Prognosis of isolated acute post-traumatic subdural haematoma

Aim. Acute subdural haematoma (ASDH) is seldom an isolated lesion and it is difficult to understand the mechanisms which determine the poor prognosis associated to this occurrence. Aim of this study was estimating the outcome of patients with ASDH without any companion lesions by analysing the haematoma volume, its thickness and midline shift. Methods. Twenty-eight severely head injured patients (Glasgow Coma Scale, GCS ≤8) with isolated unilateral ASDH admitted in intensive care unit (ICU) were retrospectively studied. The haematoma thickness, the midline shift, the ASDH volume were obtained from the first emergency computerized tomography (CT) scan and analysed by a computer assisted programme (Osiris). Patients' outcome was scored according to the Glasgow Outcome Scale (GOS) 6 months after the event. According to their GOS the patients were further divided in 2 groups (favourable outcome: GOS 4-5, poor outcome: GOS 1-2-3). Results. Midline shift ranged from 0 to 19.2 mm; we found a larger midline shift in those patients who died and in patients with severe disability or vegetative state 6 months after the trauma. Conclusion. The presence and size of midline shift was a more important determinant of outcome than ASDH volume or its thickness.