A patient with Lambert-Eaton myasthenic syndrome (LEMS) presented with
a bilateral ptosis that improved transiently after sustained upgaze.
The contralateral ptosis became aggravated on manually lifting either
eyelid with and without fixation (enhanced ptosis). Enhanced ptosis is
a common finding in many patients with ptosis resulting from myasthen
ia gravis; however, to our knowledge, this is the first description of
this sign in a patient with LEMS. The phenomenon of enhanced ptosis s
hould be sought in all patients with ptosis. Improvement of the ptosis
after sustained upward gaze suggests the diagnosis of LEMS.