["One and a half syndrome" caused by lateral pontine haemorrhage].

"One and a half syndrome" is an internuclear ophthalmoplegia combined with lateral gaze palsy on the same side. It is caused by ipsilateral lesion of the caudal part of pontine dorsal tegmentum - medial longitudinal fasciculus and paramedian pontine reticular formation or/and abducens nucleus. Usually it is of vascular origin and it can be a sign of lateral pontine haemorrhage. We described a patient with "one and a half syndrome" caused by spontaneous hypertensive hemorrhage in the lateral pontine legmentum which was visualised by brain CT scanning.