.utah.edu/ark:/87278/s69w3q5b