[Three elderly cases of hyperostosis cranii with various clinical symptoms]

We report three elderly patients with hyperostosis cranii (HC). Patient 1 had two episodes of unconsciousness; patient 2, headache; and patient 3, dementia. On the basis of the classification of Moore using skull films, patients 1 and 2 showed hyperostosis frontoparietalis and patient 3 had hyperostosis frontalis interna. Electroencephalography showed transient generalized spike and slow wave complexes over the frontal lobes in patient 1. Magnetic resonance (MR) images showed frontal lobes compressed by the thickness of the frontal bones in all patients and thickened parietal bones in patients 1 and 2. Because findings in our series and in the literature suggest that HC may show unexpected neuropsychiatric symptoms, HC should be checked in elderly patients whose presenting symptoms include epilepsy, dementia, psychiatric disease, headache and so on. MR images should reveal the relationship between clinical symptoms and the deformation of brains by the skull.