Transient total mesencephalic locked-in syndrome after bilateral ptosis due to basilar artery thrombosis

Locked-in syndrome (LIS) usually occurs as a result of pontine lesions and has been classified into various categories on the basis of neurologic conditions, of which transient total mesencephalic LIS is extremely rare. A 53-year-old man presented with bilateral ptosis followed by a total locked-in state. In the clinical course, the patient successfully recovered with only left slight hemiparesis and skew deviation remaining. Magnetic resonance imaging revealed multiple ischemic lesions caused by thrombosis at the top of basilar artery, including the bilateral cerebral peduncles, tegmentum of the midbrain, and the right cerebellar hemisphere. Antecedent bilateral ptosis before the locked-in state may be related to ischemia in the central caudal nucleus of the oculomotor nuclei. We should pay attention to this easily missed condition during the treatment of ischemic stroke involving the basilar artery.