Mastoid trepanation in a deceased from medieval Croatia: a case report

We present a rare case of infratentorial mastoid trepanation, by drilling, from medieval Croatia. An artificial ante-mortal opening was found in a male skeleton from the 11th century cemetery Zvonimirovo. It was placed roughly at the intersection of the Frankfurt's plane and the midline of the right mastoid. The right posterior parietal of the deceased also exhibited a callus-like formation consistent with the linear cranial fracture. Our aim was to investigate by computed tomography (CT) a possible presence of otopathology--a chronic middle ear infection--MEI/mastoiditis or cholesteatoma. On the other hand, both standard radiography and CT were employed in a cranial fracture diagnostic agreement. The generated CT scans confirmed the presence of an artificial hole running into a well defined trepanne canal connected with the antrum. The presence of otopathology was not established. The radiography and CT substantiated the presence of a linear posterior parietal discontinuity--without displacement, in front of the right lambdoid suture. From the medical point of view, it would be unusual to perform infratentorial--mastoid trepanation for reasons of treating supratentorial trauma, i.e. possible posttraumatic acute subdural hematoma (PTASDH). However, since there was a lack of CT evidence of osteolysis in ME, there is a possibility of medieval trepanation procedure performed for reasons of posttraumatic treat- ment. To our best knowledge, usually, ancient trepanations described in Croatian bioarchaeology and all over the world are supratentorial and do not always reveal such sophisticated surgical techniques.