A review of cerebral vasospasm.

Cerebral vasospasm is increasingly recognized as contributing to ischaemia after head injury. The reported incidence of post-traumatic vasospasm (PTV) varies between 10% and 90%, probably largely because of differences in patient selection, in definitions of vasospasm and in methods of detecting spasm. In severe head injury, based on studies with similar criteria, the incidence is approximately 40%. PTV is often associated with traumatic subarachnoid haemorrhage (tSAH), but has been reported without tSAH. These two factors are independently associated with poor outcome, but the direct links between tSAH, vasospasm and outcome are uncertain. There is evidence that calcium antagonists improve outcome in patients with head injury and tSAH; aminosteroids may also be effective here. Other strategies such as maintaining normocapnia and control of blood volume and pressure may also be useful. Further investigation of large cohorts is required to clarify fully the significance of PTV, its relationship with tSAH and outcome and possible treatment modalities.