Superior oblique myokymia associated with a posterior fossa tumor: oculographic correlation with an idiopathic case.

Superior oblique myokymia (SOM) was the only neurologic sign in a patient with an astrocytoma involving the midbrain tectum. Oculography showed monocular bursts of tonic and phasic intorsion and depression and miniature oscillations identical to those of idiopathic SOM. SOM stopped after tumor resection.