A case study of symptomatic severe diffuse cranial hyperostosis

This case report discusses an incident of cranial hyperostosis that was discovered after an episode of syncope on imaging. A CT and MRI work-up revealed intracranial volume loss and cerebral herniation into the posterior fossa. Concomitant with the episode of syncope, the patient presented with deficits in delayed short-term memory, which was supported using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) test. As far as we are aware, this is the first report of severe memory dysfunction stemming from chronic herniation of the mesial temporal lobe due to severe hyperostosis. Hyperostosis has been shown to manifest as a wide variety of symptoms, but the delayed short-term memory impairment observed in this case is completely novel.