[Lateral inferior pontine syndrome: a case report].

The patient, a man aged 57, was admitted to our clinic on May 1, 1987, because of severe vertigo and unsteadiness in standing. Since the age of 55 he had been suffered from hypertension and atrial fibrillation. In September, 1986, he experienced vertigo but recovered soon without therapy. On April 25, 1987, while working, he noticed severe vertigo, nausea and vomiting. He was admitted to a hospital, and then transferred to our clinic. On admission, he was alert and the mentality was normal. Slight ptosis abducent nerve paresis, hypalgesia on the forehead, nose and cheek, facial paresis of peripheral type and hypacusis were detected on the left side. No anisocoria was observed. Sweating was impaired over the left side of the face. Elevation of the soft palate was limited on the left side and the tongue deviated to the left on protrusion. Dysarthria was detected. Though there was no muscular weakness in the extremities, incoordination and dysmetria were noted in the left arm and leg. He could not stand up because of vertigo and unsteadiness. There was no sensory disturbance in the trunk and extremities. Deep tendon reflexes were well elicited and no pathological reflex was observed. These clinical manifestations, except for the ipsilateral palatal and lingual disturbances, were typical of the lateral inferior pontine syndrome caused by occlusion of anterior inferior cerebellar artery, and the lesion was clearly demonstrated by horizontal and coronal MRI. The palatal and lingual disturbances might be due to the involvements of the corticobulbar tracts of the 10th and 12th nerves after the fibers had decussated.