The well-described phenomenon of superior oblique myokymia and the more recently described unique motility disorder inferior oblique myokymia are both defined as monocular, high-frequency, low-amplitude contractions of the superior or inferior oblique muscles that produce torsional oscillopsia.1 Symptoms vary in duration from seconds to hours and have varying frequency, while remissions and exacerbations often last months or years.2 Although of unknown etiology, current considerations include vascular compression syndrome of the trochlear nerve and a primary brainstem disorder.3- 5 Therapies include topical β-blockers, carbamazepine, oxcarbazepine, phenytoin sodium, gabapentin, baclofen, and extraocular muscle surgery in severe cases. We describe a unique form of myokymia involving monocular, high-frequency, low-amplitude contractions with vacillating incyclotorsion and excyclotorsion, which suggest an alternating superior and inferior oblique myokymia. To our knowledge and according to a PubMed search, this has not been described to date.
Smith TA, Cornblath WT. Alternating Superior and Inferior Oblique Myokymia. JAMA Ophthalmol. 2014;132(7):898-899. doi:10.1001/jamaophthalmol.2014.366