Ptosis.

Twenty-five examples of ptosis occuring with an acute stroke are analysed. Thirteen of these patients had hemispheral infarctions in which ptosis could not be explained by third nerve or sympathetic dysfunction. The ptosis in these `cerebral' cases was bilateral, with other factors such as pyramidal tract damage determining the asymmetry of the ptosis. In some patients, the eyelid was ptosed on the side of a hemiparesis, narrowing the palpebral fissure. The anatomical basis for this is probably damage to pyramidal neurones or their fibres. The 10 cases of ptosis in relationship to brain-stem infarction included two patients with isolated complete ptosis in one eye in association with a contralateral third nerve palsy.