The importance of traumatic subarachnoid haemorrhage.

Post-traumatic cerebral vasospasm is being increasingly recognised as a possibly significant complication after head injury. To assess the relationship between post-traumatic subarachnoid haemorrhage (tSAH) and post-traumatic vasospasm, 63 patients with severe head injury (GCS 3-8) were studied. Forty-seven patients had cerebral contusion on the initial CT scan. In 25 of these (Group I) there were only contusions, while 22 (Group II) also had tSAH. All patients had daily measurements of blood flow velocity in the basal cerebral arteries using transcranial Doppler ultrasound (TCD). The incidence of vasospasm detected by TCD was significantly higher in Group II. Furthermore there were significantly fewer good outcomes (GOS 1 and 2) in this group. These results suggest that the presence of subarachnoid blood in patients with severe head injury is associated with a risk of vasospasm, and with poorer outcome.