Orbicularis fatigue: the 'peek' sign of myasthenia gravis
R. H. Osher and R. C. Griggs
Three patients with myasthenia gravis demonstrated a distinctive sign of
orbicularis fatigue. After momentary opposition on gentle sustained lid
closure, the lid margins separated, resulting in widening of the palpebral
fissure and scleral exposure. The patient thus appeared to "peek" at the
examiner. The "peek" sign was not observed in 200 control patients and in
49 of 50 patients with facial weakness secondary to a spectrum of
neuromuscular disorders. Three of 25 patients with myasthenia gravis
displayed this sign, and in one patient it was the major diagnostic
finding. The presence of the "peek" sign suggests the diagnosis of
myasthenia gravis.
