[Medial medullary infarction demonstrated by MRI].

A 67-year-old woman with medial medullary infarction is reported, including clinical manifestations, MRI and angiographical findings, and results of evoked potentials. She suffered from contralateral hemiplegia and disturbance of deep sensation. Motor paresis of the tongue was absent. Magnetic resonance imaging revealed a lesion in the medial portion of the medulla oblongata. The 17 cases previously reported with medial medullary infarction are reviewed. Only 3 cases had triad of medial medullary infarction, contralateral hemiparesis, deep sensory disturbance, and ipsilateral hypoglossal paresis. Therefore, lesion detection is necessary to diagnose medial medullary infarction. Most infarctions limited to the upper third of the medulla were caused by occlusions of vertebral arteries or their branches and prognosis was good. In contrast, infarctions in the lower two thirds were caused by occlusions of anterior spinal arteries and their branches and the prognosis was poor. Thus localization of the lesion using MRI plays an important role to predict the prognosis.