Recurrent superior oblique myokymia in a patient with retinitis pigmentosa

Superior oblique myokymia is an infrequently encountered condition, presenting with episodes of oscillopsia and/or vertical or oblique nystagmus, accompanied by a fine, monocular, cyclorotational nystagmus. Recent research suggests it is caused by vascular compression of the trunk of the trochlear nerve. The clinical features of a patient reporting three episodes of superior oblique myokymia, each following childbirth, are described. She had previously been diagnosed with retinitis pigmentosa. The possible aetiologies of superior oblique myokymia are described and appropriate assessment and possible referral for further testing detailed.