A case of pontine infarction causing alternating hemiplegia with ipsilateral abducens nerve palsy and contralateral supranuclear facial nerve palsy

Abstract

We report a 73-year-old man with alternating abducent hemiplegia (Raymond syndrome) and contralateral supranuclear facial nerve palsy. On admission, he showed lateral gaze palsy of the right eye, left supranuclear facial nerve palsy, dysarthria and left hemiparesis. Brain MRI showed an infarct that was located in the paramedian and lateral area in the base of the caudal pons on the right side. MRA showed a mild stenosis of the basilar artery. Hemiplegia and supranuclear facial nerve palsy were considered to be caused by the involvement of corticospinal tract and corticobulbar tract that run at the ventromedial area of the pons. Abducens nerve palsy was considered to be caused by the involvement of intranuclear abducens nerve fibers. There has been one previously reported case of Raymond syndrome in which MRI determined the precise location of the lesion. In this case, a small hematoma was found at the ventral and medial pontomedullary junction, whereas the infarct in our case was located in the pontine base. We considered that documentation of our case was an important contribution to determine the pathogenesis of supranuclear facial nerve palsy due to caudal pontine lesions.