ELEVATION OF THE PETROUS BONE CAUSED BY HYPERPLASIA OF THE OCCIPITAL BONE PRESENTING AS HEMIFACIAL SPASM - DIAGNOSTIC VALUES OF MAGNETIC-RESONANCE-IMAGING AND 3-DIMENSIONAL COMPUTED TOMOGRAPHIC-IMAGES IN A BONE ANOMALY

A case of elevation of the petrous bone due to hyperplasia of the occipital bone presenting as hemifacial spasm is reported. A 44-year-old man sought treatment for twitching of the buccal muscles on the right side that progressed rapidly in severity within 2 weeks of the onset. The anatomical details of the petrous and occipital bones were delineated clearly by computed tomographic scans of a bone window level. Details of the brain stem were shown by magnetic resonance images. The bone anomaly was displayed more realistically by three-dimensional computed tomographic reconstructions. The faithful representation of structures with these radiological studies should be mandatory, to prepare the surgical planning of such a complicated bone anomaly.