The incidence and developmental process of delayed traumatic intracerebral haematomas.

Although delayed traumatic intracerebral haematomas (DTICH) have been frequently reported especially after the advent of computerized tomography (CT), the developmental processes of traumatic intracerebral haematomas and the incidence of DTICH have not been described precisely. Based on early sequential CT examinations of 84 intracerebral haematomas for which initial CT scans were performed as early as within 6 hours of injury, we could ascertain four types of the developmental processes: Type I (39%) included the haematomas which were already evident in the initial CT scans, Type II (11%) the haematomas which were small or medium initially and increased their sizes afterwards, Type III (24%) the haematomas of which admission CT scans could not demonstrate any changes at the sites of development of the haematomas, and Type IV (26%) the haematomas of which initial CT scans showed a salt and pepper or flecked high-density appearance. Types III and IV denoted the DTICH and accounted for 50% of all the haematomas. Therefore, DTICH are thought to be not as uncommon as previously reported. Aetiologies and changes in the concepts of the DTICH are discussed, and it is stressed that, in the cases with eventual extra- and intra-cerebral combined haematomas, any surgical treatment of an extracerebral haematoma plays an important role in the development of DTICH.