Pure ipsilateral central facial palsy and contralateral hemiparesis secondary to ventro-medial medullary stroke

Abstract

Medullary infarcts are occasionally associated with facial palsy of the central type (C-FP). This finding can be explained by the course of the facial corticobulbar (F-CB) fibers. It is believed that fibers that project to the upper facial muscles decussate at the level of the facial nucleus, whereas those destined to the lower facial muscles decussate more caudally, at the level of the mid or upper medulla. It has been proposed that the lower F-CB fibers descend ventromedially near the corticospinal tract to the upper medulla where they cross midline and ascend dorsolaterally. Accordingly, ventromedial medullary infarcts are expected to result in contralateral facial and limb weakness. We report a patient with a medial medullary infarct restricted to the right pyramid and associated with ipsilateral C-FP and contralateral hemiparesis. The neurological findings are discussed in light of the hypothetical course of the F-CB fibers in the medulla.

Keywords: Central facial palsy; Crossed paresis; Facial corticobulbar fibers; Medial medullary infarct; Millard Gubler syndrome; Stroke.