Teaching neuroimages: Postoperative bifocal stroke of the pontine tegmentum: why don't you smile anymore?

A 7-year-old boy underwent resection of a posterior fossa medulloblastoma. Two days later, he developed facial diplegia, left abducens nerve palsy, and mild hypalgesia below the neck. MRI documented 2 dot-like ischemic foci in the pons (figure). We diagnosed the unusual bilateral occurrence of Gasperini syndrome, a lesion of the sixth and seventh cranial nerve nuclei and the lateral spinothalamic tract that produces ipsilateral cranial nerve palsies with contralateral hemisensory deficits. We hypothesized a mechanism of postoperative spasm of long circumferential branches of the basilar artery. This mechanism should be considered in cases of postoperative neurologic deficits with delayed onset.