Ocular Neuromyotonia noted after Recent Botulinum Toxin Injection for Sixth Nerve Palsy following Resection of a Posterior Fossa Skull Based Meningioma

Ocular neuromyotonia (ONM) is a rare paroxysmal neuromuscular disorder characterized by involuntary contraction of one or more ocular muscles resulting in episodic diplopia and strabismus. Reported etiologies include radiation, chronic nerve palsy, Graves disease, compressive lesions, stroke or idiopathic. The disorder is thought to be secondary to axonal instability; therefore membrane-stabilizing agents such as carbamazepine and gabapentin have been utilized. Sparse literature exists describing the role of radiation, the onset of prior nerve palsies in causing ONM, or the association with botulinum toxin. We present a case of ONM following bolutinum toxin for a recent postoperative 6th nerve palsy with a prior history of radiation.