Abstract
We reported a case of 45-year-old man who presented a peculiar ocular sign “non-paralytic pontine exotropia” associated with MLF syndrome. He had a history of hypertension, and developed acute onset diplopia. On admission, severe left hemiparesis, dysarthria, right internuclear opthalmoplegia and left exotropia were noted. MRI taken 4 days after the onset showed right paramedian infarction located from ventral to dorsal portion of middle pons. Vertebral angiography demonstrated severe arteriosclerotic changes of the basilar artery.
Non-paralytic pontine exotropia is a rare ocular sign. We suggest that the posible lesion of non-paralytic pontine exotropia may be in a part of paramedian pontine reticular formation (PPRF) with ipsilateral medial longitudinal fasciculus (MLF) at the pontine tegmentum, and the lesion of non-paralytic pontine exotropia seems to be located in the area which causes the MLF syndrome and doesn't cause the one-and-a-half syndrome. And furthermore, we think that hemiparesis with non-paralytic pontine exotropia is the sign that ventral pons is affected, and the more severe hemiparesis is, the more caudal portion of pons, will be injured.
