Abstract
A 57-year-old woman was admitted due to acute onset of gait disturbance. On admission, she presented with bilateral internuclear ophthalmoplegia (INO) and cerebellar ataxia. Brain CT and MRI showed a focal infarct in the paramedian midbrain tegmentum, extending to the left cerebral peduncle. Vertebral angiogram disclosed complete occlusion of the left vertebral artery without stenosis in the basilar and posterior cerebral arteries. The patient's neurological symptoms remained unchanged for five weeks, and thereafter rhythmic tremor appeared in the head and limbs on both sides. The focal infarct might be ascribed to artery to aretry embolism in the paramedian mesencephalic artery, presumably arising from the occluded vertebral artery. The present case suggests that a focal infarct in the paramedian midbrain tegmentum involves bilateral ocular motor, cerebellar and extrapyramidal systems.
