[Two cases of well-known syndrome due to midbrain-brain stem hemorrhage--Weber's syndrome and one and a half syndrome].

Two cases of well-known syndrome due to midbrain-brain stem hemorrhage without having a history of hypertension were reported. Case 1 is a 62-year-old female, presenting Weber's syndrome due to midbrain hemorrhage and diagnosed as Moyamoya disease angiographically. Case 2 is a 24-year-old-male, presenting One and a half syndrome due to brain stem hemorrhage from a brain stem cavernous angioma, which was diagnosed angiographically and by magnetic resonance imaging (MRI). Left hemiparesis seen in case 1 had improved by conservative therapy but no improvement could be obtained in the oculomotor nerve palsy. In case 2, hematoma was aspirated surgically for the purpose of decompression and his neurological symptoms improved markedly. Their pathogenesis and pathophysiology were also discussed.