The lid twitch response is a clinical sign first described by Cogan1 in myasthenia gravis (MG). Although classically elicited by looking down and then straight ahead, lid twitches may also occur with horizontal gaze.1 A 57-year-old woman with ptosis, diplopia, generalized weakness, and dysarthria and a normal brain MRI exhibited bilateral lid twitch during horizontal saccades (video on the Neurology ® Web site at [Neurology.org][1]). This finding was more prominent when examining horizontal rather than vertical saccades. MG was confirmed by positive anti-nAChR (nicotinic acetylcholine receptor) binding antibody and repetitive nerve stimulation. This phenomenon, termed lid hopping,2 occurs with lateral gaze and may aid in the clinical diagnosis of MG. [1]: http://neurology.org/lookup/doi/10.1212/WNL.0000000000002920