[Sensory disturbance of crossed oral-pedal topography in a case of lateral medullary infarction].

We report a 40-year-old man with hypertension and diabetes mellitus, who had crossed oral-pedal sensory disturbance in lateral medullary infarction. He suddenly developed dysesthesia in the right mount and the left leg. His blood pressure was 150/90 mmHg. Neurological examination showed Horner's sign in the right eye and horizontal nystagmus. Sensory function revealed decreased temperature, hypalgesia and dysesthesia in the right mouth and the left leg. Vibratory and position sense were normal. T1- and T2-weighted images disclosed a low and high signal intensity area in the lateral portion of the right medulla oblongata, respectively. Brain and neck MRA using time-of-flight sequence revealed no obvious abnormal structures. We have diagnosed him as lateral medullary infarction. The unique topography of sensory dysfunction thought to be attributed to a far-lateral lesion in the medulla oblongata. Our patient suggests that lateral medullary infarction causes variable patterns of sensory disturbance. Thus, lateral medullary infarction should be warranted when we encounter patients with miscellaneous distribution of sensory impairment, such as crossed mouth-foot hypalgesia.